Change Startek panel to RGB666 mode

-Integrate changes from Mediatek team to change from RGB888 to RGB666
-Change pixel clock, HFP, HBP, VBP
-Modify porch control registers to match changes in panel struct. Note:
HBP and VBP registers are defined as struct H\V_SYNC + H\V_BP

Change-Id: I09bbb519efe541de72b9e779d34d7053ba5c771e

drivers/gpu/drm/panel/panel-startek-ili9488.c

diff --git a/drivers/gpu/drm/panel/panel-startek-ili9488.c b/drivers/gpu/drm/panel/panel-startek-ili9488.c
index dd6b753..dec9144 100644
--- a/drivers/gpu/drm/panel/panel-startek-ili9488.c
+++ b/drivers/gpu/drm/panel/panel-startek-ili9488.c
@@ -43,15 +43,15 @@ struct startek_panel {
 };
 
 static const struct drm_display_mode startek_default_timing = {
-	.clock = 26000000 / 1000,
+	.clock = 17700000 / 1000,
 	.hdisplay = 320,
-	.hsync_start = 320 + 170,
-	.hsync_end = 320 + 170 + 50,
-	.htotal = 320 + 170 + 50 + 50,
+	.hsync_start = 320 + 138,
+	.hsync_end = 320 + 138 + 50,
+	.htotal = 320 + 138 + 50 + 100,
 	.vdisplay = 480,
 	.vsync_start = 480 + 2,
 	.vsync_end = 480 + 2 + 1,
-	.vtotal = 480 + 2 + 1 + 1,
+	.vtotal = 480 + 2 + 1 + 2,
 	.vrefresh = 60,
 };
 
@@ -86,16 +86,16 @@ static const struct dcs_command g_startek_init[] = {
 		{.cmd = 0xc5, .para_size = 3, .para = {0x00, 0x1e, 0x80}},
 
 		// Interface Mode Control
-		{.cmd = 0x3a, .para_size = 1, .para = {0x77}},
+		{.cmd = 0x3a, .para_size = 1, .para = {0x06}},
 
-		// Frame rate 70HZ
-		{.cmd = 0xb1, .para_size = 1, .para = {0xb0}},
+		// Frame rate 60HZ
+		{.cmd = 0xb1, .para_size = 2, .para = {0xa0, 0x11}},
 
 		// Display Inversion Control
 		{.cmd = 0xb4, .para_size = 1, .para = {0x02}},
 
 		// Blanking Porch Control
-		{.cmd = 0xb5, .para_size = 4, .para = {0x02, 0x02, 0xaa, 0x64}},
+		{.cmd = 0xb5, .para_size = 4, .para = {0x02, 0x03, 0x8a, 0x96}},
 
 		// Set Image Function
 		{.cmd = 0xe9, .para_size = 1, .para = {0x01}},
@@ -156,7 +156,7 @@ static int startek_init(struct mipi_dsi_device *dsi,
 static int startek_panel_get_modes(struct drm_panel *panel)
 {
 	struct drm_display_mode *mode;
-	static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+	static const u32 bus_format = MEDIA_BUS_FMT_RGB666_1X18;
 	int ret;
 
 	mode = drm_mode_duplicate(panel->drm, &startek_default_timing);
@@ -172,7 +172,7 @@ static int startek_panel_get_modes(struct drm_panel *panel)
 	drm_mode_set_name(mode);
 	drm_mode_probed_add(panel->connector, mode);
 
-	panel->connector->display_info.bpc = 8;
+	panel->connector->display_info.bpc = 6;
 	panel->connector->display_info.height_mm = 49;
 	panel->connector->display_info.width_mm = 74;
 
@@ -332,7 +332,7 @@ static int startek_panel_probe(struct mipi_dsi_device *dsi) {
 	if (!startek)
 		return -ENOMEM;
 
-	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->format = MIPI_DSI_FMT_RGB666_PACKED;
 	dsi->mode_flags =
 		MIPI_DSI_MODE_VIDEO_HSE |
 		MIPI_DSI_MODE_VIDEO |