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path: root/drivers/gpio/gpio-aggregator.c
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2023-06-16gpio: aggregator: Set up a parser of delay line parametersAndy Shevchenko1-2/+70
The aggregator mode can also handle properties of the platform, that do not belong to the GPIO controller itself. One of such a property is a signal delay line. Set up a parser to support it. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-06-16gpio: aggregator: Support delay for setting up individual GPIOsAndy Shevchenko1-0/+31
In some cases the GPIO may require an additional delay after setting its value. Add support for that into the GPIO forwarder code. This will be fully enabled for use in the following changes. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-06-16gpio: aggregator: Remove CONFIG_OF and of_match_ptr() protectionsAndy Shevchenko1-4/+3
They stop the driver being used with ACPI PRP0001 and are something I want to avoid being cut and paste into new drivers. Also include mod_devicetable.h as we struct of_device_id is defined in there. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-03-06gpio: aggregator: Add missing header(s)Andy Shevchenko1-4/+5
Do not imply that some of the generic headers may be always included. Instead, include explicitly what we are direct user of. While at it, drop unused linux/gpio.h and split out the GPIO group of headers. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
2022-10-17gpio: aggregator: Stop using ARCH_NR_GPIOSChristophe Leroy1-3/+4
ARCH_NR_GPIOS is used locally in aggr_parse() as the maximum number of GPIOs to be aggregated together by the driver since commit ec75039d5550 ("gpio: aggregator: Use bitmap_parselist() for parsing GPIO offsets"). Don't rely on the total possible number of GPIOs in the system but define a local arbitrary macro for that, set to 512 which should be large enough as it is also the default value for ARCH_NR_GPIOS. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2022-02-02gpio: aggregator: Fix calling into sleeping GPIO controllersGeert Uytterhoeven1-4/+14
If the parent GPIO controller is a sleeping controller (e.g. a GPIO controller connected to I2C), getting or setting a GPIO triggers a might_sleep() warning. This happens because the GPIO Aggregator takes the can_sleep flag into account only for its internal locking, not for calling into the parent GPIO controller. Fix this by using the gpiod_[gs]et*_cansleep() APIs when calling into a sleeping GPIO controller. Reported-by: Mikko Salomäki <ms@datarespons.se> Fixes: 828546e24280f721 ("gpio: Add GPIO Aggregator") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-12-03gpio: aggregator: Add interrupt supportGeert Uytterhoeven1-1/+10
Currently the GPIO Aggregator does not support interrupts. This means that kernel drivers going from a GPIO to an IRQ using gpiod_to_irq(), and userspace applications using line events do not work. Add interrupt support by providing a gpio_chip.to_irq() callback, which just calls into the parent GPIO controller. Note that this does not implement full interrupt controller (irq_chip) support, so using e.g. gpio-keys with "interrupts" instead of "gpios" still does not work. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-10-13gpio: aggregator: Wrap access to gpiochip_fwd.tmp[]Geert Uytterhoeven1-14/+11
The tmp[] member of the gpiochip_fwd structure is used to store both the temporary values bitmap and the desc pointers for operations on multiple GPIOs. As both are arrays with sizes unknown at compile-time, accessing them requires offset calculations, which are currently duplicated in gpio_fwd_get_multiple() and gpio_fwd_set_multiple(). Introduce (a) accessors for both arrays and (b) a macro to calculate the needed storage size. This confines the layout of the tmp[] member into a single spot, to ease maintenance. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-05-05gpio: aggregator: Replace custom get_arg() with a generic next_arg()Andy Shevchenko1-34/+5
cmdline library provides next_arg() helper to traverse over parameters and their values given in command line. Replace custom approach in the driver by it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
2021-02-15gpio: aggregator: Remove trailing comma in terminator entriesAndy Shevchenko1-2/+2
Remove trailing comma in terminator entries to avoid potential expanding an array behind it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
2021-02-15gpio: aggregator: Use compound literal from the headerAndy Shevchenko1-2/+1
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 <andriy.shevchenko@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
2021-02-15gpio: aggregator: Replace isrange() by using get_options()Andy Shevchenko1-30/+3
We already have a nice helper called get_options() which can be used to validate the input format. Replace isrange() by using it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
2020-08-18gpio: aggregator: Refactor ->{get, set}_multiple() to make Sparse happyAndy Shevchenko1-27/+43
Sparse can't see locking scheme used in ->get_multiple() and ->set_multiple() callbacks. CHECK .../drivers/gpio/gpio-aggregator.c .../spinlock.h:409:9: warning: context imbalance in 'gpio_fwd_get_multiple' - unexpected unlock .../spinlock.h:409:9: warning: context imbalance in 'gpio_fwd_set_multiple' - unexpected unlock Refactor them to have better readability and make Sparse happy. Code size impact is +52 bytes with arm-linux-gnueabihf-gcc 7.5.0. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-07-07gpio: aggregator: Use bitmap_parselist() for parsing GPIO offsetsGeert Uytterhoeven1-33/+26
Replace the custom code to parse GPIO offsets and/or GPIO offset ranges by a call to bitmap_parselist(), and an iteration over the returned bit mask. This should have no impact on the format of the configuration parameters written to the "new_device" virtual file in sysfs. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20200701114212.8520-3-geert+renesas@glider.be Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-07-07gpio: aggregator: Drop pre-initialization in get_arg()Geert Uytterhoeven1-2/+2
In get_arg(), the variable start is pre-initialized, but overwritten again in the first statement. Rework the assignment to not rely on pre-initialization, to make the code easier to read. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20200701114212.8520-2-geert+renesas@glider.be Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-05-18gpio: Add GPIO AggregatorGeert Uytterhoeven1-0/+568
GPIO controllers are exported to userspace using /dev/gpiochip* character devices. Access control to these devices is provided by standard UNIX file system permissions, on an all-or-nothing basis: either a GPIO controller is accessible for a user, or it is not. Currently no mechanism exists to control access to individual GPIOs. Hence add a GPIO driver to aggregate existing GPIOs, and expose them as a new gpiochip. This supports the following use cases: - Aggregating GPIOs using Sysfs This is useful for implementing access control, and assigning a set of GPIOs to a specific user or virtual machine. - Generic GPIO Driver This is useful for industrial control, where it can provide userspace access to a simple GPIO-operated device described in DT, cfr. e.g. spidev for SPI-operated devices. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20200511145257.22970-5-geert+renesas@glider.be Signed-off-by: Linus Walleij <linus.walleij@linaro.org>