Re: [PATCH RFC V2 1/3] dt-bindings: hwmon: Add tachometer interrupt to pwm-fan

[Rob Herring]

On Mon, Feb 25, 2019 at 04:59:17PM +0100, Stefan Wahren wrote:
> This adds the tachometer interrupt to the pwm-fan binding, which is
> necessary for RPM support.
> 
> Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
> ---
>  Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
> index 49ca5d8..7d09623 100644
> --- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
> +++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
> @@ -8,6 +8,14 @@ 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.
> +- interrupt-ratio : defines the ratio interrupts per fan revolution as an
> +		    integer (default is 2 interrupts per revolution)

Name this for what it is, not how it is used. Using 'interrupt' is 
misleading that it is related to the interrupt binding.
'tach-pulse-per-rev' or something similar.

>  
>  Example:
>  	fan0: pwm-fan {
> @@ -38,3 +46,14 @@ Example:
>  					};
>  			     };
>  		};
> +
> +Example 2:
> +	fan0: pwm-fan {
> +		fan0: pwm-fan {
> +		compatible = "pwm-fan";
> +		pwms = <&pwm 0 40000 0>;
> +		fan-supply = <&reg_fan>;
> +		interrupt-parent = <&gpio5>;
> +		interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
> +		interrupt-ratio = <2>;
> +	};
> -- 
> 2.7.4
>