[PATCH v6 3/4] ASoC: dt-bindings: qcom,q6apm-dai: add memory-region and relax iommus

[Ajay Kumar Nandam]

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 a memory-region property (1-2 entries) for the control-path and
data-path carveouts, and require q6apm-dais nodes to describe exactly
one access path: iommus for SMMU-backed systems or memory-region for
mDSP systems. Remove iommus from the common required list since mDSP
platforms have neither IOMMU nor VMID DT properties.

Signed-off-by: Ajay Kumar Nandam <ajay.nandam@xxxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/sound/qcom,q6apm-dai.yaml       | 17 ++++++++++++++++-
 1 file changed, 16 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..c1f9fc9eab64 100644
--- a/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
+++ b/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
@@ -20,9 +20,24 @@ properties:
     minItems: 1
     maxItems: 2
 
+  memory-region:
+    minItems: 1
+    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
+
+oneOf:
+  - required:
+      - iommus
+  - required:
+      - memory-region
 
 additionalProperties: false
 

-- 
2.34.1