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: 828546e242 ("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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
