Re: [PATCH 1/9] dt-bindings: Add arm,mali-valhall compatible

[Robin Murphy <robin.murphy@arm.com>]

On 2022-02-11 20:27, alyssa.rosenzweig@collabora.com wrote:
> From: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
> 
>  From the kernel's perspective, pre-CSF Valhall is more or less
> compatible with Bifrost, although they differ to userspace. Add a
> compatible for Valhall to the existing Bifrost bindings documentation.
> 
> Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
> Cc: devicetree@vger.kernel.org
> ---
>   Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml b/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
> index 63a08f3f321d..48aeabd2ed68 100644
> --- a/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
> +++ b/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
> @@ -23,6 +23,7 @@ properties:
>             - rockchip,px30-mali
>             - rockchip,rk3568-mali
>         - const: arm,mali-bifrost # Mali Bifrost GPU model/revision is fully discoverable
> +      - const: arm,mali-valhall # Mali Valhall GPU model/revision is fully discoverable

This requires all existing Bifrost users to add the Valhall compatible 
as well - I don't think that's what you want. From what we tossed about 
on IRC the other week, I'd imagined something more in the shape of:

   compatible:
     oneOf:
       - items:
           - enum:
               - vendor,soc-mali
               - ...
           - const: arm,mali-bifrost
       - items:
           - enum:
               - vendor,soc-mali
               - ...
           - const: arm,mali-valhall
           - const: arm,mali-bifrost #or not, depending on 
forward-compatibility preferences

Cheers,
Robin.