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: Documentation/devicetree/bindings/thermal/thermal.txt
16  min and max states are derived from the speed-map of the fan.
17
18Note: At least one the "gpios" or "alarm-gpios" properties must be set.
19
20Examples:
21
22	gpio_fan {
23		compatible = "gpio-fan";
24		gpios = <&gpio1 14 1
25			 &gpio1 13 1>;
26		gpio-fan,speed-map = <0    0
27				      3000 1
28				      6000 2>;
29		alarm-gpios = <&gpio1 15 1>;
30	};
31	gpio_fan_cool: gpio_fan {
32		compatible = "gpio-fan";
33		gpios = <&gpio2 14 1
34			 &gpio2 13 1>;
35		gpio-fan,speed-map =	<0    0>,
36					<3000 1>,
37					<6000 2>;
38		alarm-gpios = <&gpio2 15 1>;
39		#cooling-cells = <2>; /* min followed by max */
40	};
41