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2019-12-05gpiolib: Fix return value of gpio_to_desc() stub if !GPIOLIBKrzysztof Kozlowski
[ Upstream commit c5510b8dafce5f3f5a039c9b262ebcae0092c462 ] If CONFIG_GPOILIB is not set, the stub of gpio_to_desc() should return the same type of error as regular version: NULL. All the callers compare the return value of gpio_to_desc() against NULL, so returned ERR_PTR would be treated as non-error case leading to dereferencing of error value. Fixes: 79a9becda894 ("gpiolib: export descriptor-based GPIO interface") Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2015-10-16gpiolib: provide generic request/free implementationsJonas Gorski
Provide generic request/free implementations that pinctrl aware gpio drivers can use instead of open coding if they use a 1:1 pin to gpio signal mapping. Signed-off-by: Jonas Gorski <jogo@openwrt.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-24gpio: keep the GPIO line names internalLinus Walleij
This refactors the changes to the GPIO line naming mechanism to not have so widespread effects, instead we conclude the patch series by having created a name attribute in the GPIO descriptor, that need not be globally unique, and it will be initialized from the old .names array in struct gpio_chip if it exists, then used in the legacy sysfs code like the array was used previously. The associated changes to name lines from the device tree are controversial and need to stand alone from this. Resulting changes: 1. Remove the export and the header for the gpio_name_to_desc() as so far the only use is inside gpiolib.c. Staticize gpio_name_to_desc() and move it above the only function using it. 2. Only print a warning if there are two GPIO lines with the same name. The reason is to preserve current behaviour: before the previous changes to the naming mechanism this would not reject probing the driver, instead the error would occur when trying to export the line in sysfs, so restore this behaviour, but print a friendly warning if names collide. Cc: Johan Hovold <johan@kernel.org> Cc: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-09-24gpio: Introduce gpio descriptor 'name'Markus Pargmann
The latest gpio hogging mechanism assigns each gpio a 'line-name' in the devicetree. The 'name' field is different from the 'label' field. 'label' is only used for requested GPIOs to describe its current use by driver or userspace. The 'name' field describes the GPIO itself, not the use. This is most likely identical to the label in the schematic on the GPIO line and should help to find this particular GPIO. This is equivalent to the gpiochip->names array. However names should be stored in the GPIO descriptor. We will use gpiochip->names in the future only as initializer for the GPIO descriptors for drivers that assign GPIO names hardcoded. All other GPIO names will be parsed from DT and directly assigned to the GPIO descriptor. This patch adds a helper function to find gpio descriptors by name instead of gpio number. Signed-off-by: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-08-26gpiolib: add description for gpio irqchip fields in struct gpio_chipGrygorii Strashko
Add missed description for GPIO irqchip fields in struct gpio_chip. Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-08-17gpiolib: irqchip: use different lockdep class for each gpio irqchipGrygorii Strashko
Since IRQ chip helpers were introduced drivers lose ability to register separate lockdep classes for each registered GPIO IRQ chip and the gpiolib now is using shared lockdep class for all GPIO IRQ chips (gpiochip_irq_lock_class). As result, lockdep will produce warning when there are min two stacked GPIO chips and all of them are interrupt controllers. HW configuration which generates lockdep warning (TI dra7-evm): [SOC GPIO bankA.gpioX] <- irq - [pcf875x.gpioY] <- irq - DevZ.enable_irq_wake(pcf_gpioY_irq); The issue was reported in [1] and discussed [2]. ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc6-00013-g5d050ed-dirty #55 Not tainted --------------------------------------------- sh/63 is trying to acquire lock: (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94 but task is already holding lock: (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(class); lock(class); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by sh/63: #0: (sb_writers#4){.+.+.+}, at: [<c016bbb8>] vfs_write+0x13c/0x164 #1: (&of->mutex){+.+.+.}, at: [<c01debf4>] kernfs_fop_write+0x4c/0x1a0 #2: (s_active#36){.+.+.+}, at: [<c01debfc>] kernfs_fop_write+0x54/0x1a0 #3: (pm_mutex){+.+.+.}, at: [<c009758c>] pm_suspend+0xec/0x4c4 #4: (&dev->mutex){......}, at: [<c03f77f8>] __device_suspend+0xd4/0x398 #5: (&gpio->lock){+.+.+.}, at: [<c009b940>] __irq_get_desc_lock+0x74/0x94 #6: (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94 stack backtrace: CPU: 0 PID: 63 Comm: sh Not tainted 4.2.0-rc6-00013-g5d050ed-dirty #55 Hardware name: Generic DRA74X (Flattened Device Tree) [<c0016e24>] (unwind_backtrace) from [<c0013338>] (show_stack+0x10/0x14) [<c0013338>] (show_stack) from [<c05f6b24>] (dump_stack+0x84/0x9c) [<c05f6b24>] (dump_stack) from [<c00903f4>] (__lock_acquire+0x19c0/0x1e20) [<c00903f4>] (__lock_acquire) from [<c0091098>] (lock_acquire+0xa8/0x128) [<c0091098>] (lock_acquire) from [<c05fd61c>] (_raw_spin_lock_irqsave+0x38/0x4c) [<c05fd61c>] (_raw_spin_lock_irqsave) from [<c009b91c>] (__irq_get_desc_lock+0x50/0x94) [<c009b91c>] (__irq_get_desc_lock) from [<c009c4f4>] (irq_set_irq_wake+0x20/0xfc) [<c009c4f4>] (irq_set_irq_wake) from [<c0393ac4>] (pcf857x_irq_set_wake+0x24/0x54) [<c0393ac4>] (pcf857x_irq_set_wake) from [<c009c560>] (irq_set_irq_wake+0x8c/0xfc) [<c009c560>] (irq_set_irq_wake) from [<c04a02ac>] (gpio_keys_suspend+0x70/0xd4) [<c04a02ac>] (gpio_keys_suspend) from [<c03f6a00>] (dpm_run_callback+0x50/0x124) [<c03f6a00>] (dpm_run_callback) from [<c03f7830>] (__device_suspend+0x10c/0x398) [<c03f7830>] (__device_suspend) from [<c03f90f0>] (dpm_suspend+0x134/0x2f4) [<c03f90f0>] (dpm_suspend) from [<c0096e20>] (suspend_devices_and_enter+0xa8/0x728) [<c0096e20>] (suspend_devices_and_enter) from [<c00977cc>] (pm_suspend+0x32c/0x4c4) [<c00977cc>] (pm_suspend) from [<c0096060>] (state_store+0x64/0xb8) [<c0096060>] (state_store) from [<c01dec64>] (kernfs_fop_write+0xbc/0x1a0) [<c01dec64>] (kernfs_fop_write) from [<c016b280>] (__vfs_write+0x20/0xd8) [<c016b280>] (__vfs_write) from [<c016bb0c>] (vfs_write+0x90/0x164) [<c016bb0c>] (vfs_write) from [<c016c330>] (SyS_write+0x44/0x9c) [<c016c330>] (SyS_write) from [<c000f500>] (ret_fast_syscall+0x0/0x54) Lets fix it by using separate lockdep class for each registered GPIO IRQ Chip. This is done by wrapping gpiochip_irqchip_add call into macros. The implementation of this patch inspired by solution done by Nicolas Boichat for regmap [3] [1] http://www.spinics.net/lists/linux-gpio/msg05844.html [2] http://www.spinics.net/lists/linux-gpio/msg06021.html [3] http://www.spinics.net/lists/arm-kernel/msg429834.html Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roger Quadros <rogerq@ti.com> Reported-by: Roger Quadros <rogerq@ti.com> Tested-by: Roger Quadros <rogerq@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-21gpiolib: Add support for removing registered consumer lookup tableShobhit Kumar
In case we unload and load a driver module again that is registering a lookup table, without this it will result in multiple entries. Provide an option to remove the lookup table on driver unload Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Thierry Reding <thierry.reding@gmail.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-07-16gpio: Remove double "base" in commentGeert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-06gpio: make flags mandatory for gpiod_get functionsUwe Kleine-König
Now that all[1] users of the gpiod_get functions are converted to make use of the up to now optional flags parameter, make it mandatory which allows to remove some cpp magic. [1] all but etraxfs-uart which is broken anyhow and I'm allowed to ignore it by Jesper Nilsson :-) Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2015-06-01gpiolib: rename gpiod_set_array to gpiod_set_array_valueRojhalat Ibrahim
There have been concerns that the function names gpiod_set_array() and gpiod_get_array() might be confusing to users. One might expect gpiod_get_array() to return array values, while it is actually the array counterpart of gpiod_get(). To be consistent with the single descriptor API we could rename gpiod_set_array() to gpiod_set_array_value(). This makes some function names a bit lengthy: gpiod_set_raw_array_value_cansleep(). Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-25gpiolib: Add missing dummies for the unified device properties interfaceGeert Uytterhoeven
If GPIOLIB=n: drivers/leds/leds-gpio.c: In function ‘gpio_leds_create’: drivers/leds/leds-gpio.c:187: error: implicit declaration of function ‘devm_get_gpiod_from_child’ drivers/leds/leds-gpio.c:187: warning: assignment makes pointer from integer without a cast Add dummies for fwnode_get_named_gpiod() and devm_get_gpiod_from_child() for the !GPIOLIB case to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: 40b7318319281b1b ("gpio: Support for unified device properties interface") Acked-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2015-05-14gpio: discourage passing base to gpio_chipLinus Walleij
Passing a fixed base in struct gpio_chip is done for legacy systems that cannot handle dynamic allocation. Discourage this behaviour in the kerneldoc. Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-13gpiolib: cleanup chained handler and dataDmitry Eremin-Solenikov
Clean up chained handler and handler data if they were set by gpiochip_set_chained_irqchip(). Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12gpio: remove gpiod_sysfs_set_active_lowJohan Hovold
Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which allowed code to change the polarity of a gpio line even after it had been exported through sysfs. Drivers should not care, and generally does not know, about gpio-line polarity which is a hardware feature that needs to be described by firmware. It is currently possible to define gpio-line polarity in device-tree and acpi firmware or using platform data. Userspace can also change the polarity through sysfs. Note that drivers using the legacy gpio interface could still use GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio. There are no in-kernel users of this interface. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Harry Wei <harryxiyou@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@zh-kernel.org Cc: linux-arch@vger.kernel.org Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12gpio: sysfs: clean up chip class-device handlingJohan Hovold
Clean gpio-chip class device registration and deregistration. The class device is registered when a gpio-chip is added (or from gpiolib_sysfs_init post-core init call), and deregistered when the chip is removed. Store the class device in struct gpio_chip directly rather than do a class-device lookup on deregistration. This also removes the need for the exported flag. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-03-19gpio: move pincontrol calls to <linux/gpio/driver.h>Linus Walleij
These functions do not belong in <asm-generic/gpio.h> since the split into separate GPIO headers under <linux/gpio/*>. Move them to <linux/gpio/driver.h> as is apropriate. Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-03-05gpiolib: add devm_gpiod_get_array and devm_gpiod_put_array functionsRojhalat Ibrahim
Add device managed variants of gpiod_get_array() / gpiod_put_array() functions for conveniently obtaining and disposing of an entire array of GPIOs with one function call. Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-03-05gpiolib: add gpiod_get_array and gpiod_put_array functionsRojhalat Ibrahim
Introduce new functions for conveniently obtaining and disposing of an entire array of GPIOs with one function call. ACPI parts tested by Mika Westerberg, DT parts tested by Rojhalat Ibrahim. Change log: v5: move the ACPI functions to gpiolib-acpi.c v4: - use shorter names for members of struct gpio_descs - rename lut_gpio_count to platform_gpio_count for clarity - add check for successful memory allocation - use ERR_CAST() v3: - rebase on current linux-gpio devel branch - fix ACPI GPIO counting - allow for zero-sized arrays - make the flags argument mandatory for the new functions - clarify documentation v2: change interface Suggested-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Rojhalat Ibrahim <imr@rtschenk.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-03-04gpio: add parameter to allow the use named gpiosOlliver Schinagl
The gpio binding document says that new code should always use named gpios. Patch 40b73183 added support to parse a list of gpios from child nodes, but does not make it possible to use named gpios. This patch adds the con_id property and implements it is done in gpiolib.c, where the old-style of using unnamed gpios still works. Signed-off-by: Olliver Schinagl <oliver@schinagl.nl> Acked-by: Bryan Wu <cooloney@gmail.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-01-15gpio: Make the vararg hacks not pass magic valuesOlliver Schinagl
Right now, in consumer.h, there's some vararg hacks that pass 0 as the flags. What actually is passed however is GPIOD_ASIS, which naturally is also 0. Using the define/enum rather then the magic 0 makes it the define more readable to a passer by. Signed-off-by: Olliver Schinagl <oliver@schinagl.nl> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-11-28gpio: remove const modifier from gpiod_get_direction()Alexandre Courbot
Although gpiod_get_direction() can be considered side-effect free for consumers, its internals involve setting or clearing bits in the affected GPIO descriptor, for which we need to force-cast the const descriptor variable to non-const. This could lead to incorrect behavior if the compiler decides to optimize here, so remove this const attribute. The intent is to make gpiod_get_direction() private anyway, so it does not really matter. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-11-27gpiolib: allow simultaneous setting of multiple GPIO outputsRojhalat Ibrahim
Introduce new functions gpiod_set_array & gpiod_set_raw_array to the consumer interface which allow setting multiple outputs with just one function call. Also add an optional set_multiple function to the driver interface. Without an implementation of that function in the chip driver outputs are set sequentially. Implementing the set_multiple function in a chip driver allows for: - Improved performance for certain use cases. The original motivation for this was the task of configuring an FPGA. In that specific case, where 9 GPIO lines have to be set many times, configuration time goes down from 48 s to 20 s when using the new function. - Simultaneous glitch-free setting of multiple pins on any kind of parallel bus attached to GPIOs provided they all reside on the same chip and bank. Limitations: Performance is only improved for normal high-low outputs. Open drain and open source outputs are always set separately from each other. Those kinds of outputs could probably be accelerated in a similar way if we could forgo the error checking when setting GPIO directions. Change log: v6: - rebase on current linux-gpio devel branch v5: - check can_sleep property per chip - remove superfluous checks - supplement documentation v4: - add gpiod_set_array function for setting logical values - change interface of the set_multiple driver function to use unsigned long as type for the bit fields - use generic bitops (which also use unsigned long for bit fields) - do not use ARCH_NR_GPIOS any more v3: - add documentation - change commit message v2: - use descriptor interface - allow arbitrary groups of GPIOs spanning multiple chips Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mark Brown <broonie@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-11-04gpio: Support for unified device properties interfaceMika Westerberg
Some drivers need to deal with only firmware representation of its GPIOs. An example would be a GPIO button array driver where each button is described as a separate firmware node in device tree. Typically these child nodes do not have physical representation in the Linux device model. In order to help device drivers to handle such firmware child nodes we add dev[m]_get_named_gpiod_from_child() that takes a child firmware node pointer as its second argument (the first one is the parent device itself), finds the GPIO using whatever is the underlying firmware method, and requests the GPIO properly. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-10-28gpio: rename gpio_lock_as_irq to gpiochip_lock_as_irqAlexandre Courbot
This function actually operates on a gpio_chip, so its prefix should reflect that fact for consistency with other functions defined in gpio/driver.h. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-24gpiolib: add irq_not_threaded flag to gpio_chipOctavian Purdila
Some GPIO chips (e.g. the DLN2 USB adapter) have blocking get/set operation but do not need a threaded irq handler. Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-23gpio: gpiolib: set gpiochip_remove retval to voidabdoulaye berthe
This avoids handling gpiochip remove error in device remove handler. Signed-off-by: Abdoulaye Berthe <berthe.ab@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-05gpio: fix 'CONFIG_GPIO_IRQCHIP' commentsPaul Bolle
These two typos were introduced in commit 1425052097b5 ("gpio: add IRQ chip helpers in gpiolib"). The correct symbol name is CONFIG_GPIOLIB_IRQCHIP. [jkosina@suse.cz: add changelog] Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-02gpio: move varargs hack outside #ifdef GPIOLIBLinus Walleij
commit 39b2bbe3d715cf5013b5c48695ccdd25bd3bf120 "gpio: add flags argument to gpiod_get*() functions" added a dynamic flags argument to all the GPIOD getter functions, however this did not cover the stubs so when people used gpiod stubs to compile out descriptor code, compilation failed. Solve this by: - Also rename all the stub functions __gpiod_* - Moving the vararg hack outside of #ifdef CONFIG_GPIOLIB so these will always be available. Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-08-29gpio: change gpiochip_request_own_desc() prototypeAlexandre Courbot
The current prototype of gpiochip_request_own_desc() requires to obtain a pointer to a descriptor. This is in contradiction to all other GPIO request schemes, and imposes an extra step of obtaining a descriptor to drivers. Most drivers actually cannot even perform that step since the function that does it (gpichip_get_desc()) is gpiolib-private. Change gpiochip_request_own_desc() to return a descriptor from a (chip, hwnum) tuple and update users of this function (currently gpiolib-acpi only). Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-08-21gpio: move GPIOD flags outside #ifdefLinus Walleij
The GPIOD flags are defined inside the #ifdef CONFIG_GPIOLIB switch, making the gpiolib stubs fail if these flags are used by a consumer. This is not correct: the stubs should compile fine without GPIOLIB. Reported-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-08-07gpio: add missing includes in machine.hAlexandre Courbot
linux/types.h and linux/list.h should be included so the typed used in the header file are always properly declared. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-28gpio: add flags argument to gpiod_get*() functionsAlexandre Courbot
The huge majority of GPIOs have their direction and initial value set right after being obtained by one of the gpiod_get() functions. The integer GPIO API had gpio_request_one() that took a convenience flags parameter allowing to specify an direction and value applied to the returned GPIO. This feature greatly simplifies client code and ensures errors are always handled properly. A similar feature has been requested for the gpiod API. Since setting the direction of a GPIO is so often the very next action done after obtaining its descriptor, we prefer to extend the existing functions instead of introducing new functions that would raise the number of gpiod getters to 16 (!). The drawback of this approach is that all gpiod clients need to be updated. To limit the pain, temporary macros are introduced that allow gpiod_get*() to be called with or without the extra flags argument. They will be removed once all consumer code has been updated. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mark Brown <broonie@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-28gpio: split gpiod board registration into machine headerLinus Walleij
As per example from the regulator subsystem: put all defines and functions related to registering board info for GPIO descriptors into a separate <linux/gpio/machine.h> header. Cc: Andrew Victor <linux@maxim.org.za> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thierry Reding <thierry.reding@gmail.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Reviewed-by: Alexandre Courbot <gnurou@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-24gpiolib: Export gpiochip_request_own_desc and gpiochip_free_own_descGuenter Roeck
Both functions were introduced to let gpio drivers request their own gpio pins. Without exporting the functions, this can however only be used by gpio drivers built into the kernel. Secondary impact is that the functions can not currently be used by platform initialization code associated with the gpio-pca953x driver. This code permits auto-export of gpio pins through platform data, but if this functionality is used, the module can no longer be unloaded due to the problem solved with the introduction of gpiochip_request_own_desc and gpiochip_free_own_desc. Export both function so they can be used from modules and from platform initialization code. Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23gpio: remove gpiod_lock/unlock_as_irq()Alexandre Courbot
gpio_lock/unlock_as_irq() are working with (chip, offset) arguments and are thus not using the old integer namespace. Therefore, there is no reason to have gpiod variants of these functions working with descriptors, especially since the (chip, offset) tuple is more suitable to the users of these functions (GPIO drivers, whereas GPIO descriptors are targeted at GPIO consumers). Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23gpio: make gpiochip_get_desc() gpiolib-privateAlexandre Courbot
As GPIO descriptors are not going to remain unique anymore, having this function public is not safe. Restrain its use to gpiolib since we have no user outside of it. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23gpio: drop retval check enforcing from gpiochip_remove()Linus Walleij
As we start to decomission the return value from gpiochip_remove() the compilers emit warnings due to the function being tagged __must_check. So drop this until we remove the return value altogether. Cc: Abdoulaye Berthe <berthe.ab@gmail.com> Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-05-16gpio: include linux/bug.h in interface headerArnd Bergmann
Today's linux-next kernel started showing build errors for the use of WARN_ON in linux/gpio/consumer.h: In file included from drivers/video/backlight/pwm_bl.c:13:0: include/linux/gpio/consumer.h: In function 'gpiod_put': include/linux/gpio/consumer.h:81:2: error: implicit declaration of function 'WARN_ON' [-Werror=implicit-function-declaration] It's not clear why this never happened before, but this patch fixes it by including the header that contains the defintion of this macro. Signed-off-by: Arnd Bergmann <arnd@arnd.de> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-05-09gpio: Add helpers for optional GPIOsThierry Reding
Introduce gpiod_get_optional() and gpiod_get_index_optional() helpers that make it easier for drivers to handle optional GPIOs. Currently in order to handle optional GPIOs, a driver needs to special case error handling for -ENOENT, such as this: gpio = gpiod_get(dev, "foo"); if (IS_ERR(gpio)) { if (PTR_ERR(gpio) != -ENOENT) return PTR_ERR(gpio); gpio = NULL; } if (gpio) { /* set up GPIO */ } With these new helpers the above is reduced to: gpio = gpiod_get_optional(dev, "foo"); if (IS_ERR(gpio)) return PTR_ERR(gpio); if (gpio) { /* set up GPIO */ } While at it, device-managed variants of these functions are also provided. Signed-off-by: Thierry Reding <treding@nvidia.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-04-28gpio: support threaded interrupts in irqchip helpersLinus Walleij
Some off-chip GPIO expanders need to be communicated by I2C or SPI traffic, but may still support IRQs. By the sleeping nature of such buses, such IRQ handlers need to be threaded. Support such handlers in the gpiochip irqchip helpers by flagging IRQs as threaded if the .can_sleep property of the gpiochip is true. Helpfully deny registration of chained IRQ handlers if the .can_sleep property is set, as such chips will invariably need a nested handler rather than a chained handler. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-28gpio: unmap gpio irqs properlyLinus Walleij
When using the irqchip helper inside the gpiolib, make sure the IRQs are unmapped/disposed before the irqdomain is removed as part of removing the gpiochip. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-26gpio: add IRQ chip helpers in gpiolibLinus Walleij
This provides a function gpiochip_irqchip_add() to set up an irqchip for a GPIO controller, and a function gpiochip_set_chained_irqchip() to chain it to a parent irqchip. Most GPIOs are of the type where a number of lines form a cascaded interrupt controller chained onto the primary system interrupt controller (or further down the chain) so let's add this helper and factor the code to request the lines to be used as IRQs, the .to_irq() function and the irqdomain into the core as well. Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-12gpiolib: add gpiochip_get_desc() driver functionAlexandre Courbot
Some drivers dealing with a gpio_chip might need to act on its descriptors directly; one example is pinctrl drivers that need to lock a GPIO for being used as IRQ using gpiod_lock_as_irq(). This patch exports a gpiochip_get_desc() function that returns the GPIO descriptor at the requested index. It also sweeps the gpio_to_chip() function out of the consumer interface since any holder of a gpio_chip reference can manipulate its GPIOs way beyond what a consumer should be allowed to do. As a result, gpio_chip is not visible anymore to simple GPIO consumers. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-07gpio: make gpiod_direction_output take a logical valuePhilipp Zabel
The documentation was not clear about whether gpio_direction_output should take a logical value or the physical level on the output line, i.e. whether the ACTIVE_LOW status would be taken into account. This converts gpiod_direction_output to use the logical level and adds a new gpiod_direction_output_raw for the raw value. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-06gpio: consumer.h: Move forward declarations outside #ifdefLars-Peter Clausen
Make sure that the forward declared structs in gpio/consumer.h are also visible on the else branch of the CONFIG_GPIOLIB #ifdef. Fixes the following warnings and their associated errors when CONFIG_GPIOLIB is not selected: include/linux/gpio/consumer.h:67:14: warning: 'struct device' declared inside parameter list include/linux/gpio/consumer.h:67:14: warning: its scope is only this definition or declaration, which is probably not what you want [...] Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-09gpiolib: convert gpiod_lookup description to kernel-docAndy Shevchenko
The patch moves description of the fields to the top of struct definition and converts them to the kernel-doc format. There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-09gpio: better lookup method for platform GPIOsAlexandre Courbot
Change the format of the platform GPIO lookup tables to make them less confusing and improve lookup efficiency. The previous format was a single linked-list that required to compare the device name and function ID of every single GPIO defined for each lookup. Switch that to a list of per-device tables, so that the lookup can be done in two steps, omitting the GPIOs that are not relevant for a particular device. The matching rules are now defined as follows: - The device name must match *exactly*, and can be NULL for GPIOs not assigned to a particular device, - If the function ID in the lookup table is NULL, the con_id argument of gpiod_get() will not be used for lookup. However, if it is defined, it must match exactly. - The index must always match. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-04gpio/pinctrl: make gpio_chip members typed booleanLinus Walleij
This switches the two members of struct gpio_chip that were defined as unsigned foo:1 to bool, because that is indeed what they are. Switch all users in the gpio and pinctrl subsystems to assign these values with true/false instead of 0/1. The users outside these subsystems will survive since true/false is 1/0, atleast we set some kind of more strict typing example. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-03gpiolib: add missing declarationsAlexandre Courbot
Add declaration of 'struct of_phandle_args' to avoid the following warning: In file included from arch/arm/mach-tegra/board-paz00.c:21:0: include/linux/gpio/driver.h:102:17: warning: 'struct of_phandle_args' declared inside parameter list include/linux/gpio/driver.h:102:17: warning: its scope is only this definition or declaration, which is probably not what you want Also proactively add other definitions/includes that could be missing in other contexts. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reported-by: Stephen Warren <swarren@wwwdotorg.org> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-11-25gpiolib: use dedicated flags for GPIO propertiesAlexandre Courbot
GPIO mapping properties were defined using the GPIOF_* flags, which are declared in linux/gpio.h. This file is not included when using the GPIO descriptor interface. This patch declares the flags that can be used as GPIO mappings properties in linux/gpio/driver.h, and uses them in gpiolib, so that no deprecated declarations are used by the GPIO descriptor interface. This patch also allows GPIO_OPEN_DRAIN and GPIO_OPEN_SOURCE to be specified as GPIO mapping properties. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>