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path: root/drivers/gpio/gpiolib.h
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2015-03-16driver core / ACPI: Represent ACPI companions using fwnode_handleRafael J. Wysocki
Now that we have struct fwnode_handle, we can use that to point to ACPI companions from struct device objects instead of pointing to struct acpi_device directly. There are two benefits from that. First, the somewhat ugly and hackish struct acpi_dev_node can be dropped and, second, the same struct fwnode_handle pointer can be used in the future to point to other (non-ACPI) firmware device node types. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Grant Likely <grant.likely@linaro.org>
2015-01-15gpio: sysfs: fix gpio attribute-creation raceJohan Hovold
Fix attribute-creation race with userspace by using the default group to create also the contingent gpio device attributes. Fixes: d8f388d8dc8d ("gpio: sysfs interface") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-11-04gpio / ACPI: Add support for _DSD device propertiesMika Westerberg
With release of ACPI 5.1 and _DSD method we can finally name GPIOs (and other things as well) returned by _CRS. Previously we were only able to use integer index to find the corresponding GPIO, which is pretty error prone if the order changes. With _DSD we can now query GPIOs using name instead of an integer index, like the below example shows: // Bluetooth device with reset and shutdown GPIOs Device (BTH) { Name (_HID, ...) Name (_CRS, ResourceTemplate () { GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly, "\\_SB.GPO0", 0, ResourceConsumer) {15} GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly, "\\_SB.GPO0", 0, ResourceConsumer) {27, 31} }) Name (_DSD, Package () { ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), Package () { Package () {"reset-gpio", Package() {^BTH, 1, 1, 0 }}, Package () {"shutdown-gpio", Package() {^BTH, 0, 0, 0 }}, } }) } The format of the supported GPIO property is: Package () { "name", Package () { ref, index, pin, active_low }} ref - The device that has _CRS containing GpioIo()/GpioInt() resources, typically this is the device itself (BTH in our case). index - Index of the GpioIo()/GpioInt() resource in _CRS starting from zero. pin - Pin in the GpioIo()/GpioInt() resource. Typically this is zero. active_low - If 1 the GPIO is marked as active_low. Since ACPI GpioIo() resource does not have field saying whether it is active low or high, the "active_low" argument can be used here. Setting it to 1 marks the GPIO as active low. In our Bluetooth example the "reset-gpio" refers to the second GpioIo() resource, second pin in that resource with the GPIO number of 31. This patch implements necessary support to gpiolib for extracting GPIOs using _DSD device properties. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-28gpio / ACPI: Move event handling registration to gpiolib irqchip helpersMika Westerberg
Since now we have irqchip helpers that the GPIO chip drivers are supposed to use if possible, we can move the registration of ACPI events to happen in these helpers. This seems to be more natural place and might encourage GPIO chip driver writers to take advantage of the irqchip helpers. We make the functions available to GPIO chip drivers via private gpiolib.h, just in case generic irqchip helpers are not suitable. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.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: 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>
2014-07-09gpio: move sysfs support to its own fileAlexandre Courbot
sysfs support is currently entangled within the core GPIO support, while it should relly just be a (privileged) user of the integer GPIO API. This patch is a first step towards making the gpiolib code more readable by splitting it into logical parts. Move all sysfs support to their own source file, and share static members of gpiolib that need to be in the private gpiolib.h file. In the future we will want to put some of them back into gpiolib.c, but this first patch let us at least identify them. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-05-21gpio: make of_get_named_gpiod_flags() privateAlexandre Courbot
of_get_named_gpiod_flags() is visible and directly usable by GPIO consumers, but it really should not as the gpiod interface relies on the simpler gpiod_get() to provide properly-configured GPIOs. of_get_named_gpiod_flags() is just used internally by gpiolib to implement gpiod_get(), and by the old of_get_named_gpio_flags() function, therefore it makes sense to make it gpiolib-private. As a side-effect, the unused (and unneeded) of_get_gpiod_flags() inline function is also removed, and of_get_named_gpio_flags() is moved from a static inline function to a regular one in gpiolib-of.c This results in all references to gpiod_* functions in of_gpio.h being gone, which is the way it should be since this file is part of the old integer GPIO interface. Changes since v1: - Fixed compilation error when CONFIG_OF_GPIO is not defined - Fixed warning due to of_gpio_flags enum not being declared in private gpiolib.h header Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-03-13gpiolib: Allow GPIO chips to request their own GPIOsMika Westerberg
Sometimes it is useful to allow GPIO chips themselves to request GPIOs they own through gpiolib API. One use case is ACPI ASL code that should be able to toggle GPIOs through GPIO operation regions. We can't use gpio_request() because it will pin the module to the kernel forever (it calls try_module_get()). To solve this we move module refcount manipulation to gpiod_request() and let __gpiod_request() handle the actual request. This changes the sequence a bit as now try_module_get() is called outside of gpio_lock (I think this is safe, try_module_get() handles serialization it needs already). Then we provide gpiolib internal functions gpiochip_request/free_own_desc() that do the same as gpio_request() but don't manipulate module refrence count. This allows the GPIO chip driver to request and free descriptors it owns without being pinned to the kernel forever. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-01-08gpio / ACPI: get rid of acpi_gpio.hMika Westerberg
Now that all users of acpi_gpio.h have been moved to use either the GPIO descriptor interface or to the internal gpiolib.h we can get rid of acpi_gpio.h entirely. Once this is done the only interface to get GPIOs to drivers enumerated from ACPI namespace is the descriptor based interface. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-01-08gpio / ACPI: register to ACPI events automaticallyMika Westerberg
Instead of asking each driver to register to ACPI events we can just call acpi_gpiochip_register_interrupts() for each chip that has an ACPI handle. The function checks chip->to_irq and if it is set to NULL (a GPIO driver that doesn't do interrupts) the function does nothing. We also add the a new header drivers/gpio/gpiolib.h that is used for functions internal to gpiolib and add ACPI GPIO chip registering functions to that header. Once that is done we can remove call to acpi_gpiochip_register_interrupts() from its only user, pinctrl-baytrail.c Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>