linux/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
Lukasz Majewski 41553f267a 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 <l.majewski@samsung.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>
2015-09-17 07:48:11 +09:00

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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:
fan0: pwm-fan {
compatible = "pwm-fan";
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>;
};
};
};