media: dt-bindings: gc0308: add binding

Add DT binding for GalaxyCore GC0308 camera sensor.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Documentation/devicetree/bindings/media/i2c/galaxycore,gc0308.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/media/i2c/galaxycore,gc0308.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Galaxycore GC0308 and GC0309 Image Sensors
+
+maintainers:
+  - Sebastian Reichel <sre@kernel.org>
+
+description: |
+  The GalaxyCore GC0308 (1/6.5") and GC0309 (1/9") are 640x480 VGA sensors
+  programmable through an I2C interface and connected via parallel bus.
+  They include an ISP capable of auto exposure and auto white balance.
+
+allOf:
+  - $ref: ../video-interface-devices.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - const: galaxycore,gc0308
+      - items:
+          - const: galaxycore,gc0309
+          - const: galaxycore,gc0308
+
+  reg:
+    const: 0x21
+
+  clocks:
+    description: Reference to the xclk clock.
+    maxItems: 1
+
+  reset-gpios:
+    description: GPIO descriptor for the reset pin.
+    maxItems: 1
+
+  powerdown-gpios:
+    description: GPIO descriptor for the powerdown pin.
+    maxItems: 1
+
+  vdd28-supply:
+    description: 2.8V supply
+
+  port:
+    $ref: /schemas/graph.yaml#/$defs/port-base
+    description: |
+      Video output port.
+
+    properties:
+      endpoint:
+        $ref: /schemas/media/video-interfaces.yaml#
+        unevaluatedProperties: false
+
+        properties:
+          bus-width: true
+          data-shift: true
+          hsync-active: true
+          vsync-active: true
+          data-active: true
+          pclk-sample: true
+
+        required:
+          - bus-width
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - powerdown-gpios
+  - port
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        camera-sensor@21 {
+            compatible = "galaxycore,gc0308";
+            reg = <0x21>;
+            clocks = <&camera_clk>;
+            powerdown-gpios = <&gpio1 5 GPIO_ACTIVE_HIGH>;
+            reset-gpios = <&gpio1 6 GPIO_ACTIVE_LOW>;
+            vdd28-supply = <&vdd28>;
+
+            port {
+                gc0308_ep: endpoint {
+                    remote-endpoint = <&parallel_from_gc0308>;
+                    bus-width = <8>;
+                    data-shift = <2>; /* lines 9:2 are used */
+                    hsync-active = <1>; /* active high */
+                    vsync-active = <1>; /* active high */
+                    data-active = <1>; /* active high */
+                    pclk-sample = <1>; /* sample on rising edge */
+                };
+            };
+        };
+    };
+
+...