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| * gpiolib: allow simultaneous setting of multiple GPIO outputsRojhalat Ibrahim2014-11-271-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | gpio: Support for unified device properties interfaceMika Westerberg2014-11-041-0/+7
|/ | | | | | | | | | | | | | | | | | | 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>
* gpio: move varargs hack outside #ifdef GPIOLIBLinus Walleij2014-09-021-45/+60
| | | | | | | | | | | | | | | | | 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>
* gpio: move GPIOD flags outside #ifdefLinus Walleij2014-08-211-2/+2
| | | | | | | | | | | 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>
* gpio: add flags argument to gpiod_get*() functionsAlexandre Courbot2014-07-281-16/+65
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* gpio: include linux/bug.h in interface headerArnd Bergmann2014-05-161-0/+1
| | | | | | | | | | | | | | | | | 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>
* gpio: Add helpers for optional GPIOsThierry Reding2014-05-091-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge tag 'v3.14-rc6' into develLinus Walleij2014-03-141-2/+2
|\ | | | | | | Linux 3.14-rc6
| * gpio: consumer.h: Move forward declarations outside #ifdefLars-Peter Clausen2014-02-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | gpiolib: add gpiochip_get_desc() driver functionAlexandre Courbot2014-02-121-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | gpio: make gpiod_direction_output take a logical valuePhilipp Zabel2014-02-071-0/+7
|/ | | | | | | | | | | | | | 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>
* gpiolib: add gpiod_get() and gpiod_put() functionsAlexandre Courbot2013-10-191-0/+15
| | | | | | | | | | | | Add gpiod_get(), gpiod_get_index() and gpiod_put() functions that provide safer management of GPIOs. These functions put the GPIO framework in line with the conventions of other frameworks in the kernel, and help ensure every GPIO is declared properly and valid while it is used. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
* gpiolib: export descriptor-based GPIO interfaceAlexandre Courbot2013-10-191-0/+238
This patch exports the gpiod_* family of API functions, a safer alternative to the legacy GPIO interface. Differences between the gpiod and legacy gpio APIs are: - gpio works with integers, whereas gpiod operates on opaque handlers which cannot be forged or used before proper acquisition - gpiod get/set functions are aware of the active low state of a GPIO - gpio consumers should now include <linux/gpio/consumer.h> to access the new interface, whereas chips drivers will use <linux/gpio/driver.h> The legacy gpio API is now built as inline functions on top of gpiod. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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