drm/amd/display: Add support for extended DSC DPCD caps

[why]
A few of the new DSC DPCD caps were introduced by a DP 1.4a SCR in order
to give DSC branch decoders a chance to expose their maximum throughput
and maximum line width limitations.
Signed-off-by: NNikola Cornij <nikola.cornij@amd.com>
Reviewed-by: NWenjing Liu <Wenjing.Liu@amd.com>
Acked-by: NBhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -2383,8 +2383,8 @@ static bool retrieve_link_cap(struct dc_link *link)
 	int i;
 	struct dp_sink_hw_fw_revision dp_hw_fw_revision;
 #ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
-	uint8_t dsc_data[16];
-	struct dsc_dec_dpcd_caps *dsc_caps;
+	uint8_t dsc_data[16]; /* DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT + 1 == 16 */
+	struct dsc_dec_dpcd_caps *dsc_dec_caps;
 #endif
 
 	memset(dpcd_data, '\0', sizeof(dpcd_data));
@@ -2558,8 +2558,8 @@ static bool retrieve_link_cap(struct dc_link *link)
 		sizeof(dp_hw_fw_revision.ieee_fw_rev));
 
 #ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
-	dsc_caps = &link->dpcd_caps.dsc_sink_caps;
-	memset(dsc_caps, '\0', sizeof(*dsc_caps));
+	dsc_dec_caps = &link->dpcd_caps.dsc_sink_caps;
+	memset(dsc_dec_caps, '\0', sizeof(*dsc_dec_caps));
 	memset(&link->dpcd_caps.dsc_sink_caps, '\0',
 			sizeof(link->dpcd_caps.dsc_sink_caps));
 	memset(&link->dpcd_caps.fec_cap, '\0', sizeof(link->dpcd_caps.fec_cap));
@@ -2571,7 +2571,7 @@ static bool retrieve_link_cap(struct dc_link *link)
 				dsc_data,
 				sizeof(dsc_data));
 		if (status == DC_OK) {
-			DC_LOG_DSC("DSC capability read at link %d:",
+			DC_LOG_DSC("DSC DPCD capability read at link %d:",
 					link->link_index);
 			DC_LOG_DSC("\t%02x %02x %02x %02x",
 					dsc_data[0], dsc_data[1],
@@ -2590,37 +2590,43 @@ static bool retrieve_link_cap(struct dc_link *link)
 			return false;
 		}
 
-		if (dc_dsc_parse_dsc_dpcd(dsc_data,
-				dsc_caps)) {
-			DC_LOG_DSC("DSC capability parsed at link %d:",
+		if (dc_dsc_parse_dsc_dpcd(dsc_data, NULL,
+				dsc_dec_caps)) {
+			DC_LOG_DSC("DSC DPCD capabilities parsed at link %d:",
 					link->link_index);
 			DC_LOG_DSC("\tis_dsc_supported:\t%d",
-					dsc_caps->is_dsc_supported);
-			DC_LOG_DSC("\tdsc_version:\t%d", dsc_caps->dsc_version);
+					dsc_dec_caps->is_dsc_supported);
+			DC_LOG_DSC("\tdsc_version:\t%d", dsc_dec_caps->dsc_version);
 			DC_LOG_DSC("\trc_buffer_size:\t%d",
-					dsc_caps->rc_buffer_size);
+					dsc_dec_caps->rc_buffer_size);
 			DC_LOG_DSC("\tslice_caps1:\t0x%x20",
-					dsc_caps->slice_caps1.raw);
+					dsc_dec_caps->slice_caps1.raw);
 			DC_LOG_DSC("\tslice_caps2:\t0x%x20",
-					dsc_caps->slice_caps2.raw);
+					dsc_dec_caps->slice_caps2.raw);
 			DC_LOG_DSC("\tlb_bit_depth:\t%d",
-					dsc_caps->lb_bit_depth);
+					dsc_dec_caps->lb_bit_depth);
 			DC_LOG_DSC("\tis_block_pred_supported:\t%d",
-					dsc_caps->is_block_pred_supported);
+					dsc_dec_caps->is_block_pred_supported);
 			DC_LOG_DSC("\tedp_max_bits_per_pixel:\t%d",
-					dsc_caps->edp_max_bits_per_pixel);
+					dsc_dec_caps->edp_max_bits_per_pixel);
 			DC_LOG_DSC("\tcolor_formats:\t%d",
-					dsc_caps->color_formats.raw);
+					dsc_dec_caps->color_formats.raw);
 			DC_LOG_DSC("\tcolor_depth:\t%d",
-					dsc_caps->color_depth.raw);
+					dsc_dec_caps->color_depth.raw);
 			DC_LOG_DSC("\tthroughput_mode_0_mps:\t%d",
-					dsc_caps->throughput_mode_0_mps);
+					dsc_dec_caps->throughput_mode_0_mps);
 			DC_LOG_DSC("\tthroughput_mode_1_mps:\t%d",
-					dsc_caps->throughput_mode_1_mps);
+					dsc_dec_caps->throughput_mode_1_mps);
 			DC_LOG_DSC("\tmax_slice_width:\t%d",
-					dsc_caps->max_slice_width);
+					dsc_dec_caps->max_slice_width);
 			DC_LOG_DSC("\tbpp_increment_div:\t%d",
-					dsc_caps->bpp_increment_div);
+					dsc_dec_caps->bpp_increment_div);
+			DC_LOG_DSC("\tbranch_overall_throughput_0_mps:\t%d",
+					dsc_dec_caps->branch_overall_throughput_0_mps);
+			DC_LOG_DSC("\tbranch_overall_throughput_1_mps:\t%d",
+					dsc_dec_caps->branch_overall_throughput_1_mps);
+			DC_LOG_DSC("\tbranch_max_line_width:\t%d",
+					dsc_dec_caps->branch_max_line_width);
 		} else {
 			/* Some sinks return bogus DSC DPCD data
 			 * when they don't support DSC.

drivers/gpu/drm/amd/display/dc/dc_dsc.h

@@ -34,7 +34,8 @@ struct dc_dsc_bw_range {
 };
 
 
-bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_data,
+bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_basic_data,
+		const uint8_t *dpcd_dsc_ext_data,
 		struct dsc_dec_dpcd_caps *dsc_sink_caps);
 
 bool dc_dsc_compute_bandwidth_range(

drivers/gpu/drm/amd/display/dc/dc_types.h

@@ -773,6 +773,11 @@ struct dsc_dec_dpcd_caps {
 	int32_t throughput_mode_1_mps; /* In MPs */
 	int32_t max_slice_width;
 	uint32_t bpp_increment_div; /* bpp increment divisor, e.g. if 16, it's 1/16th of a bit */
+
+	/* Extended DSC caps */
+	uint32_t branch_overall_throughput_0_mps; /* In MPs */
+	uint32_t branch_overall_throughput_1_mps; /* In MPs */
+	uint32_t branch_max_line_width;
 };
 #endif
 #endif /* DC_TYPES_H_ */

drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c

@@ -252,7 +252,7 @@ struct dc_dsc_policy {
 	int min_target_bpp; // Minimum target bits per pixel
 };
 
-static inline uint32_t dsc_round_up(uint32_t value)
+static inline uint32_t dsc_div_by_10_round_up(uint32_t value)
 {
 	return (value + 9) / 10;
 }
@@ -304,7 +304,7 @@ static void get_dsc_bandwidth_range(
 	range->stream_kbps = dc_bandwidth_in_kbps_from_timing(timing);
 
 	/* max dsc target bpp */
-	range->max_kbps = dsc_round_up(max_bpp * timing->pix_clk_100hz);
+	range->max_kbps = dsc_div_by_10_round_up(max_bpp * timing->pix_clk_100hz);
 	range->max_target_bpp_x16 = max_bpp * 16;
 	if (range->max_kbps > range->stream_kbps) {
 		/* max dsc target bpp is capped to native bandwidth */
@@ -313,7 +313,7 @@ static void get_dsc_bandwidth_range(
 	}
 
 	/* min dsc target bpp */
-	range->min_kbps = dsc_round_up(min_bpp * timing->pix_clk_100hz);
+	range->min_kbps = dsc_div_by_10_round_up(min_bpp * timing->pix_clk_100hz);
 	range->min_target_bpp_x16 = min_bpp * 16;
 	if (range->min_kbps > range->max_kbps) {
 		/* min dsc target bpp is capped to max dsc bandwidth*/
@@ -532,16 +532,23 @@ static bool setup_dsc_config(
 	int pic_width;
 	int slice_width;
 	int target_bpp;
-	int sink_per_slice_throughput;
+	int sink_per_slice_throughput_mps;
+	int branch_max_throughput_mps = 0;
 	bool is_dsc_possible = false;
 	int num_slices_v;
 	int pic_height;
 
 	memset(dsc_cfg, 0, sizeof(struct dc_dsc_config));
 
+	pic_width = timing->h_addressable + timing->h_border_left + timing->h_border_right;
+	pic_height = timing->v_addressable + timing->v_border_top + timing->v_border_bottom;
+
 	if (!dsc_sink_caps->is_dsc_supported)
 		goto done;
 
+	if (dsc_sink_caps->branch_max_line_width && dsc_sink_caps->branch_max_line_width < pic_width)
+		goto done;
+
 	// Intersect decoder with encoder DSC caps and validate DSC settings
 	is_dsc_possible = intersect_dsc_caps(dsc_sink_caps, dsc_enc_caps, timing->pixel_encoding, &dsc_common_caps);
 	if (!is_dsc_possible)
@@ -554,39 +561,46 @@ static bool setup_dsc_config(
 	if (!is_dsc_possible)
 		goto done;
 
-	sink_per_slice_throughput = 0;
+	sink_per_slice_throughput_mps = 0;
 
 	// Validate available DSC settings against the mode timing
 
-	// Color format
+	// Validate color format (and pick up the throughput values)
 	dsc_cfg->ycbcr422_simple = false;
 	switch (timing->pixel_encoding)	{
 	case PIXEL_ENCODING_RGB:
 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.RGB;
-		sink_per_slice_throughput = dsc_sink_caps->throughput_mode_0_mps;
+		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
+		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
 		break;
 	case PIXEL_ENCODING_YCBCR444:
 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_444;
-		sink_per_slice_throughput = dsc_sink_caps->throughput_mode_0_mps;
-		break;
-	case PIXEL_ENCODING_YCBCR422: {
-			is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_422;
-			sink_per_slice_throughput = dsc_sink_caps->throughput_mode_1_mps;
-			if (!is_dsc_possible) {
-				is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_SIMPLE_422;
-				dsc_cfg->ycbcr422_simple = is_dsc_possible;
-				sink_per_slice_throughput = dsc_sink_caps->throughput_mode_0_mps;
-			}
+		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
+		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_0_mps;
+		break;
+	case PIXEL_ENCODING_YCBCR422:
+		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_422;
+		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
+		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
+		if (!is_dsc_possible) {
+			is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_SIMPLE_422;
+			dsc_cfg->ycbcr422_simple = is_dsc_possible;
+			sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_0_mps;
 		}
 		break;
 	case PIXEL_ENCODING_YCBCR420:
 		is_dsc_possible = (bool)dsc_common_caps.color_formats.bits.YCBCR_NATIVE_420;
-		sink_per_slice_throughput = dsc_sink_caps->throughput_mode_1_mps;
+		sink_per_slice_throughput_mps = dsc_sink_caps->throughput_mode_1_mps;
+		branch_max_throughput_mps = dsc_sink_caps->branch_overall_throughput_1_mps;
 		break;
 	default:
 		is_dsc_possible = false;
 	}
 
+	// Validate branch's maximum throughput
+	if (branch_max_throughput_mps && dsc_div_by_10_round_up(timing->pix_clk_100hz) > branch_max_throughput_mps * 1000)
+		is_dsc_possible = false;
+
 	if (!is_dsc_possible)
 		goto done;
 
@@ -611,7 +625,6 @@ static bool setup_dsc_config(
 	// DSC slicing
 	max_slices_h = get_max_dsc_slices(dsc_common_caps.slice_caps);
 
-	pic_width = timing->h_addressable + timing->h_border_left + timing->h_border_right;
 	while (max_slices_h > 0) {
 		if (pic_width % max_slices_h == 0)
 			break;
@@ -630,7 +643,8 @@ static bool setup_dsc_config(
 	min_slices_h = fit_num_slices_up(dsc_common_caps.slice_caps, min_slices_h);
 
 	while (min_slices_h <= max_slices_h) {
-		if (dsc_round_up(timing->pix_clk_100hz) / (min_slices_h) <= sink_per_slice_throughput * 1000)
+		int pix_clk_per_slice_khz = dsc_div_by_10_round_up(timing->pix_clk_100hz) / min_slices_h;
+		if (pix_clk_per_slice_khz <= sink_per_slice_throughput_mps * 1000)
 			break;
 
 		min_slices_h = inc_num_slices(dsc_common_caps.slice_caps, min_slices_h);
@@ -673,7 +687,6 @@ static bool setup_dsc_config(
 
 	// Vertical number of slices: start from policy and pick the first one that height is divisible by.
 	// For 4:2:0 make sure the slice height is divisible by 2 as well.
-	pic_height = timing->v_addressable + timing->v_border_top + timing->v_border_bottom;
 	num_slices_v = dsc_policy.num_slices_v;
 	if (num_slices_v < 1)
 		num_slices_v = 1;
@@ -710,41 +723,41 @@ static bool setup_dsc_config(
 	return is_dsc_possible;
 }
 
-bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_data, struct dsc_dec_dpcd_caps *dsc_sink_caps)
+bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_basic_data, const uint8_t *dpcd_dsc_ext_data, struct dsc_dec_dpcd_caps *dsc_sink_caps)
 {
-	dsc_sink_caps->is_dsc_supported = (dpcd_dsc_data[DP_DSC_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) != 0;
+	dsc_sink_caps->is_dsc_supported = (dpcd_dsc_basic_data[DP_DSC_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_DECOMPRESSION_IS_SUPPORTED) != 0;
 	if (!dsc_sink_caps->is_dsc_supported)
 		return true;
 
-	dsc_sink_caps->dsc_version = dpcd_dsc_data[DP_DSC_REV - DP_DSC_SUPPORT];
+	dsc_sink_caps->dsc_version = dpcd_dsc_basic_data[DP_DSC_REV - DP_DSC_SUPPORT];
 
 	{
 		int buff_block_size;
 		int buff_size;
 
-		if (!dsc_buff_block_size_from_dpcd(dpcd_dsc_data[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT], &buff_block_size))
+		if (!dsc_buff_block_size_from_dpcd(dpcd_dsc_basic_data[DP_DSC_RC_BUF_BLK_SIZE - DP_DSC_SUPPORT], &buff_block_size))
 			return false;
 
-		buff_size = dpcd_dsc_data[DP_DSC_RC_BUF_SIZE - DP_DSC_SUPPORT] + 1;
+		buff_size = dpcd_dsc_basic_data[DP_DSC_RC_BUF_SIZE - DP_DSC_SUPPORT] + 1;
 		dsc_sink_caps->rc_buffer_size = buff_size * buff_block_size;
 	}
 
-	dsc_sink_caps->slice_caps1.raw = dpcd_dsc_data[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
-	if (!dsc_line_buff_depth_from_dpcd(dpcd_dsc_data[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT], &dsc_sink_caps->lb_bit_depth))
+	dsc_sink_caps->slice_caps1.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
+	if (!dsc_line_buff_depth_from_dpcd(dpcd_dsc_basic_data[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT], &dsc_sink_caps->lb_bit_depth))
 		return false;
 
 	dsc_sink_caps->is_block_pred_supported =
-		(dpcd_dsc_data[DP_DSC_BLK_PREDICTION_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_BLK_PREDICTION_IS_SUPPORTED) != 0;
+		(dpcd_dsc_basic_data[DP_DSC_BLK_PREDICTION_SUPPORT - DP_DSC_SUPPORT] & DP_DSC_BLK_PREDICTION_IS_SUPPORTED) != 0;
 
 	dsc_sink_caps->edp_max_bits_per_pixel =
-		dpcd_dsc_data[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
-		dpcd_dsc_data[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] << 8;
+		dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_LOW - DP_DSC_SUPPORT] |
+		dpcd_dsc_basic_data[DP_DSC_MAX_BITS_PER_PIXEL_HI - DP_DSC_SUPPORT] << 8;
 
-	dsc_sink_caps->color_formats.raw = dpcd_dsc_data[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT];
-	dsc_sink_caps->color_depth.raw = dpcd_dsc_data[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
+	dsc_sink_caps->color_formats.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_FORMAT_CAP - DP_DSC_SUPPORT];
+	dsc_sink_caps->color_depth.raw = dpcd_dsc_basic_data[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
 
 	{
-		int dpcd_throughput = dpcd_dsc_data[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT];
+		int dpcd_throughput = dpcd_dsc_basic_data[DP_DSC_PEAK_THROUGHPUT - DP_DSC_SUPPORT];
 
 		if (!dsc_throughput_from_dpcd(dpcd_throughput & DP_DSC_THROUGHPUT_MODE_0_MASK, &dsc_sink_caps->throughput_mode_0_mps))
 			return false;
@@ -754,12 +767,43 @@ bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_data, struct dsc_dec_dpcd_cap
 			return false;
 	}
 
-	dsc_sink_caps->max_slice_width = dpcd_dsc_data[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] * 320;
-	dsc_sink_caps->slice_caps2.raw = dpcd_dsc_data[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
+	dsc_sink_caps->max_slice_width = dpcd_dsc_basic_data[DP_DSC_MAX_SLICE_WIDTH - DP_DSC_SUPPORT] * 320;
+	dsc_sink_caps->slice_caps2.raw = dpcd_dsc_basic_data[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
 
-	if (!dsc_bpp_increment_div_from_dpcd(dpcd_dsc_data[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT], &dsc_sink_caps->bpp_increment_div))
+	if (!dsc_bpp_increment_div_from_dpcd(dpcd_dsc_basic_data[DP_DSC_BITS_PER_PIXEL_INC - DP_DSC_SUPPORT], &dsc_sink_caps->bpp_increment_div))
 		return false;
 
+	/* Extended caps */
+	if (dpcd_dsc_ext_data == NULL) { // Extended DPCD DSC data can be null, e.g. because it doesn't apply to SST
+		dsc_sink_caps->branch_overall_throughput_0_mps = 0;
+		dsc_sink_caps->branch_overall_throughput_1_mps = 0;
+		dsc_sink_caps->branch_max_line_width = 0;
+		return true;
+	}
+
+	dsc_sink_caps->branch_overall_throughput_0_mps = dpcd_dsc_ext_data[DP_DSC_BRANCH_OVERALL_THROUGHPUT_0 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
+	if (dsc_sink_caps->branch_overall_throughput_0_mps == 0)
+		dsc_sink_caps->branch_overall_throughput_0_mps = 0;
+	else if (dsc_sink_caps->branch_overall_throughput_0_mps == 1)
+		dsc_sink_caps->branch_overall_throughput_0_mps = 680;
+	else {
+		dsc_sink_caps->branch_overall_throughput_0_mps *= 50;
+		dsc_sink_caps->branch_overall_throughput_0_mps += 600;
+	}
+
+	dsc_sink_caps->branch_overall_throughput_1_mps = dpcd_dsc_ext_data[DP_DSC_BRANCH_OVERALL_THROUGHPUT_1 - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0];
+	if (dsc_sink_caps->branch_overall_throughput_1_mps == 0)
+		dsc_sink_caps->branch_overall_throughput_1_mps = 0;
+	else if (dsc_sink_caps->branch_overall_throughput_1_mps == 1)
+		dsc_sink_caps->branch_overall_throughput_1_mps = 680;
+	else {
+		dsc_sink_caps->branch_overall_throughput_1_mps *= 50;
+		dsc_sink_caps->branch_overall_throughput_1_mps += 600;
+	}
+
+	dsc_sink_caps->branch_max_line_width = dpcd_dsc_ext_data[DP_DSC_BRANCH_MAX_LINE_WIDTH - DP_DSC_BRANCH_OVERALL_THROUGHPUT_0] * 320;
+	ASSERT(dsc_sink_caps->branch_max_line_width == 0 || dsc_sink_caps->branch_max_line_width >= 5120);
+
 	return true;
 }
 

drivers/gpu/drm/amd/display/include/dpcd_structs.h

+/*
+ * dpcd_structs.h
+ *
+ *  Created on: Oct 31, 2018
+ *      Author: jlei
+ */
+
+#ifndef DAL_INCLUDE_DPCD_STRUCTS_H_
+#define DAL_INCLUDE_DPCD_STRUCTS_H_
+
+struct dpcd_receive_port0_cap01 {
+	union {
+		struct {
+			// Byte 0
+			unsigned char reserved0				:1; // Bit0
+			unsigned char local_edid_present		:1;
+			unsigned char associated_to_preceding_port	:1;
+			unsigned char hblank_expansion_capable		:1;
+			unsigned char buffer_size_unit			:1; // Bit4
+			unsigned char buffer_size_per_port		:1;
+			unsigned char reserved1				:2;
+
+			// Byte 1
+			unsigned char buffer_size			:8;
+		} fields;
+		unsigned char raw[2];
+	};
+};
+
+#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
+
+struct dpcd_dsc_basic_capabilities {
+	union {
+		struct {
+			// Byte 0
+			struct {
+
+				unsigned char dsc_support				:1; // Bit0
+				unsigned char reserved					:7;
+			} dsc_support;
+
+			// Byte 1
+			struct {
+				unsigned char dsc_version_major	:4;
+				unsigned char dsc_version_minor	:4;
+			} dsc_algorithm_revision;
+
+			// Byte 2
+			struct {
+				unsigned char rc_block_buffer_size	:2;
+				unsigned char reserved	:6;
+			} dsc_rc_buffer_block_size;
+
+			// Byte 3
+			unsigned char dsc_rc_buffer_size;
+
+			// Byte 4
+			struct {
+				unsigned char one_slice_per_dp_dsc_sink_device		:1; // Bit0
+				unsigned char two_slices_per_dp_dsc_sink_device		:1;
+				unsigned char reserved					:1;
+				unsigned char four_slices_per_dp_dsc_sink_device	:1;
+				unsigned char six_slices_per_dp_dsc_sink_device		:1; // Bit 4
+				unsigned char eight_slices_per_dp_dsc_sink_device	:1;
+				unsigned char ten_slices_per_dp_dsc_sink_device		:1;
+				unsigned char twelve_slices_per_dp_dsc_sink_device	:1;
+			} dsc_slice_capabilities_1;
+
+			// Byte 5
+			struct {
+				unsigned char line_buffer_bit_depth	:4;
+				unsigned char reserved			:4;
+			} dsc_line_buffer_bit_depth;
+
+			// Byte 6
+			struct {
+				unsigned char block_prediction_support	:1;
+				unsigned char reserved			:7;
+			} dsc_block_prediction_support;
+
+			// Byte 7,8
+			struct {
+				unsigned char maximum_bits_per_pixel_supported_by_the_decompressor_low	:7;
+				unsigned char maximum_bits_per_pixel_supported_by_the_decompressor_high	:7;
+			} maximum_bits_per_pixel_supported_by_the_decompressor;
+
+			// Byte 9
+			struct {
+				unsigned char rgb_support			:1; // Bit0
+				unsigned char y_cb_cr_444_support		:1;
+				unsigned char y_cb_cr_simple_422_support	:1;
+				unsigned char y_cb_cr_native_422_support	:1;
+				unsigned char y_cb_cr_native_420_support	:1; // Bit 4
+				unsigned char reserved				:3;
+			} dsc_decoder_color_format_capabilities;
+
+			// Byte 10
+			struct {
+				unsigned char reserved0				:1; // Bit0
+				unsigned char eight_bits_per_color_support	:1;
+				unsigned char ten_bits_per_color_support	:1;
+				unsigned char twelve_bits_per_color_support	:1;
+				unsigned char reserved1				:4; // Bit 4
+			} dsc_decoder_color_depth_capabilities;
+
+			// Byte 11
+			struct {
+				unsigned char throughput_mode_0			:4;
+				unsigned char throughput_mode_1			:4;
+			} peak_dsc_throughput_dsc_sink;
+
+			// Byte 12
+			unsigned char dsc_maximum_slice_width;
+
+			// Byte 13
+			struct {
+				unsigned char sixteen_slices_per_dsc_sink_device	:1;
+				unsigned char twenty_slices_per_dsc_sink_device		:1;
+				unsigned char twentyfour_slices_per_dsc_sink_device	:1;
+				unsigned char reserved					:5;
+			} dsc_slice_capabilities_2;
+
+			// Byte 14
+			unsigned char reserved;
+
+			// Byte 15
+			struct {
+				unsigned char increment_of_bits_per_pixel_supported	:3;
+				unsigned char reserved					:5;
+			} bits_per_pixel_increment;
+		} fields;
+		unsigned char raw[16];
+	};
+};
+
+struct dpcd_dsc_ext_capabilities {
+	union {
+		struct {
+			unsigned char branch_overall_throughput_0; // Byte 0
+			unsigned char branch_overall_throughput_1; // Byte 1
+			unsigned char branch_max_line_width; // Byte 2
+		} fields;
+		unsigned char raw[3];
+	};
+};
+
+struct dpcd_dsc_capabilities {
+	struct dpcd_dsc_basic_capabilities dsc_basic_caps;
+	struct dpcd_dsc_ext_capabilities dsc_ext_caps;
+};
+
+struct dpcd_fec_capability {
+	union {
+		struct {
+			// Byte 0
+			unsigned char fec_capable				:1; // Bit0
+			unsigned char uncorrected_block_error_count_capable	:1;
+			unsigned char corrected_block_error_count_capable	:1;
+			unsigned char bit_error_count_capable			:1;
+			unsigned char reserved					:4; // Bit4
+		} fields;
+		unsigned char raw[1];
+	};
+};
+
+#endif
+
+#endif /* DAL_INCLUDE_DPCD_STRUCTS_H_ */

include/drm/drm_dp_helper.h

@@ -356,6 +356,11 @@
 # define DP_FEC_CORR_BLK_ERROR_COUNT_CAP    (1 << 2)
 # define DP_FEC_BIT_ERROR_COUNT_CAP	    (1 << 3)
 
+/* DP Extended DSC Capabilities */
+#define DP_DSC_BRANCH_OVERALL_THROUGHPUT_0  0x0a0   /* DP 1.4a SCR */
+#define DP_DSC_BRANCH_OVERALL_THROUGHPUT_1  0x0a1
+#define DP_DSC_BRANCH_MAX_LINE_WIDTH        0x0a2
+
 /* link configuration */
 #define	DP_LINK_BW_SET		            0x100
 # define DP_LINK_RATE_TABLE		    0x00    /* eDP 1.4 */