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alistair23-linux/drivers/pinctrl/pinmux.c

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drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/*
* Core driver for the pin muxing portions of the pin control subsystem
*
pinctrl: move generic functions to the pinctrl_ namespace Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-08 23:23:28 -07:00
* Copyright (C) 2011-2012 ST-Ericsson SA
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
* Written on behalf of Linaro for ST-Ericsson
* Based on bits of regulator core, gpio core and clk core
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) "pinmux core: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <linux/err.h>
#include <linux/list.h>
pinctrl: make a copy of pinmux map This makes a deep copy of the pinmux function map instead of keeping the copy supplied from the platform around. This makes it possible to tag the platforms map with __initdata as is also done as part of this patch. Rationale: a certain target platform (PXA) has numerous pinmux maps, many of which will be lying around unused after boot in a multi-platform binary. Instead, deep-copy the one we're going to use and tag them all __initdata so they go away after boot. ChangeLog v1->v2: - Fixup the deep copy, missed a few items on the struct, plus mark bool member non-const since we're making runtime copies if this stuff now. ChangeLog v2->v3: - Make a shallow copy (just copy the array of map structs) as Arnd noticed, string constants never get discarded by the kernel anyway, so these pointers may be safely copied over. Reviewed-by: Arnd Bergmann <arnd.bergmann@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-11-29 04:52:39 -07:00
#include <linux/string.h>
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
#include <linux/sysfs.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinmux.h>
#include "core.h"
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
#include "pinmux.h"
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/**
* struct pinmux_group - group list item for pinmux groups
* @node: pinmux group list node
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
* @func_selector: the function selector for the pinmux device handling
* this pinmux
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
* @group_selector: the group selector for this group
*/
struct pinmux_group {
struct list_head node;
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
unsigned func_selector;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
unsigned group_selector;
};
pinctrl: Re-order pinmux.[ch] to match each-other Modify the two files so that the order of function prototypes in the header matches the order of implementations in the .c file. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:45 -07:00
int pinmux_check_ops(struct pinctrl_dev *pctldev)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
unsigned selector = 0;
/* Check that we implement required operations */
if (!ops->list_functions ||
!ops->get_function_name ||
!ops->get_function_groups ||
!ops->enable ||
!ops->disable)
return -EINVAL;
/* Check that all functions registered have names */
while (ops->list_functions(pctldev, selector) >= 0) {
const char *fname = ops->get_function_name(pctldev,
selector);
if (!fname) {
pr_err("pinmux ops has no name for function%u\n",
selector);
return -EINVAL;
}
selector++;
}
return 0;
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/**
* pin_request() - request a single pin to be muxed in, typically for GPIO
* @pin: the pin number in the global pin space
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
* @owner: a representation of the owner of this pin; typically the device
* name that controls its mux function, or the requested GPIO name
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
* @gpio_range: the range matching the GPIO pin if this is a request for a
* single GPIO pin
*/
static int pin_request(struct pinctrl_dev *pctldev,
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
int pin, const char *owner,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
struct pinctrl_gpio_range *gpio_range)
{
struct pin_desc *desc;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
int status = -EINVAL;
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
dev_dbg(pctldev->dev, "request pin %d for %s\n", pin, owner);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
desc = pin_desc_get(pctldev, pin);
if (desc == NULL) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
"pin is not registered so it cannot be requested\n");
goto out;
}
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
if (desc->owner && strcmp(desc->owner, owner)) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
"pin already requested\n");
goto out;
}
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
desc->owner = owner;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/* Let each pin increase references to this module */
if (!try_module_get(pctldev->owner)) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
"could not increase module refcount for pin %d\n",
pin);
status = -EINVAL;
goto out_free_pin;
}
/*
* If there is no kind of request function for the pin we just assume
* we got it by default and proceed.
*/
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
if (gpio_range && ops->gpio_request_enable)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/* This requests and enables a single GPIO pin */
status = ops->gpio_request_enable(pctldev, gpio_range, pin);
else if (ops->request)
status = ops->request(pctldev, pin);
else
status = 0;
if (status)
pinctrl: unbreak error messages It's better to not line break error messages to allow easier grepping for them even when the line gets >80 chars. Additionally some minor reformating is done. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-19 14:42:48 -07:00
dev_err(pctldev->dev, "->request on device %s failed for pin %d\n",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pctldev->desc->name, pin);
out_free_pin:
pinctrl: fix and simplify locking There are many problems with the current pinctrl locking: struct pinctrl_dev's gpio_ranges_lock isn't effective; pinctrl_match_gpio_range() only holds this lock while searching for a gpio range, but the found range is return and manipulated after releading the lock. This could allow pinctrl_remove_gpio_range() for that range while it is in use, and the caller may very well delete the range after removing it, causing pinctrl code to touch the now-free range object. Solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which both gpio range registration and pinctrl_get()/put() will acquire. There is missing locking on HW programming; pin controllers may pack the configuration for different pins/groups/config options/... into one register, and hence have to read-modify-write the register. This needs to be protected, but currently isn't. Related, a future change will add a "complete" op to the pin controller drivers, the idea being that each state's programming will be programmed into the pinctrl driver followed by the "complete" call, which may e.g. flush a register cache to HW. For this to work, it must not be possible to interleave the pinctrl driver calls for different devices. As above, solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which will be held for the duration of any pinctrl_enable()/disable() call. However, each pinctrl mapping table entry may affect a different pin controller if necessary. Hence, with a per-pin-controller lock, almost any pinctrl API may need to acquire multiple locks, one per controller. To avoid deadlock, these would need to be acquired in the same order in all cases. This is extremely difficult to implement in the case of pinctrl_get(), which doesn't know which pin controllers to lock until it has parsed the entire mapping table, since it contains somewhat arbitrary data. The simplest solution here is to introduce a single lock that covers all pin controllers at once. This will be acquired by all pinctrl APIs. This then makes struct pinctrl's mutex irrelevant, since that single lock will always be held whenever this mutex is currently held. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 13:05:44 -07:00
if (status)
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
desc->owner = NULL;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
out:
if (status)
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
pin, owner, status);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
return status;
}
/**
* pin_free() - release a single muxed in pin so something else can be muxed
* @pctldev: pin controller device handling this pin
* @pin: the pin to free
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
* @gpio_range: the range matching the GPIO pin if this is a request for a
* single GPIO pin
pinctrl: documentation update Update the docs removing an obsolete __refdata tag and document the mysterious return value of pin_free(). And fixes up some various confusions in the pinctrl documentation. Reported-by: Rajendra Nayak <rnayak@ti.com> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: Thomas Abraham <thomas.abraham@linaro.org> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-11-10 01:27:41 -07:00
*
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
* This function returns a pointer to the previous owner. This is used
* for callers that dynamically allocate an owner name so it can be freed
pinctrl: documentation update Update the docs removing an obsolete __refdata tag and document the mysterious return value of pin_free(). And fixes up some various confusions in the pinctrl documentation. Reported-by: Rajendra Nayak <rnayak@ti.com> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: Thomas Abraham <thomas.abraham@linaro.org> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-11-10 01:27:41 -07:00
* once the pin is free. This is done for GPIO request functions.
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
struct pinctrl_gpio_range *gpio_range)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
struct pin_desc *desc;
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
const char *owner;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
desc = pin_desc_get(pctldev, pin);
if (desc == NULL) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
"pin is not registered so it cannot be freed\n");
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
return NULL;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
/*
* If there is no kind of request function for the pin we just assume
* we got it by default and proceed.
*/
if (gpio_range && ops->gpio_disable_free)
ops->gpio_disable_free(pctldev, gpio_range, pin);
else if (ops->free)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
ops->free(pctldev, pin);
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
owner = desc->owner;
desc->owner = NULL;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
module_put(pctldev->owner);
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
return owner;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
/**
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
* pinmux_request_gpio() - request pinmuxing for a GPIO pin
* @pctldev: pin controller device affected
* @pin: the pin to mux in for GPIO
* @range: the applicable GPIO range
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
int pinmux_request_gpio(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned pin, unsigned gpio)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
char gpiostr[16];
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
const char *owner;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
int ret;
/* Conjure some name stating what chip and pin this is taken by */
snprintf(gpiostr, 15, "%s:%d", range->name, gpio);
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
owner = kstrdup(gpiostr, GFP_KERNEL);
if (!owner)
pinctrl: Don't copy function name when requesting a pin Instead, store a pointer to the currently assigned function. This allows us to delete the mux_requested variable from pin_desc; a pin is requested if its currently assigned function is non-NULL. When a pin is requested as a GPIO rather than a regular function, the assigned function name is dynamically constructed. In this case, we have to kstrdup() the dynamically constructed name, so that mux_function doesn't pointed at stack data. This requires pin_free to be told whether to free the mux_function pointer or not. This removes the hard-coded maximum function name length. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:19:28 -06:00
return -EINVAL;
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
ret = pin_request(pctldev, pin, owner, range);
pinctrl: Don't copy function name when requesting a pin Instead, store a pointer to the currently assigned function. This allows us to delete the mux_requested variable from pin_desc; a pin is requested if its currently assigned function is non-NULL. When a pin is requested as a GPIO rather than a regular function, the assigned function name is dynamically constructed. In this case, we have to kstrdup() the dynamically constructed name, so that mux_function doesn't pointed at stack data. This requires pin_free to be told whether to free the mux_function pointer or not. This removes the hard-coded maximum function name length. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:19:28 -06:00
if (ret < 0)
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
kfree(owner);
pinctrl: Don't copy function name when requesting a pin Instead, store a pointer to the currently assigned function. This allows us to delete the mux_requested variable from pin_desc; a pin is requested if its currently assigned function is non-NULL. When a pin is requested as a GPIO rather than a regular function, the assigned function name is dynamically constructed. In this case, we have to kstrdup() the dynamically constructed name, so that mux_function doesn't pointed at stack data. This requires pin_free to be told whether to free the mux_function pointer or not. This removes the hard-coded maximum function name length. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:19:28 -06:00
return ret;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
/**
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
* pinmux_free_gpio() - release a pin from GPIO muxing
* @pctldev: the pin controller device for the pin
* @pin: the affected currently GPIO-muxed in pin
* @range: applicable GPIO range
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
struct pinctrl_gpio_range *range)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
const char *owner;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
owner = pin_free(pctldev, pin, range);
kfree(owner);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
/**
* pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
* @pctldev: the pin controller handling this pin
* @range: applicable GPIO range
* @pin: the affected GPIO pin in this controller
* @input: true if we set the pin as input, false for output
*/
int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned pin, bool input)
pinctrl: GPIO direction support for muxing When requesting a single GPIO pin to be muxed in, some controllers will need to poke a different value into the control register depending on whether the pin will be used for GPIO output or GPIO input. So create pinmux counterparts to gpio_direction_[input|output] in the pinctrl framework. ChangeLog v1->v2: - This also amends the documentation to make it clear the this function and associated machinery is *ONLY* intended as a backend to gpiolib machinery, not for everyone and his dog to start playing around with pins. ChangeLog v2->v3: - Don't pass an argument to the common request function, instead provide pinmux_* counterparts to the gpio_direction_[input|output] calls, simpler and anyone can understand it. ChangeLog v3->v4: - Fix numerous spelling mistakes and dangling text in documentation. Add Ack and Rewewed-by. Cc: Igor Grinberg <grinberg@compulab.co.il> Acked-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Thomas Abraham <thomas.abraham@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-11-14 02:06:22 -07:00
{
const struct pinmux_ops *ops;
int ret;
ops = pctldev->desc->pmxops;
if (ops->gpio_set_direction)
ret = ops->gpio_set_direction(pctldev, range, pin, input);
else
ret = 0;
return ret;
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/**
pinctrl: fix some pinmux typos Fix some pinmux typos so implementing pinmux drivers is a bit easier. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-20 09:17:33 -07:00
* acquire_pins() - acquire all the pins for a certain function on a pinmux
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
* @pctldev: the device to take the pins on
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
* @owner: a representation of the owner of this pin; typically the device
* name that controls its mux function
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
* @group_selector: the group selector containing the pins to acquire
*/
static int acquire_pins(struct pinctrl_dev *pctldev,
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
const char *owner,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
unsigned group_selector)
{
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
pinctrl: get_group_pins() const fixes get_group_pins() "returns" a pointer to an array of const objects, through a pointer parameter. Fix the prototype so what's pointed at by the returned pointer is const, rather than the function parameter being const. This also allows the removal of a cast in each of the two current pinmux drivers. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:19:25 -06:00
const unsigned *pins;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
unsigned num_pins;
int ret;
int i;
ret = pctlops->get_group_pins(pctldev, group_selector,
&pins, &num_pins);
if (ret)
return ret;
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_dbg(pctldev->dev, "requesting the %u pins from group %u\n",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
num_pins, group_selector);
/* Try to allocate all pins in this group, one by one */
for (i = 0; i < num_pins; i++) {
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
ret = pin_request(pctldev, pins[i], owner, NULL);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
if (ret) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
"could not get request pin %d on device %s - conflicting mux mappings?\n",
pins[i],
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl_dev_get_name(pctldev));
/* On error release all taken pins */
i--; /* this pin just failed */
for (; i >= 0; i--)
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
pin_free(pctldev, pins[i], NULL);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
return -ENODEV;
}
}
return 0;
}
/**
* release_pins() - release pins taken by earlier acquirement
pinctrl: fix some pinmux typos Fix some pinmux typos so implementing pinmux drivers is a bit easier. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-20 09:17:33 -07:00
* @pctldev: the device to free the pins on
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
* @group_selector: the group selector containing the pins to free
*/
static void release_pins(struct pinctrl_dev *pctldev,
unsigned group_selector)
{
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
pinctrl: get_group_pins() const fixes get_group_pins() "returns" a pointer to an array of const objects, through a pointer parameter. Fix the prototype so what's pointed at by the returned pointer is const, rather than the function parameter being const. This also allows the removal of a cast in each of the two current pinmux drivers. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 16:19:25 -06:00
const unsigned *pins;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
unsigned num_pins;
int ret;
int i;
ret = pctlops->get_group_pins(pctldev, group_selector,
&pins, &num_pins);
if (ret) {
pinctrl: unbreak error messages It's better to not line break error messages to allow easier grepping for them even when the line gets >80 chars. Additionally some minor reformating is done. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-19 14:42:48 -07:00
dev_err(pctldev->dev, "could not get pins to release for group selector %d\n",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
group_selector);
return;
}
for (i = 0; i < num_pins; i++)
pinctrl: add explicit gpio_disable_free pinmux_op Some pinctrl drivers (Tegra at least) program a pin to be a GPIO in a completely different manner than they select which function to mux out of that pin. In order to support a single "free" pinmux_op, the driver would need to maintain a per-pin state of requested-for-gpio vs. requested-for- function. However, that's a lot of work when the core already has explicit separate paths for gpio request/free and function request/free. So, add a gpio_disable_free op to struct pinmux_ops, and make pin_free() call it when appropriate. When doing this, I noticed that when calling pin_request(): !!gpio == (gpio_range != NULL) ... and so I collapsed those two parameters in both pin_request(), and when adding writing the new code in pin_free(). Also, for pin_free(): !!free_func == (gpio_range != NULL) However, I didn't want pin_free() to know about the GPIO function naming special case, so instead, I reworked pin_free() to always return the pin's previously requested function, and now pinmux_free_gpio() calls kfree(function). This is much more balanced with the allocation having been performed in pinmux_request_gpio(). Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-21 12:25:53 -06:00
pin_free(pctldev, pins[i], NULL);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
/**
* pinmux_check_pin_group() - check function and pin group combo
* @pctldev: device to check the pin group vs function for
* @func_selector: the function selector to check the pin group for, we have
* already looked this up in the calling function
* @pin_group: the pin group to match to the function
*
* This function will check that the pinmux driver can supply the
* selected pin group for a certain function, returns the group selector if
* the group and function selector will work fine together, else returns
* negative
*/
static int pinmux_check_pin_group(struct pinctrl_dev *pctldev,
unsigned func_selector,
const char *pin_group)
{
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
int ret;
/*
* If the driver does not support different pin groups for the
* functions, we only support group 0, and assume this exists.
*/
if (!pctlops || !pctlops->list_groups)
return 0;
/*
* Passing NULL (no specific group) will select the first and
* hopefully only group of pins available for this function.
*/
if (!pin_group) {
char const * const *groups;
unsigned num_groups;
ret = pmxops->get_function_groups(pctldev, func_selector,
&groups, &num_groups);
if (ret)
return ret;
if (num_groups < 1)
return -EINVAL;
pinctrl: move group lookup to core Now also the core needs to look up pin groups so move the lookup function there and expose it in the internal header. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 09:07:16 -06:00
ret = pinctrl_get_group_selector(pctldev, groups[0]);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
if (ret < 0) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
pinctrl: unbreak error messages It's better to not line break error messages to allow easier grepping for them even when the line gets >80 chars. Additionally some minor reformating is done. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-19 14:42:48 -07:00
"function %s wants group %s but the pin controller does not seem to have that group\n",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pmxops->get_function_name(pctldev, func_selector),
groups[0]);
return ret;
}
if (num_groups > 1)
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_dbg(pctldev->dev,
pinctrl: unbreak error messages It's better to not line break error messages to allow easier grepping for them even when the line gets >80 chars. Additionally some minor reformating is done. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-19 14:42:48 -07:00
"function %s support more than one group, default-selecting first group %s (%d)\n",
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pmxops->get_function_name(pctldev, func_selector),
groups[0],
ret);
return ret;
}
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_dbg(pctldev->dev,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
"check if we have pin group %s on controller %s\n",
pin_group, pinctrl_dev_get_name(pctldev));
pinctrl: move group lookup to core Now also the core needs to look up pin groups so move the lookup function there and expose it in the internal header. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-19 09:07:16 -06:00
ret = pinctrl_get_group_selector(pctldev, pin_group);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
if (ret < 0) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_dbg(pctldev->dev,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
"%s does not support pin group %s with function %s\n",
pinctrl_dev_get_name(pctldev),
pin_group,
pmxops->get_function_name(pctldev, func_selector));
}
return ret;
}
/**
* pinmux_search_function() - check pin control driver for a certain function
* @pctldev: device to check for function and position
* @map: function map containing the function and position to look for
* @func_selector: returns the applicable function selector if found
* @group_selector: returns the applicable group selector if found
*
* This will search the pinmux driver for an applicable
* function with a specific pin group, returns 0 if these can be mapped
* negative otherwise
*/
static int pinmux_search_function(struct pinctrl_dev *pctldev,
pinctrl: move generic functions to the pinctrl_ namespace Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-08 23:23:28 -07:00
struct pinctrl_map const *map,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
unsigned *func_selector,
unsigned *group_selector)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
unsigned selector = 0;
/* See if this pctldev has this function */
while (ops->list_functions(pctldev, selector) >= 0) {
const char *fname = ops->get_function_name(pctldev,
selector);
int ret;
if (!strcmp(map->function, fname)) {
/* Found the function, check pin group */
ret = pinmux_check_pin_group(pctldev, selector,
map->group);
if (ret < 0)
return ret;
/* This function and group selector can be used */
*func_selector = selector;
*group_selector = ret;
return 0;
}
selector++;
}
pr_err("%s does not support function %s\n",
pinctrl_dev_get_name(pctldev), map->function);
return -EINVAL;
}
/**
* pinmux_enable_muxmap() - enable a map entry for a certain pinmux
*/
static int pinmux_enable_muxmap(struct pinctrl_dev *pctldev,
pinctrl: move generic functions to the pinctrl_ namespace Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-08 23:23:28 -07:00
struct pinctrl *p,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
struct device *dev,
const char *devname,
pinctrl: move generic functions to the pinctrl_ namespace Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-08 23:23:28 -07:00
struct pinctrl_map const *map)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
unsigned func_selector;
unsigned group_selector;
struct pinmux_group *grp;
int ret;
/*
* Note that we're not locking the pinmux mutex here, because
* this is only called at pinmux initialization time when it
* has not been added to any list and thus is not reachable
* by anyone else.
*/
pinctrl: move generic functions to the pinctrl_ namespace Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-08 23:23:28 -07:00
if (p->pctldev && p->pctldev != pctldev) {
pinctrl: don't create a device for each pin controller Pin controllers should already be instantiated as a device, so there's no need for the pinctrl core to create a new struct device for each controller. This allows the controller's real name to be used in the mux mapping table, rather than e.g. "pinctrl.0", "pinctrl.1", etc. This necessitates removal of the PINMUX_MAP_PRIMARY*() macros, since their sole purpose was to hard-code the .ctrl_dev_name field to be "pinctrl.0". Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-12-09 16:59:05 -07:00
dev_err(pctldev->dev,
pinctrl: unbreak error messages It's better to not line break error messages to allow easier grepping for them even when the line gets >80 chars. Additionally some minor reformating is done. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-19 14:42:48 -07:00
"different pin control devices given for device %s, function %s\n",
devname, map->function);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
return -EINVAL;
}
pinctrl: move generic functions to the pinctrl_ namespace Since we want to use the former pinmux handles and mapping tables for generic control involving both muxing and configuration we begin refactoring by renaming them from pinmux_* to pinctrl_*. ChangeLog v1->v2: - Also rename the PINMUX_* macros in machine.h to PIN_ as indicated in the documentation so as to reflect the generic nature of these mapping entries from now on. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-08 23:23:28 -07:00
p->dev = dev;
p->pctldev = pctldev;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
/* Now go into the driver and try to match a function and group */
ret = pinmux_search_function(pctldev, map, &func_selector,
&group_selector);
if (ret < 0)
return ret;
/* Now add this group selector, we may have many of them */
pinctrl: allocate sizeof(*p) instead of sizeof(struct foo) This hopefully makes it harder to take the sizeof the wrong type. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 14:26:00 -07:00
grp = kmalloc(sizeof(*grp), GFP_KERNEL);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
if (!grp)
return -ENOMEM;
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
grp->func_selector = func_selector;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
grp->group_selector = group_selector;
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
ret = acquire_pins(pctldev, devname, group_selector);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
if (ret) {
kfree(grp);
return ret;
}
pinctrl: use list_add_tail instead of list_add This mostly makes debugfs files print things in the order that they were added or acquired, which just feels a little more consistent. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:42 -07:00
list_add_tail(&grp->node, &p->groups);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
return 0;
}
/**
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
* pinmux_apply_muxmap() - apply a certain mux mapping entry
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
int pinmux_apply_muxmap(struct pinctrl_dev *pctldev,
struct pinctrl *p,
struct device *dev,
const char *devname,
struct pinctrl_map const *map)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
int ret;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
ret = pinmux_enable_muxmap(pctldev, p, dev,
devname, map);
if (ret) {
pinmux_put(p);
return ret;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
return 0;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
/**
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
* pinmux_put() - free up the pinmux portions of a pin controller handle
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
void pinmux_put(struct pinctrl *p)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
struct list_head *node, *tmp;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
list_for_each_safe(node, tmp, &p->groups) {
struct pinmux_group *grp =
list_entry(node, struct pinmux_group, node);
/* Release all pins taken by this group */
release_pins(p->pctldev, grp->group_selector);
list_del(node);
kfree(grp);
}
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
/**
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
* pinmux_enable() - enable the pinmux portion of a pin control handle
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
int pinmux_enable(struct pinctrl *p)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
struct pinctrl_dev *pctldev = p->pctldev;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
struct pinmux_group *grp;
int ret;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
list_for_each_entry(grp, &p->groups, node) {
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
ret = ops->enable(pctldev, grp->func_selector,
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
grp->group_selector);
if (ret)
/*
* TODO: call disable() on all groups we called
* enable() on to this point?
*/
return ret;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
return 0;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
/**
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
* pinmux_disable() - disable the pinmux portions of a pin control handle
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
*/
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
void pinmux_disable(struct pinctrl *p)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
struct pinctrl_dev *pctldev = p->pctldev;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
struct pinmux_group *grp;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
list_for_each_entry(grp, &p->groups, node) {
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
ops->disable(pctldev, grp->func_selector,
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
grp->group_selector);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
}
#ifdef CONFIG_DEBUG_FS
/* Called from pincontrol core */
static int pinmux_functions_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
unsigned func_selector = 0;
pinctrl: fix and simplify locking There are many problems with the current pinctrl locking: struct pinctrl_dev's gpio_ranges_lock isn't effective; pinctrl_match_gpio_range() only holds this lock while searching for a gpio range, but the found range is return and manipulated after releading the lock. This could allow pinctrl_remove_gpio_range() for that range while it is in use, and the caller may very well delete the range after removing it, causing pinctrl code to touch the now-free range object. Solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which both gpio range registration and pinctrl_get()/put() will acquire. There is missing locking on HW programming; pin controllers may pack the configuration for different pins/groups/config options/... into one register, and hence have to read-modify-write the register. This needs to be protected, but currently isn't. Related, a future change will add a "complete" op to the pin controller drivers, the idea being that each state's programming will be programmed into the pinctrl driver followed by the "complete" call, which may e.g. flush a register cache to HW. For this to work, it must not be possible to interleave the pinctrl driver calls for different devices. As above, solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which will be held for the duration of any pinctrl_enable()/disable() call. However, each pinctrl mapping table entry may affect a different pin controller if necessary. Hence, with a per-pin-controller lock, almost any pinctrl API may need to acquire multiple locks, one per controller. To avoid deadlock, these would need to be acquired in the same order in all cases. This is extremely difficult to implement in the case of pinctrl_get(), which doesn't know which pin controllers to lock until it has parsed the entire mapping table, since it contains somewhat arbitrary data. The simplest solution here is to introduce a single lock that covers all pin controllers at once. This will be acquired by all pinctrl APIs. This then makes struct pinctrl's mutex irrelevant, since that single lock will always be held whenever this mutex is currently held. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 13:05:44 -07:00
mutex_lock(&pinctrl_mutex);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
while (pmxops->list_functions(pctldev, func_selector) >= 0) {
const char *func = pmxops->get_function_name(pctldev,
func_selector);
const char * const *groups;
unsigned num_groups;
int ret;
int i;
ret = pmxops->get_function_groups(pctldev, func_selector,
&groups, &num_groups);
if (ret)
seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
func);
seq_printf(s, "function: %s, groups = [ ", func);
for (i = 0; i < num_groups; i++)
seq_printf(s, "%s ", groups[i]);
seq_puts(s, "]\n");
func_selector++;
}
pinctrl: fix and simplify locking There are many problems with the current pinctrl locking: struct pinctrl_dev's gpio_ranges_lock isn't effective; pinctrl_match_gpio_range() only holds this lock while searching for a gpio range, but the found range is return and manipulated after releading the lock. This could allow pinctrl_remove_gpio_range() for that range while it is in use, and the caller may very well delete the range after removing it, causing pinctrl code to touch the now-free range object. Solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which both gpio range registration and pinctrl_get()/put() will acquire. There is missing locking on HW programming; pin controllers may pack the configuration for different pins/groups/config options/... into one register, and hence have to read-modify-write the register. This needs to be protected, but currently isn't. Related, a future change will add a "complete" op to the pin controller drivers, the idea being that each state's programming will be programmed into the pinctrl driver followed by the "complete" call, which may e.g. flush a register cache to HW. For this to work, it must not be possible to interleave the pinctrl driver calls for different devices. As above, solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which will be held for the duration of any pinctrl_enable()/disable() call. However, each pinctrl mapping table entry may affect a different pin controller if necessary. Hence, with a per-pin-controller lock, almost any pinctrl API may need to acquire multiple locks, one per controller. To avoid deadlock, these would need to be acquired in the same order in all cases. This is extremely difficult to implement in the case of pinctrl_get(), which doesn't know which pin controllers to lock until it has parsed the entire mapping table, since it contains somewhat arbitrary data. The simplest solution here is to introduce a single lock that covers all pin controllers at once. This will be acquired by all pinctrl APIs. This then makes struct pinctrl's mutex irrelevant, since that single lock will always be held whenever this mutex is currently held. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 13:05:44 -07:00
mutex_unlock(&pinctrl_mutex);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
return 0;
}
static int pinmux_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
pinctrl: correct a offset while enumerating pins This patch modifies a offset while enumerating pins to support a partial pin space. If we use a pin number for enumerating pins, the pin space always starts with zero base. Indeed, we always check the pin is in the pin space. An extreme example, there is only two pins. One is 0. Another is 1000. We always enumerate whole offsets until 1000. For solving this problem, we use the offset of the pin array instead of the zero-based pin number. Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> [Restored sparse pin space comment] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03 00:47:50 -07:00
unsigned i, pin;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
seq_puts(s, "Pinmux settings per pin\n");
pinctrl: record a pin owner, not mux function, when requesting pins When pins are requested/acquired/got, some device becomes the owner of their mux setting. At this point, it isn't certain which mux function will be selected for the pin, since this may vary between each of the device's states in the pinctrl mapping table. As such, we should record the owning device, not what we think the initial mux setting will be, when requesting pins. This doesn't make a lot of difference right now since pinctrl_get gets only one single device/state combination, but this will make a difference when pinctrl_get gets all states, and pinctrl_select_state can switch between states. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-19 23:45:44 -07:00
seq_puts(s, "Format: pin (name): owner\n");
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: fix and simplify locking There are many problems with the current pinctrl locking: struct pinctrl_dev's gpio_ranges_lock isn't effective; pinctrl_match_gpio_range() only holds this lock while searching for a gpio range, but the found range is return and manipulated after releading the lock. This could allow pinctrl_remove_gpio_range() for that range while it is in use, and the caller may very well delete the range after removing it, causing pinctrl code to touch the now-free range object. Solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which both gpio range registration and pinctrl_get()/put() will acquire. There is missing locking on HW programming; pin controllers may pack the configuration for different pins/groups/config options/... into one register, and hence have to read-modify-write the register. This needs to be protected, but currently isn't. Related, a future change will add a "complete" op to the pin controller drivers, the idea being that each state's programming will be programmed into the pinctrl driver followed by the "complete" call, which may e.g. flush a register cache to HW. For this to work, it must not be possible to interleave the pinctrl driver calls for different devices. As above, solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which will be held for the duration of any pinctrl_enable()/disable() call. However, each pinctrl mapping table entry may affect a different pin controller if necessary. Hence, with a per-pin-controller lock, almost any pinctrl API may need to acquire multiple locks, one per controller. To avoid deadlock, these would need to be acquired in the same order in all cases. This is extremely difficult to implement in the case of pinctrl_get(), which doesn't know which pin controllers to lock until it has parsed the entire mapping table, since it contains somewhat arbitrary data. The simplest solution here is to introduce a single lock that covers all pin controllers at once. This will be acquired by all pinctrl APIs. This then makes struct pinctrl's mutex irrelevant, since that single lock will always be held whenever this mutex is currently held. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 13:05:44 -07:00
mutex_lock(&pinctrl_mutex);
pinctrl: correct a offset while enumerating pins This patch modifies a offset while enumerating pins to support a partial pin space. If we use a pin number for enumerating pins, the pin space always starts with zero base. Indeed, we always check the pin is in the pin space. An extreme example, there is only two pins. One is 0. Another is 1000. We always enumerate whole offsets until 1000. For solving this problem, we use the offset of the pin array instead of the zero-based pin number. Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> [Restored sparse pin space comment] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03 00:47:50 -07:00
/* The pin number can be retrived from the pin controller descriptor */
for (i = 0; i < pctldev->desc->npins; i++) {
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
struct pin_desc *desc;
pinctrl: make the pinmux-pins more helpful The debugfs file pinmux-pins used to tell which function was enabled but now states simply which device owns the pin. Being owned by the pinctrl driver itself means just that it's hogged so be a bit more helpful by printing that. ChangeLog v1->v2: - Preserve the self-referential owner field, just clarify that when the pin controller states itself as owner this means that it's hogged. Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-23 22:53:04 -07:00
bool is_hog = false;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: correct a offset while enumerating pins This patch modifies a offset while enumerating pins to support a partial pin space. If we use a pin number for enumerating pins, the pin space always starts with zero base. Indeed, we always check the pin is in the pin space. An extreme example, there is only two pins. One is 0. Another is 1000. We always enumerate whole offsets until 1000. For solving this problem, we use the offset of the pin array instead of the zero-based pin number. Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> [Restored sparse pin space comment] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03 00:47:50 -07:00
pin = pctldev->desc->pins[i].number;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
desc = pin_desc_get(pctldev, pin);
pinctrl: correct a offset while enumerating pins This patch modifies a offset while enumerating pins to support a partial pin space. If we use a pin number for enumerating pins, the pin space always starts with zero base. Indeed, we always check the pin is in the pin space. An extreme example, there is only two pins. One is 0. Another is 1000. We always enumerate whole offsets until 1000. For solving this problem, we use the offset of the pin array instead of the zero-based pin number. Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> [Restored sparse pin space comment] Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-03 00:47:50 -07:00
/* Skip if we cannot search the pin */
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
if (desc == NULL)
continue;
pinctrl: make the pinmux-pins more helpful The debugfs file pinmux-pins used to tell which function was enabled but now states simply which device owns the pin. Being owned by the pinctrl driver itself means just that it's hogged so be a bit more helpful by printing that. ChangeLog v1->v2: - Preserve the self-referential owner field, just clarify that when the pin controller states itself as owner this means that it's hogged. Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-23 22:53:04 -07:00
if (desc->owner &&
!strcmp(desc->owner, pinctrl_dev_get_name(pctldev)))
is_hog = true;
seq_printf(s, "pin %d (%s): %s%s\n", pin,
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
desc->name ? desc->name : "unnamed",
pinctrl: make the pinmux-pins more helpful The debugfs file pinmux-pins used to tell which function was enabled but now states simply which device owns the pin. Being owned by the pinctrl driver itself means just that it's hogged so be a bit more helpful by printing that. ChangeLog v1->v2: - Preserve the self-referential owner field, just clarify that when the pin controller states itself as owner this means that it's hogged. Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-23 22:53:04 -07:00
desc->owner ? desc->owner : "UNCLAIMED",
is_hog ? " (HOG)" : "");
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
pinctrl: fix and simplify locking There are many problems with the current pinctrl locking: struct pinctrl_dev's gpio_ranges_lock isn't effective; pinctrl_match_gpio_range() only holds this lock while searching for a gpio range, but the found range is return and manipulated after releading the lock. This could allow pinctrl_remove_gpio_range() for that range while it is in use, and the caller may very well delete the range after removing it, causing pinctrl code to touch the now-free range object. Solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which both gpio range registration and pinctrl_get()/put() will acquire. There is missing locking on HW programming; pin controllers may pack the configuration for different pins/groups/config options/... into one register, and hence have to read-modify-write the register. This needs to be protected, but currently isn't. Related, a future change will add a "complete" op to the pin controller drivers, the idea being that each state's programming will be programmed into the pinctrl driver followed by the "complete" call, which may e.g. flush a register cache to HW. For this to work, it must not be possible to interleave the pinctrl driver calls for different devices. As above, solving this requires the introduction of a higher-level lock, at least a lock per pin controller, which will be held for the duration of any pinctrl_enable()/disable() call. However, each pinctrl mapping table entry may affect a different pin controller if necessary. Hence, with a per-pin-controller lock, almost any pinctrl API may need to acquire multiple locks, one per controller. To avoid deadlock, these would need to be acquired in the same order in all cases. This is extremely difficult to implement in the case of pinctrl_get(), which doesn't know which pin controllers to lock until it has parsed the entire mapping table, since it contains somewhat arbitrary data. The simplest solution here is to introduce a single lock that covers all pin controllers at once. This will be acquired by all pinctrl APIs. This then makes struct pinctrl's mutex irrelevant, since that single lock will always be held whenever this mutex is currently held. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 13:05:44 -07:00
mutex_unlock(&pinctrl_mutex);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
return 0;
}
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
void pinmux_dbg_show(struct seq_file *s, struct pinctrl *p)
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
{
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
struct pinctrl_dev *pctldev = p->pctldev;
const struct pinmux_ops *pmxops;
const struct pinctrl_ops *pctlops;
struct pinmux_group *grp;
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
const char *sep = "";
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
pmxops = pctldev->desc->pmxops;
pctlops = pctldev->desc->pctlops;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
seq_printf(s, " groups: [");
list_for_each_entry(grp, &p->groups, node) {
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
seq_printf(s, "%s%s (%u)=%s (%u)",
sep,
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
pctlops->get_group_name(pctldev,
grp->group_selector),
pinctrl: enhance pinctrl_get() to handle multiple functions At present, pinctrl_get() assumes that all matching mapping table entries have the same "function" value, albeit potentially applied to different pins/groups. This change removes this restriction; pinctrl_get() can now handle a set of mapping tables where different functions are applied to the various pins/groups. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-01 18:48:31 -07:00
grp->group_selector,
pmxops->get_function_name(pctldev,
grp->func_selector),
grp->func_selector);
sep = ", ";
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
pinctrl: factor pin control handles over to the core This moves the per-devices struct pinctrl handles and device map over from the pinmux part of the subsystem to the core pinctrl part. This makes the device handles core infrastructure with the goal of using these handles also for pin configuration, so that device drivers (or boards etc) will need one and only one handle to the pin control core. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-09 11:47:48 -07:00
seq_printf(s, " ]");
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-02 12:50:54 -06:00
}
static int pinmux_functions_open(struct inode *inode, struct file *file)
{
return single_open(file, pinmux_functions_show, inode->i_private);
}
static int pinmux_pins_open(struct inode *inode, struct file *file)
{
return single_open(file, pinmux_pins_show, inode->i_private);
}
static const struct file_operations pinmux_functions_ops = {
.open = pinmux_functions_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations pinmux_pins_ops = {
.open = pinmux_pins_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
void pinmux_init_device_debugfs(struct dentry *devroot,
struct pinctrl_dev *pctldev)
{
debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
devroot, pctldev, &pinmux_functions_ops);
debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
devroot, pctldev, &pinmux_pins_ops);
}
#endif /* CONFIG_DEBUG_FS */