gpiolib: Get rid of never false gpio_is_valid() calls

In the cases when gpio_is_valid() is called with unsigned parameter
the result is always true in the GPIO library code, hence the check
for false won't ever be true. Get rid of such calls.

While at it, move GPIO device base to be unsigned to clearly show
it won't ever be negative. This requires a new definition for the
maximum GPIO number in the system.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Do not mention legacy GPIOF_* in the code

We are going to remove legacy API from kernel, don't mention
it in the code that does not use it already for a while.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: use dev_err() when gpiod_configure_flags failed

When gpio-ranges property was missed to be added in the gpio node,
using dev_err() to show an error message will helping to locate issues
easier.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: use a single SRCU struct for all GPIO descriptors

We used a per-descriptor SRCU struct in order to not impose a wait with
synchronize_srcu() for descriptor X on read-only operations of
descriptor Y. Now that we no longer call synchronize_srcu() on
descriptor label change but only when releasing descriptor resources, we
can use a single SRCU structure for all GPIO descriptors in a given chip.

Suggested-by: "Paul E. McKenney" <paulmck@kernel.org>
Acked-by: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240507172414.28513-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: fix the speed of descriptor label setting with SRCU

Commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU")
caused a massive drop in performance of requesting GPIO lines due to the
call to synchronize_srcu() on each label change. Rework the code to not
wait until all read-only users are done with reading the label but
instead atomically replace the label pointer and schedule its release
after all read-only critical sections are done.

To that end wrap the descriptor label in a struct that also contains the
rcu_head struct required for deferring tasks using call_srcu() and stop
using kstrdup_const() as we're required to allocate memory anyway. Just
allocate enough for the label string and rcu_head in one go.

Reported-by: Neil Armstrong <neil.armstrong@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/CAMRc=Mfig2oooDQYTqo23W3PXSdzhVO4p=G4+P8y1ppBOrkrJQ@mail.gmail.com/
Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU")
Suggested-by: "Paul E. McKenney" <paulmck@kernel.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Acked-by: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240507121346.16969-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Fix triggering "kobject: 'gpiochipX' is not initialized, yet" kobject_get() errors

When a gpiochip gets added by loading a module, then another driver may
be waiting for that gpiochip to load on the deferred-probe list.

If the deferred-probe for the consumer of gpiochip then triggers between
the gpiodev_add_to_list_unlocked() calls which makes gpio_device_find()
see the chip and the gpiochip_setup_dev() later then gpio_device_find()
does a kobject_get() on an uninitialized kobject since the kobject is
initialized by gpiochip_setup_dev() calling device_initialize():

arizona spi-10WM5102:00: cannot find GPIO chip arizona, deferring
arizona spi-10WM5102:00: cannot find GPIO chip arizona, deferring
------------[ cut here ]------------
kobject: 'gpiochip5' (00000000241466f2): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 3 PID: 42 at lib/kobject.c:640 kobject_get+0x43/0x70
Call Trace:
kobject_get
gpio_device_find
gpiod_find_and_request
gpiod_get
snd_byt_wm5102_mc_probe

Not only is the device not initialized yet, but when the gpio-device is
added to the list things like the irqchip also have not been initialized
yet.

So gpio_device_find() should really ignore the gpio-device until
gpiochip_add_data_with_key() is fully done. Add a device_is_registered()
check to gpio_device_find() to ignore gpio-devices on the list which are
not yet fully initialized.

Fixes: aab5c6f20023 ("gpio: set device type for GPIO chips")
Suggested-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
[Bartosz: fix a typo in commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Fix debug messaging in gpiod_find_and_request()

When consolidating GPIO lookups in ACPI code, the debug messaging
had been reworked that the user may see

[ 13.401147] (NULL device *): using ACPI '\_SB.LEDS.led-0' for '(null)' GPIO lookup
[ 13.401378] gpio gpiochip0: Persistence not supported for GPIO 40
[ 13.401402] gpio-40 (?): no flags found for (null)

instead of

[ 14.182962] gpio gpiochip0: Persistence not supported for GPIO 40
[ 14.182994] gpio-40 (?): no flags found for gpios

The '(null)' parts are less informative and likely scare the users.
Replace them by '(default)' which can point out to the default connection
IDs, such as 'gpios'.

While at it, amend other places where con_id is used in the messages.

Reported-by: Ferry Toth <ftoth@exalondelft.nl>
Fixes: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups")
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Ferry Toth <ftoth@exalondelft.nl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Deduplicate cleanup for-loop in gpiochip_add_data_with_key()

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>

gpio: acpi: Make acpi_gpio_count() take firmware node as a parameter

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>

gpio: of: Make of_gpio_get_count() take firmware node as a parameter

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>

gpiolib: Pass consumer device through to core in devm_fwnode_gpiod_get_index()

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: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: don't warn about removing GPIO chips with active users anymore

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>

gpio: fix memory leak in gpiod_request_commit()

Since commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with
SRCU"), desc_set_label() already allocates memory for the label, so there
is no need to allocate it again. If we do, we leak it.

unreferenced object 0xffff0000c3e4d0c0 (size 32):
comm "kworker/u16:4", pid 60, jiffies 4294894555
hex dump (first 32 bytes):
72 65 67 75 6c 61 74 6f 72 2d 63 61 6e 32 2d 73 regulator-can2-s
74 62 79 00 00 00 ff ff ff ff ff ff eb db ff ff tby.............
backtrace (crc 2c3a0350):
[<00000000e93c5cf4>] kmemleak_alloc+0x34/0x40
[<0000000097a2657f>] __kmalloc_node_track_caller+0x2c4/0x524
[<000000000dd1c057>] kstrdup+0x4c/0x98
[<00000000b513a96a>] kstrdup_const+0x34/0x40
[<000000008a7f0feb>] gpiod_request_commit+0xdc/0x358
[<00000000fc71ad64>] gpiod_request+0xd8/0x204
[<00000000fa24b091>] gpiod_find_and_request+0x170/0x780
[<0000000086ecf92d>] gpiod_get_index+0x70/0xe0
[<000000004aef97f9>] gpiod_get_optional+0x18/0x30
[<00000000312f1b25>] reg_fixed_voltage_probe+0x58c/0xad8
[<00000000e6f47635>] platform_probe+0xc4/0x198
[<00000000cf78fbdb>] really_probe+0x204/0x5a8
[<00000000e28d05ec>] __driver_probe_device+0x158/0x2c4
[<00000000e4fe452b>] driver_probe_device+0x60/0x18c
[<00000000479fcf5d>] __device_attach_driver+0x168/0x208
[<000000007d389f38>] bus_for_each_drv+0x104/0x190

Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU")
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: constify opaque pointer "data" in gpio_device_find()

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>

gpio: don't let lockdep complain about inherently dangerous RCU usage

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: d83cee3d2bb1 ("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>

gpio: use srcu_dereference() with SRCU-protected pointers

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: d83cee3d2bb1 ("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>

gpio: take the SRCU read lock in gpiod_hog()

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: d83cee3d2bb1 ("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>

gpio: initialize descriptor SRCU structure before adding OF-based chips

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: be711caa87c5 ("gpio: add SRCU infrastructure to struct gpio_desc")
Fixes: 1f2bcb8c8ccd ("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>

gpio: mark unsafe gpio_chip manipulators as deprecated

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>

gpio: remove the RW semaphore from the GPIO device

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>

gpio: protect the pointer to gpio_chip in gpio_device with SRCU

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>

gpio: add SRCU infrastructure to struct gpio_device

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>

gpio: add the can_sleep flag to struct gpio_device

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>

gpio: remove unnecessary checks from gpiod_to_chip()

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>

gpio: reduce the functionality of validate_desc()

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>

gpio: don't dereference gdev->chip in gpiochip_setup_dev()

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>

gpio: remove unneeded code from gpio_device_get_desc()

The GPIO chip pointer is unused. Let's remove 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>

gpio: reinforce desc->flags handling

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>

gpio: remove gpio_lock

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>

gpio: sysfs: use gpio_device_find() to iterate over existing devices

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>

gpio: protect the descriptor label with SRCU

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>

gpio: add SRCU infrastructure to struct gpio_desc

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>

gpio: don't set label from irq helpers

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>

gpio: provide and use gpiod_get_label()

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>

gpio: of: assign and read the hog pointer atomically

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>

gpio: protect the list of GPIO devices with SRCU

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>

gpio: constify opaque pointer in gpio_device_find() match function

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>

gpio: set device type for GPIO chips

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>

gpio: gpiolib: make gpio_bus_type const

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>

gpio: unexport GPIO irq domain functions only used internally

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>

gpio: fix resource unwinding order in error path

Hogs are added *after* ACPI so should be removed *before* in error path.

Fixes: a411e81e61df ("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>

gpiolib: Fix the error path order in gpiochip_add_data_with_key()

After shuffling the code, error path wasn't updated correctly.
Fix it here.

Fixes: 2f4133bb5f14 ("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>

gpiolib: Handle no pin_ranges in gpiochip_generic_config()

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 f34fd6ee1be8 ("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: 2956b5d94a76 ("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>

gpio: remove GPIO device from the list unconditionally in error path

Since commit 48e1b4d369cf ("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: 48e1b4d369cf ("gpiolib: remove the GPIO device from the list when it's unregistered")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: revert the attempt to protect the GPIO device list with an rwsem

This reverts commits 1979a2807547 ("gpiolib: replace the GPIO device
mutex with a read-write semaphore") and 65a828bab158 ("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: 1979a2807547 ("gpiolib: replace the GPIO device mutex with a read-write semaphore")
Fixes: 65a828bab158 ("gpiolib: use a mutex to protect the list of GPIO devices")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: replace the GPIO device mutex with a read-write semaphore

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>

gpiolib: remove the GPIO device from the list when it's unregistered

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: ff2b13592299 ("gpio: make the gpiochip a real device")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: drop tabs from local variable declarations

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>

gpiolib: remove extra_checks

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>

gpiolib: remove debounce_period_us from struct gpio_desc

cdev is the only user of the debounce_period_us field in
struct gpio_desc, and it no longer uses it, so remove it.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: use a mutex to protect the list of GPIO devices

The global list of GPIO devices is never modified or accessed from
atomic context so it's fine to protect it using a mutex. Add a new
global lock dedicated to the gpio_devices list and use it whenever
accessing or modifying it.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: rename static functions that are called with the lock taken

Rename two functions that read or modify the global GPIO device list but
don't take the lock themselves (and need to be called with it already
acquired). Use the _unlocked() suffix which seems to be used quite
consistently across the kernel despite there also existing the _locked()
suffix for the same purpose.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: allocate memory atomically with a spinlock held

We will eventually switch to protecting the GPIO descriptors with a mutex
but until then, we need to allocate memory for the label copy atomically
while we're holding the global spinlock.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/62588146-eed6-42f7-ba26-160226b109fe@moroto.mountain/T/#u
Fixes: f8d05e276b45 ("gpiolib: remove gpiochip_is_requested()")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: remove gpiochip_is_requested()

We have no external users of gpiochip_is_requested(). Let's remove it
and replace its internal calls with direct testing of the REQUESTED flag.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpiochip_dup_line_label()

gpiochip_is_requested() not only has a misleading name but it returns
a pointer to a string that is freed when the descriptor is released.

Provide a new helper meant to replace it, which returns a copy of the
label string instead.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_get_label()

Provide a getter for the GPIO device label string so that users don't
have to dereference struct gpio_chip directly.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

treewide: rename pinctrl_gpio_set_config_new()

Now that pinctrl_gpio_set_config() is no longer used, let's drop the
'_new' suffix from its improved variant.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

treewide: rename pinctrl_gpio_free_new()

Now that pinctrl_gpio_free()() is no longer used, let's drop the '_new'
suffix from its improved variant.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

treewide: rename pinctrl_gpio_request_new()

Now that pinctrl_gpio_request() is no longer used, let's drop the '_new'
suffix from its improved variant.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: generic: use new pinctrl GPIO helpers

Replace the pinctrl helpers taking the global GPIO number as argument
with the improved variants that instead take a pointer to the GPIO chip
and the controller-relative offset.

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>

gpiolib: remove gpiochip_find()

With all users of gpiochip_find() converted to using gpio_device_find(),
we can now remove this function from the kernel.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_get_base()

Let's start adding getters for the opaque struct gpio_device. Start with
a function allowing to retrieve the base GPIO number.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpiod_to_gpio_device()

Accessing struct gpio_chip backing a GPIO device is only allowed for the
actual providers of that chip.

Similarly to how we introduced gpio_device_find() in order to replace
the abused gpiochip_find(), let's introduce a counterpart to
gpiod_to_chip() that returns a reference to the GPIO device owning the
descriptor. This is done in order to later remove gpiod_to_chip()
entirely.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Peter Rosin <peda@axentia.se>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_to_device()

There are users in the kernel who need to retrieve the address of the
struct device backing the GPIO device. Currently they needlessly poke in
the internals of GPIOLIB. Add a dedicated getter function.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_find_by_fwnode()

One of the ways of looking up GPIO devices is using their fwnode.
Provide a helper for that to avoid every user implementing their
own matching function.

Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Tested-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20231010151709.4104747-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: replace find_chip_by_name() with gpio_device_find_by_label()

Remove all remaining uses of find_chip_by_name() (and subsequently:
gpiochip_find()) from gpiolib.c and use the new
gpio_device_find_by_label() instead.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: reluctantly provide gpio_device_get_chip()

The process of converting all unauthorized users of struct gpio_chip to
using dedicated struct gpio_device function will be long so in the
meantime we must provide a way of retrieving the pointer to struct
gpio_chip from a GPIO device.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_get_desc()

Getting the GPIO descriptor directly from the gpio_chip struct is
dangerous as we don't take the reference to the underlying GPIO device.
In order to start working towards removing gpiochip_get_desc(), let's
provide a safer variant that works with an existing reference to struct
gpio_device.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_find_by_label()

By far the most common way of looking up GPIO devices is using their
label. Provide a helpers for that to avoid every user implementing their
own matching function.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpio_device_find()

gpiochip_find() is wrong and its kernel doc is misleading as the
function doesn't return a reference to the gpio_chip but just a raw
pointer. The chip itself is not guaranteed to stay alive, in fact it can
be deleted at any point. Also: other than GPIO drivers themselves,
nobody else has any business accessing gpio_chip structs.

Provide a new gpio_device_find() function that returns a real reference
to the opaque gpio_device structure that is guaranteed to stay alive for
as long as there are active users of it.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: make gpio_device_get() and gpio_device_put() public

In order to start migrating away from accessing struct gpio_chip by
users other than their owners, let's first make the reference management
functions for the opaque struct gpio_device public in the driver.h
header.

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>

gpiolib: extend the critical sections of lookup tables

There are two places in the code where we retrieve a lookup table using
gpiod_find_lookup_table() (which protects the table list with the lookup
table lock) and then use it after the lock is released.

We need to keep the lookup table mutex locked the entire time we're using
the tables. Remove the locking from gpiod_find_lookup_table() and use
guards to protect the code actually using the table objects.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: unexport gpiod_set_transitory()

There are no and never have been any users of gpiod_set_transitory()
outside the core GPIOLIB code. Make it private.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide and use gpiod_line_state_notify()

Wrap the calls to blocking_notifier_call_chain() for the line state
notifier with a helper that allows us to use fewer lines of code and
simpler syntax.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: add a second blocking notifier to struct gpio_device

Add a new blocking notifier to struct gpio_device and use it to notify
subscribers about the GPIO device being unregistered from the device
model.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>

gpiolib: rename the gpio_device notifier

Change the generic "notifier" name to "line_state_notifier" in order to
reflect its purpose in preparation for adding a second notifier which
will be used to notify wait queues about device unregistering.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>

gpio: mmio: handle "ngpios" properly in bgpio_init()

bgpio_init() uses "sz" argument to populate ngpio, which is not
accurate. Instead, read the "ngpios" property from the DT and if it
doesn't exist, use the "sz" argument. With this change, drivers no
longer need to overwrite the ngpio variable after calling bgpio_init().

If the "ngpios" property is specified, bgpio_bits is calculated
as the round up value of ngpio. At the moment, the only requirement
specified is that the round up value must be a multiple of 8 but
it should also be a power of 2 because we provide accessors based
on the bank size in bgpio_setup_accessors().

Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Replace open coded gpiochip_irqchip_add_allocated_domain()

Replace open coded variant of gpiochip_irqchip_add_allocated_domain()
in gpiochip_add_irqchip().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Split out gpiochip_irqchip_add_allocated_domain() helper

The gpiochip_irqchip_add_allocated_domain() can be used
in another place in the code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Do not assign error pointer to the GPIO IRQ chip domain

Check domain for being an error pointer before assigning it to
the GPIO IRQ chip domain.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Factor out gpiochip_simple_create_domain()

As a preparatory patch and for the sake of consistency,
factor out gpiochip_simple_create_domain().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Make gpiochip_hierarchy_add_domain() return domain

As a preparatory patch and for the sake of consistency, make
gpiochip_hierarchy_add_domain() return IRQ domain. While at it,
rename it to gpiochip_hierarchy_create_domain() to show
the change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Do not alter GPIO chip fwnode member

Ideally we should not touch data in the given GPIO chip structure.
Let's become closer to it by avoiding altering fwnode member.

The GPIO library must use fwnode from GPIO device and the drivers
might use one from GPIO chip in case they initialized it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Benjamin Tissoires <bentiss@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: fix reference leaks when removing GPIO chips still in use

After we remove a GPIO chip that still has some requested descriptors,
gpiod_free_commit() will fail and we will never put the references to the
GPIO device and the owning module in gpiod_free().

Rework this function to:
- not warn on desc == NULL as this is a use-case on which most free
functions silently return
- put the references to desc->gdev and desc->gdev->owner unconditionally
so that the release callback actually gets called when the remaining
references are dropped by external GPIO users

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Drop unused domain_ops memeber of GPIO IRQ chip

It seems there is no driver that requires custom IRQ chip
domain options. Drop the member and respective code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Fix irq_domain resource tracking for gpiochip_irqchip_add_domain()

Up until commit 6a45b0e2589f ("gpiolib: Introduce
gpiochip_irqchip_add_domain()") all irq_domains were allocated
by gpiolib itself and thus gpiolib also takes care of freeing it.

With gpiochip_irqchip_add_domain() a user of gpiolib can associate an
irq_domain with the gpio_chip. This irq_domain is not managed by
gpiolib and therefore must not be freed by gpiolib.

Fixes: 6a45b0e2589f ("gpiolib: Introduce gpiochip_irqchip_add_domain()")
Reported-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Fix GPIO chip IRQ initialization restriction

In case of gpio-regmap, IRQ chip is added by regmap-irq and associated with
GPIO chip by gpiochip_irqchip_add_domain(). The initialization flag was not
added in gpiochip_irqchip_add_domain(), causing gpiochip_to_irq() to return
-EPROBE_DEFER.

Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Do not unexport GPIO on freeing

Since the legacy exporting is gone with 2f804aca4832 ("gpiolib:
Kill unused GPIOF_EXPORT and Co") there is no need to unexport
GPIO on freeing. Remove that call.

Note, the other users of this functionality do that explicitly,
except one SH and one OMAP boardfile which don't free GPIO anyways,
so it is safe to drop the call.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: demote the hogging log messages to debug

Drivers should be silent when they work correctly. There's no reason to
emit info messages when GPIO lines are hogged. Demote the message to
debug.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Suggested-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: Unify allocation and initialization of GPIO valid mask

Now that the of_gpiochip_add() doesn't use valid mask, we may
unify GPIO valid mask allocation and initialization. With this
it makes a symmetry to the similar which we done for IRQ chip.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Consolidate the allocated mask freeing APIs

There is a common API to allocate a mask, but more than one duplicative
counterparts. Consolidate the latter into a single common API beneath.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: fix allocation of mixed dynamic/static GPIOs

If static allocation and dynamic allocation GPIOs are present,
dynamic allocation pollutes the numberspace for static allocation,
causing static allocation to fail.
Enforce dynamic allocation above GPIO_DYNAMIC_BASE.

Seen on a GTA04 when omap-gpio (static) and twl-gpio (dynamic)
raced:
[some successful registrations of omap_gpio instances]
[ 2.553833] twl4030_gpio twl4030-gpio: gpio (irq 145) chaining IRQs 161..178
[ 2.561401] gpiochip_find_base: found new base at 160
[ 2.564392] gpio gpiochip5: (twl4030): added GPIO chardev (254:5)
[ 2.564544] gpio gpiochip5: registered GPIOs 160 to 177 on twl4030
[...]
[ 2.692169] omap-gpmc 6e000000.gpmc: GPMC revision 5.0
[ 2.697357] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
[ 2.703643] gpiochip_find_base: found new base at 178
[ 2.704376] gpio gpiochip6: (omap-gpmc): added GPIO chardev (254:6)
[ 2.704589] gpio gpiochip6: registered GPIOs 178 to 181 on omap-gpmc
[...]
[ 2.840393] gpio gpiochip7: Static allocation of GPIO base is deprecated, use dynamic allocation.
[ 2.849365] gpio gpiochip7: (gpio-160-191): GPIO integer space overlap, cannot add chip
[ 2.857513] gpiochip_add_data_with_key: GPIOs 160..191 (gpio-160-191) failed to register, -16
[ 2.866149] omap_gpio 48310000.gpio: error -EBUSY: Could not register gpio chip

On that device it is fixed invasively by
commit 92bf78b33b0b4 ("gpio: omap: use dynamic allocation of base")
but let's also fix that for devices where there is still
a mixture of static and dynamic allocation.

Fixes: 7b61212f2a07 ("gpiolib: Get rid of ARCH_NR_GPIOS")
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: gpiolib: Simplify gpiochip_add_data_with_key() fwnode

The code defaulting to the parents fwnode if no fwnode was assigned
is unnecessarily convoluted, probably due to refactoring. Simplify
it and make it more human-readable.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Add gpiochip_set_data() helper

There are too many 'data' parameters here and there.

For the better maintenance keep access GPIO device data
via getter and setter.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Move gpiochip_get_data() higher in the code

Move gpiochip_get_data() higher in the code as a preparation
for further refactoring.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Bartosz: tweak the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Check array_info for NULL only once in gpiod_get_array()

gpiod_get_array() has a long if-else-if branching where each of them
tests for the same variable to be not NULL. Instead, check for NULL
before even going to that flow.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Replace open coded krealloc()

gpiod_get_array() does a new allocation in some cases, followed
by copying previously allocated placeholder for the descriptors.

Replace that with krealloc(__GFP_ZERO), since it was kzalloc()
originally.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Use IRQ hardware number getter instead of direct access

IRQ framework provides special type and getter to transform
the Linux IRQ to the hardware pin. Use that type and getter
function instead of direct access.

While at it, amend an indentation in a couple of places.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Remove duplicative check in gpiod_find_and_request()

The gpiod_find_by_fwnode() already checks for NULL and returns
correct error code in case fwnode is invalid. Drop the respective
check and assignment in the gpiod_find_and_request().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Move gpiodevice_*() to gpiodev namespace

The functions that operates on the same device object would
have the same namespace for better code understanding and
maintenance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Get rid of devprop prefix in one function

The devprop prefix in the devprop_gpiochip_set_names() adds confusion.
Get rid of it.

Note we have more than one function in the same module that handles
one or more device properties. This change will unify the naming schema
for all of them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Get rid of gpio_bus_match() forward declaration

There is nothing specific about gpio_bus_match(), so we may
simply move it to the top of the file and get rid of forward
declaration.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Access device's fwnode via dev_fwnode()

GPIO device's fwnode should be accessed via dev_fwnode().
Make sure that gpiochip_setup_dev() follows that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Clean up headers

There is a few things done:
- include only the headers we are direct user of
- when pointer is in use, provide a forward declaration
- add missing headers
- group generic headers and subsystem headers
- sort each group alphabetically

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: Clear the gpio_device's fwnode initialized flag before adding

Registering an irqdomain sets the flag for the fwnode. But having the
flag set when a device is added is interpreted by fw_devlink to mean the
device has already been initialized and will never probe. This prevents
fw_devlink from creating device links with the gpio_device as a
supplier. So, clear the flag before adding the device.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Luca Weiss <luca.weiss@fairphone.com> # qcom/sm7225-fairphone-fp4
Link: https://lore.kernel.org/r/20230207014207.1678715-5-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpiolib: sort header inclusion alphabetically

Sort header inclusion alphabetically.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Get rid of not used of_node member

All new drivers should use fwnode and / or parent to provide the
necessary information to the GPIO library.

Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Introduce gpio_device_get() and gpio_device_put()

Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: use irq_domain_alloc_irqs()

Use the irq_domain_alloc_irqs() wrapper instead of the full
__irq_domain_alloc_irqs() interface, which was only intended for some
legacy (x86) use cases.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Check "gpio-ranges" before calling ->add_pin_ranges()

The ->add_pin_ranges() is supposed to be called for the backward
compatiblity on Device Tree platforms or non-DT ones. Ensure that
by checking presense of the "gpio-ranges" property.

This allows to clean up a few existing drivers to avoid duplication
of the check.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20230113215352.44272-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Fix using uninitialized lookup-flags on ACPI platforms

Commit 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups") refactors
fwnode_get_named_gpiod() and gpiod_get_index() into a unified
gpiod_find_and_request() helper.

The old functions both initialized their local lookupflags variable to
GPIO_LOOKUP_FLAGS_DEFAULT, but the new code leaves it uninitialized.

This is a problem for at least ACPI platforms, where acpi_find_gpio()
only does a bunch of *lookupflags |= GPIO_* statements and thus relies
on the variable being initialized.

The variable not being initialized leads to:

1. Potentially the wrong flags getting used
2. The check for conflicting lookup flags in gpiod_configure_flags():
"multiple pull-up, pull-down or pull-disable enabled, invalid config"
sometimes triggering, making the GPIO unavailable

Restore the initialization of lookupflags to GPIO_LOOKUP_FLAGS_DEFAULT
to fix this.

Fixes: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: protect the GPIO device against being dropped while in use by user-space

While any of the GPIO cdev syscalls is in progress, the kernel can call
gpiochip_remove() (for instance, when a USB GPIO expander is disconnected)
which will set gdev->chip to NULL after which any subsequent access will
cause a crash.

To avoid that: use an RW-semaphore in which the syscalls take it for
reading (so that we don't needlessly prohibit the user-space from calling
syscalls simultaneously) while gpiochip_remove() takes it for writing so
that it can only happen once all syscalls return.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL")
Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Fixes: a54756cb24ea ("gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL")
Fixes: 7b8e00d98168 ("gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
[Nick: fixed a build failure with CDEV_V1 disabled]
Co-authored-by: Nick Hainke <vincent@systemli.org>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Provide to_gpio_device() helper

Provide to_gpio_device() helper which can be utilized in the existing
and future code.

While at it, make sure it becomes no-op at compilation time.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Unify access to the device properties

Some of the functions are using struct fwnode_handle, some struct device
pointer. In the GPIO library the firmware node of the GPIO device is the
same as GPIO node of the GPIO chip. Due to this fact we may use former
to access properties everywhere in the code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Tested-by: Marijn Suijten <marijn.suijten@somainline.org>
[Bartosz: stick to the 80-char limit where it's not hurting readability]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: ensure that fwnode is properly set

Note that this is a RFC patch and not meant to be merged. I looked into
a problem with linux-next-20221110 on the Qualcomm SA8540P automotive
board (sc8280xp) where the UFS host controller would fail to probe due
to repeated probe deferrals when trying to get reset-gpios via
devm_gpiod_get_optional().

of_get_named_gpiod_flags() returns -EPROBE_DEFER, which is caused by
of_gpiochip_match_node_and_xlate() returning 0 since the of_xlate function
pointer is not set for the qcom,sc8280xp-tlmm pinctrl driver. The
pinctrl driver doesn't define one, so of_gpiochip_add() should
automatically setup of_gpio_simple_xlate() on it's behalf. This doesn't
happen since the fwnode member on the struct gpiochip is set to null
when of_gpiochip_add() is called. Let's work around this by ensuring
that it's set if available.

Note that this broke sometime within the last few weeks within
linux-next and I haven't bisected this. I'm posting this in the hopes
that someone may know offhand which patch(es) may have broken this.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Tested-by: Marijn Suijten <marijn.suijten@somainline.org>
Tested-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Tested-by: Steev Klimaszewski <steev@kali.org> #Lenovo Thinkpad X13s
Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: add support for software nodes

Now that static device properties understand notion of child nodes and
references, let's teach gpiolib to handle them:

- GPIOs are represented as a references to software nodes representing
gpiochip
- references must have 2 arguments - GPIO number within the chip and
GPIO flags (GPIO_ACTIVE_LOW/GPIO_ACTIVE_HIGH, etc)
- a new PROPERTY_ENTRY_GPIO() macro is supplied to ensure the above
- name of the software node representing gpiochip must match label of
the gpiochip, as we use it to locate gpiochip structure at runtime

The following illustrates use of software nodes to describe a "System"
button that is currently specified via use of gpio_keys_platform_data
in arch/mips/alchemy/board-mtx1.c. It follows bindings specified in
Documentation/devicetree/bindings/input/gpio-keys.yaml.

static const struct software_node mxt1_gpiochip2_node = {
.name = "alchemy-gpio2",
};

static const struct property_entry mtx1_gpio_button_props[] = {
PROPERTY_ENTRY_U32("linux,code", BTN_0),
PROPERTY_ENTRY_STRING("label", "System button"),
PROPERTY_ENTRY_GPIO("gpios", &mxt1_gpiochip2_node, 7, GPIO_ACTIVE_LOW),
{ }
};

Similarly, arch/arm/mach-tegra/board-paz00.c can be converted to:

static const struct software_node tegra_gpiochip_node = {
.name = "tegra-gpio",
};

static struct property_entry wifi_rfkill_prop[] __initdata = {
PROPERTY_ENTRY_STRING("name", "wifi_rfkill"),
PROPERTY_ENTRY_STRING("type", "wlan"),
PROPERTY_ENTRY_GPIO("reset-gpios",
&tegra_gpiochip_node, 25, GPIO_ACTIVE_HIGH);
PROPERTY_ENTRY_GPIO("shutdown-gpios",
&tegra_gpiochip_node, 85, GPIO_ACTIVE_HIGH);
{ },
};

static struct platform_device wifi_rfkill_device = {
.name = "rfkill_gpio",
.id = -1,
};

...

software_node_register(&tegra_gpiochip_node);
device_create_managed_software_node(&wifi_rfkill_device.dev,
wifi_rfkill_prop, NULL);

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: consolidate GPIO lookups

Ensure that all paths to obtain/look up GPIOD from generic
consumer-visible APIs go through the new gpiod_find_and_request()
helper, so that we can easily extend it with support for new firmware
mechanisms.

The only exception is OF-specific [devm_]gpiod_get_from_of_node() API
that is still being used by a couple of drivers and will be removed as
soon as patches converting them to use generic fwnode/device APIs are
accepted.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers

There is no need for the generic parts of GPIOLIB to be aware of
implementation details of ACPI-bases lookups.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: acpi: change acpi_find_gpio() to accept firmware node

In preparation of switching all ACPI-based GPIO lookups to go through
acpi_find_gpio() let's change it to accept device node as its argument
as we do not always have access to device structure.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: of: change of_find_gpio() to accept device node

In preparation of switching all OF-based GPIO lookups to go through
of_find_gpio() let's change it to accept device node as its argument as
we do not always have access to device structure.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: of: Integrate of_gpiochip_init_valid_mask() into gpiochip_init_valid_mask()

In preparation to complete fwnode switch, integrate
of_gpiochip_init_valid_mask() into gpiochip_init_valid_mask().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Get rid of ARCH_NR_GPIOS

Since commit 14e85c0e69d5 ("gpio: remove gpio_descs global array")
there is no limitation on the number of GPIOs that can be allocated
in the system since the allocation is fully dynamic.

ARCH_NR_GPIOS is today only used in order to provide downwards
gpiobase allocation from that value, while static allocation is
performed upwards from 0. However that has the disadvantage of
limiting the number of GPIOs that can be registered in the system.

To overcome this limitation without requiring each and every
platform to provide its 'best-guess' maximum number, rework the
allocation to allocate upwards, allowing approx 2 millions of
GPIOs.

In order to still allow static allocation for legacy drivers, define
GPIO_DYNAMIC_BASE with the value 512 as the start for dynamic
allocation. The 512 value is chosen because it is the end of
the current default range so all current static allocations are
expected to be below that value. Of course that's just a rough
estimate based on the default value, but assuming static
allocations come first, even if there are more static allocations
it should fit under the 512 value.

In the future, it is expected that all static allocations go away
and then dynamic allocation will be patched to start at 0.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Warn on drivers still using static gpiobase allocation

In the preparation of getting completely rid of static gpiobase
allocation in the future, emit a warning in drivers still doing so.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: fix memory leak in gpiochip_setup_dev()

Here is a backtrace report about memory leak detected in
gpiochip_setup_dev():

unreferenced object 0xffff88810b406400 (size 512):
comm "python3", pid 1682, jiffies 4295346908 (age 24.090s)
backtrace:
kmalloc_trace
device_add device_private_init at drivers/base/core.c:3361
(inlined by) device_add at drivers/base/core.c:3411
cdev_device_add
gpiolib_cdev_register
gpiochip_setup_dev
gpiochip_add_data_with_key

gcdev_register() & gcdev_unregister() would call device_add() &
device_del() (no matter CONFIG_GPIO_CDEV is enabled or not) to
register/unregister device.

However, if device_add() succeeds, some resource (like
struct device_private allocated by device_private_init())
is not released by device_del().

Therefore, after device_add() succeeds by gcdev_register(), it
needs to call put_device() to release resource in the error handle
path.

Here we move forward the register of release function, and let it
release every piece of resource by put_device() instead of kfree().

While at it, fix another subtle issue, i.e. when gc->ngpio is equal
to 0, we still call kcalloc() and, in case of further error, kfree()
on the ZERO_PTR pointer, which is not NULL. It's not a bug per se,
but rather waste of the resources and potentially wrong expectation
about contents of the gdev->descs variable.

Fixes: 159f3cd92f17 ("gpiolib: Defer gpio device setup until after gpiolib initialization")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: make fwnode_get_named_gpiod() static

There are no external users of fwnode_get_named_gpiod() anymore, so
let's stop exporting it and mark it as static.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: add support for bias pull disable

This change prepares the gpio core to look at firmware flags and set
'FLAG_BIAS_DISABLE' if necessary. It works in similar way to
'GPIO_PULL_DOWN' and 'GPIO_PULL_UP'.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: gpiolib: Allow free() callback to be overridden

Allow free() callback to be overridden from irq_domain_ops for
hierarchical chips.

This allows drivers to free up resources which are allocated during
child_to_parent_hwirq()/populate_parent_alloc_arg() callbacks.

On Renesas RZ/G2L platform a bitmap is maintained for TINT slots, a slot
is allocated in child_to_parent_hwirq() callback which is freed up in free
callback hence this override.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220707182314.66610-5-prabhakar.mahadev-lad.rj@bp.renesas.com

gpio: Remove dynamic allocation from populate_parent_alloc_arg()

The gpiolib is unique in the way it uses intermediate fwspecs
when feeding an interrupt specifier to the parent domain, as it
relies on the populate_parent_alloc_arg() callback to perform
a dynamic allocation.

This is pretty inefficient (we free the structure almost immediately),
and the only reason this isn't a stack allocation is that our
ThunderX friend uses MSIs rather than a FW-constructed structure.

Let's solve it by providing a new type composed of the union
of a struct irq_fwspec and a msi_info_t, which satisfies both
requirements. This allows us to use a stack allocation, and we
can move the handful of users to this new scheme.

Also perform some additional cleanup, such as getting rid of the
stub versions of the irq_domain_translate_*cell helpers, which
are never used when CONFIG_IRQ_DOMAIN_HIERARCHY isn't selected.

Tested on a Tegra186.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Daniel Palmer <daniel@thingy.jp>
Cc: Romain Perier <romain.perier@gmail.com>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Robert Richter <rric@kernel.org>
Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
Link: https://lore.kernel.org/r/20220707182314.66610-2-prabhakar.mahadev-lad.rj@bp.renesas.com

gpiolib: Add HTE support

Some GPIO chip can provide hardware timestamp support on its GPIO lines
, in order to support that, additional API needs to be added which
can talk to both GPIO chip and HTE (hardware timestamping engine)
providers if there is any dependencies. This patch introduces optional
hooks to enable and disable hardware timestamping related features
in the GPIO controller chip.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

gpiolib: Extract gpio_chip_get_value() wrapper

In couple of cases we are using the same code to wrap ->get() callback.
Extract that code into a helper for the sake of better maintenance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Refactor gpiolib_dbg_show() with help of for_each_gpio_desc()

Use for_each_gpio_desc() and since we would need to touch the entire
conditionals, do the following:
- rename last occurrence of gdesc to desc
- use short ternary operator ?:
- join two seq_printf() calls into single one
- fix indentation of the seq_printf() parameters

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Split out for_each_gpio_desc() macro

In some cases we want to traverse all GPIO descriptors for given
chip, let's split out for_each_gpio_desc() macro for such cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Embed iterator variable into for_each_gpio_desc_with_flag()

The iterator loop is used exclusively to get a descriptor, which in its
turn is what is being used by the caller. Embed the iterator variable
into the loop in the for_each_gpio_desc_with_flag() macro helper.

Suggested-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Move error message out of a spinlock

An error path is a slow path, no need to block other CPUs
when printing error messages.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Get rid of redundant 'else'

In the snippets like the following

if (...)
return / goto / break / continue ...;
else
...

the 'else' is redundant. Get rid of it. In case of IOCTLs use
switch-case pattern that seems the usual in such cases.

While at it, clarify necessity of else in gpiod_direction_output()
by attaching else if to the closing curly brace on a previous line.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: Expose the gpiochip_irq_re[ql]res helpers

The GPIO subsystem has a couple of internal helpers to manage
resources on behalf of the irqchip. Expose them so that GPIO
drivers can use them directly.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419141846.598305-3-maz@kernel.org

gpio: Don't fiddle with irqchips marked as immutable

In order to move away from gpiolib messing with the internals of
unsuspecting irqchips, add a flag by which irqchips advertise
that they are not to be messed with, and do solemnly swear that
they correctly call into the gpiolib helpers when required.

Also nudge the users into converting their drivers to the
new model.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419141846.598305-2-maz@kernel.org

gpio: Request interrupts after IRQ is initialized

Commit 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members
before initialization") attempted to fix a race condition that lead to a
NULL pointer, but in the process caused a regression for _AEI/_EVT
declared GPIOs.

This manifests in messages showing deferred probing while trying to
allocate IRQs like so:

amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0000 to IRQ, err -517
amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x002C to IRQ, err -517
amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003D to IRQ, err -517
[ .. more of the same .. ]

The code for walking _AEI doesn't handle deferred probing and so this
leads to non-functional GPIO interrupts.

Fix this issue by moving the call to `acpi_gpiochip_request_interrupts`
to occur after gc->irc.initialized is set.

Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
Link: https://lore.kernel.org/linux-gpio/BL1PR12MB51577A77F000A008AA694675E2EF9@BL1PR12MB5157.namprd12.prod.outlook.com/
Link: https://bugzilla.suse.com/show_bug.cgi?id=1198697
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215850
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1979
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1976
Reported-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Shreeya Patel <shreeya.patel@collabora.com>
Tested-By: Samuel Čavoj <samuel@cavoj.net>
Tested-By: lukeluk498@gmail.com Link:
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-and-tested-by: Takashi Iwai <tiwai@suse.de>
Cc: Shreeya Patel <shreeya.patel@collabora.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpio: Restrict usage of GPIO chip irq members before initialization

GPIO chip irq members are exposed before they could be completely
initialized and this leads to race conditions.

One such issue was observed for the gc->irq.domain variable which
was accessed through the I2C interface in gpiochip_to_irq() before
it could be initialized by gpiochip_add_irqchip(). This resulted in
Kernel NULL pointer dereference.

Following are the logs for reference :-

kernel: Call Trace:
kernel: gpiod_to_irq+0x53/0x70
kernel: acpi_dev_gpio_irq_get_by+0x113/0x1f0
kernel: i2c_acpi_get_irq+0xc0/0xd0
kernel: i2c_device_probe+0x28a/0x2a0
kernel: really_probe+0xf2/0x460
kernel: RIP: 0010:gpiochip_to_irq+0x47/0xc0

To avoid such scenarios, restrict usage of GPIO chip irq members before
they are completely initialized.

Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Use list_first_entry()/list_last_entry()

Use list_first_entry()/list_last_entry() instead of open coded variants.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Simplify error path in gpiod_get_index() when requesting GPIO

Simplify error path in the gpiod_get_index() when requesting a GPIO line by:
- checking for error condition first
- dropping redundant 'else'

As a result, decrease the indentation level for better readability.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Use short form of ternary operator in gpiod_get_index()

Instead of repeating first argument for true branch, use short
form of the ternary operator, i.e. ?:.

While at it, fix a typo in the comment.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: Introduce for_each_gpio_desc_with_flag() macro

In a few places we are using a loop against all GPIO descriptors
with a given flag for a given device. Replace it with a consolidated
for_each type of macro.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

Revert "gpio: Revert regression in sysfs-gpio (gpiolib.c)"

This reverts commit fc328a7d1fcce263db0b046917a66f3aa6e68719.

This commit - while attempting to fix a regression - has caused a number
of other problems. As the fallout from it is more significant than the
initial problem itself, revert it for now before we find a correct
solution.

Link: https://lore.kernel.org/all/20220314192522.GA3031157@roeck-us.net/
Link: https://lore.kernel.org/stable/20220314155509.552218-1-michael@walle.cc/
Link: https://lore.kernel.org/all/20211217153555.9413-1-marcelo.jimenez@gmail.com/
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reported-and-bisected-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Michael Walle <michael@walle.cc>
Cc: Thorsten Leemhuis <linux@leemhuis.info>
Cc: Marcelo Roberto Jimenez <marcelo.jimenez@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpiolib: acpi: Convert ACPI value of debounce to microseconds

It appears that GPIO ACPI library uses ACPI debounce values directly.
However, the GPIO library APIs expect the debounce timeout to be in
microseconds.

Convert ACPI value of debounce to microseconds.

While at it, document this detail where it is appropriate.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215664
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Fixes: 8dcb7a15a585 ("gpiolib: acpi: Take into account debounce settings")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: Revert regression in sysfs-gpio (gpiolib.c)

Some GPIO lines have stopped working after the patch
commit 2ab73c6d8323f ("gpio: Support GPIO controllers without pin-ranges")

And this has supposedly been fixed in the following patches
commit 89ad556b7f96a ("gpio: Avoid using pin ranges with !PINCTRL")
commit 6dbbf84603961 ("gpiolib: Don't free if pin ranges are not defined")

But an erratic behavior where some GPIO lines work while others do not work
has been introduced.

This patch reverts those changes so that the sysfs-gpio interface works
properly again.

Signed-off-by: Marcelo Roberto Jimenez <marcelo.jimenez@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: Return EPROBE_DEFER if gc->to_irq is NULL

We are racing the registering of .to_irq when probing the
i2c driver. This results in random failure of touchscreen
devices.

Following explains the race condition better.

[gpio driver] gpio driver registers gpio chip
[gpio consumer] gpio is acquired
[gpio consumer] gpiod_to_irq() fails with -ENXIO
[gpio driver] gpio driver registers irqchip
gpiod_to_irq works at this point, but -ENXIO is fatal

We could see the following errors in dmesg logs when gc->to_irq is NULL

[2.101857] i2c_hid i2c-FTS3528:00: HID over i2c has not been provided an Int IRQ
[2.101953] i2c_hid: probe of i2c-FTS3528:00 failed with error -22

To avoid this situation, defer probing until to_irq is registered.
Returning -EPROBE_DEFER would be the first step towards avoiding
the failure of devices due to the race in registration of .to_irq.
Final solution to this issue would be to avoid using gc irq members
until they are fully initialized.

This issue has been reported many times in past and people have been
using workarounds like changing the pinctrl_amd to built-in instead
of loading it as a module or by adding a softdep for pinctrl_amd into
the config file.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209413
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: allow line names from device props to override driver names

Some GPIO providers set names for GPIO lines that match the names of
the pins on the SoC, or variations on that theme. These names are
generic more often that not, such as pioC12 in the at91 case. These
generic names block the possibility to set more useful GPIO line
names with device properties (i.e. gpio-line-names).

Allow overriding a generic name given by the GPIO driver if there is
a name given to the GPIO line using device properties, but leave the
generic name alone if no better name is available.

However, there is a risk. If user space is depending on the above
mentioned fixed GPIO names, AND there are device properties that
previously did not reach the surface, the name change might cause
regressions. But hopefully this stays below the radar...

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Alexander Dahl <ada@thorsis.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: allow to specify the firmware node in struct gpio_chip

Software nodes allow us to represent hierarchies for device components
that don't have their struct device representation yet - for instance:
banks of GPIOs under a common GPIO expander. The core gpiolib core
however doesn't offer any way of passing this information from the
drivers.

This extends struct gpio_chip with a pointer to fwnode that can be set
by the driver and used to pass device properties for child nodes.

This is similar to how we handle device-tree sub-nodes with
CONFIG_OF_GPIO enabled.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide gpiod_remove_hogs()

Currently all users of gpiod_add_hogs() call it only once at system
init so there never was any need for a mechanism allowing to remove
them. Now the upcoming gpio-sim will need to tear down chips with hogged
lines so provide a function that allows to remove hogs.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: check the 'ngpios' property in core gpiolib code

Several drivers read the 'ngpios' device property on their own, but
since it's defined as a standard GPIO property in the device tree bindings
anyway, it's a good candidate for generalization. If the driver didn't
set its gc->ngpio, try to read the 'ngpios' property from the GPIO
device's firmware node before bailing out.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: improve coding style for local variables

Drop unneeded whitespaces and put the variables of the same type
together for consistency with the rest of the code.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: Let gpiod_add_lookup_table() call gpiod_add_lookup_tables()

This saves 20 bytes on arm32, and 44 bytes on arm64.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpio: Allow per-parent interrupt data

The core gpiolib code is able to deal with multiple interrupt parents
for a single gpio irqchip. It however only allows a single piece
of data to be conveyed to all flow handlers (either the gpio_chip
or some other, driver-specific data).

This means that drivers have to go through some interesting dance
to find the correct context, something that isn't great in interrupt
context (see aebdc8abc9db86e2bd33070fc2f961012fff74b4 for a prime
example).

Instead, offer an optional way for a pinctrl/gpio driver to provide
an array of pointers which gets used to provide the correct context
to the flow handler.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20211026175815.52703-2-joey.gouly@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: convert 'devprop_gpiochip_set_names' to support multiple gpiochip banks per device

The default gpiolib-of implementation does not work with the multiple
gpiochip banks per device structure used for example by the gpio-mt7621
and gpio-brcmstb drivers. To fix these kind of situations driver code
is forced to fill the names to avoid the gpiolib code to set names
repeated along the banks. Instead of continue with that antipattern
fix the gpiolib core function to get expected behaviour for every
single situation adding a field 'offset' in the gpiochip structure.
Doing in this way, we can assume this offset will be zero for normal
driver code where only one gpiochip bank per device is used but
can be set explicitly in those drivers that really need more than
one gpiochip.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Switch to bitmap_alloc()

Switch to bitmap_alloc() to show clearly what we are allocating.
Besides that it returns pointer of bitmap type instead of opaque void *.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Split fastpath array to two

Split fastpath array to two, i.e. for mask and for bits.
At the same time declare them as bitmaps.

This makes code better to read and gives a clue about use of
bitmap API.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Drop duplicate offset check in gpiochip_is_requested()

gpiochip_get_desc() already does the check, drop a duplicate in
gpiochip_is_requested().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Fold conditionals into a simple ternary operator

It's quite spread code to initialize IRQ domain options.
Let's fold it into a simple oneliner.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Reuse device's fwnode to create IRQ domain

When IRQ domain is created for an ACPI case, the name of it becomes unknown-%d
since for now it utilizes of_node member only and doesn't consider fwnode case.
Convert IRQ domain creation code to utilize fwnode instead.

Before/After the change on Intel Galileo Gen 2 with two GPIO (IRQ) controllers:

unknown-1 ==> \_SB.PCI0.GIP0.GPO
unknown-2 ==> \_SB.NIO3

Due to the nature of this change we may also deduplicate the WARN():s
because in either case (DT or ACPI) the fwnode will be set correctly
and %pfw is an equivalent to what the current code prints as a prefix.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Introduce acpi_gpio_dev_init() and call it from core

In the ACPI case we may use the firmware node in the similar way
as it's done for OF case. We may use that fwnode for other purposes
in the future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Move of_node operations to gpiolib-of and correct fwnode use

The initial value of the OF node based on presence of parent, but
at the same time this operation somehow appeared separately from others
that handle the OF case. On the other hand there is no need to assign
dev->fwnode in the OF case if code properly retrieves fwnode, i.e.
via dev_fwnode() helper.

Amend gpiolib.c and gpiolib-of.c code in order to group OF operations.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Unify the checks on fwnode type

We have (historically) different approaches how we identify the type
of a given fwnode. Let's standardize them across the library code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Assign fwnode to parent's if no primary one provided

In case when the properties are supplied in the secondary fwnode
(for example, built-in device properties) the fwnode pointer left
unassigned. This makes unable to retrieve them.

Assign fwnode to parent's if no primary one provided.

Fixes: 7cba1a4d5e16 ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Fixes: 2afa97e9868f ("gpiolib: Read "gpio-line-names" from a firmware node")
Reported-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Fix error return code in gpiolib_dev_init()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Read "gpio-line-names" from a firmware node

On STM32MP1, the GPIO banks are subnodes of pin-controller@50002000,
see arch/arm/boot/dts/stm32mp151.dtsi. The driver for
pin-controller@50002000 is in drivers/pinctrl/stm32/pinctrl-stm32.c
and iterates over all of its DT subnodes when registering each GPIO
bank gpiochip. Each gpiochip has:

- gpio_chip.parent = dev,
where dev is the device node of the pin controller
- gpio_chip.of_node = np,
which is the OF node of the GPIO bank

Therefore, dev_fwnode(chip->parent) != of_fwnode_handle(chip.of_node),
i.e. pin-controller@50002000 != pin-controller@50002000/gpio@5000*000.

The original code behaved correctly, as it extracted the "gpio-line-names"
from of_fwnode_handle(chip.of_node) = pin-controller@50002000/gpio@5000*000.

To achieve the same behaviour, read property from the firmware node.

Fixes: 7cba1a4d5e162 ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Reported-by: Marek Vasut <marex@denx.de>
Reported-by: Roman Guskov <rguskov@dh-electronics.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Marek Vasut <marex@denx.de>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: fix gpio-device list corruption

Make sure to hold the gpio_lock when removing the gpio device from the
gpio_devices list (when dropping the last reference) to avoid corrupting
the list when there are concurrent accesses.

Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Cc: stable@vger.kernel.org # 4.6
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: fix NULL-deref-on-deregistration regression

Fix a NULL-pointer deference when deregistering the gpio character
device that was introduced by the recent stub-driver hack. When the new
"driver" is unbound as part of deregistration, driver core clears the
driver-data pointer which is used to retrieve the struct gpio_device in
its release callback.

Fix this by using container_of() in the release callback as should have
been done all along.

Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default")
Cc: Saravana Kannan <saravanak@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: syzbot+d27b4c8adbbff70fbfde@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Don't probe gpio_device if it's not the primary device

Dmitry reported[1] boot error messages caused by
commit 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default").

gpio-1022 (cpu-pwr-req-hog): hogged as input
max77620-pinctrl max77620-pinctrl: pin gpio4 already requested by max77620-pinctrl; cannot claim for gpiochip1
max77620-pinctrl max77620-pinctrl: pin-4 (gpiochip1) status -22
max77620-pinctrl max77620-pinctrl: could not request pin 4 (gpio4) from group gpio4 on device max77620-pinctrl
gpio_stub_drv gpiochip1: Error applying setting, reverse things back
gpio_stub_drv: probe of gpiochip1 failed with error -22

This happens because when we try to probe a device, driver core calls
into pinctrl to set up the pins. However, if the GPIO DT node already
has a proper device created and probed, trying to probe the gpio_device
with a stub driver makes the pins be claimed twice. pinctrl doesn't like
this and throws an error.

So, this patch makes sure the gpio_stub_drv doesn't match with a
gpio_device if it's not the primary device for the fwnode.

[1] - https://lore.kernel.org/lkml/544ad0e4-0954-274c-8e77-866aaa5661a8@gmail.com/

Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default")
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210205020730.1746354-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default

There are multiple instances of GPIO device tree nodes of the form:

foo {
compatible = "acme,foo";
...

gpio0: gpio0@xxxxxxxx {
compatible = "acme,bar";
...
gpio-controller;
};

gpio1: gpio1@xxxxxxxx {
compatible = "acme,bar";
...
gpio-controller;
};

...
}

bazz {
my-gpios = <&gpio0 ...>;
}

Case 1: The driver for "foo" populates struct device for these gpio*
nodes and then probes them using a driver that binds with "acme,bar".
This driver for "acme,bar" then registers the gpio* nodes with gpiolib.
This lines up with how DT nodes with the "compatible" property are
typically converted to struct devices and then registered with driver
core to probe them. This also allows the gpio* devices to hook into all
the driver core capabilities like runtime PM, probe deferral,
suspend/resume ordering, device links, etc.

Case 2: The driver for "foo" doesn't populate struct devices for these
gpio* nodes before registering them with gpiolib. Instead it just loops
through its child nodes and directly registers the gpio* nodes with
gpiolib.

Drivers that follow case 2 cause problems with fw_devlink=on. This is
because fw_devlink will prevent bazz from probing until there's a struct
device that has gpio0 as its fwnode (because bazz lists gpio0 as a GPIO
supplier). Once the struct device is available, fw_devlink will create a
device link with gpio0 device as the supplier and bazz device as the
consumer. After this point, since the gpio0 device will never bind to a
driver, the device link will prevent bazz device from ever probing.

Finding and refactoring all the instances of drivers that follow case 2
will cause a lot of code churn and it is not something that can be done
in one shot. In some instances it might not even be possible to refactor
them cleanly. Examples of such instances are [1] [2].

This patch works around this problem and avoids all the code churn by
simply setting the fwnode of the gpio_device and creating a stub driver
to bind to the gpio_device. This allows all the consumers to continue
probing when the driver follows case 2.

[1] - https://lore.kernel.org/lkml/20201014191235.7f71fcb4@xhacker.debian/
[2] - https://lore.kernel.org/lkml/e28e1f38d87c12a3c714a6573beba6e1@kernel.org/

Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default")
Cc: Marc Zyngier <maz@kernel.org>
Cc: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Cc: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210122193600.1415639-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpiolib: Follow usual pattern for gpiod_remove_lookup_table() call

The usual pattern for the remove calls, like gpiod_remove_lookup_table(),
is to be NULL-aware, i.o.w. become a no-op whenever parameter is NULL.
Update gpiod_remove_lookup_table() call to follow this pattern.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

gpio: gpiolib: remove shadowed variable

After refactoring, we had two variables for the same thing. Remove the
second declaration, one is enough here. Found by cppcheck.

drivers/gpio/gpiolib.c:2551:17: warning: Local variable 'ret' shadows outer variable [shadowVariable]

Fixes: d377f56f34f5 ("gpio: gpiolib: Normalize return code variable name")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: free device name on error path to fix kmemleak

In gpiochip_add_data_with_key, we should check the return value of
dev_set_name to ensure that device name is allocated successfully
and then add a label on the error path to free device name to fix
kmemleak as below:

unreferenced object 0xc2d6fc40 (size 64):
comm "kworker/0:1", pid 16, jiffies 4294937425 (age 65.120s)
hex dump (first 32 bytes):
67 70 69 6f 63 68 69 70 30 00 1a c0 54 63 1a c0 gpiochip0...Tc..
0c ed 84 c0 48 ed 84 c0 3c ee 84 c0 10 00 00 00 ....H...<.......
backtrace:
[<962810f7>] kobject_set_name_vargs+0x2c/0xa0
[<f50797e6>] dev_set_name+0x2c/0x5c
[<94abbca9>] gpiochip_add_data_with_key+0xfc/0xce8
[<5c4193e0>] omap_gpio_probe+0x33c/0x68c
[<3402f137>] platform_probe+0x58/0xb8
[<7421e210>] really_probe+0xec/0x3b4
[<000f8ada>] driver_probe_device+0x58/0xb4
[<67e0f7f7>] bus_for_each_drv+0x80/0xd0
[<4de545dc>] __device_attach+0xe8/0x15c
[<2e4431e7>] bus_probe_device+0x84/0x8c
[<c18b1de9>] device_add+0x384/0x7c0
[<5aff2995>] of_platform_device_create_pdata+0x8c/0xb8
[<061c3483>] of_platform_bus_create+0x198/0x230
[<5ee6d42a>] of_platform_populate+0x60/0xb8
[<2647300f>] sysc_probe+0xd18/0x135c
[<3402f137>] platform_probe+0x58/0xb8

Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: add a warning on gpiochip->to_irq defined

gpiochip->to_irq method is redefined in gpiochip_add_irqchip.

A lot of gpiod driver's still define ->to_irq method, let's give
a gentle warning that they can no longer rely on it, so they can remove
it on ocassion.

Fixes: e0d8972898139 ("gpio: Implement tighter IRQ chip integration")
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: irq hooks: fix recursion in gpiochip_irq_unmask

irqchip shared with multiple gpiochips, leads to recursive call of
gpiochip_irq_mask/gpiochip_irq_unmask which was assigned to
rqchip->irq_mask/irqchip->irq_unmask, these happens becouse of
only irqchip->irq_enable == gpiochip_irq_enable is checked.

Let's add an additional check to make sure shared irqchip is detected
even if irqchip->irq_enable wasn't defined.

Fixes: a8173820f441 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable")
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Link: https://lore.kernel.org/r/20201210070514.13238-1-nikita.shubin@maquefel.me
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: just plain warning when nonexisting gpio requested

When trying to export an nonexisting gpio ID, the kernel prints out a
big warning w/ stacktrace, sounding like a huge problem. In fact it's
a pretty normal situation, like file or device not found.

So, just print a more relaxed warning instead.

changes v2: drop defining pr_fmt()

Signed-off-by: Enrico Weigelt <info@metux.net>
Link: https://lore.kernel.org/r/20201202133754.32045-1-info@metux.net
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Don't free if pin ranges are not defined

A similar check was added in gpiochip_generic_request, but not in free.
This has caused an imbalance count of request vs. free calls to the
pinctrl driver. This patch is targeted to fix that issue.

Fixes: 2ab73c6d8323 ("gpio: Support GPIO controllers without pin-ranges")
Signed-off-by: Edmond Chung <edmondchung@google.com>
Signed-off-by: Andrew Chant <achant@google.com>
Signed-off-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: do not print err message for EPROBE_DEFER

The gpiochip may have dependencies from pinmux and so got deferred. Now it
will print error message every time -EPROBE_DEFER is returned which is
unnecessary:

"gpiochip_add_data_with_key: GPIOs 0..31 (gpio-0-31) failed to register, -517"

Hence, do suppress error message for -EPROBE_DEFER case.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Introduce gpio_set_debounce_timeout() for internal use

In some cases we would like to have debounce setter which doesn't fail
when a feature is not supported by a controller.

Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

gpiolib: Extract gpio_set_config_with_argument_optional() helper

This function is useful for internal use in the GPIO library.
There will be new user coming, prepare a helper for the new comer
and the existing ones.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: move bias related code from gpio_set_config() to gpio_set_bias()

Move bias related code from gpio_set_config() to gpio_set_bias().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: Extract gpio_set_config_with_argument() for future use

In the future we will need to have a separate function
that takes an arbitrary argument value.

Extract gpio_set_config_with_argument() for that purpose.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: use proper API to pack pin configuration parameters

Instead of open coded macro use, call pinconf_to_config_packed().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: add missed break statement

It's no difference in the functionality, but after the change the code
is less error prone to various checkers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: Replace unsigned by unsigned int

Replace unsigned by unsigned int in GPIO library code.
Note, legacy API left untouched.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: fix sysfs when cdev is not selected

In gpiochip_setup_dev() the call to gpiolib_cdev_register() indirectly
calls device_add(). This is still required for the sysfs even when
CONFIG_GPIO_CDEV is not selected in the build.

Replace the stubbed functions in gpiolib-cdev.h with macros in gpiolib.c
that perform the required device_add() and device_del() when
CONFIG_GPIO_CDEV is not selected.

Fixes: d143493c01b7 (gpiolib: make cdev a build option)
Reported-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Tested-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Retire the explicit gpio irqchip code

Now that all gpiolib irqchip users have been over to use
the irqchip template, we can finally retire the old code
path and leave just one way in to the irqchip: set up the
template when registering the gpio_chip. For a while
we had two code paths for this which was a bit confusing.

This brings this work to a conclusion, there is now one
way of doing this.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Link: https://lore.kernel.org/r/20201019134046.65101-1-linus.walleij@linaro.org

gpiolib: Use proper type for bias enumerator in gpio_set_bias()

First of all, bias has a special type as being a part of enum pin_config_param.
Second, 0 is also defined bias which is equivalent to BUS_HOLD.

Taking into account above, change type of bias variable and refactor
gpio_set_bias() in a way that it doesn't use BUS_HOLD as a place holder.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201009184359.16427-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: split error path in gpiod_request_commit()

For better maintenance and micro optimization split error path
in the gpiod_request_commit().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Unify expectations about ->request() returned value

Half of the code in the GPIO library is written in an expectation that
any non-zero value returned from the ->request() callback is an error code,
while some code checks only for negative values.

Unify expectations about ->request() returned value to be non-zero
for an error and 0 for the success.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Extract gpiod_not_found() helper

Several places in the code are using same idiom, i.e.
IS_ERR(desc) && PTR_ERR(desc) == -ENOENT
which meaning is GPIO description is not found.

For better readability extract gpiod_not_found() helper and use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: cdev: support setting debounce

Add support for setting debounce on a line via the GPIO uAPI.
Where debounce is not supported by hardware, a software debounce is
provided.

The implementation of the software debouncer waits for the line to be
stable for the debounce period before determining if a level change,
and a corresponding edge event, has occurred. This provides maximum
protection against glitches, but also introduces a debounce_period
latency to edge events.

The software debouncer is integrated with the edge detection as it
utilises the line interrupt, and integration is simpler than getting
the two to interwork. Where software debounce AND edge detection is
required, the debouncer provides both.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: cdev: support edge detection for uAPI v2

Add support for edge detection to lines requested using
GPIO_V2_GET_LINE_IOCTL.

The edge_detector implementation is based on the v1 lineevent
implementation. Unlike the v1 implementation, an overflow of the event
buffer results in discarding older events, rather than the most
recent, so the final event in a burst will correspond to the current
state of the line.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: check for parent device in devprop_gpiochip_set_names()

It's possible for a GPIO chip to not have a parent device (whose
properties we inspect for 'gpio-line-names'). In this case we should
simply return from devprop_gpiochip_set_names(). Add an appropriate
check for this use-case.

Fixes: 7cba1a4d5e16 ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: unexport devprop_gpiochip_set_names()

Now that devprop_gpiochip_set_names() is only used in a single place
inside drivers/gpio/gpiolib.c, there's no need anymore for it to be
exported or to even live in its own source file. Pull this function into
the core source file for gpiolib.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: generalize devprop_gpiochip_set_names() for device properties

devprop_gpiochip_set_names() is overly complicated with taking the
fwnode argument (which requires using dev_fwnode() & of_fwnode_handle()
in ACPI and OF GPIO code respectively). Let's just switch to using the
generic device properties.

This allows us to pull the code setting line names directly into
gpiochip_add_data_with_key() instead of handling it separately for
ACPI and OF.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

gpiolib: switch to simpler IDA interface

We don't need to specify any ranges when allocating IDs so we can switch
to ida_alloc() and ida_free() instead of the ida_simple_ counterparts.

ida_simple_get(ida, 0, 0, gfp) is equivalent to
ida_alloc_range(ida, 0, UINT_MAX, gfp) which is equivalent to
ida_alloc(ida, gfp). Note: IDR will never actually allocate an ID
larger than INT_MAX.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: convert to use DEFINE_SEQ_ATTRIBUTE macro

Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: cdev: use blocking notifier call chain instead of atomic

Replace usage of atomic_notifier_call_chain with
blocking_notifier_call_chain as the notifier function,
lineinfo_changed_notify, calls gpio_desc_to_lineinfo,
which calls pinctrl_gpio_can_use_line, which can sleep.

The chain isn't being called from an atomic context so the
the blocking notifier is a suitable substitute.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: move gpiolib-sysfs function declarations into their own header

Move gpiolib-sysfs function declarations into their own header.

These functions are in gpiolib-sysfs.c, and are only required by gpiolib.c,
and so should be in a module header, not gpiolib.h.

This brings gpiolib-sysfs into line with gpiolib-cdev, and is another step
towards removing the sysfs inferface.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Deduplicate find_first_zero_bit() call

bitmap_full() is a shortcut to find_first_zero_bit().
Thus, no need to call it twice.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: split character device into gpiolib-cdev

Split the cdev specific functionality out of gpiolib.c and into
gpiolib-cdev.c. This improves the readability and maintainability of both
the cdev and core gpiolib code.

Suggested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20200616093615.5167-1-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Introduce gpiochip_irqchip_add_domain()

The function connects an IRQ domain to a gpiochip and reuses
gpiochip_to_irq() which is provided by gpiolib.

gpiochip_irqchip_* and regmap_irq partially provide the same
functionality. This function will help to connect just the
minimal functionality of the gpiochip_irqchip which is needed to
work together with regmap-irq.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200528145845.31436-2-michael@walle.cc
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: fix locking open drain IRQ lines

We provided the right semantics on open drain lines being
by definition output but incidentally the irq set up function
would only allow IRQs on lines that were "not output".

Fix the semantics to allow output open drain lines to be used
for IRQs.

Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Tested-by: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Russell King <linux@armlinux.org.uk>
Cc: stable@vger.kernel.org # v5.3+
Link: https://lore.kernel.org/r/20200527140758.162280-1-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: gpiolib: Allow GPIO IRQs to lazy disable

With 'commit 461c1a7d4733 ("gpiolib: override irq_enable/disable")' gpiolib
overrides irqchip's irq_enable and irq_disable callbacks. If irq_disable
callback is implemented then genirq takes unlazy path to disable irq.

Underlying irqchip may not want to implement irq_disable callback to lazy
disable irq when client drivers invokes disable_irq(). By overriding
irq_disable callback, gpiolib ends up always unlazy disabling IRQ.

Allow gpiolib to lazy disable IRQs by overriding irq_disable callback only
if irqchip implemented irq_disable. In cases where irq_disable is not
implemented irq_mask is overridden. Similarly override irq_enable callback
only if irqchip implemented irq_enable otherwise irq_unmask is overridden.

Fixes: 461c1a7d4733 ("gpiolib: override irq_enable/disable")
Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/1590253873-11556-2-git-send-email-mkshah@codeaurora.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Separate GPIO_GET_LINEINFO_WATCH_IOCTL conditional

We already have two conditionals inside the outer one to check
if the command is GPIO_GET_LINEINFO_WATCH_IOCTL. I think it's
time to actually do what I have proposed in the first place, i.e.
to separate GPIO_GET_LINEINFO_WATCH_IOCTL from GPIO_GET_LINEINFO_IOCTL.
It's +13 LOCs, and surprisingly only +13 bytes of binary on x86_32,
but for the price of much better readability.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200525194028.74236-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Add support for GPIO lookup by line name

Currently a GPIO lookup table can only refer to a specific GPIO by a
tuple, consisting of a GPIO controller label and a GPIO offset inside
the controller.

However, a GPIO may also carry a line name, defined by DT or ACPI.
If present, the line name is the most use-centric way to refer to a
GPIO. Hence add support for looking up GPIOs by line name.
Note that there is no guarantee that GPIO line names are globally
unique, so this will use the first match found.

Implement this by reusing the existing gpiod_lookup infrastructure.
Rename gpiod_lookup.chip_label to gpiod_lookup.key, to make it clear
that this field can have two meanings, and update the kerneldoc and
GPIO_LOOKUP*() macros.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Link: https://lore.kernel.org/r/20200511145257.22970-4-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Document that GPIO line names are not globally unique

gpiochip_set_desc_names() no longer rejects GPIO line name collisions.
Hence GPIO line names are not guaranteed to be globally unique.
In case of multiple GPIO lines with the same name, gpio_name_to_desc()
will return the first match found.

Update the comments for gpio_name_to_desc() and
gpiochip_set_desc_names() to match reality.

Fixes: f881bab038c9667d ("gpio: keep the GPIO line names internal")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200511101828.30046-1-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: notify user-space about line status changes after flags are set

Currently we emit the REQUESTED line state event after the line is
requested but before the flags are configured. This is obviously wrong
as we want to pass the updated lineinfo to user-space together with the
event.

Since the flags can be configured in different ways depending on how the
line is being requested - we need to call the notifier chain in different
places separately.

Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: of: Build fails if CONFIG_OF_DYNAMIC enabled without CONFIG_OF_GPIO

The symbol 'gpio_of_notifier' doesn't exist without both CONFIG_OF_GPIO
and CONFIG_OF_DYNAMIC enabled, but is referenced when only
CONFIG_OF_DYNAMIC is enabled.

This broke building with 'make ARCH=um allyesconfig':
---------------
/usr/bin/ld: drivers/gpio/gpiolib.o: in function `gpiolib_dev_init':
./drivers/gpio/gpiolib.c:5293: undefined reference to `gpio_of_notifier'
collect2: error: ld returned 1 exit status
---------------

Fixes: 63636d956c45 ("gpio: of: Add DT overlay support for GPIO hogs")
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200425044655.166257-1-davidgow@google.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Improve kernel messages

Simplify the printing of kernel messages and make the messages more
accurate by using the most appropriate {dev,chip,gpiod}_*() helpers.

Sample impact:

-gpiochip_setup_dev: registered GPIOs 496 to 511 on device: gpiochip0 (e6050000.gpio)
+gpio gpiochip0: registered GPIOs 496 to 511 on e6050000.gpio

-no flags found for gpios
+gpio-953 (?): no flags found for gpios

-GPIO line 355 (PCIE/SATA switch) hogged as output/low
+gpio-355 (PCIE/SATA switch): hogged as output/low

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200424141432.11400-1-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: don't call sleeping functions with a spinlock taken

We must not call pinctrl_gpio_can_use_line() with the gpio_lock taken
as it takes a mutex internally. Let's move the call before taking the
spinlock and store the return value.

This isn't perfect - there's a moment between calling
pinctrl_gpio_can_use_line() and taking the spinlock where the situation
can change but it isn't a regression either: previously this part wasn't
protected at all and it only affects the information user-space is
seeing.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: d2ac25798208 ("gpiolib: provide a dedicated function for setting lineinfo")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: improve the robustness of watch/unwatch ioctl()

This makes the new ioctl() a bit more robust - we now check if a line
is already being watched and return -EBUSY if the user-space tries to
start watching it again. Same for unwatch - return -EBUSY if user-space
tries to unwatch a line that's not being watched.

Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Rename variable in core APIs

There is struct gpio *gc, *chip and *gpiochip, and yes
I am responsible for some of the inconsistencies. I want
this to be just gc everywhere for minimizing cognitive
resistance when reading the code: more compact function
signatures and less clutter.

Purely syntactic changes intended. No semantic effects.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200329140405.52276-1-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Avoid using pin ranges with !PINCTRL

Do not use the struct gpio_device's .pin_ranges field if the PINCTRL
Kconfig symbol is not selected to avoid build failures.

Fixes: 2ab73c6d8323fa1e ("gpio: Support GPIO controllers without pin-ranges")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200330090257.2332864-1-thierry.reding@gmail.com
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Remove unused gpio_chip parameter from gpio_set_bias()

gpio_set_bias() no longer uses the passed gpio_chip pointer parameter.
Remove it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200325100439.14000-3-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Pass gpio_desc to gpio_set_config()

All callers of gpio_set_config() have to convert a gpio_desc to a
gpio_chip and offset. Avoid these duplicated conversion steps by
letting gpio_set_config() take a gpio_desc pointer directly.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200325100439.14000-2-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Introduce gpiod_set_config()

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>

gpio: gpiolib: fix a doc warning

Use a different markup for the ERR_PTR, as %FOO doesn't work
if there are parenthesis. So, use, instead:

``ERR_PTR(-EINVAL)``

This fixes the following warning:

./drivers/gpio/gpiolib.c:139: WARNING: Inline literal start-string without end-string.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/51197e3568f073e22c280f0584bfa20b44436708.1584456635.git.mchehab+huawei@kernel.org
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Support GPIO controllers without pin-ranges

Wake gpiochip_generic_request() call into the pinctrl helpers only if a
GPIO controller had any pin-ranges assigned to it. This allows a driver
to unconditionally use this helper if it supports multiple devices of
which only a subset have pin-ranges assigned to them.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200319122737.3063291-2-thierry.reding@gmail.com
Tested-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: gpio_name_to_desc: factor out !name check

Since name == NULL can't ever match, move the check out of
IRQ-disabled region.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Move devres calls to devres file

These two devres functions devm_gpiochip_[add|remove]()
were in the wrong file. They should be in gpiolib-devres.c
not gpiolib.c.

Link: https://lore.kernel.org/r/20200313081522.35143-1-linus.walleij@linaro.org
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Fix irq_disable() semantics

The implementation if .irq_disable() which kicks in between
the gpiolib and the driver is not properly mimicking the
expected semantics of the irqchip core: the irqchip will
call .irq_disable() if that exists, else it will call
mask_irq() which first checks if .irq_mask() is defined
before calling it.

Since we are calling it unconditionally, we get this bug
from drivers/pinctrl/qcom/pinctrl-ssbi-gpio.c, as it only
defines .irq_mask_ack and not .irq_mask:

Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = (ptrval)
(...)
PC is at 0x0
LR is at gpiochip_irq_disable+0x20/0x30

Fix this by only calling .irq_mask() if it exists.

Cc: Brian Masney <masneyb@onstation.org>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Fixes: 461c1a7d4733 ("gpiolib: override irq_enable/disable")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200306132326.1329640-1-linus.walleij@linaro.org

gpiolib: Fix inverted check in gpiochip_remove()

The optimization to check for requested lines actually optimized for the
uncomon error case, where one of the GPIO lines is still in use.
Hence the error message must be printed when the loop is terminated
early, not when it went through all available GPIO lines.

Fixes: 869233f81337bfb3 ("gpiolib: Optimize gpiochip_remove() when check for requested line")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200302082448.11795-1-geert+renesas@glider.be
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: fix bitmap operations related to line event watching

When operating on the bits of watched_lines bitmap, we're using
desc_to_gpio() which returns the GPIO number from the global numberspace.
This leads to all sorts of memory corruptions and invalid behavior. We
should switch to using gpio_chip_hwgpio() instead.

Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info")
Reported-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: Kent Gibson <warthog618@gmail.com>

gpiolib: fix unwatch ioctl()

Fix the field having a bit cleared by the unwatch ioctl().

Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info")
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Rename 'event' to 'ge' to be consistent with other use

Rename 'event' to 'ge' to be consistent with other use.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: Optimize gpiochip_remove() when check for requested line

Here are the following optimizations have been done:
- break the loop after first found requested line
- due to above, drop redundant boolean variable
- replace open coded variant of gpiochip_is_requested()
- due to above, drop redundant pointer to struct gpio_desc
- use 'unsigned int' instead of 'unsigned' for loop counter

Note, pointer to struct gpio_chip followed by pointer to struct gpio_device
is still valid, back link is not.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200225114725.839-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: export gpiochip_get_desc

The function was currently used internal by the gpiolib. Since commit
56cc3af4e8c8 ("pinctrl: da9062: add driver support") it is also used by
drivers so we need to export the symbol.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20200225093102.10964-1-m.felsch@pengutronix.de
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: of: Add DT overlay support for GPIO hogs

As GPIO hogs are configured at GPIO controller initialization time,
adding/removing GPIO hogs in DT overlays does not work.

Add support for GPIO hogs described in DT overlays by registering an OF
reconfiguration notifier, to handle the addition and removal of GPIO hog
subnodes to/from a GPIO controller device node.

Note that when a GPIO hog device node is being removed, its "gpios"
properties is no longer available, so we have to keep track of which
node a hog belongs to, which is done by adding a pointer to the hog's
device node to struct gpio_desc.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200220130149.26283-3-geert+renesas@glider.be
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Switch timestamps to ktime_get_ns()

The existing use of ktime_get_real_ns() in the timestamps from
the GPIO events is dubious.

We have had several discussions about this timestamp, and it is
unclear whether userspace has ever taken into account that a
timestamp from ktime_get_real_ns() can actually move backwards
in time relative the previous timetamp, and userspace is more
likely to expect a monotonic counter.

Background:
https://lore.kernel.org/linux-gpio/CAK8P3a1Skvm48sje8FNDPLYqyz9Lf8q0qX1QETWtyZTxuX4k1g@mail.gmail.com/
https://marc.info/?l=linux-gpio&m=151661955709074&w=2

The change is ABI incompatible, but incompatible in a way that
is IMO more likely to fix future bugs rather than break current
userspace. To the best of my knowledge all userspace expects
a monotonic timestamp and users are just lucky that they very
seldom move backwards in time.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: use gpiochip_get_desc() where applicable

Whenever retrieving a descriptor from a gpiochip: use the provided
helper which checks for errors.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200219094702.6463-1-brgl@bgdev.pl
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: add new ioctl() for monitoring changes in line info

Currently there is no way for user-space to be informed about changes
in status of GPIO lines e.g. when someone else requests the line or its
config changes. We can only periodically re-read the line-info. This
is fine for simple one-off user-space tools, but any daemon that provides
a centralized access to GPIO chips would benefit hugely from an event
driven line info synchronization.

This patch adds a new ioctl() that allows user-space processes to reuse
the file descriptor associated with the character device for watching
any changes in line properties. Every such event contains the updated
line information.

Currently the events are generated on three types of status changes: when
a line is requested, when it's released and when its config is changed.
The first two are self-explanatory. For the third one: this will only
happen when another user-space process calls the new SET_CONFIG ioctl()
as any changes that can happen from within the kernel (i.e.
set_transitory() or set_debounce()) are of no interest to user-space.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: provide a dedicated function for setting lineinfo

We'll soon be filling out the gpioline_info structure in multiple
places. Add a separate function that given a gpio_desc sets all relevant
fields.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: emit a debug message when adding events to a full kfifo

Currently if the line-event kfifo is full, we just silently drop any new
events. Add a ratelimited debug message so that we at least have some
trace in the kernel log of event overflow.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: rework the locking mechanism for lineevent kfifo

The read_lock mutex is supposed to prevent collisions between reading
and writing to the line event kfifo but it's actually only taken when
the events are being read from it.

Drop the mutex entirely and reuse the spinlock made available to us in
the waitqueue struct. Take the lock whenever the fifo is modified or
inspected. Drop the call to kfifo_to_user() and instead first extract
the new element from kfifo when the lock is taken and only then pass
it on to the user after the spinlock is released.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

gpiolib: remove unnecessary argument from set_config call

Remove unnecessary argument when setting PIN_CONFIG_BIAS_DISABLE. No
argument is expected by pinctrl, so removing it should be harmless.

Fixes: 2148ad7790ea ("gpiolib: add support for disabling line bias")
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: fix gpio_do_set_config()

Commit d90f36851d65 ("gpiolib: have a single place of calling
set_config()") introduced a regression where we don't pass the right
variable as argument to the set_config() callback of gpio driver from
gpio_set_config(). After reverting two additional patches that came
on top of it - this addresses the issue by changing the type of the last
argument of gpio_do_set_config() to unsigned long and making sure the
packed config variable is actually used in gpio_set_config().

Fixes: d90f36851d65 ("gpiolib: have a single place of calling set_config()")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>

Revert "gpiolib: remove set but not used variable 'config'"

This reverts commit e5e42ad224a040f93bf112e96f82b3a0ed97ffab.

This patch came on top of another patch that introduced a regression.
Revert it before addressing the culprit.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>

Revert "gpiolib: Remove duplicated function gpio_do_set_config()"

This reverts commit d18fddff061d2796525e6d4a958cb3d30aed8efd.

This patch came on top of another patch that introduced a regression.
Revert it before addressing the culprit.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>

treewide: remove redundant IS_ERR() before error code check

'PTR_ERR(p) == -E*' is a stronger condition than IS_ERR(p).
Hence, IS_ERR(p) is unneeded.

The semantic patch that generates this commit is as follows:

// <smpl>
@@
expression ptr;
constant error_code;
@@
-IS_ERR(ptr) && (PTR_ERR(ptr) == - error_code)
+PTR_ERR(ptr) == - error_code
// </smpl>

Link: http://lkml.kernel.org/r/20200106045833.1725-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Acked-by: Stephen Boyd <sboyd@kernel.org> [drivers/clk/clk.c]
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> [GPIO]
Acked-by: Wolfram Sang <wsa@the-dreams.de> [drivers/i2c]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [acpi/scan.c]
Acked-by: Rob Herring <robh@kernel.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gpiolib: hold gpio devices lock until ->descs array is initialised

If a driver consuming the GPIO chip is being probed at the same time as
the GPIO driver is registering the chip, it is possible for the
consuming driver to see the ->descs array in an uninitialised state.
For example, the gpio-keys-polled driver can fail like this:

kernel: gpiod_request: invalid GPIO (no device)
kernel: gpio-keys-polled PRP0001:07: failed to get gpio: -22
kernel: gpio-keys-polled: probe of PRP0001:07 failed with error -22

This patch makes gpiochip_add() hold the lock protecting gpio_devices
until it has finished setting desc->gdev on the newly inserted list
entry.

Signed-off-by: Dan Callaghan <dan.callaghan@opengear.com>
Link: https://lore.kernel.org/r/20200121001216.15964-1-dan.callaghan@opengear.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Drop the chained IRQ handler assign function

gpiochip_set_chained_irqchip() would assign a chained handler
to a GPIO chip. We now populate struct gpio_irq_chip for all
chained GPIO irqchips so drop this function.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200113220800.77817-1-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Lower verbosity when allocating hierarchy irq

In the current codes, the following 3 lines would be output to
the console for each irq line.
gpio gpiochip0: (gpio_thunderx): allocate IRQ 10, hwirq 0
gpio gpiochip0: (gpio_thunderx): found parent hwirq 245784
gpio gpiochip0: (gpio_thunderx): alloc_irqs_parent for 10 parent hwirq 245784

In general, there are about tens of irq lines for each gpio chip,
and then it would emit so many insignificant log in the boot process.
These infos are more suitable for the dbg purpose. So change these
to the dbg level. With this change, about 200 lines are suppressed
on my Marvell cn96xx board.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://lore.kernel.org/r/20200120095625.25164-1-haokexin@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Remove duplicated function gpio_do_set_config()

gpio_set_config() simply call gpio_do_set_config(),
so remove the duplicated function.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200116142927.58908-1-yuehaibing@huawei.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: remove set but not used variable 'config'

drivers/gpio/gpiolib.c: In function gpio_set_config:
drivers/gpio/gpiolib.c:3053:16: warning:
variable config set but not used [-Wunused-but-set-variable]

commit d90f36851d65 ("gpiolib: have a single place
of calling set_config()") left behind this unused variable.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200108121117.45060-1-yuehaibing@huawei.com
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Set lockdep class for hierarchical irq domains

I see the following lockdep splat in the qcom pinctrl driver when
attempting to suspend the device.

============================================
WARNING: possible recursive locking detected
5.4.2 #2 Tainted: G S
--------------------------------------------
cat/6536 is trying to acquire lock:
ffffff814787ccc0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

but task is already holding lock:
ffffff81436740c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&irq_desc_lock_class);
lock(&irq_desc_lock_class);

*** DEADLOCK ***

May be due to missing lock nesting notation

7 locks held by cat/6536:
#0: ffffff8140e0c420 (sb_writers#7){.+.+}, at: vfs_write+0xc8/0x19c
#1: ffffff8121eec480 (&of->mutex){+.+.}, at: kernfs_fop_write+0x128/0x1f4
#2: ffffff8147cad668 (kn->count#263){.+.+}, at: kernfs_fop_write+0x130/0x1f4
#3: ffffffd011446000 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x354
#4: ffffff814302b970 (&dev->mutex){....}, at: __device_suspend+0x16c/0x420
#5: ffffff81436740c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94
#6: ffffff81479b8c10 (&pctrl->lock){....}, at: msm_gpio_irq_set_wake+0x48/0x7c

stack backtrace:
CPU: 4 PID: 6536 Comm: cat Tainted: G S 5.4.2 #2
Call trace:
dump_backtrace+0x0/0x174
show_stack+0x20/0x2c
dump_stack+0xdc/0x144
__lock_acquire+0x52c/0x2268
lock_acquire+0x1dc/0x220
_raw_spin_lock_irqsave+0x64/0x80
__irq_get_desc_lock+0x64/0x94
irq_set_irq_wake+0x40/0x144
msm_gpio_irq_set_wake+0x5c/0x7c
set_irq_wake_real+0x40/0x5c
irq_set_irq_wake+0x70/0x144
cros_ec_rtc_suspend+0x38/0x4c
platform_pm_suspend+0x34/0x60
dpm_run_callback+0x64/0xcc
__device_suspend+0x314/0x420
dpm_suspend+0xf8/0x298
dpm_suspend_start+0x84/0xb4
suspend_devices_and_enter+0xbc/0x628
pm_suspend+0x214/0x354
state_store+0xb0/0x108
kobj_attr_store+0x14/0x24
sysfs_kf_write+0x4c/0x64
kernfs_fop_write+0x158/0x1f4
__vfs_write+0x54/0x18c
vfs_write+0xdc/0x19c
ksys_write+0x7c/0xe4
__arm64_sys_write+0x20/0x2c
el0_svc_common+0xa8/0x160
el0_svc_compat_handler+0x2c/0x38
el0_svc_compat+0x8/0x10

This is because the msm_gpio_irq_set_wake() function calls
irq_set_irq_wake() as a backup in case the irq comes in during the path
to idle. Given that we're calling irqchip functions from within an
irqchip we need to set the lockdep class to be different for this child
controller vs. the default one that the parent irqchip gets.

This used to be done before this driver was converted to hierarchical
irq domains in commit e35a6ae0eb3a ("pinctrl/msm: Setup GPIO chip in
hierarchy") via the gpiochip_irq_map() function. With hierarchical irq
domains this function has been replaced by
gpiochip_hierarchy_irq_domain_alloc(). Therefore, set the lockdep class
like was done previously in the irq domain path so we can avoid this
lockdep warning.

Fixes: fdd61a013a24 ("gpio: Add support for hierarchical IRQ domains")
Cc: Thierry Reding <treding@nvidia.com>
Cc: Brian Masney <masneyb@onstation.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200114231103.85641-1-swboyd@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Add the support for the msi parent domain

If the gpio's parent irqdomain is a msi irqdomain, we should ignore
the EEXIST error returned by the msi irqdomain because all the msi
interrupts have already been allocated.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://lore.kernel.org/r/20200114082821.14015-4-haokexin@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Add support for the irqdomain which doesn't use irq_fwspec as arg

Some gpio's parent irqdomain may not use the struct irq_fwspec as
argument, such as msi irqdomain. So rename the callback
populate_parent_fwspec() to populate_parent_alloc_arg() and make it
allocate and populate the specific struct which is needed by the
parent irqdomain.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Link: https://lore.kernel.org/r/20200114082821.14015-3-haokexin@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: use gpiochip_get_desc() in gpio_ioctl()

Unduplicate the offset check by simply calling gpiochip_get_desc() and
checking its return value.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: use gpiochip_get_desc() in lineevent_create()

Unduplicate the ngpio check by simply calling gpiochip_get_desc() and
checking its return value.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: use gpiochip_get_desc() in linehandle_create()

Unduplicate the ngpio check by simply calling gpiochip_get_desc() and
checking its return value.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: convert the type of hwnum to unsigned int in gpiochip_get_desc()

gpiochip_get_desc() takes a u16 hwnum, but it turns out most users don't
respect that and usually pass an unsigned int. Since implicit casting to
a smaller type is dangerous - let's change the type of hwnum to unsigned
int in gpiochip_get_desc() and in gpiochip_request_own_desc() where the
size of hwnum is not respected either and who's a user of the former.

This is safe as we then check the hwnum against the number of lines
before proceeding in gpiochip_get_desc().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: have a single place of calling set_config()

Instead of calling the gpiochip's set_config() callback directly and
checking its existence every time - just add a new routine that performs
this check internally. Call it in gpio_set_config() and
gpiod_set_transitory(). Also call it in gpiod_set_debounce() and drop
the check for chip->set() as it's irrelevant to this config option.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: use 'unsigned int' instead of 'unsigned' in gpio_set_config()

Checkpatch complains about using 'unsigned' instead of 'unsigned int'.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpio: gpiolib: fix confusing indention

There's a confusing indention in gpiochip_add_data_with_key(), which
could be misinterpreted on a quick walkthrough. Fixing this in order
to improve code readability a bit.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: add gpiod_toggle_active_low()

Add possibility to toggle active-low flag of a gpio descriptor. This is
useful for compatibility code, where defaults are inverted vs DT gpio
flags or the active-low flag is taken from elsewhere.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/7ce0338e01ad17fa5a227176813941b41a7c35c1.1576031637.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

gpiolib: Make use of assign_bit() API

We have for some time the assign_bit() API to replace open coded

if (foo)
set_bit(n, bar);
else
clear_bit(n, bar);

Use this API in GPIO library code.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191204194229.64251-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Add GPIOCHIP_NAME definition

The string literal "gpiochip" is used in several places.
Add a definition for it, and use it everywhere, to make sure everything
stays in sync.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191127084253.16356-2-geert+renesas@glider.be
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: fix up emulated open drain outputs

gpiolib has a corner case with open drain outputs that are emulated.
When such outputs are outputting a logic 1, emulation will set the
hardware to input mode, which will cause gpiod_get_direction() to
report that it is in input mode. This is different from the behaviour
with a true open-drain output.

Unify the semantics here.

Cc: <stable@vger.kernel.org>
Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Fix error message on out-of-range GPIO in lookup table

When a GPIO offset in a lookup table is out-of-range, the printed error
message (1) does not include the actual out-of-range value, and (2)
contains an off-by-one error in the upper bound.

Avoid user confusion by also printing the actual GPIO offset, and
correcting the upper bound of the range.
While at it, use "%u" for unsigned int.

Sample impact:

-requested GPIO 0 is out of range [0..32] for chip e6052000.gpio
+requested GPIO 0 (45) is out of range [0..31] for chip e6052000.gpio

Fixes: 2a3cf6a3599e9015 ("gpiolib: return -ENOENT if no GPIO mapping exists")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191127095919.4214-1-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Grammar s/manager/managed/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191120143745.1254-1-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: fix coding style in gpiod_hog()

There should be spaces between logical operators and their operands.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Introduce ->add_pin_ranges() callback

When IRQ chip is being added by GPIO library, the ACPI based platform expects
GPIO <-> pin mapping ranges to be initialized in order to correctly initialize
ACPI event mechanism on affected platforms. Unfortunately this step is missed.

Introduce ->add_pin_ranges() callback to fill the above mentioned gap.

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>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>

gpio: add new SET_CONFIG ioctl() to gpio chardev

Add the GPIOHANDLE_SET_CONFIG_IOCTL to the gpio chardev.
The ioctl allows some of the configuration of a requested handle to be
changed without having to release the line.
The primary use case is the changing of direction for bi-directional
lines.

Based on initial work by Bartosz Golaszewski <bgolaszewski@baylibre.com>

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: move validation of line handle flags into helper function

Move validation of line handle flags into helper function.
This reduces the size and complexity of linehandle_create and allows the
validation to be reused elsewhere.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: add support for biasing output lines

Allow pull up/down bias to be set on output lines.
Use case is for open source or open drain applications where
internal pull up/down may conflict with external biasing.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: add support for disabling line bias

Allow pull up/down bias to be disabled, allowing the line to float
or to be biased only by external circuitry.
Use case is for where the bias has been applied previously, either
by default or by the user, but that setting may conflict with the
current use of the line.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: add support for pull up/down to lineevent_create

Add support for pull up/down to lineevent_create.
Use cases include receiving asynchronous presses from a
push button without an external pull up/down.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: expose pull-up/pull-down line flags to userspace

Add pull-up/pull-down flags to the gpio line get and
set ioctl() calls. Use cases include a push button
that does not have an external resistor.

Addition use cases described by Limor Fried (ladyada) of
Adafruit in this PR for Adafruit_Blinka Python lib:
https://github.com/adafruit/Adafruit_Blinka/pull/59

Signed-off-by: Drew Fustini <drew@pdp7.com>
[Kent: added BIAS to GPIO flag names and restrict application to input
lines]
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Revert "gpio: expose pull-up/pull-down line flags to userspace"

This reverts commit 8c550e94b8835170593169a45b5ba30d3fc72a70.

This was prematurely applied and we need to back it out to merge
a better version of the development track for this feature.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: No need to call gpiochip_remove_pin_ranges() twice

of_gpiochip_add(), when fails, calls gpiochip_remove_pin_ranges().

ADD:
gpiochip_add_data_with_key() ->
of_gpiochip_add() -> (ERROR path)
gpiochip_remove_pin_ranges()

At the same time of_gpiochip_remove() calls exactly the above mentioned
function unconditionally and so does gpiochip_remove().

REMOVE:
gpiochip_remove() ->
gpiochip_remove_pin_ranges()
of_gpiochip_remove() ->
gpiochip_remove_pin_ranges()

Since gpiochip_remove() calls gpiochip_remove_pin_ranges() unconditionally,
we have duplicate call to the same function when it's not necessary.

Move gpiochip_remove_pin_ranges() from of_gpiochip_add() to gpiochip_add()
to avoid duplicate calls and be consistent with the explicit call in
gpiochip_remove().

Fixes: e93fa3f24353 ("gpiolib: remove duplicate pin range code")
Depends-on: f7299d441a4d ("gpio: of: Fix of_gpiochip_add() error path")
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Switch order of valid mask and hw init

The GPIO irqchip needs to initialize the valid mask
before initializing the IRQ hardware, because sometimes
the latter require the former to be executed first.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191030122914.967-1-linus.walleij@linaro.org
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Initialize the hardware with a callback

After changing the drivers to use GPIO core to add an IRQ chip
it appears that some of them requires a hardware initialization
before adding the IRQ chip.

Add an optional callback ->init_hw() to allow that drivers
to initialize hardware if needed.

This change is a part of the fix NULL pointer dereference
brought to the several drivers recently.

Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: expose pull-up/pull-down line flags to userspace

Add pull-up/pull-down flags to the gpio line get and
set ioctl() calls. Use cases include a push button
that does not have an external resistor.

Addition use cases described by Limor Fried (ladyada) of
Adafruit in this PR for Adafruit_Blinka Python lib:
https://github.com/adafruit/Adafruit_Blinka/pull/59

Signed-off-by: Drew Fustini <drew@pdp7.com>
Link: https://lore.kernel.org/r/20190921102522.8970-1-drew@pdp7.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: introduce fwnode_gpiod_get_index()

This introduces fwnode_gpiod_get_index() that iterates through common gpio
suffixes when trying to locate a GPIO within a given firmware node.

We also switch devm_fwnode_gpiod_get_index() to call
fwnode_gpiod_get_index() instead of iterating through GPIO suffixes on
its own.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20190913032240.50333-3-dmitry.torokhov@gmail.com
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: sanitize flags before allocating memory in lineevent_create()

Move all the flags sanitization before any memory allocation in
lineevent_create() in order to remove a couple unneeded gotos.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpiolib: don't clear FLAG_IS_OUT when emulating open-drain/open-source

When emulating open-drain/open-source by not actively driving the output
lines - we're simply changing their mode to input. This is wrong as it
will then make it impossible to change the value of such line - it's now
considered to actually be in input mode. If we want to still use the
direction_input() callback for simplicity then we need to set FLAG_IS_OUT
manually in gpiod_direction_output() and not clear it in
gpio_set_open_drain_value_commit() and
gpio_set_open_source_value_commit().

Fixes: c663e5f56737 ("gpio: support native single-ended hardware drivers")
Cc: stable@vger.kernel.org
Reported-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: remove explicit comparison with 0

No need to compare return value with 0. In case of non-zero
return value, the if condition will be true.

This makes intent a bit more clear to the reader.
"if (x) then", compared to "if (x is not zero) then".

Signed-off-by: Saiyam Doshi <saiyamdoshi.in@gmail.com>
Link: https://lore.kernel.org/r/20190907173910.GA9547@SD
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Initialize the irqchip valid_mask with a callback

After changing the valid_mask for the struct gpio_chip
to detect the need and presence of a valid mask with the
presence of a .init_valid_mask() callback to fill it in,
we augment the gpio_irq_chip to use the same logic.

Switch all driver using the gpio_irq_chio valid_mask
over to this new method.

This makes sure the valid_mask for the gpio_irq_chip gets
filled in when we add the gpio_chip, which makes it a
little easier to switch over drivers using the old
way of setting up gpio_irq_chip over to the new method
of passing the gpio_irq_chip along with the gpio_chip.
(See drivers/gpio/TODO for details.)

Cc: Joel Stanley <joel@jms.id.au>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Link: https://lore.kernel.org/r/20190904140104.32426-1-linus.walleij@linaro.org

gpio: fix line flag validation in lineevent_create

lineevent_create should not allow any of GPIOHANDLE_REQUEST_OUTPUT,
GPIOHANDLE_REQUEST_OPEN_DRAIN or GPIOHANDLE_REQUEST_OPEN_SOURCE to be set.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: fix line flag validation in linehandle_create

linehandle_create should not allow both GPIOHANDLE_REQUEST_INPUT
and GPIOHANDLE_REQUEST_OUTPUT to be set.

Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Fix further merge errors

The previous merge of v5.3-rc7 was struggle enough, now it
gave rise to new errors and now I fix those too.

Fixes: 151a41014bff ("Merge tag 'v5.3-rc7' into devel")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: gpiolib: Normalize return code variable name

It is confusing to name return variables mixedly "status",
"err" or "ret". I just changed them all to "ret", by personal
preference, to lower cognitive stress.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190716091145.8235-1-linus.walleij@linaro.org

pinctrl/gpio: Take MUX usage into account

The user space like gpioinfo only see the GPIO usage but not the
MUX usage (e.g. I2C or SPI usage) of a pin. As a user we want
to know which pin is free/safe to use. So take the MUX usage of
strict pinmux controllers into account to get a more realistic
view for ioctl GPIO_GET_LINEINFO_IOCTL.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
Link: https://lore.kernel.org/r/20190814110035.13451-1-ramon.fried@linux.intel.com
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Fix irqchip initialization order

The new API for registering a gpio_irq_chip along with a
gpio_chip has a different semantic ordering than the old
API which added the irqchip explicitly after registering
the gpio_chip.

Move the calls to add the gpio_irq_chip *last* in the
function, so that the different hooks setting up OF and
ACPI and machine gpio_chips are called *before* we try
to register the interrupts, preserving the elder semantic
order.

This cropped up in the PL061 driver which used to work
fine with no special ACPI quirks, but started to misbehave
using the new API.

Fixes: e0d897289813 ("gpio: Implement tighter IRQ chip integration")
Cc: Thierry Reding <treding@nvidia.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: Wei Xu <xuwei5@hisilicon.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190820080527.11796-1-linus.walleij@linaro.org

gpio: Use callback presence to determine need of valid_mask

After we switched the two drivers that have .need_valid_mask
set to use the callback for setting up the .valid_mask,
we can just use the presence of the .init_valid_mask()
callback (or the OF reserved ranges, nota bene) to determine
whether to allocate the mask or not and we can drop the
.need_valid_mask field altogether.

Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Amelie Delaunay <amelie.delaunay@st.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190819093058.10863-1-linus.walleij@linaro.org

gpio: Pass mask and size with the init_valid_mask()

It is more helpful for drivers to have the affected fields
directly available when we use the callback to set up the
valid mask. Change this and switch over the only user
(MSM) to use the passed parameters. If we do this we can
also move the mask out of publicly visible struct fields.

Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190819084904.30027-1-linus.walleij@linaro.or
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Add support for hierarchical IRQ domains

Hierarchical IRQ domains can be used to stack different IRQ
controllers on top of each other.

Bring hierarchical IRQ domains into the GPIOLIB core with the
following basic idea:

Drivers that need their interrupts handled hierarchically
specify a callback to translate the child hardware IRQ and
IRQ type for each GPIO offset to a parent hardware IRQ and
parent hardware IRQ type.

Users have to pass the callback, fwnode, and parent irqdomain
before calling gpiochip_irqchip_add().

We use the new method of just filling in the struct
gpio_irq_chip before adding the gpiochip for all hierarchical
irqchips of this type.

The code path for device tree is pretty straight-forward,
while the code path for old boardfiles or anything else will
be more convoluted requireing upfront allocation of the
interrupts when adding the chip.

One specific use-case where this can be useful is if a power
management controller has top-level controls for wakeup
interrupts. In such cases, the power management controller can
be a parent to other interrupt controllers and program
additional registers when an IRQ has its wake capability
enabled or disabled.

The hierarchical irqchip helper code will only be available
when IRQ_DOMAIN_HIERARCHY is selected to GPIO chips using
this should select or depend on that symbol. When using
hierarchical IRQs, the parent interrupt controller must
also be hierarchical all the way up to the top interrupt
controller wireing directly into the CPU, so on systems
that do not have this we can get rid of all the extra
code for supporting hierarchical irqs.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Sowjanya Komatineni <skomatineni@nvidia.com>
Cc: Bitan Biswas <bbiswas@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Brian Masney <masneyb@onstation.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Brian Masney <masneyb@onstation.org>
Co-developed-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190808123242.5359-1-linus.walleij@linaro.org