drm/panel: simple: Add support for Rocktech RK070ER9427 LCD panel

This adds support for the Rocktech Display Ltd. RK070ER9427
800(RGB)x480 TFT LCD panel, which can be supported by the
simple panel driver.
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180607134648.2902-1-jagan@amarulasolutions.com

Documentation/devicetree/bindings/display/panel/rocktech,rk070er9427.txt

+Rocktech Display Ltd. RK070ER9427 800(RGB)x480 TFT LCD panel
+
+This binding is compatible with the simple-panel binding, which is specified
+in simple-panel.txt in this directory.
+
+Required properties:
+- compatible: should be "rocktech,rk070er9427"
+
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+
+Optional nodes:
+- Video port for LCD panel input.
+
+Example:
+	panel {
+		compatible = "rocktech,rk070er9427";
+		backlight = <&backlight_lcd>;
+
+		port {
+			lcd_panel_in: endpoint {
+				remote-endpoint = <&lcd_display_out>;
+			};
+		};
+	};

drivers/gpu/drm/panel/panel-simple.c

@@ -1747,6 +1747,36 @@ static const struct panel_desc qd43003c0_40 = {
 	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
 };
 
+static const struct display_timing rocktech_rk070er9427_timing = {
+	.pixelclock = { 26400000, 33300000, 46800000 },
+	.hactive = { 800, 800, 800 },
+	.hfront_porch = { 16, 210, 354 },
+	.hback_porch = { 46, 46, 46 },
+	.hsync_len = { 1, 1, 1 },
+	.vactive = { 480, 480, 480 },
+	.vfront_porch = { 7, 22, 147 },
+	.vback_porch = { 23, 23, 23 },
+	.vsync_len = { 1, 1, 1 },
+	.flags = DISPLAY_FLAGS_DE_HIGH,
+};
+
+static const struct panel_desc rocktech_rk070er9427 = {
+	.timings = &rocktech_rk070er9427_timing,
+	.num_timings = 1,
+	.bpc = 6,
+	.size = {
+		.width = 154,
+		.height = 86,
+	},
+	.delay = {
+		.prepare = 41,
+		.enable = 50,
+		.unprepare = 41,
+		.disable = 50,
+	},
+	.bus_format = MEDIA_BUS_FMT_RGB666_1X18,
+};
+
 static const struct drm_display_mode samsung_lsn122dl01_c01_mode = {
 	.clock = 271560,
 	.hdisplay = 2560,
@@ -2283,6 +2313,9 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "qiaodian,qd43003c0-40",
 		.data = &qd43003c0_40,
+	}, {
+		.compatible = "rocktech,rk070er9427",
+		.data = &rocktech_rk070er9427,
 	}, {
 		.compatible = "samsung,lsn122dl01-c01",
 		.data = &samsung_lsn122dl01_c01,