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2020-05-18gpiolib: Add support for GPIO lookup by line nameGeert Uytterhoeven
Currently a GPIO lookup table can only refer to a specific GPIO by a tuple, consisting of a GPIO controller label and a GPIO offset inside the controller. However, a GPIO may also carry a line name, defined by DT or ACPI. If present, the line name is the most use-centric way to refer to a GPIO. Hence add support for looking up GPIOs by line name. Note that there is no guarantee that GPIO line names are globally unique, so this will use the first match found. Implement this by reusing the existing gpiod_lookup infrastructure. Rename gpiod_lookup.chip_label to gpiod_lookup.key, to make it clear that this field can have two meanings, and update the kerneldoc and GPIO_LOOKUP*() macros. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20200511145257.22970-4-geert+renesas@glider.be Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-06-08docs: fix broken documentation linksMauro Carvalho Chehab
Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-02-11Documenation: driver-api: fix gpio/board.rst warningRandy Dunlap
Fix markup warning: insert a blank line before the list. Documentation/driver-api/gpio/board.rst:209: WARNING: Unexpected indentation. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: linux-gpio@vger.kernel.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-24gpiolib: Fix array members of same chip processed separatelyJanusz Krzysztofik
New code introduced by commit bf9346f5d47b ("gpiolib: Identify arrays matching GPIO hardware") forcibly tries to find an array member which has its array index number equal to its hardware pin number and set up an array info for possible fast bitmap processing of all arrray pins belonging to that chip which also satisfy that numbering rule. Depending on array content, it may happen that consecutive array members which belong to the same chip but don't have array indexes equal to their pin hardware numbers will be split into groups, some of them processed together via the fast bitmap path, and rest of them separetely. However, applications may expect all those pins being processed together with a single call to .set_multiple() chip callback, like that was done before the change. Limit applicability of fast bitmap processing path to cases where all pins of consecutive array members starting from 0 which belong to the same chip have their hardware numbers equal to their corresponding array indexes. That should still speed up processing of applications using whole GPIO banks as I/O ports, while not breaking simultaneous manipulation of consecutive pins of the same chip which don't follow the equal numbering rule. Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-13gpiolib: Implement fast processing path in get/set arrayJanusz Krzysztofik
Certain GPIO descriptor arrays returned by gpio_get_array() may contain information on direct mapping of array members to pins of a single GPIO chip in hardware order. In such cases, bitmaps of values can be passed directly from/to the chip's .get/set_multiple() callbacks without wasting time on iterations. Add respective code to gpiod_get/set_array_bitmap_complex() functions. Pins not applicable for fast path are processed as before, skipping over the 'fast' ones. Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-05-16gpiolib: add hogs support for machine codeBartosz Golaszewski
Board files constitute a significant part of the users of the legacy GPIO framework. In many cases they only export a line and set its desired value. We could use GPIO hogs for that like we do for DT and ACPI but there's no support for that in machine code. This patch proposes to extend the machine.h API with support for registering hog tables in board files. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-03-23Documentation: gpio: Move GPIO mapping documentation to driver-apiJonathan Neuschäfer
Move gpio/board.txt to driver-api/gpio/board.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>