linux_dsm_epyc7002/Documentation/devicetree/bindings/hwmon/gpio-fan.txt
Linus Walleij 9dfe310ed5 hwmon: (gpio-fan) Move DT bindings to the right place
This moves the GPIO fan bindings to the hwmon bindings. The GPIO
fan is a hwmon class hardware, not related to GPIO other than being
a consumer of GPIOs.

Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-10-29 18:36:03 -07:00

41 lines
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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.txt
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 */
};