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.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

1 files changed, 10 insertions, 4 deletions

diff --git a/Documentation/devicetree/bindings/display/msm/qcom,sc7180-mdss.yaml b/Documentation/devicetree/bindings/display/msm/qcom,sc7180-mdss.yaml
index 3432a2407caa..7a0555b15ddf 100644
--- a/Documentation/devicetree/bindings/display/msm/qcom,sc7180-mdss.yaml
+++ b/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;