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2018-03-23Documentation: gpio: Move driver documentation to driver-apiJonathan Neuschäfer1-427/+0
Move gpio/driver.txt to driver-api/gpio/driver.rst and make sure it builds cleanly as ReST. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-01-18gpio: Documentation updateLinus Walleij1-0/+4
Update a slew of documentation files with the latest changes in the API/ABI. Again stress that sysfs is deprecated. Add all new flags and clean up and move some text. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-11-08gpio: Move irq_valid_mask into struct gpio_irq_chipThierry Reding1-2/+2
In order to consolidate the multiple ways to associate an IRQ chip with a GPIO chip, move more fields into the new struct gpio_irq_chip. Signed-off-by: Thierry Reding <treding@nvidia.com> Acked-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-11-08gpio: Move irqdomain into struct gpio_irq_chipThierry Reding1-1/+1
In order to consolidate the multiple ways to associate an IRQ chip with a GPIO chip, move more fields into the new struct gpio_irq_chip. Signed-off-by: Thierry Reding <treding@nvidia.com> Acked-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-31gpio: random documentation updateLinus Walleij1-9/+46
Updated and proofread the documentation for GPIO drivers a bit when looking over the changes for generic configuration. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26pinctrl / gpio: Introduce .set_config() callback for GPIO chipsMika Westerberg1-4/+5
Currently we already have two pin configuration related callbacks available for GPIO chips .set_single_ended() and .set_debounce(). In future we expect to have even more, which does not scale well if we need to add yet another callback to the GPIO chip structure for each possible configuration parameter. Better solution is to reuse what we already have available in the generic pinconf. To support this, we introduce a new .set_config() callback for GPIO chips. The callback takes a single packed pin configuration value as parameter. This can then be extended easily beyond what is currently supported by just adding new types to the generic pinconf enum. If the GPIO driver is backed up by a pinctrl driver the GPIO driver can just assign gpiochip_generic_config() (introduced in this patch) to .set_config and that will take care configuration requests are directed to the pinctrl driver. We then convert the existing drivers over .set_config() and finally remove the .set_single_ended() and .set_debounce() callbacks. Suggested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-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>
2016-11-25gpio: simplify adding threaded interruptsLinus Walleij1-26/+36
This tries to simplify the use of CONFIG_GPIOLIB_IRQCHIP when using threaded interrupts: add a new call gpiochip_irqchip_add_nested() to indicate that we're dealing with a nested rather than a chained irqchip, then create a separate gpiochip_set_nested_irqchip() to mirror the gpiochip_set_chained_irqchip() call to connect the parent and child interrupts. In the nested case gpiochip_set_nested_irqchip() does nothing more than call irq_set_parent() on each valid child interrupt, which has little semantic effect in the kernel, but this is probably still formally correct. Update all drivers using nested interrupts to use gpiochip_irqchip_add_nested() so we can now see clearly which these users are. The DLN2 driver can drop its specific hack with .irq_not_threaded as we now recognize whether a chip is threaded or not from its use of gpiochip_irqchip_add_nested() signature rather than from inspecting .can_sleep. We rename the .irq_parent to .irq_chained_parent since this parent IRQ is only really kept around for the chained interrupt handlers. Cc: Lars Poeschel <poeschel@lemonage.de> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Daniel Baluta <daniel.baluta@intel.com> Cc: Bin Gao <bin.gao@linux.intel.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com> Cc: Semen Protsenko <semen.protsenko@globallogic.com> Cc: Alexander Stein <alexander.stein@systec-electronic.com> Cc: Phil Reid <preid@electromag.com.au> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Patrice Chotard <patrice.chotard@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-23gpiolib: Make it possible to exclude GPIOs from IRQ domainMika Westerberg1-0/+6
When using GPIO irqchip helpers to setup irqchip for a gpiolib based driver, it is not possible to select which GPIOs to add to the IRQ domain. Instead it just adds all GPIOs which is not always desired. For example there might be GPIOs that for some reason cannot generated normal interrupts at all. To support this we add a flag irq_need_valid_mask to struct gpio_chip. When this flag is set the core allocates irq_valid_mask that holds one bit for each GPIO the chip has. By default all bits are set but drivers can manipulate this using set_bit() and clear_bit() accordingly. Then when gpiochip_irqchip_add() is called, this mask is checked and all GPIOs with bit is set are added to the IRQ domain created for the GPIO chip. Suggested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-27gpio: clarify open drain/source docsLinus Walleij1-6/+14
Make the text clearer, remove reference to confusing "positive" and "negative" and elaborate a bit. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-09gpio: document open drain/source behaviourLinus Walleij1-0/+89
This has been a totally undocumented feature for years so add some generic concepts and documentation about open drain/source, include some facts on how we now support for hardware. Cc: Michael Hennerich <michael.hennerich@analog.com> Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com> Cc: H. Nikolaus Schaller <hns@goldelico.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-11-21Doc: gpio: Fix typos in Documentation/gpioMasanari Iida1-3/+3
This patch fix some spelling typos found in Documentation/gpio. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-10-27gpio: add a real time compliance notesGrygorii Strashko1-0/+80
Put in a compliance checklist. Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-27Revert "gpio: add a real time compliance checklist"Linus Walleij1-60/+12
This reverts commit 677b2ff4afd9996eabefc9472c701211b4b49e87.
2015-10-20gpio: add a real time compliance checklistLinus Walleij1-12/+60
Add some information about real time compliance to the driver document. Inspired by Grygorii Strashko's real time compliance patches. Cc: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-10-28gpio: rename gpio_lock_as_irq to gpiochip_lock_as_irqAlexandre Courbot1-2/+2
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>
2014-09-26gpio: handle also nested irqchips in the chained handler set-upLinus Walleij1-1/+2
To unify how we connect cascaded IRQ chips to parent IRQs, if NULL us passed as handler to the gpiochip_set_chained_irqchip() function, assume the chips is nested rather than chained, and we still get the parent set up correctly by way of this function call. Alter the drivers for tc3589x and stmpe to use this to set up their chained handlers as a demonstration of the usage. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-08-29gpio: change gpiochip_request_own_desc() prototypeAlexandre Courbot1-1/+2
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>
2014-07-24gpiolib: Export gpiochip_request_own_desc and gpiochip_free_own_descGuenter Roeck1-0/+21
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 Courbot1-2/+2
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>
2014-04-28gpio: document gpio irqchips a bit more, describe helpersLinus Walleij1-0/+59
This adds some documentation about the GPIO irqchips, what types exist etc. Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-03gpio: document how to make combined GPIO+irqchip driversLinus Walleij1-0/+35
Write a few words on how GPIO drivers supplying an irqchip should be written. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-11-25Documentation: gpiolib: document new interfaceAlexandre Courbot1-0/+75
gpiolib now exports a new descriptor-based interface which deprecates the older integer-based one. This patch documents this new interface and also takes the opportunity to brush-up the GPIO documentation a little bit. The new descriptor-based interface follows the same consumer/driver model as many other kernel subsystems (e.g. clock, regulator), so its documentation has similarly been splitted into different files. The content of the former documentation has been reused whenever it made sense; however, some of its content did not apply to the new interface anymore and have this been removed. Likewise, new sections like the mapping of GPIOs to devices have been written from scratch. The deprecated legacy-based documentation is still available, untouched, under Documentation/gpio/gpio-legacy.txt. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>