Re: [RFC PATCH] dt-bindings: can: convert tcan4x5x.txt to DT schema

From: Krzysztof Kozlowski
Date: Mon Nov 04 2024 - 05:41:02 EST


On 04/11/2024 11:31, Marc Kleine-Budde wrote:
> On 04.11.2024 10:27:04, Krzysztof Kozlowski wrote:
>>> +properties:
>>> + compatible:
>>> + oneOf:
>>> + - enum:
>>> + - ti,tcan4552
>>> + - ti,tcan4553
>>> + - ti,tcan4x5x
>>
>> That's not really what old binding said.
>>
>> It said for example:
>> "ti,tcan4552", "ti,tcan4x5x"
>>
>> Which is not allowed above. You need list. Considering there are no
>> in-tree users of ti,tcan4x5x alone, I would allow only lists followed by
>> ti,tcan4x5x. IOW: disallow ti,tcan4x5x alone.
>
> I'd like to keep the old binding.

Any reason why? It's against of bindings policies. If this was a new
binding, it would be a clear NAK, so here due to lack of user we can
make it correct.

>
>> Mention this change to the binding in the commit message.
>
> The tcan4x5x chip family has 2 registers for automatic detection of the
> chip variant. While the ID2 register of the tcan4550 is 0x0, the
> registers for the tcan4552 and tcan4553 contain 4552 and 4553
> respectively in ASCII.

This does not grant exception for wildcards. This only says that one
model should be used as fallback.

>
> The driver was originally added for the tcan4550 chip, but currently
> only has a compatible for "ti,tcan4x5x".

That's not really related to discussion. We do not talk about changing
driver.

Best regards,
Krzysztof