[PATCH v4 0/2] hwmon: emc2305: Support configurable fan PWM at shutdown

[florin.leotescu at oss.nxp.com]

From: Florin Leotescu <florin.leotescu at nxp.com>

This series adds support for configuring the fan PWM duty cycle applied
during system shutdown for the EMC2305 fan controller.

Some platforms require fans to transition to a predefined safe state
during shutdown or reboot handoff until firmware or the next boot stage
reconfigures the controller.

The new optional Device Tree property "fan-shutdown-percent" allows the
shutdown PWM duty cycle to be configured per fan output.

Changes in v4:
- Initialize pwm_shudown array to EMC2305_PWM_SHUTDOWN_UNSET in probe,
  to avoid treating unconfigured channels as valid and written 0
  during shutdown
Changes in v3:
- Rebased on current upstream
- Dropped already upstreamed of_node_put(child) fix
Changes in v2:
- Address feedback from Guenter Roeck
- Make shutdown behavior configurable via Device Tree
- Add optional fan-shutdown-percent property
- Apply shutdown PWM only for channels defining the property

Florin Leotescu (2):
  dt-bindings: hwmon: emc2305: Add fan-shutdown-percent property
  hwmon: emc2305: Support configurable fan PWM at shutdown

 .../bindings/hwmon/microchip,emc2305.yaml     |  8 +++++
 drivers/hwmon/emc2305.c                       | 35 +++++++++++++++++++
 2 files changed, 43 insertions(+)

-- 
2.34.1