kernel/linux.git/include/linux/gpio/machine.h, branch v5.18.12

gpiolib: provide gpiod_remove_hogs()

2021-12-17T11:26:12+00:00

Currently all users of gpiod_add_hogs() call it only once at system init so there never was any need for a mechanism allowing to remove them. Now the upcoming gpio-sim will need to tear down chips with hogged lines so provide a function that allows to remove hogs. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko Acked-by: Linus Walleij

gpio: aggregator: Use compound literal from the header

2021-02-15T10:43:32+00:00

Instead of doing it in place, convert GPIO_LOOKUP_IDX() and GPIO_HOG() to be compund literals that's allow to use them as rvalue in assignments. Due to above conversion, use compound literal from the header in the gpio-aggregator.c. Signed-off-by: Andy Shevchenko Reviewed-by: Geert Uytterhoeven

gpiolib: Add support for GPIO lookup by line name

2020-05-18T08:12:42+00:00

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 Tested-by: Eugeniu Rosca Reviewed-by: Ulrich Hecht Reviewed-by: Eugeniu Rosca Link: https://lore.kernel.org/r/20200511145257.22970-4-geert+renesas@glider.be Signed-off-by: Linus Walleij

gpio: Add comments on #if/#else/#endif

2019-06-27T14:56:50+00:00

Improve readability a bit by commenting #if/#else/#endif statements with the checked preprocessor symbols. Signed-off-by: Enrico Weigelt Signed-off-by: Linus Walleij

gpiolib: Introduce GPIO_LOOKUP_FLAGS_DEFAULT

2019-04-23T08:55:10+00:00

Since GPIO library operates with enumerator when it's subject to handle the GPIO lookup flags, it will be better to clearly see what default means. Thus, introduce GPIO_LOOKUP_FLAGS_DEFAULT entry to describe the default assumptions. While here, replace 0 by newly introduced constant. Signed-off-by: Andy Shevchenko Reviewed-by: Mika Westerberg Signed-off-by: Linus Walleij

gpiolib: Make use of enum gpio_lookup_flags consistent

2019-04-23T08:55:07+00:00

The library uses enum gpio_lookup_flags to define the possible characteristics of GPIO pin. Since enumerator listed only individual bits the common use of it is in a form of a bitmask of gpio_lookup_flags GPIO_* values. The more correct type for this is unsigned long. Due to above convert all users to use unsigned long instead of enum gpio_lookup_flags except enumerator definition. While here, make field and parameter descriptions consistent as well. Suggested-by: Mika Westerberg Signed-off-by: Andy Shevchenko Reviewed-by: Mika Westerberg Signed-off-by: Linus Walleij

gpiolib: Indent entry values of enum gpio_lookup_flags

2019-04-23T08:54:42+00:00

Indent entry values in the enum gpio_lookup_flags for better readability. No functional change. Signed-off-by: Andy Shevchenko Acked-by: Hans de Goede Reviewed-by: Mika Westerberg Signed-off-by: Linus Walleij

gpio: add core support for pull-up/pull-down configuration

2019-02-13T08:10:14+00:00

This commit adds support for configuring the pull-up and pull-down resistors available in some GPIO controllers. While configuring pull-up/pull-down is already possible through the pinctrl subsystem, some GPIO controllers, especially simple ones such as GPIO expanders on I2C, don't have any pinmuxing capability and therefore do not use the pinctrl subsystem. This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags, which can be used from the Device Tree, to enable a pull-up or pull-down resistor on a given GPIO. The flag is simply propagated all the way to the core GPIO subsystem, where it is used to call the gpio_chip ->set_config callback with the appropriate existing PIN_CONFIG_BIAS_* values. Signed-off-by: Thomas Petazzoni Signed-off-by: Linus Walleij

gpiolib: add hogs support for machine code

2018-05-16T12:35:24+00:00

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 Signed-off-by: Linus Walleij

gpio: gpiolib: Generalise state persistence beyond sleep

2017-12-02T21:42:34+00:00

General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery Reviewed-by: Charles Keepax Acked-by: Rob Herring Signed-off-by: Linus Walleij