Re: [PATCH v2 3/3] dt-bindings: hwmon: max31790: Add maxim,pwmout-pin-as-tach-input property

[Krzysztof Kozlowski]

On 14/04/2024 06:22, Chanh Nguyen wrote:
> The max31790 supports six pins, which are dedicated PWM outputs. Any of the
> six PWM outputs can also be configured to serve as tachometer inputs,
> allowing for up to 12 tachometer fans to be monitored.
> 
> Add a new vendor-specific property, 'maxim,pwmout-pin-as-tach-input',
> to allow PWMOUT to become a TACH input.
> 
> 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.
> 
> Signed-off-by: Chanh Nguyen <chanh@xxxxxxxxxxxxxxxxxxxxxx>
> ---
> Changes in v2:
>  - Update the vendor property name to "maxim,pwmout-pin-as-tach-input"   [Rob]
>  - Update commit message                                                 [Krzysztof]

Please put binding before its user.

> ---
>  .../devicetree/bindings/hwmon/maxim,max31790.yaml     | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml
> index a561e5a3e9e4..2d4f50bc7c41 100644
> --- a/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml
> +++ b/Documentation/devicetree/bindings/hwmon/maxim,max31790.yaml
> @@ -30,6 +30,16 @@ properties:
>    resets:
>      maxItems: 1
>  
> +  maxim,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

tach-ch solves your case. You define which inputs should be used for tach.

Best regards,
Krzysztof