Re: [PATCH v2 1/3] dt-bindings: gpu: img,powervr-rogue: Document GX6250 GPU in Renesas R-Car M3-W/M3-W+

[Marek Vasut <marek.vasut@mailbox.org>]

On 10/16/25 10:48 AM, Matt Coster wrote:

Hello Matt,

>>> Would you mind splitting this conditional block up? We already have a
>>> constraint for 2 power-domains (see img,img-bxs-4-64), which should be
>>> applied to the entire img,img-gx6250 compatible.
>>
>> I will add a patch into V3 which splits the allOf section up such,
>> that clocks and power-domains limits are limited separately. That will
>> make this addition of GX6250 easy.
>>
>>> As for the clocks, for the currently supported GPUs, we have "mem" and
>>> "sys" clocks that are optional at integration time, so those
>>> conditionals are based on the vendor compatible strings (ti,... etc).
>>> However, these older GPUs always require all three clocks, so it
>>> probably makes sense to create the properties:clock{,-name}s:minItems:3
>>> constraint on the img,img-gx6250 compatible as well, rather than the
>>> renesas,r8... ones.
>>
>> OK
>>
>>> You shouldn't need to explicit list the power-domain descriptions at the
>>> constraint level at all; if there's a build warning that they're missing
>>> I guess the correct place to add them would be on the top-level
>>> power-domains entry, but I don't really think they contribute anything
>>> meaningful.
>> The descriptions basically emulate minItems/maxItems: 2 here. I can
>> also just set minItems:2 ?
> 
> I think that's probably much cleaner! We can add maxItems:2 back in
> later if/when we add additional power domains at the top level.

OK, will do.

>> I have one more question -- does GX6250 _always_ have two power
>> domains, i.e. the constrains always set minItems:2 for
>> "img,img-gx6250" "power-domains" property ?
> 
> Yes, that's correct. All PowerVR GPUs have the number of power domains
> defined in the IP. Even where the SoC does not expose control of these
> to the OS, the GPU still communicates with the SoC power controller
> directly to gate them on and off during normal operation.
Understood, thank you for the clarification.