[PATCH v3 1/6] dt-bindings: iommu: arm,smmu: Document interconnects property

[Bibek Kumar Patro]

Some SoC implementations require a bandwidth vote on an interconnect
path before the SMMU register space is accessible. Add the optional
'interconnects' property to the binding to allow platform DT nodes
to describe this path.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
Signed-off-by: Bibek Kumar Patro <bibek.patro@xxxxxxxxxxxxxxxx>
---
 .../devicetree/bindings/iommu/arm,smmu.yaml        | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml
index a701dec2fa0a..fab8944d7b63 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml
@@ -246,6 +246,13 @@ properties:
     minItems: 1
     maxItems: 3
 
+  interconnects:
+    maxItems: 1
+    description:
+      Interconnect path to the SMMU register space. Required on SoCs
+      where the SMMU registers are only accessible after a bandwidth
+      vote has been placed on the interconnect fabric.
+
   nvidia,memory-controller:
     description: |
       A phandle to the memory controller on NVIDIA Tegra186 and later SoCs.
@@ -644,6 +651,26 @@ allOf:
         clock-names: false
         clocks: false
 
+  - if:
+      properties:
+        compatible:
+          items:
+            - enum:
+                - qcom,qcs615-smmu-500
+                - qcom,qcs8300-smmu-500
+                - qcom,sa8775p-smmu-500
+                - qcom,sc7280-smmu-500
+            - const: qcom,adreno-smmu
+            - const: qcom,smmu-500
+            - const: arm,mmu-500
+    then:
+      properties:
+        interconnects:
+          maxItems: 1
+    else:
+      properties:
+        interconnects: false
+
   - if:
       properties:
         compatible:

-- 
2.34.1