[U-Boot] [PATCH v2 3/4] colibri_t20: fix display configuration

[Marcel Ziswiler]

Without this patch the following error will be shown:

stdio_add_devices: Video device failed (ret=-22)

As commit ec5507707a1d1e84056a6c864338f95f6118d3ca (video: tegra: Move
to using simple-panel and pwm-backlight) states the Colibri T20 needs
updating too which this patch finally attempts doing.

Please note that the current U-Boot implementation requires a dummy
GPIO e.g. for a fixed backlight regulator to be explicitly defined in
order to work unlike in the Linux kernel where this is taken care of
automatically.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>

---

Changes in v2:
- Rename dummy regulator to reg_3v3 as suggested by Stephen.
- Keep dummy N/C GPIO to work around bug in U-Boot regulator driver
  requiring such node despite its binding claiming it being optional.

 arch/arm/dts/tegra20-colibri.dts | 73 +++++++++++++++++++++++++++++-----------
 1 file changed, 53 insertions(+), 20 deletions(-)

diff --git a/arch/arm/dts/tegra20-colibri.dts b/arch/arm/dts/tegra20-colibri.dts
index 2cf24d3..616c329 100644
--- a/arch/arm/dts/tegra20-colibri.dts
+++ b/arch/arm/dts/tegra20-colibri.dts
@@ -21,12 +21,24 @@
 	};
 
 	host1x at 50000000 {
-		status = "okay";
 		dc at 54200000 {
-			status = "okay";
 			rgb {
 				status = "okay";
 				nvidia,panel = <&lcd_panel>;
+				display-timings {
+					timing at 0 {
+						/* VESA VGA */
+						clock-frequency = <25175000>;
+						hactive = <640>;
+						vactive = <480>;
+						hback-porch = <48>;
+						hfront-porch = <16>;
+						hsync-len = <96>;
+						vback-porch = <31>;
+						vfront-porch = <11>;
+						vsync-len = <2>;
+					};
+				};
 			};
 		};
 	};
@@ -60,6 +72,10 @@
 		};
 	};
 
+	pwm at 7000a000 {
+		status = "okay";
+	};
+
 	/*
 	 * GEN1_I2C: I2C_SDA/SCL on SODIMM pin 194/196 (e.g. RTC on carrier
 	 * board)
@@ -91,6 +107,18 @@
 		cd-gpios = <&gpio TEGRA_GPIO(C, 7) GPIO_ACTIVE_LOW>;
 	};
 
+	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>;
+		/* PWM<A> */
+		pwms = <&pwm 0 5000000>;
+	};
+
 	clocks {
 		compatible = "simple-bus";
 		#address-cells = <1>;
@@ -104,25 +132,30 @@
 		};
 	};
 
-	pwm: pwm at 7000a000 {
-		status = "okay";
+	lcd_panel: panel {
+		/*
+		 * edt,et057090dhu: EDT 5.7" LCD TFT
+		 * edt,et070080dh6: EDT 7.0" LCD TFT
+		 */
+		compatible = "edt,et057090dhu", "simple-panel";
+
+		backlight = <&backlight>;
 	};
 
-	lcd_panel: panel {
-		clock = <25175000>;
-		xres = <640>;
-		yres = <480>;
-		left-margin = <48>;	/* horizontal back porch */
-		right-margin = <16>;	/* horizontal front porch */
-		hsync-len = <96>;
-		lower-margin = <11>;	/* vertical front porch */
-		upper-margin = <31>;	/* vertical back porch */
-		vsync-len = <2>;
-		hsync-active-high;
-		vsync-active-high;
-		nvidia,bits-per-pixel = <16>;
-		nvidia,pwm = <&pwm 0 0>;
-		nvidia,backlight-enable-gpios = <&gpio TEGRA_GPIO(T, 4) GPIO_ACTIVE_HIGH>;
-		nvidia,panel-timings = <0 0 0 0>;
+	regulators {
+		compatible = "simple-bus";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		reg_3v3: regulator at 0 {
+			compatible = "regulator-fixed";
+			reg = <0>;
+			regulator-name = "+V3.3";
+			regulator-min-microvolt = <3300000>;
+			regulator-max-microvolt = <3300000>;
+			regulator-always-on;
+			/* Dummy N/C */
+			gpio = <&gpio TEGRA_GPIO(V, 7) GPIO_ACTIVE_HIGH>;
+		};
 	};
 };
-- 
2.5.5