stable inclusion
from stable-v5.10.111
commit 7e88a50704b0c49ad3f2d11e8b963341cf68a89f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5GL1Z

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7e88a50704b0c49ad3f2d11e8b963341cf68a89f

--------------------------------

commit 5467801f upstream.

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: NShreeya Patel <shreeya.patel@collabora.com>
Cc: stable@vger.kernel.org
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

stable inclusion
from stable-v5.10.110
commit 8fb7af1b5a8350ad1052051f8c9fe88a22f3064e
bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8fb7af1b5a8350ad1052051f8c9fe88a22f3064e

--------------------------------

[ Upstream commit 56e337f2 ]

This reverts commit fc328a7d.

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: NBartosz Golaszewski <brgl@bgdev.pl>
Reported-and-bisected-by: NGuenter Roeck <linux@roeck-us.net>
Reported-by: NMichael Walle <michael@walle.cc>
Cc: Thorsten Leemhuis <linux@leemhuis.info>
Cc: Marcelo Roberto Jimenez <marcelo.jimenez@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-v5.10.110
commit a4f4ce3deedb52cd01942a684b0aa30d3b78e890
bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a4f4ce3deedb52cd01942a684b0aa30d3b78e890

--------------------------------

[ Upstream commit fc328a7d ]

Some GPIO lines have stopped working after the patch
commit 2ab73c6d ("gpio: Support GPIO controllers without pin-ranges")

And this has supposedly been fixed in the following patches
commit 89ad556b ("gpio: Avoid using pin ranges with !PINCTRL")
commit 6dbbf846 ("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: NMarcelo Roberto Jimenez <marcelo.jimenez@gmail.com>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-v5.10.106
commit a0e2768fb901093eff7d4cad1603659ae38a2449
bugzilla: https://gitee.com/openeuler/kernel/issues/I573US

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a0e2768fb901093eff7d4cad1603659ae38a2449

--------------------------------

[ Upstream commit ae42f928 ]

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=209413Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NShreeya Patel <shreeya.patel@collabora.com>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-5.10.30
commit 138a6e1dc35ec5d49515547955d0f917065b7213
bugzilla: 51791

--------------------------------

commit b41ba2ec upstream.

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: 7cba1a4d ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Reported-by: NMarek Vasut <marex@denx.de>
Reported-by: NRoman Guskov <rguskov@dh-electronics.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NMarek Vasut <marex@denx.de>
Reviewed-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-5.10.26
commit b3901ceb120df061133097e46e56fa35d5902446
bugzilla: 51363

--------------------------------

[ Upstream commit 6cb59afe ]

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: 7cba1a4d ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Fixes: 2afa97e9868f ("gpiolib: Read "gpio-line-names" from a firmware node")
Reported-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-5.10.24
commit ccc942eaf570241d3c2968de8daa3b6f7f227e2f
bugzilla: 51348

--------------------------------

commit cf25ef6b upstream.

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: ff2b1359 ("gpio: make the gpiochip a real device")
Cc: stable@vger.kernel.org      # 4.6
Reviewed-by: NSaravana Kannan <saravanak@google.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
[ johan: adjust context to 5.11 ]
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

stable inclusion
from stable-5.10.15
commit 8847a756e1df06767e64717f79e19f48b6524c44
bugzilla: 48167

--------------------------------

commit c351bb64 upstream.

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: NQuanyang Wang <quanyang.wang@windriver.com>
Cc: stable@vger.kernel.org
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

stable inclusion
from stable-5.10.4
commit 2d9284c18862480bcabb331088692b51c70dad2c
bugzilla: 46903

--------------------------------

[ Upstream commit 9d552219 ]

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: a8173820 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable")
Signed-off-by: NNikita Shubin <nikita.shubin@maquefel.me>
Link: https://lore.kernel.org/r/20201210070514.13238-1-nikita.shubin@maquefel.meSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

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: 2ab73c6d ("gpio: Support GPIO controllers without pin-ranges")
Signed-off-by: NEdmond Chung <edmondchung@google.com>
Signed-off-by: NAndrew Chant <achant@google.com>
Signed-off-by: NWill McVicker <willmcvicker@google.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

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: d143493c (gpiolib: make cdev a build option)
Reported-by: NNicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NKent Gibson <warthog618@gmail.com>
Tested-by: NNicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

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

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

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: 7cba1a4d ("gpiolib: generalize devprop_gpiochip_set_names() for device properties")
Reported-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NAnders Roxell <anders.roxell@linaro.org>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>

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: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

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: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>

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: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

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

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

bitmap_full() is a shortcut to find_first_zero_bit().
Thus, no need to call it twice.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

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: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NKent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20200616093615.5167-1-warthog618@gmail.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NMichael Walle <michael@walle.cc>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200528145845.31436-2-michael@walle.ccSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Tested-by: NHans 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.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

With 'commit 461c1a7d ("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: 461c1a7d ("gpiolib: override irq_enable/disable")
Signed-off-by: NMaulik Shah <mkshah@codeaurora.org>
Tested-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/1590253873-11556-2-git-send-email-mkshah@codeaurora.orgSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200525194028.74236-1-andriy.shevchenko@linux.intel.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NEugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: NUlrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: NEugeniu Rosca <erosca@de.adit-jv.com>
Link: https://lore.kernel.org/r/20200511145257.22970-4-geert+renesas@glider.beSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: f881bab0 ("gpio: keep the GPIO line names internal")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200511101828.30046-1-geert+renesas@glider.beSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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: 51c1064e ("gpiolib: add new ioctl() for monitoring changes in line info")
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>

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: 63636d95 ("gpio: of: Add DT overlay support for GPIO hogs")
Signed-off-by: NDavid Gow <davidgow@google.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200425044655.166257-1-davidgow@google.comSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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

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: NGeert Uytterhoeven <geert@linux-m68k.org>
Fixes: d2ac2579 ("gpiolib: provide a dedicated function for setting lineinfo")
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

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: 51c1064e ("gpiolib: add new ioctl() for monitoring changes in line info")
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>

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

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

Fixes: 2ab73c6d ("gpio: Support GPIO controllers without pin-ranges")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200330090257.2332864-1-thierry.reding@gmail.comReviewed-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Tested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

gpio_set_bias() no longer uses the passed gpio_chip pointer parameter.
Remove it.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200325100439.14000-3-geert+renesas@glider.beSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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

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: NGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200324135653.6676-5-geert+renesas@glider.beSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

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

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: NThierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200319122737.3063291-2-thierry.reding@gmail.comTested-by: NVidya Sagar <vidyas@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>