sch_irq_unmask() enables the GPIO IRQ and then updates the controller
state through sch_irq_mask_unmask(), which takes sch->lock with
spin_lock_irqsave().  The callback can be reached from irq_startup()
while setting up a requested IRQ.  That path is not sleepable, but on
PREEMPT_RT a regular spinlock_t becomes a sleeping lock.

This issue was found by our static analysis tool and then manually
reviewed against the current tree.

The grounded PoC kept the request_threaded_irq() -> __setup_irq() ->
irq_startup() -> sch_irq_unmask() -> sch_irq_mask_unmask() carrier and
used the original spin_lock_irqsave(&sch->lock) edge.  Lockdep reported:

  BUG: sleeping function called from invalid context
  hardirqs last disabled at ... __setup_irq.constprop.0 ... [vuln_msv]
  sch_rt_spin_lock_irqsave+0x1c/0x30 [vuln_msv]
  sch_irq_mask_unmask.constprop.0+0x31/0x70 [vuln_msv]
  __setup_irq.constprop.0+0xd/0x30 [vuln_msv]

Convert the SCH controller lock to raw_spinlock_t.  The same lock is
also used by the GPIO direction and value callbacks, but those critical
sections only update MMIO-backed GPIO registers and do not contain
sleepable operations.  Keeping this register lock non-sleeping is
therefore appropriate for the irqchip callbacks and does not change the
GPIO-side locking contract.

Fixes: 7a81638485c1 ("gpio: sch: Add edge event support")
Cc: stable@vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Link: https://patch.msgid.link/20260617154035.1199948-2-runyu.xiao@seu.edu.cn
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

The conversion of all GPIO drivers to using the .set_rv() and
.set_multiple_rv() callbacks from struct gpio_chip (which - unlike their
predecessors - return an integer and allow the controller drivers to
indicate failures to users) is now complete and the legacy ones have
been removed. Rename the new callbacks back to their original names in
one sweeping change.

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

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250625-gpiochip-set-rv-gpio-round2-v1-3-bc110a3b52ff@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

We have a temporary variable to keep a pointer to struct device.
Utilise it where it makes sense.

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

Convert driver to use memory mapped IO accessors.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: William Breathitt Gray <wbg@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

This function call was found to be unnecessary as there is no equivalent
platform_get_drvdata() call to access the private data of the driver. Also,
the private data is defined in this driver, so there is no risk of it being
accessed outside of this driver file.

Reviewed-by: Alexandru Ardelean <alex@shruggie.ro>
Signed-off-by: Andrei Coardos <aboutphysycs@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Since recently, the kernel is nagging about mutable irq_chips:

   "not an immutable chip, please consider fixing it!"

Drop the unneeded copy, flag it as IRQCHIP_IMMUTABLE, add the new
helper functions and call the appropriate gpiolib functions.

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

The double `the' in the comment in line 142 is repeated. Remove one
of them from the comment.

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

Wherever possible, replace constructs that match either
generic_handle_irq(irq_find_mapping()) or
generic_handle_irq(irq_linear_revmap()) to a single call to
generic_handle_domain_irq().

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Neither the ACPI description on Intel Minnowboard (v1) platform provides
the required information to establish a generic handling nor the hardware
capable of doing it. According to the data sheet the hardware can generate
SCI events. Therefore, we need to hook from the driver into GPE handler of
the ACPI subsystem in order to catch and report GPIO-related events.

Validated on the Inlel Minnowboard (v1) platform and Intel Galileo Gen 2.

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