linux/Documentation/devicetree/bindings/hwmon/gpio-fan.txt
Amit Kucheria cff1d293bb dt-bindings: thermal: Get rid of thermal.txt and replace references
Now that we have yaml bindings for the thermal subsystem, get rid of the
old bindings (thermal.txt).

Replace all references to thermal.txt in the Documentation with a link
to the appropriate YAML bindings using the following search and replace
pattern:
 - If the reference is specific to the thermal-sensor-cells property,
 replace with a pointer to thermal-sensor.yaml
 - If the reference is to the cooling-cells property, replace with a
 pointer to thermal-cooling-devices.yaml
 - If the reference is generic thermal bindings, replace with a
 reference to thermal*.yaml.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/e9aacd33071a00568b67e110fa3bcc4d86d3e1e4.1595245166.git.amit.kucheria@linaro.org
2020-07-21 10:40:08 +02:00

42 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-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 */
};