[PATCH v5 00/13] notifier: add device-managed registration APIs and convert drivers

[Eliav Farber <farbere@amazon.com>]

Many drivers repeat the same boilerplate when registering notifiers with
device lifetime:

  1. Register the notifier with *_notifier_chain_register()
  2. Check for error
  3. Register a devm action to unregister on teardown
  4. Implement a per-driver static unregister callback

This series adds devm_atomic_notifier_chain_register() and
devm_blocking_notifier_chain_register() that automatically unregister
the notifier when the device is unbound, then converts 11 drivers to use
them.

Each conversion eliminates a per-driver unregister callback and the
associated devm_add_action_or_reset() call, reducing code by ~15 lines
per driver.

The implementation follows the established devres pattern used by other
device-managed kernel APIs.

Changes in v5:
- Patch 1: rename notifier_block parameter from 'n' to 'nb' to match
  the devres struct field name (Uwe Kleine-König)
- Patch 2: remove extra blank line left after deleting the unregister
  callback (Uwe Kleine-König)

Changes in v4:
- Patch 8: split the removal of unused
  ghes_register_vendor_record_notifier() and
  ghes_unregister_vendor_record_notifier() into a separate preceding
  patch (Andy Shevchenko)

Changes in v3:
- Patch 1: drop devm_raw_notifier_chain_register() since raw notifiers
  require caller-provided locking which is incompatible with the devres
  teardown callback (Sashiko)
- Patch 12: fix commit message to accurately describe the old code as
  using devres_alloc() + register_reboot_notifier() (Sashiko)

Changes in v2:
- Patch 1: drop 'extern' from new function prototypes (Bart Van Assche)
- Patch 1: fix kerneldoc to use 'Return:' format (Bart Van Assche)
- Patch 1: use <linux/device/devres.h> instead of <linux/device.h>
  (Andy Shevchenko)
- Patch 8: also remove unused ghes_register_vendor_record_notifier() and
  ghes_unregister_vendor_record_notifier() along with their exports and
  ghes.h declarations (Jonathan Cameron)

Eliav Farber (13):
  notifier: add device-managed registration APIs
  pwm: iqs620a: use devm_blocking_notifier_chain_register()
  iio: light: iqs621-als: use devm_blocking_notifier_chain_register()
  iio: position: iqs624: use devm_blocking_notifier_chain_register()
  gpio: adp5585: use devm_blocking_notifier_chain_register()
  platform/x86: bitland-mifs-wmi: use
    devm_blocking_notifier_chain_register()
  Input: adp5585: use devm_blocking_notifier_chain_register()
  ACPI: APEI: GHES: remove unused
    ghes_{,un}register_vendor_record_notifier()
  ACPI: APEI: GHES: use devm_blocking_notifier_chain_register()
  platform/x86: uniwill-wmi: use devm_blocking_notifier_chain_register()
  gpio: eic-sprd: use devm_atomic_notifier_chain_register()
  gpio: gpiolib-kunit: use devm_blocking_notifier_chain_register()
  reboot: use devm_blocking_notifier_chain_register()

 drivers/acpi/apei/ghes.c                   |  27 +-----
 drivers/gpio/gpio-adp5585.c                |  20 +---
 drivers/gpio/gpio-eic-sprd.c               |  17 +---
 drivers/gpio/gpiolib-kunit.c               |  14 +--
 drivers/iio/light/iqs621-als.c             |  24 +----
 drivers/iio/position/iqs624-pos.c          |  24 +----
 drivers/input/keyboard/adp5585-keys.c      |  18 +---
 drivers/platform/x86/bitland-mifs-wmi.c    |  17 +---
 drivers/platform/x86/uniwill/uniwill-wmi.c |  17 +---
 drivers/pwm/pwm-iqs620a.c                  |  23 +----
 include/acpi/ghes.h                        |  16 ----
 include/linux/notifier.h                   |   7 ++
 kernel/notifier.c                          | 103 +++++++++++++++++++++
 kernel/reboot.c                            |  24 +----
 14 files changed, 140 insertions(+), 211 deletions(-)

-- 
2.47.3