workqueue / drivers: Add device-managed allocate workqueue

Merging / Dependency
====================
All further patches depend on the first one, thus this probably should go via one tree, e.g. power supply. The first patch might be needed for other trees as well, e.g. if more drivers are discovered, so the best if it is on dedicated branch in case it has to be shared.

Changes in v2:
==============
- See individual patches
- Link to v1: https://patch.msgid.link/[email protected]

Description
===========
Add a Resource-managed version of alloc_workqueue() to fix common problem of drivers mixing devm() calls with destroy_workqueue. Such naive and discouraged driver approach leads to difficult to debug bugs when the driver:

1. Allocates workqueue in standard way and destroys it in driver remove() callback,
2. Sets work struct with devm_work_autocancel(),
3. Registers interrupt handler with devm_request_threaded_irq().

Which leads to following unbind/removal path:

1. destroy_workqueue() via driver remove(),
Any interrupt coming now would still execute the interrupt handler, which queues work on destroyed workqueue.
2. devm_irq_release(),
3. devm_work_drop() -> cancel_work_sync() on destroyed workqueue.

devm_alloc_workqueue() has two benefits:
1. Solves above problem of mix-and-match devres and non-devres code in driver,
2. Simplify any sane drivers which were correctly using alloc_workqueue() + devm_add_action_or_reset().

Best regards,
Krzysztof

---
Krzysztof Kozlowski (10):
workqueue: devres: Add device-managed allocate workqueue
power: supply: cw2015: Free allocated workqueue
power: supply: max77705: Drop duplicated IRQ error message
power: supply: max77705: Free allocated workqueue and fix removal order
power: supply: mt6370: Simplify with devm_alloc_ordered_workqueue()
power: supply: ipaq_micro: Simplify with devm
mfd: ezx-pcap: Drop memory allocation error message
mfd: ezx-pcap: Return directly instead of empty gotos
mfd: ezx-pcap: Avoid rescheduling after destroying workqueue platform/chrome: cros_usbpd_logger: Simplify with devm

 Documentation/driver-api/driver-model/devres.rst |  4 ++
 drivers/mfd/ezx-pcap.c                           | 27 +++++--------
 drivers/platform/chrome/cros_usbpd_logger.c      | 18 ++++-----
 drivers/power/supply/cw2015_battery.c            |  3 +-
 drivers/power/supply/ipaq_micro_battery.c        | 50 ++++++++----------------
 drivers/power/supply/max77705_charger.c          | 36 ++++++-----------
 drivers/power/supply/mt6370-charger.c            | 13 +-----
 include/linux/workqueue.h                        | 22 +++++++++++
 kernel/workqueue.c                               | 28 +++++++++++++
 9 files changed, 100 insertions(+), 101 deletions(-)

---
base-commit: 9739e59909e70058fab7a131d7bee60d447ab732
change-id: 20260220-workqueue-devm-d9591e5e70eb

Best regards,

Krzysztof Kozlowski <[email protected]>