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Diffstat (limited to 'Documentation/devicetree/bindings/hwmon/gpio-fan.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/hwmon/gpio-fan.txt | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/hwmon/gpio-fan.txt b/Documentation/devicetree/bindings/hwmon/gpio-fan.txt new file mode 100644 index 000000000..f4cfa350f --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/gpio-fan.txt @@ -0,0 +1,41 @@ +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 */ + }; |