Re: [PATCH v5 3/4] dt-bindings: sound: qcom,q6apm-dai: add memory-region and relax iommus

[Krzysztof Kozlowski]

On 21/09/2026 21:08, Ajay Kumar Nandam wrote:
> On modem-DSP (mDSP) platforms the DSP runs in a stage-2 protected
> context and cannot use the SMMU. PCM buffers must live in reserved-memory
> carveouts that are SCM-assigned to the appropriate VMIDs.
> 
> Add an optional memory-region property (1-2 entries) for the
> control-path and data-path carveouts, and remove iommus from the
> required list since mDSP platforms have neither IOMMU nor VMID DT
> properties.
> 
> Signed-off-by: Ajay Kumar Nandam <ajay.nandam@xxxxxxxxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml b/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
> index 9e5b30d9c6e6..7d0415f2463a 100644
> --- a/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
> +++ b/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
> @@ -20,9 +20,19 @@ properties:
>      minItems: 1
>      maxItems: 2
>  
> +  memory-region:
> +    minItems: 1
> +    maxItems: 2
> +    items:
> +      - description:
> +          Control-path buffer (audio_heap_mem) for platforms where the DSP
> +          runs in a stage-2 protected context (e.g. modem-DSP).
> +      - description:
> +          Data-path buffer pool from which per-stream DMA buffers are
> +          allocated.
> +
>  required:
>    - compatible
> -  - iommus

I imagine you either have iommus or memory-region, no? IOW,
oneOf:
  - required:
      - iommus
  - required:
      - memory-region
?

Best regards,
Krzysztof