[PATCH 6/7] dt-bindings: display: allwinner: Update H616 DE33 binding

[Jernej Skrabec <jernej.skrabec@gmail.com>]

As it turns out, current H616 DE33 binding was written based on
incomplete understanding of DE33 design. Namely, planes are shared
resource and not tied to specific mixer, which was the case for previous
generations of Display Engine (DE3 and earlier).

This means that current DE33 binding doesn't properly reflect HW and
using it would mean that second mixer (used for second display output)
can't be supported.

Update DE33 mixer binding so instead of referencing planes register
space, it contains phandle to newly introduced DE33 planes node.

There is no user of this binding yet, so changes can be made safely,
without breaking any backward compatibility.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 .../display/allwinner,sun8i-a83t-de2-mixer.yaml  | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml b/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml
index cbd18fd83e52..064e4ca7e419 100644
--- a/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml
+++ b/Documentation/devicetree/bindings/display/allwinner,sun8i-a83t-de2-mixer.yaml
@@ -46,6 +46,10 @@ properties:
   resets:
     maxItems: 1
 
+  allwinner,planes:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: Phandle of Display Engine 3.3 planes node
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
 
@@ -74,22 +78,22 @@ allOf:
       properties:
         reg:
           description: |
-            Registers for controlling individual layers of the display
-            engine (layers), global control (top), and display blending
-            control (display). Names are from Allwinner BSP kernel.
-          maxItems: 3
+            Registers for display blending control (display) and global
+            control (top). Names are from Allwinner BSP kernel.
+          maxItems: 2
         reg-names:
           items:
-            - const: layers
-            - const: top
             - const: display
+            - const: top
       required:
         - reg-names
+        - allwinner,planes
 
     else:
       properties:
         reg:
           maxItems: 1
+        allwinner,planes: false
 
 required:
   - compatible
-- 
2.51.2