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: Paul Barker <pbarker@konsulko.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200920180943.352526-2-pbarker@konsulko.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Paul Barker 2020-09-20 19:09:40 +01:00 committed by Guenter Roeck
parent bde58ca86d
commit 09c7188be3

View File

@ -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>;
};