dt-bindings: media: Convert video-mux to DT schema

Now that we have the graph schema, convert the video-mux binding to DT
schema.

Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://lore.kernel.org/r/20210311234042.1588310-1-robh@kernel.org

Documentation/devicetree/bindings/media/video-mux.yaml

@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/video-mux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Video Multiplexer
+
+maintainers:
+  - Sakari Ailus <sakari.ailus@linux.intel.com>
+  - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+
+description:
+  Video multiplexers allow to select between multiple input ports. Video
+  received on the active input port is passed through to the output port. Muxes
+  described by this binding are controlled by a multiplexer controller.
+
+properties:
+  compatible:
+    const: video-mux
+
+  mux-controls:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    patternProperties:
+      '^port@':
+        $ref: /schemas/graph.yaml#/properties/port
+
+    required:
+      - port@0
+      - port@1
+      - port@2
+
+patternProperties:
+  '^port@':
+    $ref: /schemas/graph.yaml#/properties/port
+    description:
+      At least three port nodes containing endpoints connecting to the source
+      and sink devices according to of_graph bindings. The last port is the
+      output port, all others are inputs.
+
+required:
+  - compatible
+  - mux-controls
+
+oneOf:
+  - required:
+      - ports
+  - required:
+      - port@0
+      - port@1
+      - port@2
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    mux: mux-controller {
+        compatible = "gpio-mux";
+        #mux-control-cells = <0>;
+
+        mux-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
+    };
+
+    video-mux {
+        compatible = "video-mux";
+        mux-controls = <&mux>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        port@0 {
+            reg = <0>;
+
+            mux_in0: endpoint {
+                remote-endpoint = <&video_source0_out>;
+            };
+        };
+
+        port@1 {
+            reg = <1>;
+
+            mux_in1: endpoint {
+                remote-endpoint = <&video_source1_out>;
+            };
+        };
+
+        port@2 {
+            reg = <2>;
+
+            mux_out: endpoint {
+                remote-endpoint = <&capture_interface_in>;
+            };
+        };
+    };
+...