Re: [PATCH v6 1/2] dt-bindings: gpio: add gpio-line-mux controller

[Jonas Jelonek <jelonek.jonas@gmail.com>]

Hi Rob,

On 11.11.25 13:57, Rob Herring wrote:
> On Tue, Nov 11, 2025 at 09:27:03AM +0000, Jonas Jelonek wrote:
>> +    maxItems: 1
>> +    description:
>> +      Phandle to the multiplexer to control access to the GPIOs.
>> +
>> +  ngpios: false
> No need for this.
(...)
>> +        gpio-line-names = "SFP1_LOS", "SFP1_MOD_ABS", "SFP1_TX_FAULT";
>> +        gpio-line-mux-states = <0>, <1>, <3>;
> gpio-line-names is defined to have an entry for all lines. So 
> gpio-line-mux-states is not necessary. You can just do:
>
> gpio-line-names = "SFP1_LOS", "SFP1_MOD_ABS", "", "SFP1_TX_FAULT";

Not sure if I'm getting this wrong, but this ties the GPIO line index to the
multiplexer state. Is that still the correct way if my multiplexer needs
states '15', '17, '18'? Then I would need something like this:

gpio-line-names = "", "", "", "", "", "", "", "", "", "", "", "", "", "", "A", "", "B", "C"; 

And it would cause the virtual GPIO controller to provide more GPIO lines than
desired/expected/needed.

> Rob

Best,
Jonas