drm/panel: simple: Add Sharp LQ035Q7DB03 panel support

The change adds support for Sharp LQ035Q7DB03 3.5" QVGA TFT panel.

Note that this aged panel is already found in the kernel sources,
for instance in board mach files mach-mx21ads.c, mach-mx27ads.c,
mach-pcm043.c, lpd270.c and imx27-phytec-phycore-rdk.dts.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706185101.31186-1-vz@mleia.com

Documentation/devicetree/bindings/display/panel/sharp,lq035q7db03.txt

@@ -0,0 +1,12 @@
+Sharp LQ035Q7DB03 3.5" QVGA TFT LCD panel
+
+Required properties:
+- compatible: should be "sharp,lq035q7db03"
+- power-supply: phandle of the regulator that provides the supply voltage
+
+Optional properties:
+- enable-gpios: GPIO pin to enable or disable the panel
+- backlight: phandle of the backlight device attached to the panel
+
+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

@@ -1991,6 +1991,30 @@ static const struct panel_desc samsung_ltn140at29_301 = {
 	},
 };
 
+static const struct drm_display_mode sharp_lq035q7db03_mode = {
+	.clock = 5500,
+	.hdisplay = 240,
+	.hsync_start = 240 + 16,
+	.hsync_end = 240 + 16 + 7,
+	.htotal = 240 + 16 + 7 + 5,
+	.vdisplay = 320,
+	.vsync_start = 320 + 9,
+	.vsync_end = 320 + 9 + 1,
+	.vtotal = 320 + 9 + 1 + 7,
+	.vrefresh = 60,
+};
+
+static const struct panel_desc sharp_lq035q7db03 = {
+	.modes = &sharp_lq035q7db03_mode,
+	.num_modes = 1,
+	.bpc = 6,
+	.size = {
+		.width = 54,
+		.height = 72,
+	},
+	.bus_format = MEDIA_BUS_FMT_RGB666_1X18,
+};
+
 static const struct display_timing sharp_lq101k1ly04_timing = {
 	.pixelclock = { 60000000, 65000000, 80000000 },
 	.hactive = { 1280, 1280, 1280 },
@@ -2492,6 +2516,9 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "samsung,ltn140at29-301",
 		.data = &samsung_ltn140at29_301,
+	}, {
+		.compatible = "sharp,lq035q7db03",
+		.data = &sharp_lq035q7db03,
 	}, {
 		.compatible = "sharp,lq101k1ly04",
 		.data = &sharp_lq101k1ly04,