arm64: dts: renesas: Add EK874 board with idk-2121wr display support

The EK874 is advertised as compatible with panel IDK-2121WR from
Advantech, however the panel isn't sold alongside the board.
A new dts, adding everything that's required to get the panel to
to work with the EK874, is the most convenient way to support the
EK874 when it's connected to the IDK-2121WR.
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/1576590361-28244-7-git-send-email-fabrizio.castro@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/Makefile

@@ -3,7 +3,8 @@ dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m.dtb
 dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m-ex.dtb
 dtb-$(CONFIG_ARCH_R8A774B1) += r8a774b1-hihope-rzg2n.dtb
 dtb-$(CONFIG_ARCH_R8A774B1) += r8a774b1-hihope-rzg2n-ex.dtb
-dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb
+dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb \
+			       r8a774c0-ek874-idk-2121wr.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-x.dtb r8a7795-h3ulcb.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-h3ulcb-kf.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-xs.dtb

arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source for the Silicon Linux RZ/G2E evaluation kit (EK874),
+ * connected to an Advantech IDK-2121WR 21.5" LVDS panel
+ *
+ * Copyright (C) 2019 Renesas Electronics Corp.
+ */
+
+#include "r8a774c0-ek874.dts"
+
+/ {
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pwms = <&pwm5 0 50000>;
+
+		brightness-levels = <0 4 8 16 32 64 128 255>;
+		default-brightness-level = <6>;
+
+		power-supply = <&reg_12p0v>;
+		enable-gpios = <&gpio6 12 GPIO_ACTIVE_HIGH>;
+	};
+
+	panel-lvds {
+		compatible = "advantech,idk-2121wr", "panel-lvds";
+
+		width-mm = <476>;
+		height-mm = <268>;
+
+		data-mapping = "vesa-24";
+
+		panel-timing {
+			clock-frequency = <148500000>;
+			hactive = <1920>;
+			vactive = <1080>;
+			hsync-len = <44>;
+			hfront-porch = <88>;
+			hback-porch = <148>;
+			vfront-porch = <4>;
+			vback-porch = <36>;
+			vsync-len = <5>;
+		};
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+				dual-lvds-odd-pixels;
+				panel_in0: endpoint {
+					remote-endpoint = <&lvds0_out>;
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+				dual-lvds-even-pixels;
+				panel_in1: endpoint {
+					remote-endpoint = <&lvds1_out>;
+				};
+			};
+		};
+	};
+};
+
+&gpio0 {
+	/*
+	 * When GP0_17 is low LVDS[01] are connected to the LVDS connector
+	 * When GP0_17 is high LVDS[01] are connected to the LT8918L
+	 */
+	lvds-connector-en-gpio{
+		gpio-hog;
+		gpios = <17 GPIO_ACTIVE_HIGH>;
+		output-low;
+		line-name = "lvds-connector-en-gpio";
+	};
+};
+
+&lvds0 {
+	ports {
+		port@1 {
+			lvds0_out: endpoint {
+				remote-endpoint = <&panel_in0>;
+			};
+		};
+	};
+};
+
+&lvds1 {
+	status = "okay";
+
+	clocks = <&cpg CPG_MOD 727>, <&x13_clk>, <&extal_clk>;
+	clock-names = "fck", "dclkin.0", "extal";
+
+	ports {
+		port@1 {
+			lvds1_out: endpoint {
+				remote-endpoint = <&panel_in1>;
+			};
+		};
+	};
+};
+
+&pfc {
+	pwm5_pins: pwm5 {
+		groups = "pwm5_a";
+		function = "pwm5";
+	};
+};
+
+&pwm5 {
+	pinctrl-0 = <&pwm5_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
+};