Re: [PATCH net-next v2 1/2] dt-bindings: net: adin: add property for link-status pin polarity

[Josua Mayer]

Am 20.04.24 um 18:10 schrieb Andrew Lunn:
>> +  adi,link-st-polarity:
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    description:
>> +      LINK_ST pin polarity.
>> +    enum:
>> +      - 0 # active high
>> +      - 1 # active low
>> +    default: 0
>> +
> How does this differ from:
>
> Documentation/devicetree/bindings/leds/common.yaml
>
> +  active-low:
> +    type: boolean
> +    description:
> +      Makes LED active low. To turn the LED ON, line needs to be
> +      set to low voltage instead of high.
>
>
> Why do we need a vendor property when there is a generic property?
It differs in tree depth and naming.
To use led binding we need to add a leds node with a led node inside,
and decide on an index for this not-an-led pin.
Sure, could be done but  maybe should be documented somewhere
as it is not intuitive.

Main reason for having a vendor-specific and non-led property
is that this pin is not a led, it is merely a signal.
The PHY can  be configured to provide via this signal either:
- link-status
- collision detection
- carrier sense
- tx packet start
- rx packet start

The purpose of the binding I propose is just polarity of this signal.
A more complete binding would also allow selection from the
above listed functions.
This kind of configuration is much more like pinctrl than led.