Commit 09c7188b authored by Paul Barker's avatar Paul Barker Committed by Guenter Roeck
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dt-bindings: hwmon: pwm-fan: Support multiple fan tachometer inputs 



Document and give an example of how to define multiple fan tachometer
inputs for the pwm-fan driver.

Signed-off-by: default avatarPaul Barker <pbarker@konsulko.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200920180943.352526-2-pbarker@konsulko.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent bde58ca8

Documentation/devicetree/bindings/hwmon/pwm-fan.txt

+19 −9
Original line number Diff line number Diff line
@@ -8,15 +8,16 @@ Required properties: 


Optional properties:

- fan-supply		: phandle to the regulator that provides power to the fan

- interrupts		: This contains a single interrupt specifier which

			  describes the tachometer output of the fan as an

			  interrupt source. The output signal must generate a

			  defined number of interrupts per fan revolution, which

			  require that it must be self resetting edge interrupts.

			  See interrupt-controller/interrupts.txt for the format.

- pulses-per-revolution : define the tachometer pulses per fan revolution as

			  an integer (default is 2 interrupts per revolution).

			  The value must be greater than zero.

- interrupts		: This contains an interrupt specifier for each fan

			  tachometer output connected to an interrupt source.

			  The output signal must generate a defined number of

			  interrupts per fan revolution, which require that

			  it must be self resetting edge interrupts. See

			  interrupt-controller/interrupts.txt for the format.

- pulses-per-revolution : define the number of pulses per fan revolution for

			  each tachometer input as an integer (default is 2

			  interrupts per revolution). The value must be

			  greater than zero.



Example:

	fan0: pwm-fan {
@@ -55,3 +56,12 @@ Example 2: 
		interrupts = <1 IRQ_TYPE_EDGE_FALLING>;

		pulses-per-revolution = <2>;

	};



Example 3:

	fan0: pwm-fan {

		compatible = "pwm-fan";

		pwms = <&pwm1 0 25000 0>;

		interrupts-extended = <&gpio1 1 IRQ_TYPE_EDGE_FALLING>,

			<&gpio2 5 IRQ_TYPE_EDGE_FALLING>;

		pulses-per-revolution = <2>, <1>;

	};