dt-bindings: hwmon: (pwm-fan) Add tachometer interrupt

This adds the tachometer interrupt to the pwm-fan binding, which is
necessary for RPM support.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
index 49ca5d83ed138c1e90b448e03d62581506965952..6ced829b0e588532a397f80b732a5abe938fd0a8 100644 (file)
--- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
+++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
@@ -7,7 +7,16 @@ Required properties:
                        which correspond to thermal cooling states
 
 Optional properties:
-- fan-supply    : phandle to the regulator that provides power to the fan
+- 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.
 
 Example:
        fan0: pwm-fan {
@@ -38,3 +47,13 @@ Example:
                                        };
                             };
                };
+
+Example 2:
+       fan0: pwm-fan {
+               compatible = "pwm-fan";
+               pwms = <&pwm 0 40000 0>;
+               fan-supply = <&reg_fan>;
+               interrupt-parent = <&gpio5>;
+               interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
+               pulses-per-revolution = <2>;
+       };