ARM: tegra: colibri_t20: iris: display controller rgb panel support

Add display controller parallel RGB panel support incl. backlight PWM.
Signed-off-by: NMarcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra20-colibri-iris.dts

@@ -21,6 +21,13 @@
 	};
 
 	host1x@50000000 {
+		dc@54200000 {
+			rgb {
+				status = "okay";
+				nvidia,panel = <&panel>;
+			};
+		};
+
 		hdmi@54280000 {
 			status = "okay";
 			hdmi-supply = <&reg_5v0>;
@@ -99,6 +106,10 @@
 		status = "okay";
 	};
 
+	pwm@7000a000 {
+		status = "okay";
+	};
+
 	/*
 	 * GEN1_I2C: I2C_SDA/SCL on SODIMM pin 194/196 (e.g. RTC on carrier
 	 * board)
@@ -149,6 +160,26 @@
 		no-1-8-v;
 	};
 
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		brightness-levels = <255 128 64 32 16 8 4 0>;
+		default-brightness-level = <6>;
+		/* BL_ON */
+		enable-gpios = <&gpio TEGRA_GPIO(T, 4) GPIO_ACTIVE_HIGH>;
+		power-supply = <&reg_3v3>;
+		pwms = <&pwm 0 5000000>; /* PWM<A> */
+	};
+
+	panel: panel {
+		/*
+		 * edt,et057090dhu: EDT 5.7" LCD TFT
+		 * edt,et070080dh6: EDT 7.0" LCD TFT
+		 */
+		compatible = "edt,et057090dhu", "simple-panel";
+		backlight = <&backlight>;
+		power-supply = <&reg_3v3>;
+	};
+
 	reg_3v3: regulator-3v3 {
 		compatible = "regulator-fixed";
 		regulator-name = "3.3V";