drm/tidss: Add support for AM62A7 DSS

Add support for the DSS controller on TI's AM62A7 SoC in the tidss
driver.

This controller has 2 video pipelines that can render 2 video planes on
over a screen, using the overlay managers. The output of the DSS comes
from video port 2 (VP2) in the form of RGB88 DPI signals, while the VP1
is tied off inside the SoC.

Also add and use a new type of VP, DISPC_VP_TIED_OFF, for the tied-off
VP1 of AM62A DSS.

Signed-off-by: Aradhya Bhatia <[e-mail]>
Reviewed-by: Tomi Valkeinen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Tomi Valkeinen <[e-mail]>

drivers/gpu/drm/tidss/tidss_dispc.c

···
 	.vid_order = { 1, 0 },
 };
 
+const struct dispc_features dispc_am62a7_feats = {
+	/*
+	 * if the code reaches dispc_mode_valid with VP1,
+	 * it should return MODE_BAD.
+	 */
+	.max_pclk_khz = {
+		[DISPC_VP_TIED_OFF] = 0,
+		[DISPC_VP_DPI] = 165000,
+	},
+
+	.scaling = {
+		.in_width_max_5tap_rgb = 1280,
+		.in_width_max_3tap_rgb = 2560,
+		.in_width_max_5tap_yuv = 2560,
+		.in_width_max_3tap_yuv = 4096,
+		.upscale_limit = 16,
+		.downscale_limit_5tap = 4,
+		.downscale_limit_3tap = 2,
+		/*
+		 * The max supported pixel inc value is 255. The value
+		 * of pixel inc is calculated like this: 1+(xinc-1)*bpp.
+		 * The maximum bpp of all formats supported by the HW
+		 * is 8. So the maximum supported xinc value is 32,
+		 * because 1+(32-1)*8 < 255 < 1+(33-1)*4.
+		 */
+		.xinc_max = 32,
+	},
+
+	.subrev = DISPC_AM62A7,
+
+	.common = "common",
+	.common_regs = tidss_am65x_common_regs,
+
+	.num_vps = 2,
+	.vp_name = { "vp1", "vp2" },
+	.ovr_name = { "ovr1", "ovr2" },
+	.vpclk_name =  { "vp1", "vp2" },
+	/* VP1 of the DSS in AM62A7 SoC is tied off internally */
+	.vp_bus_type = { DISPC_VP_TIED_OFF, DISPC_VP_DPI },
+
+	.vp_feat = { .color = {
+			.has_ctm = true,
+			.gamma_size = 256,
+			.gamma_type = TIDSS_GAMMA_8BIT,
+		},
+	},
+
+	.num_planes = 2,
+	/* note: vid is plane_id 0 and vidl1 is plane_id 1 */
+	.vid_name = { "vid", "vidl1" },
+	.vid_lite = { false, true, },
+	.vid_order = { 1, 0 },
+};
+
 static const u16 *dispc_common_regmap;
 
 struct dss_vp_data {
···
 	case DISPC_K2G:
 		return dispc_k2g_read_and_clear_irqstatus(dispc);
 	case DISPC_AM625:
+	case DISPC_AM62A7:
 	case DISPC_AM65X:
 	case DISPC_J721E:
 		return dispc_k3_read_and_clear_irqstatus(dispc);
···
 		dispc_k2g_set_irqenable(dispc, mask);
 		break;
 	case DISPC_AM625:
+	case DISPC_AM62A7:
 	case DISPC_AM65X:
 	case DISPC_J721E:
 		dispc_k3_set_irqenable(dispc, mask);
···
 					x, y, layer);
 		break;
 	case DISPC_AM625:
+	case DISPC_AM62A7:
 	case DISPC_AM65X:
 		dispc_am65x_ovr_set_plane(dispc, hw_plane, hw_videoport,
 					  x, y, layer);
···
 		dispc_k2g_plane_init(dispc);
 		break;
 	case DISPC_AM625:
+	case DISPC_AM62A7:
 	case DISPC_AM65X:
 	case DISPC_J721E:
 		dispc_k3_plane_init(dispc);
···
 		dispc_k2g_vp_write_gamma_table(dispc, hw_videoport);
 		break;
 	case DISPC_AM625:
+	case DISPC_AM62A7:
 	case DISPC_AM65X:
 		dispc_am65x_vp_write_gamma_table(dispc, hw_videoport);
 		break;

drivers/gpu/drm/tidss/tidss_dispc.h

···
 	DISPC_VP_DPI,		/* DPI output */
 	DISPC_VP_OLDI,		/* OLDI (LVDS) output */
 	DISPC_VP_INTERNAL,	/* SoC internal routing */
+	DISPC_VP_TIED_OFF,	/* Tied off / Unavailable */
 	DISPC_VP_MAX_BUS_TYPE,
 };
 
 enum dispc_dss_subrevision {
 	DISPC_K2G,
 	DISPC_AM625,
+	DISPC_AM62A7,
 	DISPC_AM65X,
 	DISPC_J721E,
 };
···
 
 extern const struct dispc_features dispc_k2g_feats;
 extern const struct dispc_features dispc_am625_feats;
+extern const struct dispc_features dispc_am62a7_feats;
 extern const struct dispc_features dispc_am65x_feats;
 extern const struct dispc_features dispc_j721e_feats;
 

drivers/gpu/drm/tidss/tidss_drv.c

···
 static const struct of_device_id tidss_of_table[] = {
 	{ .compatible = "ti,k2g-dss", .data = &dispc_k2g_feats, },
 	{ .compatible = "ti,am625-dss", .data = &dispc_am625_feats, },
+	{ .compatible = "ti,am62a7-dss", .data = &dispc_am62a7_feats, },
 	{ .compatible = "ti,am65x-dss", .data = &dispc_am65x_feats, },
 	{ .compatible = "ti,j721e-dss", .data = &dispc_j721e_feats, },
 	{ }