[PATCH v7 2/3] dt-bindings: hwmon: emc2305: Add fan-shutdown-percent property

florin.leotescu
2026-04-29T06:45:19Z

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

The EMC2305 fan controller supports multiple independent PWM fan
outputs. Some systems require fans to enter a defined safe state
during system shutdown or reboot handoff, until firmware or the next
boot stage reconfigures the controller.

Add an optional "fan-shutdown-percent" property to fan child nodes
allowing the PWM duty cycle applied during shutdown to be configured
per fan output.

Signed-off-by: Florin Leotescu <florin.leotescu@nxp.com>
---
.../devicetree/bindings/hwmon/microchip,emc2305.yaml | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml b/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
index d3f06ebc19fa..8c2548539d7f 100644
--- a/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
+++ b/Documentation/devicetree/bindings/hwmon/microchip,emc2305.yaml
@@ -54,6 +54,12 @@ patternProperties:
The fan number used to determine the associated PWM channel.
maxItems: 1

+ fan-shutdown-percent:
+ description:
+ PWM duty cycle in percent applied to the fan during shutdown.
+ minimum: 0
+ maximum: 100
+
required:
- reg

@@ -80,12 +86,14 @@ examples:
fan@0 {
reg = <0x0>;
pwms = <&fan_controller 26000 PWM_POLARITY_INVERTED 1>;
+ fan-shutdown-percent = <100>;
#cooling-cells = <2>;
};

fan@1 {
reg = <0x1>;
pwms = <&fan_controller 26000 0 1>;
+ fan-shutdown-percent = <50>;
#cooling-cells = <2>;
};

--
2.34.1