Add documentation of new GPIO specifiers indicating if the state of an
output pin should be maintained during sleep/low-power mode.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Commit 4c0facddb7 ("gpio: core: Decouple open drain/source flag with
active low/high") decoupled the open collector outputs from active
low/high but did not update the documentation.
Update the device tree documentation to correctly reflect this new
separation between the two concepts.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The length of the second entry is 20, so it affects GPIOs 10..29.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
When listing multiple GPIOs in the "gpios" property of a GPIO hog, only
the first GPIO is affected. The user is left clueless about the
dysfunctioning of the other GPIOs specified.
Fix this by adding and documenting support for specifying multiple
GPIOs in a single GPIO hog.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Make it possible to name the producer side of a GPIO line using
a "gpio-line-names" property array, modeled on the
"clock-output-names" property from the clock bindings.
This naming is especially useful for:
- Debugging: lines are named after function, not just opaque
offset numbers.
- Exploration: systems where some or all GPIO lines are available
to end users, such as prototyping, one-off's "makerspace usecases"
users are helped by the names of the GPIO lines when tinkering.
This usecase has been surfacing recently.
The gpio-line-names attribute is completely optional.
Example output from lsgpio on a patched Snowball tree:
GPIO chip: gpiochip6, "8000e180.gpio", 32 GPIO lines
line 0: unnamed unused
line 1: "AP_GPIO161" "extkb3" [kernel]
line 2: "AP_GPIO162" "extkb4" [kernel]
line 3: "ACCELEROMETER_INT1_RDY" unused [kernel]
line 4: "ACCELEROMETER_INT2" unused
line 5: "MAG_DRDY" unused [kernel]
line 6: "GYRO_DRDY" unused [kernel]
line 7: "RSTn_MLC" unused
line 8: "RSTn_SLC" unused
line 9: "GYRO_INT" unused
line 10: "UART_WAKE" unused
line 11: "GBF_RESET" unused
line 12: unnamed unused
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: David Mandala <david.mandala@linaro.org>
Cc: Lee Campbell <leecam@google.com>
Cc: devicetree@vger.kernel.org
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Keep the words talking about what a GPIO bank is, but remove the
binding. We have not agreed that this is something we want to have.
Acked-by: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
GPIO core:
- Define and handle flags for open drain/open collector
and open source/open emitter, also know as "single-ended"
configurations.
- Generic request/free operations that handle calling out
to the (optional) pin control backend.
- Some refactoring related to an ABI change that did not
happen, yet provide useful.
- Added a real-time compliance checklist. Many GPIO chips
have irqchips, and need to think this over with the RT
patches going upstream.
- Restructure, fix and clean up Kconfig menus a bit.
New drivers:
- New driver for AMD Promony.
- New driver for ACCES 104-IDIO-16, a port-mapped I/O
card, ISA-style. Very retro.
Subdriver changes:
- OMAP changes to handle real time requirements.
- Handle trigger types for edge and level IRQs on PL061
properly. As this hardware is very common it needs to
set a proper example for others to follow.
- Some container_of() cleanups.
- Delete the unused MSM driver in favor of the driver that
is embedded inside the pin control driver.
- Cleanup of the ath79 GPIO driver used by many, many
OpenWRT router targets.
- A consolidated IT87xx driver replacing the earlier
very specific IT8761e driver.
- Handle the TI TCA9539 in the PCA953x driver. Also
handle ACPI devices in this subdriver.
- Drop xilinx arch dependencies as these FPGAs seem to
profilate over a few different architectures. MIPS and
ARM come to mind.
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Merge tag 'gpio-v4.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"Here is the bulk of GPIO changes for the v4.4 development cycle.
The only changes hitting outside drivers/gpio are in the pin control
subsystem and these seem to have settled nicely in linux-next.
Development mistakes and catfights are nicely documented in the
reverts as you can see. The outcome of the ABI fight is that we're
working on a chardev ABI for GPIO now, where hope to show results for
the v4.5 kernel.
Summary of changes:
GPIO core:
- Define and handle flags for open drain/open collector and open
source/open emitter, also know as "single-ended" configurations.
- Generic request/free operations that handle calling out to the
(optional) pin control backend.
- Some refactoring related to an ABI change that did not happen, yet
provide useful.
- Added a real-time compliance checklist. Many GPIO chips have
irqchips, and need to think this over with the RT patches going
upstream.
- Restructure, fix and clean up Kconfig menus a bit.
New drivers:
- New driver for AMD Promony.
- New driver for ACCES 104-IDIO-16, a port-mapped I/O card,
ISA-style. Very retro.
Subdriver changes:
- OMAP changes to handle real time requirements.
- Handle trigger types for edge and level IRQs on PL061 properly. As
this hardware is very common it needs to set a proper example for
others to follow.
- Some container_of() cleanups.
- Delete the unused MSM driver in favor of the driver that is
embedded inside the pin control driver.
- Cleanup of the ath79 GPIO driver used by many, many OpenWRT router
targets.
- A consolidated IT87xx driver replacing the earlier very specific
IT8761e driver.
- Handle the TI TCA9539 in the PCA953x driver. Also handle ACPI
devices in this subdriver.
- Drop xilinx arch dependencies as these FPGAs seem to profilate over
a few different architectures. MIPS and ARM come to mind"
* tag 'gpio-v4.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (57 commits)
gpio: fix up SPI submenu
gpio: drop surplus I2C dependencies
gpio: drop surplus X86 dependencies
gpio: dt-bindings: document the official use of "ngpios"
gpio: MAINTAINERS: Add an entry for the ATH79 GPIO driver
gpio / ACPI: Allow shared GPIO event to be read via operation region
gpio: group port-mapped I/O drivers in a menu
gpio: Add ACCES 104-IDIO-16 driver maintainer entry
gpio: zynq: Document interrupt-controller DT binding
gpio: xilinx: Drop architecture dependencies
gpio: generic: Revert to old error handling in bgpio_map
gpio: add a real time compliance notes
Revert "gpio: add a real time compliance checklist"
gpio: Add GPIO support for the ACCES 104-IDIO-16
gpio: driver for AMD Promontory
gpio: xlp: Convert to use gpiolib irqchip helpers
gpio: add a real time compliance checklist
gpio/xilinx: enable for MIPS
gpiolib: Add and use OF_GPIO_SINGLE_ENDED flag
gpiolib: Split GPIO flags parsing and GPIO configuration
...
There are a bunch of drivers that utilize the "ngpios" DT property
without any vendor prefix. Try to start cleaning up the mess by
defining what we mean by this property.
Cc: devicetree@vger.kernel.org
Cc: Pramod Kumar <pramodku@broadcom.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
It is customary for GPIO controllers to support open drain/collector
and open source/emitter configurations. Add standard GPIO line flags
to account for this and augment the documentation to say that these
are the most generic bindings.
Several people approached me to add new flags to the lines, and this
makes sense, but let's first bind up the most common cases before we
start to add exotic stuff.
Thanks to H. Nikolaus Schaller for ideas on how to encode single-ended
wiring such as open drain/source and open collector/emitter.
Cc: Tony Lindgren <tony@atomide.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The gpiolib supports parsing DT properties of the form <name>-gpio but it
was only added for compatibility with older DT bindings that got it wrong
and should not be used in newer bindings.
The commit that added support for this was:
dd34c37aa3 ("gpio: of: Allow -gpio suffix for property names")
but didn't update the documentation to explain this so it's been a source
of confusion. So let's make this clear in the GPIO DT binding doc.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Now that ACPI supports named GPIO properties, either through ACPI 5.1 or
the per-driver ACPI GPIO mappings, we can be more narrow about the way
GPIOs should be specified in Device Tree bindings.
This patch updates the GPIO DT bindings documentation to highlight the
following rules for new GPIO bindings:
- All new bindings must have a meaningful name (e.g. the "gpios"
property must not be used)
- The only suffix allowed is "-gpios", no matter the number of
descriptors in the property
- GPIOs can only be grouped under the same property when they serve the
same purpose, a case that should remain exceptional (e.g. bit-banged
data lines).
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Document what we (Laurent and I, following a mailing list dicussion)
believe are best practices for the polarity flag in a GPIO specifier.
While touching the doc, I made a few minor editing changes to other
areas.
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch adds the infrastructure required to register non-linear gpio
ranges through gpiolib and the standard GPIO device tree bindings.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This change makes documentation of the the gpio-ranges property shorter
and more succinct, more consistent with the style of the rest of the
document, and not mention Linux-specifics such as the API
pinctrl_request_gpio(); DT binding documents should be OS independant
where at all possible. As part of this, the gpio-ranges property's format
is described in BNF form, in order to match the rest of the document.
This change also deprecates the #gpio-range-cells property. Such
properties are useful when one node references a second node, and that
second node dictates the format of the reference. However, that is not
the case here; the definition of gpio-ranges itself always dictates its
format entirely, and hence the value #gpio-range-cells must always be 3,
and hence there is no point requiring any referenced node to include
this property. The only remaining need for this property is to ensure
compatibility of DTs with older SW that was written to support the
previous version of the binding.
v4:
* Mention #gpio-range-cells as being deprecated, rather than removing all
documentation of that property. This allows DTs to be written in a
backwards-compatible way if desired, and also allows older DTs to be
interpreted fully using the latest documentation.
v3:
* Mention BNF in commit description.
* Fixed typo.
* Dropped patch that removed the deprecated property from *.dts, since
it's required to boot older kernels.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add gpio offset into "gpio-range-cells" property. It's used to support
sparse pinctrl range in gpio chip.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
pinctrl subsystem needs gpio chip base to prepare set of gpio
pin ranges, which a given pinctrl driver can handle. This is
important to handle pinctrl gpio request calls in order to
program a given pin properly for gpio operation.
As gpio base is allocated dynamically during gpiochip
registration, presently there exists no clean way to pass this
information to the pinctrl subsystem.
After few discussions from [1], it was concluded that may be
gpio controller reporting the pin range it supports, is a
better way than pinctrl subsystem directly registering it.
[1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/184816
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
[Edited documentation a bit]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The device tree is used by more than just PowerPC. Make the documentation
directory available to all.
v2: reorganized files while moving to create arch and driver specific
directories.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Charles Keepax