[PATCH v4 00/10] gpio: mxc: bug fixes and probe cleanup

[Peng Fan (OSS)]

This series cleans up the gpio-mxc driver in several incremental steps:
bug fixes, converting runtime state to static per-compatible data,
modernizing resource management with devres, and cleaning up
register access patterns.

Patches 1-2 are bug fixes:
  - Fix a race where the chained IRQ handler is installed before probe
    completes, allowing interrupts to fire on a half-initialized port.
  - Fix wakeup_pads bit operations that used wrong set_bit/clear_bit
    logic, folding in the assign_bit() simplification from V1.

Patches 3-4 replace runtime of_device_is_compatible() calls with static
per-compatible hwdata flags, eliminating repeated string comparisons in
the suspend/resume path.

Patches 5-6 convert probe error handling to devres and dev_err_probe().

Patches 7-9 are cosmetic cleanups: local dev variable, MXC_ICR macros
with field_prep/field_get, and BIT() macro for single-bit shifts.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
Changes in v4:
- Just a resend of V3 with below changes.
  Add R-b from Linus for patch 10.
  Update commit for patch 2 and drop empty line and separate
  for_each_set_bit changes into a new patch Per Andy.
- Link to v3: https://lore.kernel.org/all/20261006-gpio-mxc-cleanup-v3-0-129f93302a90@xxxxxxx/

Changes in v3:
- Patch ("gpio: mxc: convert probe error handling to devres"):
  Replaced pm_runtime_get_noresume() with
  devm_pm_runtime_get_noresume() to fix a PM usage counter leak on
  probe error paths. The non-devm pm_runtime_get_noresume() was not
  balanced by any devres action, so any probe failure after the PM
  block (e.g. -EPROBE_DEFER from devm_gpiochip_add_data()) would
  leave usage_count permanently elevated, preventing runtime suspend
  on re-probe.
  Dropped the explicit pm_runtime_put_noidle() on
  devm_pm_runtime_set_active_enabled() failure - the devres
  registered by devm_pm_runtime_get_noresume() handles the balance
  automatically during probe unwind.
- Patch ("gpio: mxc: use local dev variable"):
  Keep of_device_is_compatible(), only focus on switching &pdev->dev to
  dev.
- Link to v2: https://patch.msgid.link/20261005-gpio-mxc-cleanup-v2-0-bdc3afbb35e2@xxxxxxx

Changes in V2:
- Reworked compatible-string caching (V1 patch 3) from probe-time bools
  in mxc_gpio_port to static hwdata flags with per-compatible data
  instances.  Split into two patches: one introducing the flags scheme
  with MXC_GPIO_HW_DATA_COMMON macro for power_off (patch 3), one
  extending it to pad_wakeup and imx8qm (patch 4).  (Frank, bot review)
- Replaced devm_pm_runtime_get_noresume() + pm_runtime_set_active() +
  devm_pm_runtime_enable() with devm_pm_runtime_set_active_enabled().
  Keep plain pm_runtime_get_noresume() (non-devm) for the probe-scoped
  reference to avoid usage_count underflow on unbind.  (Frank, bot review)
- Replaced irq_domain_create_legacy() + devm_add_action_or_reset() with
  devm_irq_domain_instantiate().  Squashed with the PM runtime devres
  conversion (V1 patches 4+5) into a single patch (patch 5), since the
  goto labels cannot be removed until both resources are devres-managed.
- Split dev_err_probe() conversion into its own patch (patch 6) for
  bisectability — patch 5 uses bare returns with correct error values.
- Folded gpio_set_wake_irq() assign_bit simplification (V1 patch 9) into
  the wakeup_pads fix (patch 2) where it belongs.
- Used 0x3U (unsigned) in MXC_ICR_MASK() to avoid implementation-defined
  behavior when shifting by 30 bits.
- Replaced linux/of.h with linux/property.h to match the
  of_device_is_compatible() → device_is_compatible() API change (patch 7).
- Added return-value checks for devm_pm_runtime_set_active_enabled().
- Fixed stale error code returns after devm_irq_alloc_descs() and
  devm_irq_domain_instantiate() in the devres conversion patch.
- Link to v1: https://patch.msgid.link/20261003-gpio-mxc-cleanup-v1-0-dad728ce27f2@xxxxxxx

---
Peng Fan (10):
      gpio: mxc: fix race between chained IRQ handler install and probe completion
      gpio: mxc: fix wakeup_pads bit operations
      gpio: mxc: use for_each_set_bit() to iterate wakeup pads
      gpio: mxc: replace of_device_is_compatible() with hwdata flags
      gpio: mxc: convert pad wakeup compatible checks to hwdata flags
      gpio: mxc: convert probe error handling to devres
      gpio: mxc: switch probe error paths to dev_err_probe()
      gpio: mxc: use local dev variable
      gpio: mxc: introduce MXC_ICR macros and use field_prep/field_get
      gpio: mxc: use BIT() macro for single-bit operations

 drivers/gpio/gpio-mxc.c | 256 +++++++++++++++++++++++++++---------------------
 1 file changed, 144 insertions(+), 112 deletions(-)
---
base-commit: f0406245cb9855e6318335a8a223551354291a46
change-id: 20261003-gpio-mxc-cleanup-e49cc626c51e

Best regards,
--  
Peng Fan <peng.fan@xxxxxxx>