dt-bindings: display: msm: Add reg bus and rotator interconnects

Apart from the already handled data bus (MAS_MDP_Pn<->DDR), there are
other connection paths:
- a path that connects rotator block to the DDR.
- a path that needs to be handled to ensure MDSS register access
  functions properly, namely the "reg bus", a.k.a the CPU-MDSS CFG
  interconnect.

Describe these paths to allow using them in device trees and in the
driver.

[Konrad: rework for one vs two MDP paths, update examples]
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/569480/
Link: https://lore.kernel.org/r/20231125-topic-rb1_feat-v3-2-4cbb567743bb@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Documentation/devicetree/bindings/display/msm/mdss-common.yaml

@@ -61,17 +61,27 @@ properties:
 
   ranges: true
 
+  # This is not a perfect description, but it's impossible to discern and match
+  # the entries like we do with interconnect-names
   interconnects:
     minItems: 1
     items:
       - description: Interconnect path from mdp0 (or a single mdp) port to the data bus
       - description: Interconnect path from mdp1 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    minItems: 1
+    oneOf:
+      - minItems: 1
+        items:
+          - const: mdp0-mem
+          - const: cpu-cfg
+
+      - minItems: 2
         items:
           - const: mdp0-mem
           - const: mdp1-mem
+          - const: cpu-cfg
 
   resets:
     items:

Documentation/devicetree/bindings/display/msm/qcom,qcm2290-mdss.yaml

@@ -36,10 +36,14 @@ properties:
     maxItems: 2
 
   interconnects:
-    maxItems: 1
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    maxItems: 1
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":
@@ -98,8 +102,10 @@ examples:
         interrupt-controller;
         #interrupt-cells = <1>;
 
-        interconnects = <&mmrt_virt MASTER_MDP0 &bimc SLAVE_EBI1>;
-        interconnect-names = "mdp0-mem";
+        interconnects = <&mmrt_virt MASTER_MDP0 &bimc SLAVE_EBI1>,
+                        <&bimc MASTER_APPSS_PROC &config_noc SLAVE_DISPLAY_CFG>;
+        interconnect-names = "mdp0-mem",
+                             "cpu-cfg";
 
         iommus = <&apps_smmu 0x420 0x2>,
                  <&apps_smmu 0x421 0x0>;

Documentation/devicetree/bindings/display/msm/qcom,sc7180-mdss.yaml

@@ -36,10 +36,14 @@ properties:
     maxItems: 1
 
   interconnects:
-    maxItems: 1
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    maxItems: 1
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":
@@ -106,8 +110,10 @@ examples:
         interrupt-controller;
         #interrupt-cells = <1>;
 
-        interconnects = <&mmss_noc MASTER_MDP0 &mc_virt SLAVE_EBI1>;
-        interconnect-names = "mdp0-mem";
+        interconnects = <&mmss_noc MASTER_MDP0 &mc_virt SLAVE_EBI1>,
+                        <&gem_noc MASTER_APPSS_PROC &config_noc SLAVE_DISPLAY_CFG>;
+        interconnect-names = "mdp0-mem",
+                             "cpu-cfg";
 
         iommus = <&apps_smmu 0x800 0x2>;
         ranges;

Documentation/devicetree/bindings/display/msm/qcom,sc7280-mdss.yaml

@@ -36,10 +36,14 @@ properties:
     maxItems: 1
 
   interconnects:
-    maxItems: 1
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    maxItems: 1
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":
@@ -118,8 +122,10 @@ examples:
         interrupt-controller;
         #interrupt-cells = <1>;
 
-        interconnects = <&mmss_noc MASTER_MDP0 &mc_virt SLAVE_EBI1>;
-        interconnect-names = "mdp0-mem";
+        interconnects = <&mmss_noc MASTER_MDP0 &mc_virt SLAVE_EBI1>,
+                        <&gem_noc MASTER_APPSS_PROC &cnoc2 SLAVE_DISPLAY_CFG>;
+        interconnect-names = "mdp0-mem",
+                             "cpu-cfg";
 
         iommus = <&apps_smmu 0x900 0x402>;
         ranges;

Documentation/devicetree/bindings/display/msm/qcom,sm6115-mdss.yaml

@@ -29,6 +29,16 @@ properties:
   iommus:
     maxItems: 2
 
+  interconnects:
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
+
+  interconnect-names:
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
+
 patternProperties:
   "^display-controller@[0-9a-f]+$":
     type: object

Documentation/devicetree/bindings/display/msm/qcom,sm6125-mdss.yaml

@@ -35,10 +35,14 @@ properties:
     maxItems: 1
 
   interconnects:
-    maxItems: 2
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    maxItems: 2
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":

Documentation/devicetree/bindings/display/msm/qcom,sm6350-mdss.yaml

@@ -35,10 +35,14 @@ properties:
     maxItems: 1
 
   interconnects:
-    maxItems: 2
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    maxItems: 2
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":

Documentation/devicetree/bindings/display/msm/qcom,sm6375-mdss.yaml

@@ -35,10 +35,14 @@ properties:
     maxItems: 1
 
   interconnects:
-    maxItems: 2
+    items:
+      - description: Interconnect path from mdp0 port to the data bus
+      - description: Interconnect path from CPU to the reg bus
 
   interconnect-names:
-    maxItems: 2
+    items:
+      - const: mdp0-mem
+      - const: cpu-cfg
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":

Documentation/devicetree/bindings/display/msm/qcom,sm8450-mdss.yaml

@@ -30,10 +30,10 @@ properties:
     maxItems: 1
 
   interconnects:
-    maxItems: 2
+    maxItems: 3
 
   interconnect-names:
-    maxItems: 2
+    maxItems: 3
 
 patternProperties:
   "^display-controller@[0-9a-f]+$":
@@ -91,9 +91,12 @@ examples:
         reg = <0x0ae00000 0x1000>;
         reg-names = "mdss";
 
-        interconnects = <&mmss_noc MASTER_MDP_DISP 0 &mc_virt SLAVE_EBI1_DISP 0>,
-                        <&mmss_noc MASTER_MDP_DISP 0 &mc_virt SLAVE_EBI1_DISP 0>;
-        interconnect-names = "mdp0-mem", "mdp1-mem";
+        interconnects = <&mmss_noc MASTER_MDP_DISP &mc_virt SLAVE_EBI1_DISP>,
+                        <&mmss_noc MASTER_MDP_DISP &mc_virt SLAVE_EBI1_DISP>,
+                        <&gem_noc MASTER_APPSS_PROC &config_noc SLAVE_DISPLAY_CFG>;
+        interconnect-names = "mdp0-mem",
+                             "mdp1-mem",
+                             "cpu-cfg";
 
         resets = <&dispcc DISP_CC_MDSS_CORE_BCR>;