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

From: Ajay Kumar Nandam

Date: Mon Sep 21 2026 - 15:25:24 EST


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

additionalProperties: false


--
2.34.1