From: Lukasz Majewski Date: Sun, 16 Aug 2015 23:53:47 +0000 (+0900) Subject: dt-bindings: Documentation entry to explain how to use PWM FAN as a cooling device X-Git-Tag: firefly_0821_release~176^2~728^2~8^2~24 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=41553f267a369f24244867f5d6c8d4df254906b7;p=firefly-linux-kernel-4.4.55.git dt-bindings: Documentation entry to explain how to use PWM FAN as a cooling device Explanation of several properties, which allow PWM fan working as a cooling device, have been embraced in this commit. Signed-off-by: Lukasz Majewski Acked-by: Eduardo Valentin Acked-by: Krzysztof Kozlowski Signed-off-by: Kukjin Kim --- diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt index 610757ce4492..c6d533202d3e 100644 --- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt +++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt @@ -3,10 +3,35 @@ Bindings for a fan connected to the PWM lines Required properties: - compatible : "pwm-fan" - pwms : the PWM that is used to control the PWM fan +- cooling-levels : PWM duty cycle values in a range from 0 to 255 + which correspond to thermal cooling states Example: - pwm-fan { + fan0: pwm-fan { compatible = "pwm-fan"; - status = "okay"; + cooling-min-state = <0>; + cooling-max-state = <3>; + #cooling-cells = <2>; pwms = <&pwm 0 10000 0>; + cooling-levels = <0 102 170 230>; }; + + thermal-zones { + cpu_thermal: cpu-thermal { + thermal-sensors = <&tmu 0>; + polling-delay-passive = <0>; + polling-delay = <0>; + trips { + cpu_alert1: cpu-alert1 { + temperature = <100000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + }; + cooling-maps { + map0 { + trip = <&cpu_alert1>; + cooling-device = <&fan0 0 1>; + }; + }; + };