When two client of the same gpio call pinctrl_select_state() for the
same functionality, we are seeing NULL pointer issue while accessing
desc->mux_owner.

Let's say two processes A, B executing in pin_request() for the same pin
and process A updates the desc->mux_usecount but not yet updated the
desc->mux_owner while process B see the desc->mux_usecount which got
updated by A path and further executes strcmp and while accessing
desc->mux_owner it crashes with NULL pointer.

Serialize the access to mux related setting with a mutex lock.

	cpu0 (process A)			cpu1(process B)

pinctrl_select_state() {		  pinctrl_select_state() {
  pin_request() {				pin_request() {
  ...
						 ....
    } else {
         desc->mux_usecount++;
    						desc->mux_usecount && strcmp(desc->mux_owner, owner)) {

         if (desc->mux_usecount > 1)
               return 0;
         desc->mux_owner = owner;

  }						}

Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Link: https://lore.kernel.org/20241014192930.1539673-1-quic_mojha@quicinc.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Splitting error messages across multiple lines makes it harder to find
them in the kernel sources.  Fix this by joining the messages.
Remove double whitespace (end of first line + begin of second line).

Fixes: 1c8e794432c2ee75 ("pinctrl: improve warning messages")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/c8e3feeedbf42a130936a5afaea0f129bcda51f6.1724938156.git.geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

struct function_desc is a particular version of the struct pinfunction
with associated opaque data. Start switching pin control core and
drivers to use it explicitly.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240530085745.1539925-7-andy.shevchenko@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add PINCTRL_FUNCTION_DESC() macro for inline use.

While at it, fix adjective form in the comment of PINCTRL_GROUP_DESC().

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240530085745.1539925-6-andy.shevchenko@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Use DEFINE_SHOW_STORE_ATTRIBUTE() helper for read-write file to reduce some
duplicated code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Message-ID: <20240404193521.3581399-1-andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

EPROBE_DEFER error returns are not really critical, since they cancel
the probe process, but the kernel will return later and retry.
However, depending on the probe order, this might issue quite some
verbatim and scary, though pointless messages:

[    2.388731] 300b000.pinctrl: pin-224 (5000000.serial) status -517
[    2.397321] 300b000.pinctrl: could not request pin 224 (PH0) from group PH0  on device 300b000.pinctrl

Replace dev_err() with dev_err_probe(), which not only drops the
priority of the message from error to debug, but also puts some text
into debugfs' devices_deferred file, for later reference.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20240305143859.2449147-1-andre.przywara@arm.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Simple type conversion with no functional change implied.
While at it, adjust indentation where it makes sense.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20231129161459.1002323-24-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

intel-pinctrl for v6.7-1

* Merge "Drop runtime PM support for Baytrail and Lynxpoint pinctrl" (Raag)
* Small improvements here and there in the Intel pin control drivers (Raag)
* Switch to RAII for locking in the Intel core and Cherry View drivers
* Enable non-ACPI enumeration in the Intel Denverton driver
* Use MODULE_DEVICE_TABLE() instead of MODULE_ALIAS() in a couple of drivers
* Introduce array_size.h and use in in the Intel pin control drivers

The following is an automated git shortlog grouped by driver:

baytrail:
 -  Replace kernel.h by what is actually being used
 -  drop runtime PM support
 -  fix debounce disable case

broxton:
 -  Replace MODULE_ALIAS() with MODULE_DEVICE_TABLE()

cherryview:
 -  reduce scope of PIN_CONFIG_BIAS_HIGH_IMPEDANCE case
 -  Convert to platform remove callback returning void
 -  Simplify code with cleanup helpers
 -  Avoid duplicated I/O
 -  Replace kernel.h by what is actually being used

denverton:
 -  Replace MODULE_ALIAS() with MODULE_DEVICE_TABLE()
 -  Enable platform device in the absence of ACPI enumeration

intel:
 -  fetch community only when we need it
 -  refine intel_config_set_pull() function
 -  Replace kernel.h by what is actually being used
 -  Simplify code with cleanup helpers

lynxpoint:
 -  Replace kernel.h by what is actually being used
 -  drop runtime PM support

merrifield:
 -  Replace kernel.h by what is actually being used

moorefield:
 -  Replace kernel.h by what is actually being used
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The kernel.h is a mess of unrelated things and we only used it
as a proxy to array_size.h, hence switch from former to the latter.

While at it, group and sort the headers where it makes sense.

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

Detailed error message is already printed at the end of the function, so
drop redundant one a few lines earlier.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230909063613.2867-2-jernej.skrabec@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>