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 <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This adds the two new functions gpiochip_irq_domain_activate and
gpiochip_irq_domain_deactivate that can be used as the activate and
deactivate functions in the struct irq_domain_ops. This is for
situations where only gpiochip_{lock,unlock}_as_irq needs to be called.
SPMI and SSBI GPIO are two users that will initially use these
functions.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for the v4.21 kernel series.

  Core changes:

   - Some core changes are already in outside of this pull request as
     they came through the regulator tree, most notably
     devm_gpiod_unhinge() that removes devres refcount management from a
     GPIO descriptor. This is needed in subsystems such as regulators
     where the regulator core need to take over the reference counting
     and lifecycle management for a GPIO descriptor.

   - We dropped devm_gpiochip_remove() and devm_gpio_chip_match() as
     nothing needs it. We can bring it back if need be.

   - Add a global TODO so people see where we are going. This helps
     setting the direction now that we are two GPIO maintainers.

   - Handle the MMC CD/WP properties in the device tree core. (The bulk
     of patches activating this code is already merged through the
     MMC/SD tree.)

   - Augment gpiochip_request_own_desc() to pass a flag so we as
     gpiochips can request lines as active low or open drain etc even
     from ourselves.

  New drivers:

   - New driver for Cadence GPIO blocks.

   - New driver for Atmel SAMA5D2 PIOBU GPIO lines.

  Driver improvements:

   - A major refactoring of the PCA953x driver - this driver has been
     around for ages, and is now modernized to reduce code duplication
     that has stacked up and is using regmap to read write and cache
     registers.

   - Intel drivers are now maintained in a separate tree and start with
     a round of cleanups and unifications"

* tag 'gpio-v4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (99 commits)
  gpio: sama5d2-piobu: Depend on OF_GPIO
  gpio: Add Cadence GPIO driver
  dt-bindings: gpio: Add bindings for Cadence GPIO
  gpiolib-acpi: remove unused variable 'err', cleans up build warning
  gpio: mxs: read pin level directly instead of using .get
  gpio: aspeed: remove duplicated statement
  gpio: add driver for SAMA5D2 PIOBU pins
  dt-bindings: arm: atmel: describe SECUMOD usage as a GPIO controller
  gpio/mmc/of: Respect polarity in the device tree
  dt-bindings: gpio: rcar: Add r8a774c0 (RZ/G2E) support
  memory: omap-gpmc: Get the header of the enum
  ARM: omap1: Fix new user of gpiochip_request_own_desc()
  gpio: pca953x: Add regmap dependency for PCA953x driver
  gpio: raspberrypi-exp: decrease refcount on firmware dt node
  gpiolib: Fix return value of gpio_to_desc() stub if !GPIOLIB
  gpio: pca953x: Restore registers after suspend/resume cycle
  gpio: pca953x: Zap single use of pca953x_read_single()
  gpio: pca953x: Zap ad-hoc reg_output cache
  gpio: pca953x: Zap ad-hoc reg_direction cache
  gpio: pca953x: Perform basic regmap conversion
  ...

If CONFIG_GPOILIB is not set, the stub of gpio_to_desc() should return
the same type of error as regular version: NULL.  All the callers
compare the return value of gpio_to_desc() against NULL, so returned
ERR_PTR would be treated as non-error case leading to dereferencing of
error value.

Fixes: 79a9becda894 ("gpiolib: export descriptor-based GPIO interface")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Before things go out of hand, make it possible to pass
flags when requesting "own" descriptors from a gpio_chip.
This is necessary if the chip wants to request a GPIO with
active low semantics, for example.

Cc: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Roger Quadros <rogerq@ti.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This adds a function named devm_gpiod_unhinge() that removes
the resource management from a GPIO descriptor.

I am not sure if this is the best anglosaxon name for the
function, no other managed resources have an equivalent
currently, but I chose "unhinge" as the closest intuitive
thing I could imagine that fits Rusty Russell's API design
criterions "the obvious use is the correct one" and
"the name tells you how to use it".

The idea came out of a remark from Mark Brown that it should
be possible to handle over management of a resource from
devres to the regulator core, and indeed we can do that.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

This function already exist inside gpiolib, we were just
reluctant to make it available to the kernel at large as
the devm_* seemed to be enough for anyone.

However we found out that regulators need to do their own
lifecycle/refcounting on GPIO descriptors and explicitly
call gpiod_put() when done with a descriptor, so export
this function so we can hand the refcounting over to the
regulator core for these descriptors after retrieveal.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Drop the broken to_gpio_irq_chip() container_of() helper, which would
break the build for anyone who tries to use it.

Specifically, struct gpio_irq_chip only holds a pointer to a struct
irq_chip so using container_of() on an irq-chip pointer makes no sense.

Fixes: da80ff81a8f5 ("gpio: Move irqchip into struct gpio_irq_chip")
Cc: Thierry Reding <treding@nvidia.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiod_request_commit() copies the pointer to the label passed as
an argument only to be used later. But there's a chance the caller
could immediately free the passed string(e.g., local variable).
This could trigger a use after free when we use gpio label(e.g.,
gpiochip_unlock_as_irq(), gpiochip_is_requested()).

To be on the safe side: duplicate the string with kstrdup_const()
so that if an unaware user passes an address to a stack-allocated
buffer, we won't get the arbitrary label.

Also fix gpiod_set_consumer_name().

Signed-off-by: Muchun Song <smuchun@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>