The GPIO Aggregator will need a method to forward a .set_config() call
to its parent gpiochip. This requires obtaining the gpio_chip and
offset for a given gpio_desc. While gpiod_to_chip() is public,
gpio_chip_hwgpio() is not, so there is currently no method to obtain the
needed GPIO offset parameter.
Hence introduce a public gpiod_set_config() helper, which invokes the
.set_config() callback through a gpio_desc pointer, like is done for
most other gpio_chip callbacks.
Rewrite the existing gpiod_set_debounce() helper as a wrapper around
gpiod_set_config(), to avoid duplication.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200324135653.6676-5-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Inclusion of kernel.h increases the mess with the header dependencies.
Avoid kernel.h inclusion where it's possible.
Besides that, clean up a bit other inclusions inside GPIO subsystem headers.
It includes:
- removal pin control bits (forward declaration and header) from linux/gpio.h
- removal of.h from asm-generic/gpio.h
- use of explicit headers in gpio/consumer.h
- add FIXME note with regard to gpio.h inclusion in of_gpio,h
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200205134336.20197-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Kernel build bot reported a compilation error after the commit
f626d6dfb7 ("gpio: of: Break out OF-only code"):
drivers/gpio/gpiolib-devres.o: In function `devm_gpiod_get_from_of_node':
gpiolib-devres.c:(.text+0x19a): undefined reference to `gpiod_get_from_of_node'
This happens due to move the latter under umbrella of CONFIG_OF_GPIO while
customer.h contains staled data.
Fix it by reshuffling contents of consumer.h to satisfy build dependencies.
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: f626d6dfb7 ("gpio: of: Break out OF-only code"):
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190730104337.21235-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
If gpiolib is disabled, we use the inline stubs from gpio/consumer.h
instead of regular definitions of GPIO API. The stubs for 'optional'
variants of gpiod_get routines return NULL in this case as if the
relevant GPIO wasn't found. This is correct so far.
Calling other (non-gpio_get) stubs from this header triggers a warning
because the GPIO descriptor couldn't have been requested. The warning
however is unconditional (WARN_ON(1)) and is emitted even if the passed
descriptor pointer is NULL.
We don't want to force the users of 'optional' gpio_get to check the
returned pointer before calling e.g. gpiod_set_value() so let's only
WARN on non-NULL descriptors.
Cc: stable@vger.kernel.org
Reported-by: Claus H. Stovgaard <cst@phaseone.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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: 79a9becda8 ("gpiolib: export descriptor-based GPIO interface")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
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>
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>
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.20 series:
Core changes:
- A patch series from Hans Verkuil to make it possible to
enable/disable IRQs on a GPIO line at runtime and drive GPIO lines
as output without having to put/get them from scratch.
The irqchip callbacks have been improved so that they can use only
the fastpatch callbacks to enable/disable irqs like any normal
irqchip, especially the gpiod_lock_as_irq() has been improved to be
callable in fastpath context.
A bunch of rework had to be done to achieve this but it is a big
win since I never liked to restrict this to slowpath. The only call
requireing slowpath was try_module_get() and this is kept at the
.request_resources() slowpath callback. In the GPIO CEC driver this
is a big win sine a single line is used for both outgoing and
incoming traffic, and this needs to use IRQs for incoming traffic
while actively driving the line for outgoing traffic.
- Janusz Krzysztofik improved the GPIO array API to pass a "cookie"
(struct gpio_array) and a bitmap for setting or getting multiple
GPIO lines at once.
This improvement orginated in a specific need to speed up an OMAP1
driver and has led to a much better API and real performance gains
when the state of the array can be used to bypass a lot of checks
and code when we want things to go really fast.
The previous code would minimize the number of calls down to the
driver callbacks assuming the CPU speed was orders of magnitude
faster than the I/O latency, but this assumption was wrong on
several platforms: what we needed to do was to profile and improve
the speed on the hot path of the array functions and this change is
now completed.
- Clean out the painful and hard to grasp BNF experiments from the
device tree bindings. Future approaches are looking into using JSON
schema for this purpose. (Rob Herring is floating a patch series.)
New drivers:
- The RCAR driver now supports r8a774a1 (RZ/G2M).
- Synopsys GPIO via CREGs driver.
Major improvements:
- Modernization of the EP93xx driver to use irqdomain and other
contemporary concepts.
- The ingenic driver has been merged into the Ingenic pin control
driver and removed from the GPIO subsystem.
- Debounce support in the ftgpio010 driver"
* tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (116 commits)
gpio: Clarify kerneldoc on gpiochip_set_chained_irqchip()
gpio: Remove unused 'irqchip' argument to gpiochip_set_cascaded_irqchip()
gpio: Drop parent irq assignment during cascade setup
mmc: pwrseq_simple: Fix incorrect handling of GPIO bitmap
gpio: fix SNPS_CREG kconfig dependency warning
gpiolib: Initialize gdev field before is used
gpio: fix kernel-doc after devres.c file rename
gpio: fix doc string for devm_gpiochip_add_data() to not talk about irq_chip
gpio: syscon: Fix possible NULL ptr usage
gpiolib: Show correct direction from the beginning
pinctrl: msm: Use init_valid_mask exported function
gpiolib: Add init_valid_mask exported function
GPIO: add single-register GPIO via CREG driver
dt-bindings: Document the Synopsys GPIO via CREG bindings
gpio: mockup: use device properties instead of platform_data
gpio: Slightly more helpful debugfs
gpio: omap: Remove set but not used variable 'dev'
gpio: omap: drop omap_gpio_list
Accept partial 'gpio-line-names' property.
gpio: omap: get rid of the conditional PM runtime calls
...
This allows nonexclusive (simultaneous) access to a single
GPIO line for the fixed regulator enable line. This happens
when several regulators use the same GPIO for enabling and
disabling a regulator, and all need a handle on their GPIO
descriptor.
This solution with a special flag is not entirely elegant
and should ideally be replaced by something more careful as
this makes it possible for several consumers to
enable/disable the same GPIO line to the left and right
without any consistency. The current use inside the regulator
core should however be fine as it takes special care to
handle this.
For the state of the GPIO backend, this is still the
lesser evil compared to going back to global GPIO
numbers.
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Fixes: efdfeb079c ("regulator: fixed: Convert to use GPIO descriptor only")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Internal helper function gpiod_set_array_value_complex() was changed to
return an error value, but not all gpiolib callers were updated to
propagate the new error up.
Fixes: 3027743f83 ("gpio: Remove VLA from gpiolib")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Certain GPIO array lookup results may map directly to GPIO pins of a
single GPIO chip in hardware order. If that condition is recognized
and handled efficiently, significant performance gain of get/set array
functions may be possible.
While processing a request for an array of GPIO descriptors, identify
those which represent corresponding pins of a single GPIO chip. Skip
over pins which require open source or open drain special processing.
Moreover, identify pins which require inversion. Pass a pointer to
that information with the array to the caller so it can benefit from
enhanced performance as soon as get/set array functions can accept and
make efficient use of it.
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
There should not be anything more than stated by the name of newly
introduced constants, i.e.
GPIOD_OUT_LOW_OPEN_DRAIN == GPIOD_OUT_LOW + open drain
and nothing more.
Make it better to read and slightly more robust by using GPIOD_OUT_LOW
and GPIOD_OUT_HIGH constants with open drain flag.
No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIO (descriptor) API registers a "label" naming what is
currently using the GPIO line. Typically this is taken from
things like the device tree node, so "reset-gpios" will result
in he line being labeled "reset".
The technical effect is pretty much zero: the use is for
debug and introspection, such as "lsgpio" and debugfs files.
However sometimes the user want this cuddly feeling of
listing all GPIO lines and seeing exactly what they are for
and it gives a very fulfilling sense of control. Especially
in the cases when the device tree node doesn't provide a
good name, or anonymous GPIO lines assigned just to
"gpios" in the device tree because the usage is implicit.
For these cases it may be nice to be able to label the
line directly and explicitly.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The new challenge is to remove VLAs from the kernel
(see https://lkml.org/lkml/2018/3/7/621) to eventually
turn on -Wvla.
Using a kmalloc array is the easy way to fix this but kmalloc is still
more expensive than stack allocation. Introduce a fast path with a
fixed size stack array to cover most chip with gpios below some fixed
amount. The slow path dynamically allocates an array to cover those
chips with a large number of gpios.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Reviewed-and-tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
We have been holding back on adding an API for fetching GPIO handles
directly from device nodes, strongly preferring to get it from the
spawn devices instead.
The fwnode interface however already contains an API for doing this,
as it is used for opaque device tree nodes or ACPI nodes for getting
handles to LEDs and keys that use GPIO: those are specified as one
child per LED/key in the device tree and are not individual devices.
However regulators present a special problem as they already have
helper functions to traverse the device tree from a regulator node
and two levels down to fill in data, and as it already traverses
GPIO nodes in its own way, and already holds a pointer to each
regulators device tree node, it makes most sense to export an
API to fetch the GPIO descriptor directly from the node.
We only support the devm_* version for now, hopefully no non-devres
version will be needed.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
