Re: [PATCH 1/7] dt-bindings: media: renesas,isp: Add ISP core function block

[Krzysztof Kozlowski <krzk@kernel.org>]

On 17/03/2025 12:49, Niklas Söderlund wrote:
> Hi Krzysztof,
> 
> Thanks for your feedback.
> 
> On 2025-03-17 12:31:51 +0100, Krzysztof Kozlowski wrote:
>> On Sat, Mar 15, 2025 at 04:27:02PM +0100, Niklas Söderlund wrote:
>>> diff --git a/Documentation/devicetree/bindings/media/renesas,isp.yaml b/Documentation/devicetree/bindings/media/renesas,isp.yaml
>>> index c4de4555b753..de9bc739e084 100644
>>> --- a/Documentation/devicetree/bindings/media/renesas,isp.yaml
>>> +++ b/Documentation/devicetree/bindings/media/renesas,isp.yaml
>>> @@ -25,19 +25,54 @@ properties:
>>>            - renesas,r8a779h0-isp # V4M
>>>        - const: renesas,rcar-gen4-isp # Generic R-Car Gen4
>>>    reg:
>>> -    maxItems: 1
>>> +    minItems: 1
>>> +    maxItems: 2
>>> +
>>> +  reg-names:
>>> +    minItems: 1
>>> +    items:
>>> +      - const: cs
>>> +      - const: core
>>
>> All of this and further must be restricted per compatible. Otherwise
>> commit msg should explain why one SoC can have it different on different
>> boards.
> 
> I will expand the commit message. In short this can't be restricted per 
> compatible, different instances of the IP on the same board can and can 
> not have a core part.

s/Same board/same SoC/? Or you really meant that same SoC on different
boards will have or have not that ISP core?

Both are odd, first even weirder.

I wonder if some other difference is not the documented. E.g. same IP
blocks are not exactly the same, but have different programming model.

What is this ISP core responsible for inside Renesas ISP? How many ISPs
are inside of SoC?

And how would it work? You have two exactly the same IP blocks in the
SoC, but one you program differently than other. How do you know which one?

Best regards,
Krzysztof