Document endpoint properties for the parallel bus type and
add them to the example.
Specify a few constraints:
- If the bus type is BT.656 no hsync or vsync polarities can be
  specified.
- If the bus width is 10 bits, not data-shift can be applied.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
           bus-type:
             enum: [5, 6]
 
+          bus-width:
+            enum: [8, 10]
+            default: 10
+
+          data-shift:
+            enum: [0, 2]
+            default: 0
+
+          hsync-active:
+            enum: [0, 1]
+            default: 1
+
+          vsync-active:
+            enum: [0, 1]
+            default: 1
+
+          pclk-sample:
+            enum: [0, 1]
+            default: 1
+
+        allOf:
+          - if:
+              properties:
+                bus-type:
+                  const: 6
+            then:
+                properties:
+                  hsync-active: false
+                  vsync-active: false
+
+          - if:
+              properties:
+                bus-width:
+                  const: 10
+            then:
+                properties:
+                  data-shift:
+                    const: 0
+
         required:
           - bus-type
 
             port {
                 ov772x_0: endpoint {
                     bus-type = <5>;
+                    vsync-active = <0>;
+                    hsync-active = <0>;
+                    pclk-sample = <0>;
+                    bus-width = <8>;
+                    data-shift = <0>;
                     remote-endpoint = <&vcap1_in0>;
                 };
             };