Re: [PATCH v2 2/3] dt-bindings: i2c: realtek,rtl9301-i2c: extend for RTL9310 support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 22/07/2025 20:25, Jonas Jelonek wrote:
>>> Since you have a lot of expertise on that and I obviously fail to find
>>> documentation that helps me to do that properly, could you give me some hints
>>> on how that has to look? I'd really appreciate this.
>>
>> So in your if:then: block where you narrow mst-id, you add on same level
>> as properties:
>>
>> patternProperties:
>>   YOUR_REGEX: false
> 
> How I thought of narrowing that in the first place was to make mst-id required
> for RTL9310 but optional for RTL9300. In terms of describing the hardware, this
> is valid for RTL9300 too (but there's no need for the driver or anything else to
> know that).
> 
> But I don't mind if you'd rather have it only defined in the 'then' block, or
> just disallowed for RTL9300, effectively forbidding the usage for RTL9300.
> 
> Either way, it seems I'm still doing it wrong with the regex. Adding as you
> suggested:
> 
> if:
>     properties:
>         compatible:
>             contains:
>                 const: realtek,rtl9301-i2c
> then:
>     patternProperties:
>         '^i2c@([0-9]|1[0-1])$': false
> 
> breaks validation of the RTL9300 example. Probably I don't see how this
> is expected to look like in a working state.

RTL9300 has 8 controllers, so why are you disallowing them? We talk here
only about new stuff. Why would you change EXISTING behavior when adding
something new?

You need pattern matching redundant children for existing device.


Best regards,
Krzysztof