1Bindings for fan connected to GPIO lines 2 3Required properties: 4- compatible : "gpio-fan" 5 6Optional properties: 7- gpios: Specifies the pins that map to bits in the control value, 8 ordered MSB-->LSB. 9- gpio-fan,speed-map: A mapping of possible fan RPM speeds and the 10 control value that should be set to achieve them. This array 11 must have the RPM values in ascending order. 12- alarm-gpios: This pin going active indicates something is wrong with 13 the fan, and a udev event will be fired. 14- #cooling-cells: If used as a cooling device, must be <2> 15 Also see: 16 Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml 17 min and max states are derived from the speed-map of the fan. 18 19Note: At least one the "gpios" or "alarm-gpios" properties must be set. 20 21Examples: 22 23 gpio_fan { 24 compatible = "gpio-fan"; 25 gpios = <&gpio1 14 1 26 &gpio1 13 1>; 27 gpio-fan,speed-map = <0 0 28 3000 1 29 6000 2>; 30 alarm-gpios = <&gpio1 15 1>; 31 }; 32 gpio_fan_cool: gpio_fan { 33 compatible = "gpio-fan"; 34 gpios = <&gpio2 14 1 35 &gpio2 13 1>; 36 gpio-fan,speed-map = <0 0>, 37 <3000 1>, 38 <6000 2>; 39 alarm-gpios = <&gpio2 15 1>; 40 #cooling-cells = <2>; /* min followed by max */ 41 }; 42