[PATCH v2 2/2] dt-bindings: drm/bridge: ti-sn65dsi86: Improve the yaml validation

[Douglas Anderson <dianders@chromium.org>]

This patch adds the following checks to the yaml:
- Remapping of the eDP output lanes is now limited to the subset of
  remappings that the hardware supports.
- No more additional properties can be added under 'ports'.

This patch fixes the following bugs in the original yaml conversion:
- Fixed dependency between 'data-lanes' and 'lane-polarities', which
  was backwards.  Now you can only specify 'lane-polarities' if you
  specified 'data-lanes'.  I could have sworn I tried this before.
- We can't remap input lanes in this hardware.

This patch doesn't do, but if someone knew how I'd love to:
- Make sure if we have both 'lane-polarities' and 'data-lanes' that
  they have the same number of elements.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This patch could be squashed atop the patch adding the yaml [1].  I'm
sending separately for now to avoid churning the series another time.

[1] https://lore.kernel.org/r/20200430124442.v4.4.Ifcdc4ecb12742a27862744ee1e8753cb95a38a7f@changeid

Changes in v2:
- ("... Improve the yaml validation") new for v2.

 .../bindings/display/bridge/ti,sn65dsi86.yaml | 74 ++++++++++---------
 1 file changed, 40 insertions(+), 34 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.yaml
index 75c4e8b8e4b7..be10e8cf31e1 100644
--- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi86.yaml
@@ -72,6 +72,7 @@ properties:
 
   ports:
     type: object
+    additionalProperties: false
 
     properties:
       "#address-cells":
@@ -94,33 +95,9 @@ properties:
           endpoint:
             type: object
             additionalProperties: false
-
             properties:
               remote-endpoint: true
 
-              data-lanes:
-                minItems: 1
-                maxItems: 4
-                items:
-                  enum:
-                    - 0
-                    - 1
-                    - 2
-                    - 3
-                description: See ../../media/video-interface.txt
-
-              lane-polarities:
-                minItems: 1
-                maxItems: 4
-                items:
-                  enum:
-                    - 0
-                    - 1
-                description: See ../../media/video-interface.txt
-
-            dependencies:
-              data-lanes: [lane-polarities]
-
         required:
           - reg
 
@@ -143,15 +120,44 @@ properties:
               remote-endpoint: true
 
               data-lanes:
-                minItems: 1
-                maxItems: 4
-                items:
-                  enum:
-                    - 0
-                    - 1
-                    - 2
-                    - 3
-                description: See ../../media/video-interface.txt
+                oneOf:
+                  - minItems: 1
+                    maxItems: 1
+                    uniqueItems: true
+                    items:
+                      enum:
+                        - 0
+                        - 1
+                    description:
+                      If you have 1 logical lane the bridge supports routing
+                      to either port 0 or port 1.  Port 0 is suggested.
+                      See ../../media/video-interface.txt for details.
+
+                  - minItems: 2
+                    maxItems: 2
+                    uniqueItems: true
+                    items:
+                      enum:
+                        - 0
+                        - 1
+                    description:
+                      If you have 2 logical lanes the bridge supports
+                      reordering but only on physical ports 0 and 1.
+                      See ../../media/video-interface.txt for details.
+
+                  - minItems: 4
+                    maxItems: 4
+                    uniqueItems: true
+                    items:
+                      enum:
+                        - 0
+                        - 1
+                        - 2
+                        - 3
+                    description:
+                      If you have 4 logical lanes the bridge supports
+                      reordering in any way.
+                      See ../../media/video-interface.txt for details.
 
               lane-polarities:
                 minItems: 1
@@ -163,7 +169,7 @@ properties:
                 description: See ../../media/video-interface.txt
 
             dependencies:
-              data-lanes: [lane-polarities]
+              lane-polarities: [data-lanes]
 
         required:
           - reg
-- 
2.26.2.645.ge9eca65c58-goog