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Bindings for fan connected to GPIO lines
Required properties:
- compatible : "gpio-fan"
Optional properties:
- gpios: Specifies the pins that map to bits in the control value,
ordered MSB-->LSB.
- gpio-fan,speed-map: A mapping of possible fan RPM speeds and the
control value that should be set to achieve them. This array
must have the RPM values in ascending order.
- alarm-gpios: This pin going active indicates something is wrong with
the fan, and a udev event will be fired.
- #cooling-cells: If used as a cooling device, must be <2>
Also see:
Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml
min and max states are derived from the speed-map of the fan.
Note: At least one the "gpios" or "alarm-gpios" properties must be set.
Examples:
gpio_fan {
compatible = "gpio-fan";
gpios = <&gpio1 14 1
&gpio1 13 1>;
gpio-fan,speed-map = <0 0
3000 1
6000 2>;
alarm-gpios = <&gpio1 15 1>;
};
gpio_fan_cool: gpio_fan {
compatible = "gpio-fan";
gpios = <&gpio2 14 1
&gpio2 13 1>;
gpio-fan,speed-map = <0 0>,
<3000 1>,
<6000 2>;
alarm-gpios = <&gpio2 15 1>;
#cooling-cells = <2>; /* min followed by max */
};
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