Re: [PATCH 3/3] dt-bindings: hwmon: max31790: Add pwmout-pin-as-tach-input property

[Rob Herring <robh@kernel.org>]

On Mon, Mar 11, 2024 at 06:13:47PM +0700, Chanh Nguyen wrote:
> Add pwmout-pin-as-tach-input property.
> 
> Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
> ---
>  Documentation/devicetree/bindings/hwmon/max31790.yaml | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/max31790.yaml b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> index 5a93e6bdebda..447cac17053a 100644
> --- a/Documentation/devicetree/bindings/hwmon/max31790.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/max31790.yaml
> @@ -25,6 +25,16 @@ properties:
>    reg:
>      maxItems: 1
>  
> +  pwmout-pin-as-tach-input:
> +    description: |
> +      An array of six integers responds to six PWM channels for
> +      configuring the pwm to tach mode.
> +      When set to 0, the associated PWMOUT produces a PWM waveform for
> +      control of fan speed. When set to 1, PWMOUT becomes a TACH input
> +    $ref: /schemas/types.yaml#/definitions/uint8-array
> +    maxItems: 6
> +    minItems: 6

Seems incomplete. For example, fan tachs have different number of 
pulses per revolution, don't you need to know that too? 

There's a common fan binding now (or pending). You should use that and 
this property won't be needed.

Rob