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