drm/panel: sitronix-st7789v: add Inanbo T28CP45TN89 support

UNI-T UTi260b has a Inanbo T28CP45TN89 v17 panel. I could not find
proper documentation for the panel apart from a technical drawing, but
according to the vendor U-Boot it is based on a Sitronix st7789v chip.
I generated the init sequence by modifying the default one until proper
graphics output has been seen on the device.
Reviewed-by: Michael Riesch <michael.riesch@wolfvision.net>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714013756.1546769-14-sre@kernel.org

drivers/gpu/drm/panel/panel-sitronix-st7789v.c

@@ -173,6 +173,21 @@ static const struct drm_display_mode default_mode = {
 	.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
 };
 
+static const struct drm_display_mode t28cp45tn89_mode = {
+	.clock = 6008,
+	.hdisplay = 240,
+	.hsync_start = 240 + 38,
+	.hsync_end = 240 + 38 + 10,
+	.htotal = 240 + 38 + 10 + 10,
+	.vdisplay = 320,
+	.vsync_start = 320 + 8,
+	.vsync_end = 320 + 8 + 4,
+	.vtotal = 320 + 8 + 4 + 4,
+	.width_mm = 43,
+	.height_mm = 57,
+	.flags = DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC,
+};
+
 static const struct st7789_panel_info default_panel = {
 	.mode = &default_mode,
 	.invert_mode = true,
@@ -181,6 +196,14 @@ static const struct st7789_panel_info default_panel = {
 		     DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE,
 };
 
+static const struct st7789_panel_info t28cp45tn89_panel = {
+	.mode = &t28cp45tn89_mode,
+	.invert_mode = false,
+	.bus_format = MEDIA_BUS_FMT_RGB565_1X16,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH |
+		     DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
+};
+
 static int st7789v_get_modes(struct drm_panel *panel,
 			     struct drm_connector *connector)
 {
@@ -446,12 +469,14 @@ static void st7789v_remove(struct spi_device *spi)
 
 static const struct spi_device_id st7789v_spi_id[] = {
 	{ "st7789v", (unsigned long) &default_panel },
+	{ "t28cp45tn89-v17", (unsigned long) &t28cp45tn89_panel },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, st7789v_spi_id);
 
 static const struct of_device_id st7789v_of_match[] = {
 	{ .compatible = "sitronix,st7789v", .data = &default_panel },
+	{ .compatible = "inanbo,t28cp45tn89-v17", .data = &t28cp45tn89_panel },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, st7789v_of_match);