dt-bindings: gpu: v3d: Add per-compatible register restrictions

In order to enforce per-SoC register rules, add per-compatible
restrictions. V3D 3.3 (represented by brcm,7268-v3d) has a cache
controller (GCA), which is not present in other V3D generations.
Declaring these differences helps ensure the DTB accurately reflect
the hardware design.

While not ideal, this commit keeps the register order flexible for
brcm,7268-v3d with the goal to keep the ABI backwards compatible.

Signed-off-by: Maíra Canal <mcanal@igalia.com>

Author: mairacanal

Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.yaml

@@ -23,20 +23,12 @@ properties:
       - brcm,7278-v3d
 
   reg:
-    items:
-      - description: hub register (required)
-      - description: core0 register (required)
-      - description: GCA cache controller register (if GCA controller present)
-      - description: bridge register (if no external reset controller)
     minItems: 2
+    maxItems: 4
 
   reg-names:
-    items:
-      - const: hub
-      - const: core0
-      - enum: [ bridge, gca ]
-      - enum: [ bridge, gca ]
     minItems: 2
+    maxItems: 4
 
   interrupts:
     items:
@@ -59,6 +51,49 @@ required:
   - reg-names
   - interrupts
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - brcm,2711-v3d
+              - brcm,2712-v3d
+              - brcm,7278-v3d
+    then:
+      properties:
+        reg:
+          items:
+            - description: hub register (required)
+            - description: core0 register (required)
+            - description: bridge register (if no external reset controller)
+        reg-names:
+          items:
+            - const: hub
+            - const: core0
+            - const: bridge
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: brcm,7268-v3d
+    then:
+      properties:
+        reg:
+          items:
+            - description: hub register (required)
+            - description: core0 register (required)
+            - description: GCA cache controller register (required)
+            - description: bridge register (if no external reset controller)
+          minItems: 3
+        reg-names:
+          items:
+            - const: hub
+            - const: core0
+            - enum: [ bridge, gca ]
+            - enum: [ bridge, gca ]
+          minItems: 3
+
 additionalProperties: false
 
 examples: