Re: [PATCH v3 1/3] media: dt-bindings: rockchip,vdec: Add alternative reg-names order for RK35{76,88}

[Krzysztof Kozlowski <krzk@kernel.org>]

On 26/02/2026 08:25, Krzysztof Kozlowski wrote:
> On Thu, Feb 26, 2026 at 12:26:37AM +0200, Cristian Ciocaltea wrote:
>>>> Sorry, but I don't quite get why would this be a better approach than just
>>>> properly list the items according to the HW layout, i.e. following the
>>>> address-based ordering?
>>>
>>> We always expect the list to grow, to have common set. That's rule given
>>> during reviews multiple times. For multiple reasons, also explained
>>> (consistency, maintenance and actually proper description of hardware
>>> like the main reg address space).
>>>
>>> Probably this was also given to that binding during discussions when it
>>> was upstream, so your change reverts previous discussion and to that I
>>> do not agree.
>>
>> Thank you for detailing this, I get your point now.
>>
>> After digging a bit further, it looks like the "function" naming has been
>> introduced as part of the RK3588 support via commit c6ffb7e1fb90 ("media:
>> dt-bindings: rockchip: Document RK3588 Video Decoder bindings").
>>
>> Morever, it also sets `reg-names: false` for all the SoCs other than RK3588 -
>> sorry for missing this initially.
>>
>> Hence "function" wasn't used at all in the context of the older SoCs, while on
>> RK3588 & RK3576 there is no indication that "function" should be treated as the
>> main address space or anything like that.  E.g. RK3588 TRM clearly shows the
>> "link" range at the top of the listing, starting at video decoder unit base
>> address:
>>
>> --------------------------------------------------------------------------------
>> Config Register                         |   Base addr
>> --------------------------------------------------------------------------------
>> VDPU381 core0/1 link table config base  |   VDPU381_core0/1_base+0x000
>> VDPU381 core0/1 function config base    |   VDPU381_core0/1_base+0x100
>> --------------------------------------------------------------------------------
>>                                         |   VDPU381_core0/1_base+0x600 for Y channel
>> VDPU381 core0/1 cache config base       |   VDPU381_core0/1_base+0x640 for C channel
>>                                         |   VDPU381_core0/1_base+0x680 for head channel
>> --------------------------------------------------------------------------------
>>
>> Assuming the reasoning above is now good enough to move further with the
>> proposed approach, I can prepare a new revision dropping the unnecessary
>> one-entry item from the reg-names, while keeping all the rest in the series as
>> is.
> 
> Yes, with drop of the oneOf this would be fine.

I meant, the "one item option" in oneOf.

Best regards,
Krzysztof