Re: [RFC PATCH v3 0/2] hwmon: emc2305: Support configurable fan PWM at shutdown

From: Guenter Roeck

Date: Tue Mar 17 2026 - 12:23:55 EST


On 3/12/26 07:43, florin.leotescu@xxxxxxxxxxx wrote:
From: Florin Leotescu <florin.leotescu@xxxxxxx>

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 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 | 34 +++++++++++++++++++
2 files changed, 42 insertions(+)

AI review of series is here:

https://sashiko.dev/#/patchset/20260312144325.1311314-1-florin.leotescu%40oss.nxp.com

Please take a look.

Thanks,
Guenter