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

From: Guenter Roeck

Date: Fri Mar 20 2026 - 16:06:19 EST


On 3/20/26 08:29, 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.


Sashiko stil finds some problems. Please check.

https://sashiko.dev/#/patchset/20260320152959.1575978-1-florin.leotescu%40oss.nxp.com

Thanks,
Guenter

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(+)