dt-bindings: display: bridge: Add i.MX8qm/qxp LVDS display bridge binding

This patch adds bindings for i.MX8qm/qxp LVDS display bridge(LDB).
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220611141421.718743-11-victor.liu@nxp.com

Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-ldb.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/fsl,imx8qxp-ldb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale i.MX8qm/qxp LVDS Display Bridge
+
+maintainers:
+  - Liu Ying <victor.liu@nxp.com>
+
+description: |
+  The Freescale i.MX8qm/qxp LVDS Display Bridge(LDB) has two channels.
+
+  The i.MX8qm/qxp LDB is controlled by Control and Status Registers(CSR) module.
+  The CSR module, as a system controller, contains the LDB's configuration
+  registers.
+
+  For i.MX8qxp LDB, each channel supports up to 24bpp parallel input color
+  format and can map the input to VESA or JEIDA standards.  The two channels
+  cannot be used simultaneously, that is to say, the user should pick one of
+  them to use.  Two LDB channels from two LDB instances can work together in
+  LDB split mode to support a dual link LVDS display.  The channel indexes
+  have to be different.  Channel0 outputs odd pixels and channel1 outputs
+  even pixels.
+
+  For i.MX8qm LDB, each channel additionally supports up to 30bpp parallel
+  input color format.  The two channels can be used simultaneously, either
+  in dual mode or split mode.  In dual mode, the two channels output identical
+  data.  In split mode, channel0 outputs odd pixels and channel1 outputs even
+  pixels.
+
+  A side note is that i.MX8qm/qxp LDB is officially called pixel mapper in
+  the SoC reference manuals.  The pixel mapper uses logic of LDBs embedded in
+  i.MX6qdl/sx SoCs, i.e., it is essentially based on them.  To keep the naming
+  consistency, this binding calls it LDB.
+
+properties:
+  compatible:
+    enum:
+      - fsl,imx8qm-ldb
+      - fsl,imx8qxp-ldb
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  clocks:
+    items:
+      - description: pixel clock
+      - description: bypass clock
+
+  clock-names:
+    items:
+      - const: pixel
+      - const: bypass
+
+  power-domains:
+    maxItems: 1
+
+  fsl,companion-ldb:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: |
+      A phandle which points to companion LDB which is used in LDB split mode.
+
+patternProperties:
+  "^channel@[0-1]$":
+    type: object
+    description: Represents a channel of LDB.
+
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+      reg:
+        description: The channel index.
+        enum: [ 0, 1 ]
+
+      phys:
+        description: A phandle to the phy module representing the LVDS PHY.
+        maxItems: 1
+
+      phy-names:
+        const: lvds_phy
+
+      port@0:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: Input port of the channel.
+
+      port@1:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: Output port of the channel.
+
+    required:
+      - "#address-cells"
+      - "#size-cells"
+      - reg
+      - phys
+      - phy-names
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - "#address-cells"
+  - "#size-cells"
+  - clocks
+  - clock-names
+  - power-domains
+  - channel@0
+  - channel@1
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: fsl,imx8qm-ldb
+    then:
+      properties:
+        fsl,companion-ldb: false
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/firmware/imx/rsrc.h>
+    ldb {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        compatible = "fsl,imx8qxp-ldb";
+        clocks = <&clk IMX_SC_R_LVDS_0 IMX_SC_PM_CLK_MISC2>,
+                 <&clk IMX_SC_R_LVDS_0 IMX_SC_PM_CLK_BYPASS>;
+        clock-names = "pixel", "bypass";
+        power-domains = <&pd IMX_SC_R_LVDS_0>;
+
+        channel@0 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            reg = <0>;
+            phys = <&mipi_lvds_0_phy>;
+            phy-names = "lvds_phy";
+
+            port@0 {
+                reg = <0>;
+
+                mipi_lvds_0_ldb_ch0_mipi_lvds_0_pxl2dpi: endpoint {
+                    remote-endpoint = <&mipi_lvds_0_pxl2dpi_mipi_lvds_0_ldb_ch0>;
+                };
+            };
+        };
+
+        channel@1 {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            reg = <1>;
+            phys = <&mipi_lvds_0_phy>;
+            phy-names = "lvds_phy";
+
+            port@0 {
+                reg = <0>;
+
+                mipi_lvds_0_ldb_ch1_mipi_lvds_0_pxl2dpi: endpoint {
+                    remote-endpoint = <&mipi_lvds_0_pxl2dpi_mipi_lvds_0_ldb_ch1>;
+                };
+            };
+        };
+    };