drm/amd/display: cache additional dpcd caps for HDR capability check

[Why]
Currently we are missing a few checks to see if HDR10 is allowed.
In particular we never check for the extended colorimetry bit (whether its
present or set to 1). Further we don't read in the dpcd block in DC that
would provide these bits.

[How]
- Added in DC code to read in the block containing the extended colorimetry
bit.
Signed-off-by: Harmanprit Tatla <Harmanprit.Tatla@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -2418,6 +2418,10 @@ static bool retrieve_link_cap(struct dc_link *link)
 {
 	uint8_t dpcd_data[DP_ADAPTER_CAP - DP_DPCD_REV + 1];
 
+	/*Only need to read 1 byte starting from DP_DPRX_FEATURE_ENUMERATION_LIST.
+	 */
+	uint8_t dpcd_dprx_data = '\0';
+
 	struct dp_device_vendor_id sink_id;
 	union down_stream_port_count down_strm_port_count;
 	union edp_configuration_cap edp_config_cap;
@@ -2454,7 +2458,10 @@ static bool retrieve_link_cap(struct dc_link *link)
 		aux_rd_interval.raw =
 			dpcd_data[DP_TRAINING_AUX_RD_INTERVAL];
 
-		if (aux_rd_interval.bits.EXT_RECIEVER_CAP_FIELD_PRESENT == 1) {
+		link->dpcd_caps.ext_receiver_cap_field_present =
+				aux_rd_interval.bits.EXT_RECEIVER_CAP_FIELD_PRESENT == 1 ? true:false;
+
+		if (aux_rd_interval.bits.EXT_RECEIVER_CAP_FIELD_PRESENT == 1) {
 			uint8_t ext_cap_data[16];
 
 			memset(ext_cap_data, '\0', sizeof(ext_cap_data));
@@ -2474,6 +2481,31 @@ static bool retrieve_link_cap(struct dc_link *link)
 		}
 	}
 
+	link->dpcd_caps.dpcd_rev.raw =
+			dpcd_data[DP_DPCD_REV - DP_DPCD_REV];
+
+	if (link->dpcd_caps.dpcd_rev.raw >= 0x14) {
+		for (i = 0; i < read_dpcd_retry_cnt; i++) {
+			status = core_link_read_dpcd(
+					link,
+					DP_DPRX_FEATURE_ENUMERATION_LIST,
+					&dpcd_dprx_data,
+					sizeof(dpcd_dprx_data));
+			if (status == DC_OK)
+				break;
+		}
+
+		link->dpcd_caps.dprx_feature.raw = dpcd_dprx_data;
+
+		if (status != DC_OK)
+			dm_error("%s: Read DPRX caps data failed.\n", __func__);
+	}
+
+	else {
+		link->dpcd_caps.dprx_feature.raw = 0;
+	}
+
+
 	/* Error condition checking...
 	 * It is impossible for Sink to report Max Lane Count = 0.
 	 * It is possible for Sink to report Max Link Rate = 0, if it is
@@ -2483,9 +2515,6 @@ static bool retrieve_link_cap(struct dc_link *link)
 	if (dpcd_data[DP_MAX_LANE_COUNT - DP_DPCD_REV] == 0)
 		return false;
 
-	link->dpcd_caps.dpcd_rev.raw =
-		dpcd_data[DP_DPCD_REV - DP_DPCD_REV];
-
 	ds_port.byte = dpcd_data[DP_DOWNSTREAMPORT_PRESENT -
 				 DP_DPCD_REV];
 

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

@@ -681,6 +681,7 @@ struct dpcd_caps {
 	union dpcd_rev dpcd_rev;
 	union max_lane_count max_ln_count;
 	union max_down_spread max_down_spread;
+	union dprx_feature dprx_feature;
 
 	/* valid only for eDP v1.4 or higher*/
 	uint8_t edp_supported_link_rates_count;
@@ -707,6 +708,7 @@ struct dpcd_caps {
 	bool allow_invalid_MSA_timing_param;
 	bool panel_mode_edp;
 	bool dpcd_display_control_capable;
+	bool ext_receiver_cap_field_present;
 };
 
 #include "dc_link.h"

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

@@ -422,10 +422,24 @@ union edp_configuration_cap {
 	uint8_t raw;
 };
 
+union dprx_feature {
+	struct {
+		uint8_t GTC_CAP:1;                             // bit 0: DP 1.3+
+		uint8_t SST_SPLIT_SDP_CAP:1;                   // bit 1: DP 1.4
+		uint8_t AV_SYNC_CAP:1;                         // bit 2: DP 1.3+
+		uint8_t VSC_SDP_COLORIMETRY_SUPPORTED:1;       // bit 3: DP 1.3+
+		uint8_t VSC_EXT_VESA_SDP_SUPPORTED:1;          // bit 4: DP 1.4
+		uint8_t VSC_EXT_VESA_SDP_CHAINING_SUPPORTED:1; // bit 5: DP 1.4
+		uint8_t VSC_EXT_CEA_SDP_SUPPORTED:1;           // bit 6: DP 1.4
+		uint8_t VSC_EXT_CEA_SDP_CHAINING_SUPPORTED:1;  // bit 7: DP 1.4
+	} bits;
+	uint8_t raw;
+};
+
 union training_aux_rd_interval {
 	struct {
 		uint8_t TRAINIG_AUX_RD_INTERVAL:7;
-		uint8_t EXT_RECIEVER_CAP_FIELD_PRESENT:1;
+		uint8_t EXT_RECEIVER_CAP_FIELD_PRESENT:1;
 	} bits;
 	uint8_t raw;
 };