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 25/02/2026 13:19, Cristian Ciocaltea wrote:
> With the introduction of the RK3588 SoC, and RK3576 afterwards, the
> 'link' and 'cache' register blocks have been provided for the video
> decoder unit in addition to the existing 'function' one, which now shows
> up in between them (from address-based ordering point of view).
> 
> However, the binding does not properly describe this hardware layout, as
> the new blocks are listed after the old one.  Therefore it breaks the
> convention expecting the unit address to indicate the first register
> range.
> 
> Since the binding changes have been already released and a fix would
> bring up an ABI break, mark the current 'reg-names' listing as
> deprecated and introduce an alternative 'link,function,cache' one.
> 
> Additionally, drop the 'reg' description items as the order is not fixed
> anymore, while the information they offer is not very relevant anyway.
> 
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
> ---
>  .../devicetree/bindings/media/rockchip,vdec.yaml      | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/media/rockchip,vdec.yaml b/Documentation/devicetree/bindings/media/rockchip,vdec.yaml
> index 809fda45b3bd..3f6072e8baa5 100644
> --- a/Documentation/devicetree/bindings/media/rockchip,vdec.yaml
> +++ b/Documentation/devicetree/bindings/media/rockchip,vdec.yaml
> @@ -28,16 +28,21 @@ properties:
>  
>    reg:
>      minItems: 1
> -    items:
> -      - description: The function configuration registers base
> -      - description: The link table configuration registers base
> -      - description: The cache configuration registers base
> +    maxItems: 3
>  
>    reg-names:
> -    items:
> +    oneOf:
>        - const: function

This is confusing, I think I missed that in previous patch because it
did not leave that part or I misread the diff hunk - why do you allow
one entry?

If the first entry is function, then all others MUST built on top, thus
this:

> +          - const: link
> +          - const: function
> +          - const: cache

is not correct.

No, you don't change the orders. So again, if you have such binding,
then you just fix the unit address leaving the binding as is.


> -      - const: link
> -      - const: cache
> +      - items:
> +          - const: link
> +          - const: function
> +          - const: cache
> +      - items:
> +          - const: function
> +          - const: link
> +          - const: cache
> +        deprecated: true
> +        description: Use link,function,cache block order instead.
>  
Best regards,
Krzysztof