Using BUG_ON() is discouraged and also the check wasn't done early
enough to prevent an out of bounds access. Check earlier and return
an error instead of calling BUG().
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/ae643df0-3a3e-4270-8dbf-be390ee4b478@moroto.mountain
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
It would make sense to return -EPERM if the bit was already set (already
used), not if it was cleared. Before this fix pins can only be exported on
the 2nd attempt:
$ echo 522 > /sys/class/gpio/export
sh: write error: Operation not permitted
$ echo 522 > /sys/class/gpio/export
Fixes: 35b545332b ("gpio: remove gpio_lock")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Several commits introduce managed resources (devm_*) into the
nmk_gpio_populate_chip() function.
This isn't always working because when called from the Nomadik pin
control driver we just want to populate some states for the device as
the same states are used by the pin control driver.
Some managed resources such as devm_kzalloc() etc will work, as the
passed in platform device will be used for lifecycle management,
but in some cases where we used the looked-up platform device
for the GPIO block, this will cause problems for the combined
pin control and GPIO driver, because it adds managed resources
to the GPIO device before it is probed, which is something that
the device core will not accept, and all of the GPIO blocks will
refuse to probe:
platform 8012e000.gpio: Resources present before probing
platform 8012e080.gpio: Resources present before probing
(...)
Fix this by not tying any managed resources to the looked-up
gpio_pdev/gpio_dev device, let's just live with the fact that
these need imperative resource management for now.
Drop in some notes and use a local *dev variable to clarify the
code.
Cc: Théo Lebrun <theo.lebrun@bootlin.com>
Fixes: 12410e9590 ("gpio: nomadik: use devm_platform_ioremap_resource() helper")
Link: https://lore.kernel.org/r/20240305-fix-nomadik-gpio-v2-1-e5d1fbdc3f5c@linaro.org
[Fixed some last minut print formatting]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
There is no need to repeat for-loop twice in the error path in
gpiochip_add_data_with_key(). Deduplicate it. While at it,
rename loop variable to be more specific and avoid ambguity.
It also properly unwinds the SRCU, i.e. in reversed order of allocating.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Previously driver got a few updates in order to replace OF APIs by
respective firmware node, however it was not finished to the logical
end, e.g., some APIs that has been used are still require OF node
to be passed. Finish that job by converting leftovers to use firmware
node APIs.
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240302173401.217830-1-andy.shevchenko@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Hogs are added *after* ACPI so should be removed *before* in error path.
Fixes: a411e81e61 ("gpiolib: add hogs support for machine code")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Make acpi_gpio_count() take firmware node as a parameter in order
to be aligned with other functions and decouple from unused device
pointer. The latter helps to create a common fwnode_gpio_count()
in the future.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Make of_gpio_get_count() take firmware node as a parameter in order
to be aligned with other functions and decouple from unused device
pointer. The latter helps to create a common fwnode_gpio_count()
in the future.
While at it, rename to be of_gpio_count() to be aligned with the others.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
After shuffling the code, error path wasn't updated correctly.
Fix it here.
Fixes: 2f4133bb5f ("gpiolib: No need to call gpiochip_remove_pin_ranges() twice")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Chip outputs are enabled[1] before actual reset is performed[2] which might
cause pin output value to flip flop if previous pin value was set to 1.
Fix that behavior by making sure chip is fully reset before all outputs are
enabled.
Flip-flop can be noticed when module is removed and inserted again and one of
the pins was changed to 1 before removal. 100 microsecond flipping is
noticeable on oscilloscope (100khz SPI bus).
For a properly reset chip - output is enabled around 100 microseconds (on 100khz
SPI bus) later during probing process hence should be irrelevant behavioral
change.
Fixes: 7ebc194d0f (gpio: 74x164: Introduce 'enable-gpios' property)
Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L130 [1]
Link: https://elixir.bootlin.com/linux/v6.7.4/source/drivers/gpio/gpio-74x164.c#L150 [2]
Signed-off-by: Arturas Moskvinas <arturas.moskvinas@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Fetch a reference to the optional shared reset control and deassert it
if it exists.
Optional because not all platforms that use this driver have a reset
attached to the reset block. Shared because some platforms that use the
reset (at least Mobileye EyeQ5) share the reset across banks.
Do not keep a reference to the reset control as it is not needed
afterwards; the driver does not handle suspend, does not use runtime
PM, does not register a remove callback and does not support unbinding
from sysfs (made explicit with suppress_bind_attrs).
The operation is done in nmk_gpio_populate_chip(). This function is
called by either gpio-nomadik or pinctrl-nomadik, whoever comes first.
This is here for historic reasons and could probably be removed now; it
seems gpio-ranges enforces the ordering to be pinctrl-first. It is not
the topic of the present patch however.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-25-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
We create a custom compatible for the STA2X11 IP block as integrated
into the Mobileye EyeQ5 platform. Its wake and alternate functions have
been disabled, we want to avoid touching those registers.
We both do: (1) early return in functions that do not support the
platform, but with warnings, and (2) avoid calling those functions in
the first place.
We ensure that pinctrl-nomadik is not used with this STA2X11 variant.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-24-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Read the "ngpios" property to determine the number of GPIOs for a bank.
If not available, fallback to NMK_GPIO_PER_CHIP ie 32 ie the current
behavior.
The IP block always supports 32 GPIOs, but platforms can expose a lesser
amount. The Mobileye EyeQ5 is in this case; one bank is 29 GPIOs and
the other is 23.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-23-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Support a single IRQs used by multiple GPIO banks. Change the IRQ
handler type from a chained handler (as used by gpiolib
for ->parent_handler) to a threaded IRQ.
Use the generic_handle_domain_irq_safe() helper. The non-safe version
must be called in a no-IRQ context.
The Mobileye EyeQ5 platform uses this GPIO controller and share an IRQ
for its two banks.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-22-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This GPIO driver is historically related to the Nomadik platform. It
however can be used by others as it implements the ST STA2X11 IP block.
Pick a less ambiguous name for it.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-21-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Not all platforms using this platform driver expose a clock for this
GPIO controller. Turn devm_clk_get() into devm_clk_get_optional() to
avoid failing when no clocks are provided.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-20-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Move away from statically allocated GPIO IDs. Switch to dynamic ID
allocation. Static IDs are deprecated because they cause issues when
multiple GPIO controllers are to be found on the same platform.
Add a bit of complexity to do pin number -> GPIO chip + offset.
Previously, bank number and offsets were retrieved using division and
remainder (bank size being constant 32). Now, to get the pin number
matching a bank base, we must know the sum of ngpios of previous banks.
This is done in find_nmk_gpio_from_pin() which also exposes the offset
inside the bank.
Also remove the assumption that bank sizes are constant. Instead of
using NMK_GPIO_PER_CHIP as bank size, use nmk_gpio_chips[i]->ngpio.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-19-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Replace call to clk_get() by call to devm_clk_get(). Allow automatic
cleanup of the clock in case of probe error.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-18-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Replace calls to platform_get_resource() then devm_ioremap_resource() by
a single call to devm_platform_ioremap_resource().
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-17-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Avoid OF APIs in the GPIO subsystem. Here, replace
of_find_device_by_node() call by bus_find_device_by_of_node().
The new helper returns a struct device pointer. Store it in a new local
variable and use it down the road.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-15-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Previously, drivers/pinctrl/nomadik/pinctrl-nomadik.c registered two
platform drivers: pinctrl & GPIO. Move the GPIO aspect to the
drivers/gpio/ folder, as would be expected.
Both drivers are intertwined for a reason; pinctrl requires access to
GPIO registers for pinmuxing, pull-disable, disabling interrupts while
setting the muxing and wakeup control. Information sharing is done
through a shared array containing GPIO chips and a few helper
functions. That shared array is not touched from gpio-nomadik when
CONFIG_PINCTRL_NOMADIK is not defined.
Make no change to the code that moved into gpio-nomadik; there should be
no behavior change following. A few functions are shared and header
comments are added. Checkpatch warnings are addressed. NUM_BANKS is
renamed to NMK_MAX_BANKS.
It is supported to compile gpio-nomadik without pinctrl-nomadik. The
opposite is not true.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-6-3ba757474006@bootlin.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This devm API takes a consumer device as an argument to setup the devm
action, but throws it away when calling further into gpiolib. This leads
to odd debug messages like this:
(NULL device *): using DT '/gpio-keys/switch-pen-insert' for '(null)' GPIO lookup
Let's pass the consumer device down, by directly calling what
fwnode_gpiod_get_index() calls but pass the device used for devm. This
changes the message to look like this instead:
gpio-keys gpio-keys: using DT '/gpio-keys/switch-pen-insert' for '(null)' GPIO lookup
Note that callers of fwnode_gpiod_get_index() will still see the NULL
device pointer debug message, but there's not much we can do about that
because the API doesn't take a struct device.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Fixes: 8eb1f71e7a ("gpiolib: consolidate GPIO lookups")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Display debugfs information about all simulated GPIOs, not only the
requested ones.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
With SRCU we can now correctly handle the situation when a GPIO provider
is removed while having users still holding references to GPIO
descriptors. Remove all warnings emitted in this situation.
Suggested-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Herve Codina <herve.codina@bootlin.com>
Typically, whenever a human-readable name is created for objects using
a software node, its name is delimited with ":" as dashes are often used
in other parts of the name. Make gpio-sim use the same pattern. This
results in better looking default names:
gpio-sim.0:node0
gpio-sim.0:node1
gpio-sim.1:node0
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
We have three functions in gpio-sim that are called with the device lock
already held. We use the "_unlocked" suffix in their names to indicate
that. This has proven to be confusing though as the naming convention in
the kernel varies between using "_locked" or "_unlocked" for this
purpose. Naming convention also doesn't enforce anything. Let's remove
the suffix and add lockdep annotation at the top of these functions.
This makes it clear the function requires a lock to be held (and which
one specifically!) as well as results in a warning if it's not the case.
The only place where the information is lost is the place where the
function is called but the caller doesn't care about that information
anyway.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The ChromeOS embedded controller (EC) supports setting the state of
GPIOs when the system is unlocked, and getting the state of GPIOs in all
cases. The GPIOs are on the EC itself, so the EC acts similar to a GPIO
expander. Add a driver to get and set the GPIOs on the EC through the
host command interface.
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Similar to gpiochip_generic_request() and gpiochip_generic_free() the
gpiochip_generic_config() function needs to handle the case where there
are no pinctrl pins mapped to the GPIOs, usually through the gpio-ranges
device tree property.
Commit f34fd6ee1b ("gpio: dwapb: Use generic request, free and
set_config") set the .set_config callback to gpiochip_generic_config()
in the dwapb GPIO driver so the GPIO API can set pinctrl configuration
for the corresponding pins. Most boards using the dwapb driver do not
set the gpio-ranges device tree property though, and in this case
gpiochip_generic_config() would return -EPROPE_DEFER rather than the
previous -ENOTSUPP return value. This in turn makes
gpio_set_config_with_argument_optional() fail and propagate the error to
any driver requesting GPIOs.
Fixes: 2956b5d94a ("pinctrl / gpio: Introduce .set_config() callback for GPIO chips")
Reported-by: Jisheng Zhang <jszhang@kernel.org>
Closes: https://lore.kernel.org/linux-gpio/ZdC_g3U4l0CJIWzh@xhacker/
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Pointer to the struct of_phandle_args can be made const after
gpio_device_find() arguments got constified. This should be part of
commit 4a92857d6e ("gpio: constify opaque pointer "data" in
gpio_device_find()").
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The opaque pointer "data" in each match function used by
gpio_device_find() is a pointer to const, thus the same argument passed
to gpio_device_find() can adjusted similarly.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
We are actually passing the gc pointer to chip_dbg() so we have to
srcu_dereference() it.
Fixes: 8574b5b476 ("gpio: cdev: use correct pointer accessors with SRCU")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Closes: https://lore.kernel.org/lkml/179caa10-5f86-4707-8bb0-fe1b316326d6@samsung.com/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
There are two legacy, deprecated functions - gpiod_to_chip() and
gpio_device_get_chip() - that still have users in tree. They return the
address of the SRCU-protected chip outside of the read-only critical
sections. They are inherently dangerous and the users should convert to
safer alternatives. Let's explicitly silence lockdep warnings by using
rcu_dereference_check(ptr, 1). While at it: reuse
gpio_device_get_chip() in gpiod_to_chip().
Fixes: d83cee3d2b ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Lockdep with CONFIG_PROVE_RCU enabled reports false positives about
suspicious rcu_dereference() usage. Let's silence it by using
srcu_dereference() which is the correct helper with SRCU.
Fixes: d83cee3d2b ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
We never dereference the chip pointer in character device code so we can
use the lighter rcu_access_pointer() helper. This also makes lockep
happier as it no longer complains about suspicious rcu_dereference()
usage.
Fixes: d83cee3d2b ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
gpiod_hog() may be called without the gpio_device SRCU read lock taken
so we need to do it here as well. It's alright if someone else is
already holding the lock as SRCU read critical sections can be nested.
Fixes: d83cee3d2b ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122234.d85cca9b-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
In certain situations we may end up taking the GPIO descriptor SRCU read
lock in of_gpiochip_add() before the SRCU struct is initialized. Move
the initialization before the call to of_gpiochip_add().
Fixes: be711caa87 ("gpio: add SRCU infrastructure to struct gpio_desc")
Fixes: 1f2bcb8c8c ("gpio: protect the descriptor label with SRCU")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202402122228.e607a080-lkp@intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
We still have some functions that return the address of the GPIO chip
associated with the GPIO device. This is dangerous and the users should
find a better solution. Let's add appropriate comments to the kernel
docs.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
With all accesses to gdev->chip being protected with SRCU, we can now
remove the RW-semaphore specific to the character device which
fulfilled the same role up to this point.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Ensure we cannot crash if the GPIO device gets unregistered (and the
chip pointer set to NULL) during any of the API calls.
To that end: wait for all users of gdev->chip to exit their read-only
SRCU critical sections in gpiochip_remove().
For brevity: add a guard class which can be instantiated at the top of
every function requiring read-only access to the chip pointer and use it
in all API calls taking a GPIO descriptor as argument. In places where
we only deal with the GPIO device - use regular guard() helpers and
rcu_dereference() for chip access. Do the same in API calls taking a
const pointer to gpio_desc.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Add the SRCU struct to GPIO device. It will be used to serialize access
to the GPIO chip pointer. Initialize and clean it up where applicable.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Duplicating the can_sleep value in GPIO device will allow us to not
needlessly dereference the chip pointer in several places and reduce the
number of SRCU read-only critical sections.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We don't need to check the gdev pointer in struct gpio_desc - it's
always assigned and never cleared. It's also pointless to check
gdev->chip before we actually serialize access to it.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Checking desc->gdev->chip for NULL without holding it in place with some
serializing mechanism is pointless. Remove this check. Also don't check
desc->gdev for NULL as it can never happen. We'll be protecting
gdev->chip with SRCU soon but we will provide a dedicated, automatic
class for that.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We don't need to dereference gdev->chip in gpiochip_setup_dev() as at
the time it's called, the label in the associated struct gpio_device is
already set.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Don't dereference gdev->chip if the same information can be obtained
from struct gpio_device.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The variable holding the number of GPIO lines is duplicated in GPIO
device so read it instead of unnecessarily dereferencing the chip
pointer.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
gpio_device_get_desc() is the safer alternative to gpiochip_get_desc().
As we don't really need to dereference the chip pointer to retrieve the
descriptors in character device code, let's use it.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We're working towards protecting the chip pointer in struct gpio_device
with SRCU. In order to use it in sysfs callbacks we must pass the pointer
to the GPIO device that wraps the chip instead of the address of the
chip itself as the user data.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Checking the gdev->mockdev pointer for NULL must be part of the critical
section.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We now removed the gpio_lock spinlock and modified the places
previously protected by it to handle desc->flags access in a consistent
way. Let's improve other places that were previously unprotected by
reading the flags field of gpio_desc once and using the stored value for
logic consistency. If we need to modify the field, let's also write it
back once with a consistent value resulting from the function's logic.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The "multi-function" gpio_lock is pretty much useless with how it's used
in GPIOLIB currently. Because many GPIO API calls can be called from all
contexts but may also call into sleeping driver callbacks, there are
many places with utterly broken workarounds like yielding the lock to
call a possibly sleeping function and then re-acquiring it again without
taking into account that the protected state may have changed.
It was also used to protect several unrelated things: like individual
descriptors AND the GPIO device list. We now serialize access to these
two with SRCU and so can finally remove the spinlock.
There is of course the question of consistency of lockless access to
GPIO descriptors. Because we only support exclusive access to GPIOs
(officially anyway, I'm looking at you broken
GPIOD_FLAGS_BIT_NONEXCLUSIVE bit...) and the API contract with providers
does not guarantee serialization, it's enough to ensure we cannot
accidentally dereference an invalid pointer and that the state we present
to both users and providers remains consistent. To achieve that: read the
flags field atomically except for a few special cases. Read their current
value before executing callback code and use this value for any subsequent
logic. Modifying the flags depends on the particular use-case and can
differ. For instance: when requesting a GPIO, we need to set the
REQUESTED bit immediately so that the next user trying to request the
same line sees -EBUSY.
While at it: the allocations that used GFP_ATOMIC until this point can
now switch to GFP_KERNEL.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
With the list of GPIO devices now protected with SRCU we can use
gpio_device_find() to traverse it from sysfs.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
In order to ensure that the label is not freed while it's being
accessed, let's protect it with SRCU and synchronize it everytime it's
changed.
Let's modify desc_set_label() to manage the memory used for the label as
it can only be freed once synchronize_srcu() returns.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Extend the GPIO descriptor with an SRCU structure in order to serialize
the access to the label. Initialize and clean it up where applicable.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We will soon serialize access to the descriptor label using SRCU. The
write-side of the protection will require calling synchronize_srcu()
which must not be called from atomic context. We have two irq helpers:
gpiochip_lock_as_irq() and gpiochip_unlock_as_irq() that set the label
if the GPIO is not requested but is being used as interrupt. They are
called with a spinlock held from the interrupt subsystem.
They must not do it if we are to use SRCU so instead let's move the
special corner case to a dedicated getter.
Don't actually set the label to "interrupt" in the above case but rather
use the newly added gpiod_get_label() helper to hide the logic that
atomically checks the descriptor flags and returns the address of a
static "interrupt" string.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We will soon serialize access to the descriptor label using SRCU. The
write-side of the protection will require calling synchronize_srcu()
which must not be called from atomic context. We have two irq helpers:
gpiochip_lock_as_irq() and gpiochip_unlock_as_irq() that set the label
if the GPIO is not requested but is being used as interrupt. They are
called with a spinlock held from the interrupt subsystem.
They must not do it if we are to use SRCU so instead let's move the
special corner case to a dedicated getter.
First: let's implement and use the getter where it's applicable.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The general rule of the kernel is to not provide symbols that have no
users upstream. Let's remove logging helpers that are not used anywhere.
This will save us work later when we'll be modifying them to use the
upcoming SRCU infrastructure.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The device nodes representing GPIO hogs cannot be deleted without
unregistering the GPIO chip so there's no need to serialize their access.
However we must ensure that users can get the right address so write and
read it atomically.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
We're working towards removing the "multi-function" GPIO spinlock that's
implemented terribly wrong. We tried using an RW-semaphore to protect
the list of GPIO devices but it turned out that we still have old code
using legacy GPIO calls that need to translate the global GPIO number to
the address of the associated descriptor and - to that end - traverse
the list while holding the lock. If we change the spinlock to a sleeping
lock then we'll end up with "scheduling while atomic" bugs.
Let's allow lockless traversal of the list using SRCU and only use the
mutex when modyfing the list.
While at it: let's protect the period between when we start the lookup
and when we finally request the descriptor (increasing the reference
count of the GPIO device) with the SRCU read lock.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The match function used in gpio_device_find() should not modify the
contents of passed opaque pointer, because such modification would not
be necessary for actual matching and it could lead to quite unreadable,
spaghetti code.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Bartosz: fix coding style in header]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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Merge tag 'v6.8-rc4' into gpio/for-next
Linux 6.8-rc4
Pulling this for a bugfix upstream with which the gpio/for-next branch
conflicts.
It's useful to have the device type information for those sub-devices
that are actually GPIO chips registered with GPIOLIB. While at it: use
the device type struct to setup the release callback which is the
preferred way to use the device API.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 48e1b4d369 ("gpiolib: remove the GPIO device from the list
when it's unregistered") we remove the GPIO device entry from the global
list (used to order devices by their GPIO ranges) when unregistering the
chip, not when releasing the device. It will not happen when the last
reference is put anymore. This means, we need to remove it in error path
in gpiochip_add_data_with_key() unconditionally, without checking if the
device's .release() callback is set.
Fixes: 48e1b4d369 ("gpiolib: remove the GPIO device from the list when it's unregistered")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Now that the driver core can properly handle constant struct bus_type,
move the gpio_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Enable COMPILE_TEST for the vf610 gpio driver to support test builds on
systems without this hardware.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The vf610 gpio driver is enabled by default for all i.MX machines,
without any option to disable it in a board-specific config file.
Most i.MX chipsets have no hardware for this driver. Change the default
to enable GPIO_VF610 for SOC_VF610 and disable it otherwise.
Add a text description after the bool type, this makes the driver
selectable by make config etc.
Fixes: 30a35c07d9 ("gpio: vf610: drop the SOC_VF610 dependency for GPIO_VF610")
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
There are no external users for the irq domain helpers so unexport them
and remove the prototypes from the driver header.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The locking wrappers were replaces with lock guards. These typedefs are
no longer needed.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
The raw interrupt status of eic maybe set before the interrupt is enabled,
since the eic interrupt has a latch function, which would trigger the
interrupt event once enabled it from user side. To solve this problem,
interrupts generated before setting the interrupt trigger type are ignored.
Fixes: 25518e024e ("gpio: Add Spreadtrum EIC driver support")
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The num_eics is a default value, but some SoCs support more than 8.
In order to adapt to all projects, the total number of eics is
automatically calculated through dts.
Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com>
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Spurious wakeups are reported on the GPD G1619-04 which
can be absolved by programming the GPIO to ignore wakeups.
Cc: stable@vger.kernel.org
Reported-and-tested-by: George Melikov <mail@gmelikov.ru>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3073
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
We've recently had someone try to use of_get_named_gpio() in new code.
Mark legacy interfaces as deprecated in kernel docs to avoid any
confusion.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
- revert the changes aiming to use a read-write semaphore to protect the
list of GPIO devices due to calls to legacy API taking that lock from
atomic context in old code
- fix inverted logic in DEFINE_FREE() for GPIO device references
- check the return value of bgpio_init() in gpio-mlxbf3
- fix node address in the DT bindings example for gpio-xilinx
- fix signedness bug in gpio-rtd
- fix kernel-doc warnings in gpio-en7523
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Merge tag 'gpio-fixes-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
"Apart from some regular driver fixes there's a relatively big revert
of the locking changes that were introduced to GPIOLIB in this merge
window.
This is because it turned out that some legacy GPIO interfaces - that
need to translate a number from the global GPIO numberspace to the
address of the relevant descriptor, thus running a GPIO device lookup
and taking the GPIO device list lock - are still used in old code from
atomic context resulting in "scheduling while atomic" errors.
I'll try to make the read-only part of the list access entirely
lockless using SRCU but this will take some time so let's go back to
the old global spinlock for now.
Summary:
- revert the changes aiming to use a read-write semaphore to protect
the list of GPIO devices due to calls to legacy API taking that
lock from atomic context in old code
- fix inverted logic in DEFINE_FREE() for GPIO device references
- check the return value of bgpio_init() in gpio-mlxbf3
- fix node address in the DT bindings example for gpio-xilinx
- fix signedness bug in gpio-rtd
- fix kernel-doc warnings in gpio-en7523"
* tag 'gpio-fixes-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpiolib: revert the attempt to protect the GPIO device list with an rwsem
gpio: EN7523: fix kernel-doc warnings
gpiolib: Fix scope-based gpio_device refcounting
gpio: mlxbf3: add an error code check in mlxbf3_gpio_probe
dt-bindings: gpio: xilinx: Fix node address in gpio
gpio: rtd: Fix signedness bug in probe
- Add support for Monolithic Power Systems MP3309C WLED Step-up Converter
- Fix-ups
- Use/convert to new/better APIs/helpers/MACROs instead of hand-rolling implementations
- Device Tree Binding updates
- Demote non-kerneldoc header comments
- Improve error handling; return proper error values, simplify, avoid duplicates, etc
- Convert over to the new (kinda) GPIOD API
- Bug Fixes
- Fix uninitialised local variable
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Merge tag 'backlight-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight
Pull backlight updates from Lee Jones:
"New Drivers:
- Add support for Monolithic Power Systems MP3309C WLED Step-up Converter
Fix-ups:
- Use/convert to new/better APIs/helpers/MACROs instead of
hand-rolling implementations
- Device Tree Binding updates
- Demote non-kerneldoc header comments
- Improve error handling; return proper error values, simplify, avoid
duplicates, etc
- Convert over to the new (kinda) GPIOD API
Bug Fixes:
- Fix uninitialised local variable"
* tag 'backlight-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
backlight: hx8357: Convert to agnostic GPIO API
backlight: ili922x: Add an error code check in ili922x_write()
backlight: ili922x: Drop kernel-doc for local macros
backlight: mp3309c: Fix uninitialized local variable
backlight: pwm_bl: Use dev_err_probe
backlight: mp3309c: Add support for MPS MP3309C
dt-bindings: backlight: mp3309c: Remove two required properties
This reverts commits 1979a28075 ("gpiolib: replace the GPIO device
mutex with a read-write semaphore") and 65a828bab1 ("gpiolib: use
a mutex to protect the list of GPIO devices").
Unfortunately the legacy GPIO API that's still used in older code has to
translate numbers from the global GPIO numberspace to descriptors. This
results in a GPIO device lookup in every call to legacy functions. Some
of those functions - like gpio_set/get_value() - can be called from
atomic context so taking a sleeping lock that is an RW semaphore results
in an error.
We'll probably have to protect this list with SRCU.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-wireless/f7b5ff1e-8f34-4d98-a7be-b826cb897dc8@moroto.mountain/
Fixes: 1979a28075 ("gpiolib: replace the GPIO device mutex with a read-write semaphore")
Fixes: 65a828bab1 ("gpiolib: use a mutex to protect the list of GPIO devices")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Add "struct" keyword and explain the @dir array differently to
prevent kernel-doc warnings:
gpio-en7523.c:22: warning: cannot understand function prototype: 'struct airoha_gpio_ctrl '
gpio-en7523.c:27: warning: Function parameter or struct member 'dir' not described in 'airoha_gpio_ctrl'
gpio-en7523.c:27: warning: Excess struct member 'dir0' description in 'airoha_gpio_ctrl'
gpio-en7523.c:27: warning: Excess struct member 'dir1' description in 'airoha_gpio_ctrl'
Fixes: 0868ad385a ("gpio: Add support for Airoha EN7523 GPIO controller")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Clang static checker warning: Value stored to 'ret' is never read.
bgpio_init() returns error code if failed, it's better to add this
check.
Fixes: cd33f216d2 ("gpio: mlxbf3: Add gpio driver support")
Signed-off-by: Su Hui <suhui@nfschina.com>
[Bartosz: add the Fixes: tag]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The "data->irqs[]" array holds unsigned int so this error handling will
not work correctly.
Fixes: eee636bff0 ("gpio: rtd: Add support for Realtek DHC(Digital Home Center) RTD SoCs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
There are only two spots where we modify (add to or remove objects from)
the GPIO device list. Readers should be able to access it concurrently.
Replace the mutex with a read-write semaphore and adjust the locking
operations accordingly.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
If we wait until the GPIO device's .release() callback gets invoked
before we remove it from the global device list, then we risk that
someone will look it up using gpio_device_find() between where we
dropped the last reference and before .release() is done taking a
reference again to an object that's being released.
The device must be removed when it's being unregistered - just like how
we remove it from the GPIO bus.
Fixes: ff2b135922 ("gpio: make the gpiochip a real device")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Add Nuvoton BMC NPCM7xx/NPCM8xx sgpio driver support.
Nuvoton NPCM SGPIO module is combine serial to parallel IC (HC595)
and parallel to serial IC (HC165), and use APB3 clock to control it.
This interface has 4 pins (D_out , D_in, S_CLK, LDSH).
BMC can use this driver to increase 64 GPI pins and 64 GPO pins to use.
Signed-off-by: Jim Liu <JJLIU0@nuvoton.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
A bank PMIC EIC contains 16 EICs, and the operating registers
are BIT0-BIT15, such as BIT0 of the register operated by EIC0.
Using the one-dimensional array reg[CACHE_NR_REGS] for maintenance
will cause the configuration of other EICs to be affected when
operating a certain EIC. In order to solve this problem, configure
the bit corresponding to the EIC through offset.
Signed-off-by: Wenhua Lin <Wenhua.Lin@unisoc.com>
Reviewed-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This way GPIO will be denied on pins already claimed by other devices
and basic pin configuration (pull-up, pull-down etc.) can be done
through the userspace GPIO API.
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Older code has an annoying habit of putting tabs between the type and the
name of the variable. This doesn't really add to readability and newer
code doesn't do it so make the entire file consistent.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Older code has an annoying habit of putting tabs between the type and the
name of the variable. This doesn't really add to readability and newer
code doesn't do it so make the entire file consistent.
While at it: convert 'unsigned' to 'unsigned int'.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
extra_checks is only used in a few places. It also depends on
a non-standard DEBUG define one needs to add to the source file. The
overhead of removing it should be minimal (we already use pure
might_sleep() in the code anyway) so drop it.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
CONFIG_DEBUG_GPIO should only be used to enable debug log messages and
for core GPIOLIB debugging. Don't use it to control the execution of
potentially buggy code. Just put it under an always-false #if.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Replace the wrapping functions that inhibit removal of the gpio chip
with equivalent guards.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
After the adoption of guard(), the locking wrappers that hold the
config_mutex for linereq_set_values() and linereq_set_config() no
longer add value, so combine them into the functions they wrap.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The size of struct linereq may exceed a page, so allocate space for
it using kvzalloc() instead of kzalloc() to handle the case where
memory is heavily fragmented and kzalloc() cannot find a sufficient
contiguous region.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
struct_size() is used to calculate struct linereq size, so explicitly
include overflow.h.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
