[PATCH 1/2] dt-bindings: sound: qcom,q6apm-dai: add memory-region property

[Ajay Kumar Nandam]

Document the new memory-region property that allows one or more
reserved-memory carveout regions to be SCM-assigned to the VMIDs
listed in qcom,vmid.

- Add memory-region as an optional phandle-array (1-8 entries).
  Each entry must point to a shared-dma-pool, no-map reserved-memory
  node. Index 0 is the control-path buffer; subsequent entries are
  data-path buffers.
- Enforce via dependentRequired that memory-region is only valid
  when qcom,vmid is also present.
- Expand qcom,vmid description to mention carveout regions and the
  qcom_scm_is_available() probe-defer requirement.
- Add a second example showing both properties in use with two
  carveout regions and two destination VMIDs.

Signed-off-by: Ajay Kumar Nandam <ajay.nandam@xxxxxxxxxxxxxxxx>
---
 .../bindings/sound/qcom,q6apm-dai.yaml        | 38 +++++++++++++++++--
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml b/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
index b767625985a7..601055182da6 100644
--- a/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
+++ b/Documentation/devicetree/bindings/sound/qcom,q6apm-dai.yaml
@@ -10,7 +10,11 @@ maintainers:
   - Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
 
 description: |
-  This binding describes the Qualcomm APM DAIs in DSP
+  This binding describes the Qualcomm APM DAIs in DSP.
+  When qcom,vmid is present, the driver performs SCM memory
+  assignment for PCM DMA buffers and any reserved-memory regions
+  listed in memory-region, granting the specified VMIDs RW access
+  while retaining HLOS as a co-owner.
 
 properties:
   compatible:
@@ -20,9 +24,24 @@ properties:
     minItems: 1
     maxItems: 2
 
+  memory-region:
+    description:
+      List of phandles to reserved-memory regions (shared-dma-pool,
+      no-map) that must be SCM-assigned to the VMIDs in qcom,vmid.
+      The first entry is the control-path buffer; subsequent entries
+      are data-path buffers. Only meaningful when qcom,vmid is present.
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      maxItems: 1
+    minItems: 1
+    maxItems: 8
+
   qcom,vmid:
-    description: Optional list of destination VMIDs to share PCM DMA buffers with.
-      HLOS retains RW access as source owner and must not be listed.
+    description:
+      Optional list of destination VMIDs to grant RW access to PCM DMA
+      buffers and any memory-region carveouts. HLOS retains RW access
+      as source owner and must not be listed. When present,
+      qcom_scm_is_available() must return true at probe time.
     $ref: /schemas/types.yaml#/definitions/uint32-array
     items:
       minimum: 1
@@ -34,6 +53,10 @@ required:
   - compatible
   - iommus
 
+dependentRequired:
+  memory-region:
+    - qcom,vmid
+
 additionalProperties: false
 
 examples:
@@ -42,3 +65,12 @@ examples:
         compatible = "qcom,q6apm-dais";
         iommus = <&apps_smmu 0x1801 0x0>;
     };
+  - |
+    #include <dt-bindings/firmware/qcom,scm.h>
+    dais {
+        compatible = "qcom,q6apm-dais";
+        iommus = <&apps_smmu 0x0c01 0x0>;
+        /* index 0: control path, index 1: data path */
+        memory-region = <&audio_heap_mem &audio_mdsp_carveout_mem>;
+        qcom,vmid = <QCOM_SCM_VMID_MSS_MSA QCOM_SCM_VMID_LPASS>;
+    };
-- 
2.34.1