[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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/*
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* spi.c - SPI init/core code
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*
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* Copyright (C) 2005 David Brownell
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/autoconf.h>
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/cache.h>
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#include <linux/spi/spi.h>
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2006-01-08 14:34:23 -07:00
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/* SPI bustype and spi_master class are registered after board init code
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* provides the SPI device tables, ensuring that both are present by the
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* time controller driver registration causes spi_devices to "enumerate".
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[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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*/
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static void spidev_release(struct device *dev)
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{
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const struct spi_device *spi = to_spi_device(dev);
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/* spi masters may cleanup for released devices */
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if (spi->master->cleanup)
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spi->master->cleanup(spi);
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2006-01-08 14:34:25 -07:00
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spi_master_put(spi->master);
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[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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kfree(dev);
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}
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static ssize_t
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modalias_show(struct device *dev, struct device_attribute *a, char *buf)
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{
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const struct spi_device *spi = to_spi_device(dev);
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return snprintf(buf, BUS_ID_SIZE + 1, "%s\n", spi->modalias);
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}
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static struct device_attribute spi_dev_attrs[] = {
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__ATTR_RO(modalias),
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__ATTR_NULL,
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};
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/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
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* and the sysfs version makes coldplug work too.
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*/
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static int spi_match_device(struct device *dev, struct device_driver *drv)
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{
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const struct spi_device *spi = to_spi_device(dev);
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return strncmp(spi->modalias, drv->name, BUS_ID_SIZE) == 0;
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}
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static int spi_uevent(struct device *dev, char **envp, int num_envp,
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char *buffer, int buffer_size)
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{
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const struct spi_device *spi = to_spi_device(dev);
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envp[0] = buffer;
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snprintf(buffer, buffer_size, "MODALIAS=%s", spi->modalias);
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envp[1] = NULL;
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return 0;
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}
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#ifdef CONFIG_PM
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2006-01-08 14:34:23 -07:00
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/*
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[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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* NOTE: the suspend() method for an spi_master controller driver
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* should verify that all its child devices are marked as suspended;
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* suspend requests delivered through sysfs power/state files don't
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* enforce such constraints.
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*/
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static int spi_suspend(struct device *dev, pm_message_t message)
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{
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2006-01-08 14:34:23 -07:00
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int value;
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struct spi_driver *drv = to_spi_driver(dev->driver);
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[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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2006-02-20 19:27:56 -07:00
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if (!drv || !drv->suspend)
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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return 0;
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/* suspend will stop irqs and dma; no more i/o */
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2006-01-08 14:34:23 -07:00
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value = drv->suspend(to_spi_device(dev), message);
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[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
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if (value == 0)
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dev->power.power_state = message;
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return value;
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}
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static int spi_resume(struct device *dev)
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{
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2006-01-08 14:34:23 -07:00
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int value;
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struct spi_driver *drv = to_spi_driver(dev->driver);
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
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|
2006-02-20 19:27:56 -07:00
|
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|
if (!drv || !drv->resume)
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
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|
return 0;
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/* resume may restart the i/o queue */
|
2006-01-08 14:34:23 -07:00
|
|
|
value = drv->resume(to_spi_device(dev));
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
if (value == 0)
|
|
|
|
dev->power.power_state = PMSG_ON;
|
|
|
|
return value;
|
|
|
|
}
|
|
|
|
|
|
|
|
#else
|
|
|
|
#define spi_suspend NULL
|
|
|
|
#define spi_resume NULL
|
|
|
|
#endif
|
|
|
|
|
|
|
|
struct bus_type spi_bus_type = {
|
|
|
|
.name = "spi",
|
|
|
|
.dev_attrs = spi_dev_attrs,
|
|
|
|
.match = spi_match_device,
|
|
|
|
.uevent = spi_uevent,
|
|
|
|
.suspend = spi_suspend,
|
|
|
|
.resume = spi_resume,
|
|
|
|
};
|
|
|
|
EXPORT_SYMBOL_GPL(spi_bus_type);
|
|
|
|
|
2006-01-08 14:34:23 -07:00
|
|
|
|
|
|
|
static int spi_drv_probe(struct device *dev)
|
|
|
|
{
|
|
|
|
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
|
|
|
|
|
|
|
|
return sdrv->probe(to_spi_device(dev));
|
|
|
|
}
|
|
|
|
|
|
|
|
static int spi_drv_remove(struct device *dev)
|
|
|
|
{
|
|
|
|
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
|
|
|
|
|
|
|
|
return sdrv->remove(to_spi_device(dev));
|
|
|
|
}
|
|
|
|
|
|
|
|
static void spi_drv_shutdown(struct device *dev)
|
|
|
|
{
|
|
|
|
const struct spi_driver *sdrv = to_spi_driver(dev->driver);
|
|
|
|
|
|
|
|
sdrv->shutdown(to_spi_device(dev));
|
|
|
|
}
|
|
|
|
|
|
|
|
int spi_register_driver(struct spi_driver *sdrv)
|
|
|
|
{
|
|
|
|
sdrv->driver.bus = &spi_bus_type;
|
|
|
|
if (sdrv->probe)
|
|
|
|
sdrv->driver.probe = spi_drv_probe;
|
|
|
|
if (sdrv->remove)
|
|
|
|
sdrv->driver.remove = spi_drv_remove;
|
|
|
|
if (sdrv->shutdown)
|
|
|
|
sdrv->driver.shutdown = spi_drv_shutdown;
|
|
|
|
return driver_register(&sdrv->driver);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_register_driver);
|
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
|
|
|
|
/* SPI devices should normally not be created by SPI device drivers; that
|
|
|
|
* would make them board-specific. Similarly with SPI master drivers.
|
|
|
|
* Device registration normally goes into like arch/.../mach.../board-YYY.c
|
|
|
|
* with other readonly (flashable) information about mainboard devices.
|
|
|
|
*/
|
|
|
|
|
|
|
|
struct boardinfo {
|
|
|
|
struct list_head list;
|
|
|
|
unsigned n_board_info;
|
|
|
|
struct spi_board_info board_info[0];
|
|
|
|
};
|
|
|
|
|
|
|
|
static LIST_HEAD(board_list);
|
|
|
|
static DECLARE_MUTEX(board_lock);
|
|
|
|
|
|
|
|
|
|
|
|
/* On typical mainboards, this is purely internal; and it's not needed
|
|
|
|
* after board init creates the hard-wired devices. Some development
|
|
|
|
* platforms may not be able to use spi_register_board_info though, and
|
|
|
|
* this is exported so that for example a USB or parport based adapter
|
|
|
|
* driver could add devices (which it would learn about out-of-band).
|
|
|
|
*/
|
|
|
|
struct spi_device *__init_or_module
|
|
|
|
spi_new_device(struct spi_master *master, struct spi_board_info *chip)
|
|
|
|
{
|
|
|
|
struct spi_device *proxy;
|
|
|
|
struct device *dev = master->cdev.dev;
|
|
|
|
int status;
|
|
|
|
|
|
|
|
/* NOTE: caller did any chip->bus_num checks necessary */
|
|
|
|
|
2006-01-08 14:34:25 -07:00
|
|
|
if (!spi_master_get(master))
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
return NULL;
|
|
|
|
|
|
|
|
proxy = kzalloc(sizeof *proxy, GFP_KERNEL);
|
|
|
|
if (!proxy) {
|
|
|
|
dev_err(dev, "can't alloc dev for cs%d\n",
|
|
|
|
chip->chip_select);
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
proxy->master = master;
|
|
|
|
proxy->chip_select = chip->chip_select;
|
|
|
|
proxy->max_speed_hz = chip->max_speed_hz;
|
|
|
|
proxy->irq = chip->irq;
|
|
|
|
proxy->modalias = chip->modalias;
|
|
|
|
|
|
|
|
snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id,
|
|
|
|
"%s.%u", master->cdev.class_id,
|
|
|
|
chip->chip_select);
|
|
|
|
proxy->dev.parent = dev;
|
|
|
|
proxy->dev.bus = &spi_bus_type;
|
|
|
|
proxy->dev.platform_data = (void *) chip->platform_data;
|
|
|
|
proxy->controller_data = chip->controller_data;
|
|
|
|
proxy->controller_state = NULL;
|
|
|
|
proxy->dev.release = spidev_release;
|
|
|
|
|
|
|
|
/* drivers may modify this default i/o setup */
|
|
|
|
status = master->setup(proxy);
|
|
|
|
if (status < 0) {
|
|
|
|
dev_dbg(dev, "can't %s %s, status %d\n",
|
|
|
|
"setup", proxy->dev.bus_id, status);
|
|
|
|
goto fail;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* driver core catches callers that misbehave by defining
|
|
|
|
* devices that already exist.
|
|
|
|
*/
|
|
|
|
status = device_register(&proxy->dev);
|
|
|
|
if (status < 0) {
|
|
|
|
dev_dbg(dev, "can't %s %s, status %d\n",
|
|
|
|
"add", proxy->dev.bus_id, status);
|
2006-01-08 14:34:23 -07:00
|
|
|
goto fail;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
}
|
|
|
|
dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id);
|
|
|
|
return proxy;
|
2006-01-08 14:34:23 -07:00
|
|
|
|
|
|
|
fail:
|
2006-01-08 14:34:25 -07:00
|
|
|
spi_master_put(master);
|
2006-01-08 14:34:23 -07:00
|
|
|
kfree(proxy);
|
|
|
|
return NULL;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_new_device);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Board-specific early init code calls this (probably during arch_initcall)
|
|
|
|
* with segments of the SPI device table. Any device nodes are created later,
|
|
|
|
* after the relevant parent SPI controller (bus_num) is defined. We keep
|
|
|
|
* this table of devices forever, so that reloading a controller driver will
|
|
|
|
* not make Linux forget about these hard-wired devices.
|
|
|
|
*
|
|
|
|
* Other code can also call this, e.g. a particular add-on board might provide
|
|
|
|
* SPI devices through its expansion connector, so code initializing that board
|
|
|
|
* would naturally declare its SPI devices.
|
|
|
|
*
|
|
|
|
* The board info passed can safely be __initdata ... but be careful of
|
|
|
|
* any embedded pointers (platform_data, etc), they're copied as-is.
|
|
|
|
*/
|
|
|
|
int __init
|
|
|
|
spi_register_board_info(struct spi_board_info const *info, unsigned n)
|
|
|
|
{
|
|
|
|
struct boardinfo *bi;
|
|
|
|
|
2006-01-08 14:34:23 -07:00
|
|
|
bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
if (!bi)
|
|
|
|
return -ENOMEM;
|
|
|
|
bi->n_board_info = n;
|
2006-01-08 14:34:23 -07:00
|
|
|
memcpy(bi->board_info, info, n * sizeof *info);
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
|
|
|
|
down(&board_lock);
|
|
|
|
list_add_tail(&bi->list, &board_list);
|
|
|
|
up(&board_lock);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_register_board_info);
|
|
|
|
|
|
|
|
/* FIXME someone should add support for a __setup("spi", ...) that
|
|
|
|
* creates board info from kernel command lines
|
|
|
|
*/
|
|
|
|
|
|
|
|
static void __init_or_module
|
|
|
|
scan_boardinfo(struct spi_master *master)
|
|
|
|
{
|
|
|
|
struct boardinfo *bi;
|
|
|
|
struct device *dev = master->cdev.dev;
|
|
|
|
|
|
|
|
down(&board_lock);
|
|
|
|
list_for_each_entry(bi, &board_list, list) {
|
|
|
|
struct spi_board_info *chip = bi->board_info;
|
|
|
|
unsigned n;
|
|
|
|
|
|
|
|
for (n = bi->n_board_info; n > 0; n--, chip++) {
|
|
|
|
if (chip->bus_num != master->bus_num)
|
|
|
|
continue;
|
|
|
|
/* some controllers only have one chip, so they
|
|
|
|
* might not use chipselects. otherwise, the
|
|
|
|
* chipselects are numbered 0..max.
|
|
|
|
*/
|
|
|
|
if (chip->chip_select >= master->num_chipselect
|
|
|
|
&& master->num_chipselect) {
|
|
|
|
dev_dbg(dev, "cs%d > max %d\n",
|
|
|
|
chip->chip_select,
|
|
|
|
master->num_chipselect);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
(void) spi_new_device(master, chip);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
up(&board_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
|
|
|
|
static void spi_master_release(struct class_device *cdev)
|
|
|
|
{
|
|
|
|
struct spi_master *master;
|
|
|
|
|
|
|
|
master = container_of(cdev, struct spi_master, cdev);
|
|
|
|
kfree(master);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct class spi_master_class = {
|
|
|
|
.name = "spi_master",
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
.release = spi_master_release,
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
* spi_alloc_master - allocate SPI master controller
|
|
|
|
* @dev: the controller, possibly using the platform_bus
|
2006-01-08 14:34:25 -07:00
|
|
|
* @size: how much driver-private data to preallocate; the pointer to this
|
|
|
|
* memory is in the class_data field of the returned class_device,
|
|
|
|
* accessible with spi_master_get_devdata().
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
*
|
|
|
|
* This call is used only by SPI master controller drivers, which are the
|
|
|
|
* only ones directly touching chip registers. It's how they allocate
|
|
|
|
* an spi_master structure, prior to calling spi_add_master().
|
|
|
|
*
|
|
|
|
* This must be called from context that can sleep. It returns the SPI
|
|
|
|
* master structure on success, else NULL.
|
|
|
|
*
|
|
|
|
* The caller is responsible for assigning the bus number and initializing
|
2006-01-08 14:34:25 -07:00
|
|
|
* the master's methods before calling spi_add_master(); and (after errors
|
|
|
|
* adding the device) calling spi_master_put() to prevent a memory leak.
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
*/
|
|
|
|
struct spi_master * __init_or_module
|
|
|
|
spi_alloc_master(struct device *dev, unsigned size)
|
|
|
|
{
|
|
|
|
struct spi_master *master;
|
|
|
|
|
2006-01-08 14:34:25 -07:00
|
|
|
if (!dev)
|
|
|
|
return NULL;
|
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
master = kzalloc(size + sizeof *master, SLAB_KERNEL);
|
|
|
|
if (!master)
|
|
|
|
return NULL;
|
|
|
|
|
2006-01-08 14:34:23 -07:00
|
|
|
class_device_initialize(&master->cdev);
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
master->cdev.class = &spi_master_class;
|
|
|
|
master->cdev.dev = get_device(dev);
|
2006-01-08 14:34:25 -07:00
|
|
|
spi_master_set_devdata(master, &master[1]);
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
|
|
|
|
return master;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_alloc_master);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* spi_register_master - register SPI master controller
|
|
|
|
* @master: initialized master, originally from spi_alloc_master()
|
|
|
|
*
|
|
|
|
* SPI master controllers connect to their drivers using some non-SPI bus,
|
|
|
|
* such as the platform bus. The final stage of probe() in that code
|
|
|
|
* includes calling spi_register_master() to hook up to this SPI bus glue.
|
|
|
|
*
|
|
|
|
* SPI controllers use board specific (often SOC specific) bus numbers,
|
|
|
|
* and board-specific addressing for SPI devices combines those numbers
|
|
|
|
* with chip select numbers. Since SPI does not directly support dynamic
|
|
|
|
* device identification, boards need configuration tables telling which
|
|
|
|
* chip is at which address.
|
|
|
|
*
|
|
|
|
* This must be called from context that can sleep. It returns zero on
|
|
|
|
* success, else a negative error code (dropping the master's refcount).
|
2006-01-08 14:34:25 -07:00
|
|
|
* After a successful return, the caller is responsible for calling
|
|
|
|
* spi_unregister_master().
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
*/
|
|
|
|
int __init_or_module
|
|
|
|
spi_register_master(struct spi_master *master)
|
|
|
|
{
|
|
|
|
static atomic_t dyn_bus_id = ATOMIC_INIT(0);
|
|
|
|
struct device *dev = master->cdev.dev;
|
|
|
|
int status = -ENODEV;
|
|
|
|
int dynamic = 0;
|
|
|
|
|
2006-01-08 14:34:25 -07:00
|
|
|
if (!dev)
|
|
|
|
return -ENODEV;
|
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
/* convention: dynamically assigned bus IDs count down from the max */
|
|
|
|
if (master->bus_num == 0) {
|
|
|
|
master->bus_num = atomic_dec_return(&dyn_bus_id);
|
2006-01-08 14:34:23 -07:00
|
|
|
dynamic = 1;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/* register the device, then userspace will see it.
|
|
|
|
* registration fails if the bus ID is in use.
|
|
|
|
*/
|
|
|
|
snprintf(master->cdev.class_id, sizeof master->cdev.class_id,
|
|
|
|
"spi%u", master->bus_num);
|
2006-01-08 14:34:23 -07:00
|
|
|
status = class_device_add(&master->cdev);
|
|
|
|
if (status < 0)
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
goto done;
|
|
|
|
dev_dbg(dev, "registered master %s%s\n", master->cdev.class_id,
|
|
|
|
dynamic ? " (dynamic)" : "");
|
|
|
|
|
|
|
|
/* populate children from any spi device tables */
|
|
|
|
scan_boardinfo(master);
|
|
|
|
status = 0;
|
|
|
|
done:
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_register_master);
|
|
|
|
|
|
|
|
|
|
|
|
static int __unregister(struct device *dev, void *unused)
|
|
|
|
{
|
|
|
|
/* note: before about 2.6.14-rc1 this would corrupt memory: */
|
2006-01-08 14:34:25 -07:00
|
|
|
spi_unregister_device(to_spi_device(dev));
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* spi_unregister_master - unregister SPI master controller
|
|
|
|
* @master: the master being unregistered
|
|
|
|
*
|
|
|
|
* This call is used only by SPI master controller drivers, which are the
|
|
|
|
* only ones directly touching chip registers.
|
|
|
|
*
|
|
|
|
* This must be called from context that can sleep.
|
|
|
|
*/
|
|
|
|
void spi_unregister_master(struct spi_master *master)
|
|
|
|
{
|
|
|
|
(void) device_for_each_child(master->cdev.dev, NULL, __unregister);
|
2006-01-08 14:34:25 -07:00
|
|
|
class_device_unregister(&master->cdev);
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_unregister_master);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* spi_busnum_to_master - look up master associated with bus_num
|
|
|
|
* @bus_num: the master's bus number
|
|
|
|
*
|
|
|
|
* This call may be used with devices that are registered after
|
|
|
|
* arch init time. It returns a refcounted pointer to the relevant
|
|
|
|
* spi_master (which the caller must release), or NULL if there is
|
|
|
|
* no such master registered.
|
|
|
|
*/
|
|
|
|
struct spi_master *spi_busnum_to_master(u16 bus_num)
|
|
|
|
{
|
|
|
|
if (bus_num) {
|
|
|
|
char name[8];
|
|
|
|
struct kobject *bus;
|
|
|
|
|
|
|
|
snprintf(name, sizeof name, "spi%u", bus_num);
|
|
|
|
bus = kset_find_obj(&spi_master_class.subsys.kset, name);
|
|
|
|
if (bus)
|
|
|
|
return container_of(bus, struct spi_master, cdev.kobj);
|
|
|
|
}
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_busnum_to_master);
|
|
|
|
|
|
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
|
2006-01-11 12:23:49 -07:00
|
|
|
static void spi_complete(void *arg)
|
|
|
|
{
|
|
|
|
complete(arg);
|
|
|
|
}
|
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
/**
|
|
|
|
* spi_sync - blocking/synchronous SPI data transfers
|
|
|
|
* @spi: device with which data will be exchanged
|
|
|
|
* @message: describes the data transfers
|
|
|
|
*
|
|
|
|
* This call may only be used from a context that may sleep. The sleep
|
|
|
|
* is non-interruptible, and has no timeout. Low-overhead controller
|
|
|
|
* drivers may DMA directly into and out of the message buffers.
|
|
|
|
*
|
|
|
|
* Note that the SPI device's chip select is active during the message,
|
|
|
|
* and then is normally disabled between messages. Drivers for some
|
|
|
|
* frequently-used devices may want to minimize costs of selecting a chip,
|
|
|
|
* by leaving it selected in anticipation that the next message will go
|
|
|
|
* to the same chip. (That may increase power usage.)
|
|
|
|
*
|
2006-01-08 14:34:25 -07:00
|
|
|
* Also, the caller is guaranteeing that the memory associated with the
|
|
|
|
* message will not be freed before this call returns.
|
|
|
|
*
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
* The return value is a negative error code if the message could not be
|
|
|
|
* submitted, else zero. When the value is zero, then message->status is
|
|
|
|
* also defined: it's the completion code for the transfer, either zero
|
|
|
|
* or a negative error code from the controller driver.
|
|
|
|
*/
|
|
|
|
int spi_sync(struct spi_device *spi, struct spi_message *message)
|
|
|
|
{
|
|
|
|
DECLARE_COMPLETION(done);
|
|
|
|
int status;
|
|
|
|
|
2006-01-11 12:23:49 -07:00
|
|
|
message->complete = spi_complete;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
message->context = &done;
|
|
|
|
status = spi_async(spi, message);
|
|
|
|
if (status == 0)
|
|
|
|
wait_for_completion(&done);
|
|
|
|
message->context = NULL;
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_sync);
|
|
|
|
|
|
|
|
#define SPI_BUFSIZ (SMP_CACHE_BYTES)
|
|
|
|
|
|
|
|
static u8 *buf;
|
|
|
|
|
|
|
|
/**
|
|
|
|
* spi_write_then_read - SPI synchronous write followed by read
|
|
|
|
* @spi: device with which data will be exchanged
|
|
|
|
* @txbuf: data to be written (need not be dma-safe)
|
|
|
|
* @n_tx: size of txbuf, in bytes
|
|
|
|
* @rxbuf: buffer into which data will be read
|
|
|
|
* @n_rx: size of rxbuf, in bytes (need not be dma-safe)
|
|
|
|
*
|
|
|
|
* This performs a half duplex MicroWire style transaction with the
|
|
|
|
* device, sending txbuf and then reading rxbuf. The return value
|
|
|
|
* is zero for success, else a negative errno status code.
|
2006-01-08 14:34:23 -07:00
|
|
|
* This call may only be used from a context that may sleep.
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
*
|
2006-01-08 14:34:25 -07:00
|
|
|
* Parameters to this routine are always copied using a small buffer;
|
|
|
|
* performance-sensitive or bulk transfer code should instead use
|
|
|
|
* spi_{async,sync}() calls with dma-safe buffers.
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
*/
|
|
|
|
int spi_write_then_read(struct spi_device *spi,
|
|
|
|
const u8 *txbuf, unsigned n_tx,
|
|
|
|
u8 *rxbuf, unsigned n_rx)
|
|
|
|
{
|
|
|
|
static DECLARE_MUTEX(lock);
|
|
|
|
|
|
|
|
int status;
|
|
|
|
struct spi_message message;
|
|
|
|
struct spi_transfer x[2];
|
|
|
|
u8 *local_buf;
|
|
|
|
|
|
|
|
/* Use preallocated DMA-safe buffer. We can't avoid copying here,
|
|
|
|
* (as a pure convenience thing), but we can keep heap costs
|
|
|
|
* out of the hot path ...
|
|
|
|
*/
|
|
|
|
if ((n_tx + n_rx) > SPI_BUFSIZ)
|
|
|
|
return -EINVAL;
|
|
|
|
|
2006-01-08 14:34:28 -07:00
|
|
|
spi_message_init(&message);
|
|
|
|
memset(x, 0, sizeof x);
|
|
|
|
if (n_tx) {
|
|
|
|
x[0].len = n_tx;
|
|
|
|
spi_message_add_tail(&x[0], &message);
|
|
|
|
}
|
|
|
|
if (n_rx) {
|
|
|
|
x[1].len = n_rx;
|
|
|
|
spi_message_add_tail(&x[1], &message);
|
|
|
|
}
|
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
/* ... unless someone else is using the pre-allocated buffer */
|
|
|
|
if (down_trylock(&lock)) {
|
|
|
|
local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
|
|
|
|
if (!local_buf)
|
|
|
|
return -ENOMEM;
|
|
|
|
} else
|
|
|
|
local_buf = buf;
|
|
|
|
|
|
|
|
memcpy(local_buf, txbuf, n_tx);
|
|
|
|
x[0].tx_buf = local_buf;
|
|
|
|
x[1].rx_buf = local_buf + n_tx;
|
|
|
|
|
|
|
|
/* do the i/o */
|
|
|
|
status = spi_sync(spi, &message);
|
|
|
|
if (status == 0) {
|
|
|
|
memcpy(rxbuf, x[1].rx_buf, n_rx);
|
|
|
|
status = message.status;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (x[0].tx_buf == buf)
|
|
|
|
up(&lock);
|
|
|
|
else
|
|
|
|
kfree(local_buf);
|
|
|
|
|
|
|
|
return status;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(spi_write_then_read);
|
|
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
|
|
|
|
static int __init spi_init(void)
|
|
|
|
{
|
2006-01-08 14:34:23 -07:00
|
|
|
int status;
|
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
buf = kmalloc(SPI_BUFSIZ, SLAB_KERNEL);
|
2006-01-08 14:34:23 -07:00
|
|
|
if (!buf) {
|
|
|
|
status = -ENOMEM;
|
|
|
|
goto err0;
|
|
|
|
}
|
|
|
|
|
|
|
|
status = bus_register(&spi_bus_type);
|
|
|
|
if (status < 0)
|
|
|
|
goto err1;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
|
2006-01-08 14:34:23 -07:00
|
|
|
status = class_register(&spi_master_class);
|
|
|
|
if (status < 0)
|
|
|
|
goto err2;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
return 0;
|
2006-01-08 14:34:23 -07:00
|
|
|
|
|
|
|
err2:
|
|
|
|
bus_unregister(&spi_bus_type);
|
|
|
|
err1:
|
|
|
|
kfree(buf);
|
|
|
|
buf = NULL;
|
|
|
|
err0:
|
|
|
|
return status;
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
}
|
2006-01-08 14:34:23 -07:00
|
|
|
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
/* board_info is normally registered in arch_initcall(),
|
|
|
|
* but even essential drivers wait till later
|
2006-01-08 14:34:23 -07:00
|
|
|
*
|
|
|
|
* REVISIT only boardinfo really needs static linking. the rest (device and
|
|
|
|
* driver registration) _could_ be dynamically linked (modular) ... costs
|
|
|
|
* include needing to have boardinfo data structures be much more public.
|
[PATCH] spi: simple SPI framework
This is the core of a small SPI framework, implementing the model of a
queue of messages which complete asynchronously (with thin synchronous
wrappers on top).
- It's still less than 2KB of ".text" (ARM). If there's got to be a
mid-layer for something so simple, that's the right size budget. :)
- The guts use board-specific SPI device tables to build the driver
model tree. (Hardware probing is rarely an option.)
- This version of Kconfig includes no drivers. At this writing there
are two known master controller drivers (PXA/SSP, OMAP MicroWire)
and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML
mentions of other drivers in development.
- No userspace API. There are several implementations to compare.
Implement them like any other driver, and bind them with sysfs.
The changes from last version posted to LKML (on 11-Nov-2005) are minor,
and include:
- One bugfix (removes a FIXME), with the visible effect of making device
names be "spiB.C" where B is the bus number and C is the chipselect.
- The "caller provides DMA mappings" mechanism now has kerneldoc, for
DMA drivers that want to be fancy.
- Hey, the framework init can be subsys_init. Even though board init
logic fires earlier, at arch_init ... since the framework init is
for driver support, and the board init support uses static init.
- Various additional spec/doc clarifications based on discussions
with other folk. It adds a brief "thank you" at the end, for folk
who've helped nudge this framework into existence.
As I've said before, I think that "protocol tweaking" is the main support
that this driver framework will need to evolve.
From: Mark Underwood <basicmark@yahoo.com>
Update the SPI framework to remove a potential priority inversion case by
reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-08 14:34:19 -07:00
|
|
|
*/
|
|
|
|
subsys_initcall(spi_init);
|
|
|
|
|