drm/panel: add support for EDT ET057090DHU panel

This panel is sold by Toradex for Colibri T20/T30 and Apalis T30
evaluation kits.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/panel/edt,et057090dhu.txt

+Emerging Display Technology Corp. 5.7" VGA TFT LCD panel
+
+Required properties:
+- compatible: should be "edt,et057090dhu"
+
+This binding is compatible with the simple-panel binding, which is specified
+in simple-panel.txt in this directory.

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

@@ -328,6 +328,29 @@ static const struct panel_desc chunghwa_claa101wb01 = {
 	},
 };
 
+static const struct drm_display_mode edt_et057090dhu_mode = {
+	.clock = 25175,
+	.hdisplay = 640,
+	.hsync_start = 640 + 16,
+	.hsync_end = 640 + 16 + 30,
+	.htotal = 640 + 16 + 30 + 114,
+	.vdisplay = 480,
+	.vsync_start = 480 + 10,
+	.vsync_end = 480 + 10 + 3,
+	.vtotal = 480 + 10 + 3 + 32,
+	.vrefresh = 60,
+	.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
+};
+
+static const struct panel_desc edt_et057090dhu = {
+	.modes = &edt_et057090dhu_mode,
+	.num_modes = 1,
+	.size = {
+		.width = 115,
+		.height = 86,
+	},
+};
+
 static const struct drm_display_mode edt_etm0700g0dh6_mode = {
 	.clock = 33260,
 	.hdisplay = 800,
@@ -405,6 +428,9 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "chunghwa,claa101wb01",
 		.data = &chunghwa_claa101wb01
+	}, {
+		.compatible = "edt,et057090dhu",
+		.data = &edt_et057090dhu,
 	}, {
 		.compatible = "edt,et070080dh6",
 		.data = &edt_etm0700g0dh6,