dt-bindings: display: convert Atmel's HLCDC to DT schema

Convert the existing DT binding to DT schema of the Atmel's HLCDC display
controller.
Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240202001733.91455-2-dharma.b@microchip.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/atmel/atmel,hlcdc-display-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Atmel's High LCD Controller (HLCDC)
+
+maintainers:
+  - Nicolas Ferre <nicolas.ferre@microchip.com>
+  - Alexandre Belloni <alexandre.belloni@bootlin.com>
+  - Claudiu Beznea <claudiu.beznea@tuxon.dev>
+
+description:
+  The LCD Controller (LCDC) consists of logic for transferring LCD image
+  data from an external display buffer to a TFT LCD panel. The LCDC has one
+  display input buffer per layer that fetches pixels through the single bus
+  host interface and a look-up table to allow palletized display
+  configurations.
+
+properties:
+  compatible:
+    const: atmel,hlcdc-display-controller
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  port@0:
+    $ref: /schemas/graph.yaml#/$defs/port-base
+    unevaluatedProperties: false
+    description:
+      Output endpoint of the controller, connecting the LCD panel signals.
+
+    properties:
+      '#address-cells':
+        const: 1
+
+      '#size-cells':
+        const: 0
+
+      reg:
+        maxItems: 1
+
+      endpoint:
+        $ref: /schemas/media/video-interfaces.yaml#
+        unevaluatedProperties: false
+        description:
+          Endpoint connecting the LCD panel signals.
+
+        properties:
+          bus-width:
+            enum: [ 12, 16, 18, 24 ]
+
+required:
+  - '#address-cells'
+  - '#size-cells'
+  - compatible
+  - port@0
+
+additionalProperties: false

Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt

-Device-Tree bindings for Atmel's HLCDC (High LCD Controller) DRM driver
-
-The Atmel HLCDC Display Controller is subdevice of the HLCDC MFD device.
-See ../../mfd/atmel-hlcdc.txt for more details.
-
-Required properties:
- - compatible: value should be "atmel,hlcdc-display-controller"
- - pinctrl-names: the pin control state names. Should contain "default".
- - pinctrl-0: should contain the default pinctrl states.
- - #address-cells: should be set to 1.
- - #size-cells: should be set to 0.
-
-Required children nodes:
- Children nodes are encoding available output ports and their connections
- to external devices using the OF graph representation (see ../graph.txt).
- At least one port node is required.
-
-Optional properties in grandchild nodes:
- Any endpoint grandchild node may specify a desired video interface
- according to ../../media/video-interfaces.txt, specifically
- - bus-width: recognized values are <12>, <16>, <18> and <24>, and
-   override any output mode selection heuristic, forcing "rgb444",
-   "rgb565", "rgb666" and "rgb888" respectively.
-
-Example:
-
-	hlcdc: hlcdc@f0030000 {
-		compatible = "atmel,sama5d3-hlcdc";
-		reg = <0xf0030000 0x2000>;
-		interrupts = <36 IRQ_TYPE_LEVEL_HIGH 0>;
-		clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
-		clock-names = "periph_clk","sys_clk", "slow_clk";
-
-		hlcdc-display-controller {
-			compatible = "atmel,hlcdc-display-controller";
-			pinctrl-names = "default";
-			pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
-			#address-cells = <1>;
-			#size-cells = <0>;
-
-			port@0 {
-				#address-cells = <1>;
-				#size-cells = <0>;
-				reg = <0>;
-
-				hlcdc_panel_output: endpoint@0 {
-					reg = <0>;
-					remote-endpoint = <&panel_input>;
-				};
-			};
-		};
-
-		hlcdc_pwm: hlcdc-pwm {
-			compatible = "atmel,hlcdc-pwm";
-			pinctrl-names = "default";
-			pinctrl-0 = <&pinctrl_lcd_pwm>;
-			#pwm-cells = <3>;
-		};
-	};
-
-Example 2: With a video interface override to force rgb565; as above
-but with these changes/additions:
-
-	&hlcdc {
-		hlcdc-display-controller {
-			pinctrl-names = "default";
-			pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
-
-			port@0 {
-				hlcdc_panel_output: endpoint@0 {
-					bus-width = <16>;
-				};
-			};
-		};
-	};