drm/amd/display: Update display endpoint control path.

[Why]
Some display endpoints may be dynamically mapped to the link encoders
which drive them.

[How]
Update the code paths for display enabling/disabling to accommodate
the dynamic association between links and link encoders.
Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1728,11 +1728,16 @@ bool perform_link_training_with_retries(
 		if (link->aux_access_disabled) {
 			dc_link_dp_perform_link_training_skip_aux(link, link_setting);
 			return true;
-		} else if (dc_link_dp_perform_link_training(
-				link,
-				link_setting,
-				skip_video_pattern) == LINK_TRAINING_SUCCESS)
-			return true;
+		} else {
+			enum link_training_result status = LINK_TRAINING_CR_FAIL_LANE0;
+
+				status = dc_link_dp_perform_link_training(
+										link,
+										link_setting,
+										skip_video_pattern);
+			if (status == LINK_TRAINING_SUCCESS)
+				return true;
+		}
 
 		/* latest link training still fail, skip delay and keep PHY on
 		 */

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

@@ -127,6 +127,32 @@ static enum engine_id find_first_avail_link_enc(
 	return eng_id;
 }
 
+/* Return stream using DIG link encoder resource. NULL if unused. */
+static struct dc_stream_state *get_stream_using_link_enc(
+		struct dc_state *state,
+		enum engine_id eng_id)
+{
+	struct dc_stream_state *stream = NULL;
+	int stream_idx = -1;
+	int i;
+
+	for (i = 0; i < state->stream_count; i++) {
+		struct link_enc_assignment assignment = state->res_ctx.link_enc_assignments[i];
+
+		if (assignment.valid && (assignment.eng_id == eng_id)) {
+			stream_idx = i;
+			break;
+		}
+	}
+
+	if (stream_idx != -1)
+		stream = state->streams[stream_idx];
+	else
+		dm_output_to_console("%s: No stream using DIG(%d).\n", __func__, eng_id);
+
+	return stream;
+}
+
 void link_enc_cfg_init(
 		struct dc *dc,
 		struct dc_state *state)
@@ -202,3 +228,76 @@ void link_enc_cfg_link_enc_unassign(
 
 	update_link_enc_assignment(state, stream, eng_id, false);
 }
+
+bool link_enc_cfg_is_transmitter_mappable(
+		struct dc_state *state,
+		struct link_encoder *link_enc)
+{
+	bool is_mappable = false;
+	enum engine_id eng_id = link_enc->preferred_engine;
+	struct dc_stream_state *stream = get_stream_using_link_enc(state, eng_id);
+
+	if (stream)
+		is_mappable = stream->link->is_dig_mapping_flexible;
+
+	return is_mappable;
+}
+
+struct dc_link *link_enc_cfg_get_link_using_link_enc(
+		struct dc_state *state,
+		enum engine_id eng_id)
+{
+	struct dc_link *link = NULL;
+	int stream_idx = -1;
+	int i;
+
+	for (i = 0; i < state->stream_count; i++) {
+		struct link_enc_assignment assignment = state->res_ctx.link_enc_assignments[i];
+
+		if (assignment.valid && (assignment.eng_id == eng_id)) {
+			stream_idx = i;
+			break;
+		}
+	}
+
+	if (stream_idx != -1)
+		link = state->streams[stream_idx]->link;
+	else
+		dm_output_to_console("%s: No link using DIG(%d).\n", __func__, eng_id);
+
+	return link;
+}
+
+struct link_encoder *link_enc_cfg_get_link_enc_used_by_link(
+		struct dc_state *state,
+		struct dc_link *link)
+{
+	struct link_encoder *link_enc = NULL;
+	struct display_endpoint_id ep_id;
+	int stream_idx = -1;
+	int i;
+
+	ep_id = (struct display_endpoint_id) {
+		.link_id = link->link_id,
+		.ep_type = link->ep_type};
+
+	for (i = 0; i < state->stream_count; i++) {
+		struct link_enc_assignment assignment = state->res_ctx.link_enc_assignments[i];
+
+		if (assignment.valid &&
+				assignment.ep_id.link_id.id == ep_id.link_id.id &&
+				assignment.ep_id.link_id.enum_id == ep_id.link_id.enum_id &&
+				assignment.ep_id.link_id.type == ep_id.link_id.type &&
+				assignment.ep_id.ep_type == ep_id.ep_type) {
+			stream_idx = i;
+			break;
+		}
+	}
+
+	if (stream_idx != -1)
+		link_enc = state->streams[stream_idx]->link_enc;
+	else
+		dm_output_to_console("%s: No link encoder used by link(%d).\n", __func__, link->link_index);
+
+	return link_enc;
+}

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

@@ -14,6 +14,7 @@
 #include "dpcd_defs.h"
 #include "dsc.h"
 #include "resource.h"
+#include "link_enc_cfg.h"
 #include "clk_mgr.h"
 
 static uint8_t convert_to_count(uint8_t lttpr_repeater_count)
@@ -95,7 +96,7 @@ void dp_enable_link_phy(
 	enum clock_source_id clock_source,
 	const struct dc_link_settings *link_settings)
 {
-	struct link_encoder *link_enc = link->link_enc;
+	struct link_encoder *link_enc;
 	struct dc  *dc = link->ctx->dc;
 	struct dmcu *dmcu = dc->res_pool->dmcu;
 
@@ -105,6 +106,13 @@ void dp_enable_link_phy(
 			link->dc->res_pool->dp_clock_source;
 	unsigned int i;
 
+	/* Link should always be assigned encoder when en-/disabling. */
+	if (link->is_dig_mapping_flexible && dc->res_pool->funcs->link_encs_assign)
+		link_enc = link_enc_cfg_get_link_enc_used_by_link(link->dc->current_state, link);
+	else
+		link_enc = link->link_enc;
+	ASSERT(link_enc);
+
 	if (link->connector_signal == SIGNAL_TYPE_EDP) {
 		link->dc->hwss.edp_power_control(link, true);
 		link->dc->hwss.edp_wait_for_hpd_ready(link, true);
@@ -227,6 +235,14 @@ void dp_disable_link_phy(struct dc_link *link, enum signal_type signal)
 {
 	struct dc  *dc = link->ctx->dc;
 	struct dmcu *dmcu = dc->res_pool->dmcu;
+	struct link_encoder *link_enc;
+
+	/* Link should always be assigned encoder when en-/disabling. */
+	if (link->is_dig_mapping_flexible && dc->res_pool->funcs->link_encs_assign)
+		link_enc = link_enc_cfg_get_link_enc_used_by_link(link->dc->current_state, link);
+	else
+		link_enc = link->link_enc;
+	ASSERT(link_enc);
 
 	if (!link->wa_flags.dp_keep_receiver_powered)
 		dp_receiver_power_ctrl(link, false);
@@ -234,13 +250,13 @@ void dp_disable_link_phy(struct dc_link *link, enum signal_type signal)
 	if (signal == SIGNAL_TYPE_EDP) {
 		if (link->dc->hwss.edp_backlight_control)
 			link->dc->hwss.edp_backlight_control(link, false);
-		link->link_enc->funcs->disable_output(link->link_enc, signal);
+		link_enc->funcs->disable_output(link_enc, signal);
 		link->dc->hwss.edp_power_control(link, false);
 	} else {
 		if (dmcu != NULL && dmcu->funcs->lock_phy)
 			dmcu->funcs->lock_phy(dmcu);
 
-		link->link_enc->funcs->disable_output(link->link_enc, signal);
+		link_enc->funcs->disable_output(link_enc, signal);
 
 		if (dmcu != NULL && dmcu->funcs->unlock_phy)
 			dmcu->funcs->unlock_phy(dmcu);

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

@@ -65,4 +65,22 @@ void link_enc_cfg_link_enc_unassign(
 		struct dc_state *state,
 		struct dc_stream_state *stream);
 
+/*
+ * Check whether the transmitter driven by a link encoder is a mappable
+ * endpoint.
+ */
+bool link_enc_cfg_is_transmitter_mappable(
+		struct dc_state *state,
+		struct link_encoder *link_enc);
+
+/* Return link using DIG link encoder resource. NULL if unused. */
+struct dc_link *link_enc_cfg_get_link_using_link_enc(
+		struct dc_state *state,
+		enum engine_id eng_id);
+
+/* Return DIG link encoder used by link. NULL if unused. */
+struct link_encoder *link_enc_cfg_get_link_enc_used_by_link(
+		struct dc_state *state,
+		struct dc_link *link);
+
 #endif /* DC_INC_LINK_ENC_CFG_H_ */