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Documentation / devicetree / bindings / gpio / gpio-fan.txt


Based on kernel version 4.13.3. Page generated on 2017-09-23 13:55 EST.

1	Bindings for fan connected to GPIO lines
2	
3	Required properties:
4	- compatible : "gpio-fan"
5	
6	Optional 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	
18	Note: At least one the "gpios" or "alarm-gpios" properties must be set.
19	
20	Examples:
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		};
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