drm/amd/display: Move link_enc init logic to DC

[Why]

We shouldn't be accessing res_pool funcs from DM level,
therefore, we should create API and let the flow
be done in DC level.

[How]

We create new interface dp_get_link_enc to access and get the correct link_enc
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Jude Shih <shenshih@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -8330,15 +8330,8 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 		break;
 	case DRM_MODE_CONNECTOR_DisplayPort:
 		aconnector->base.polled = DRM_CONNECTOR_POLL_HPD;
-		if (link->is_dig_mapping_flexible &&
-		    link->dc->res_pool->funcs->link_encs_assign) {
-			link->link_enc =
-				link_enc_cfg_get_link_enc_used_by_link(link->ctx->dc, link);
-			if (!link->link_enc)
-				link->link_enc =
-					link_enc_cfg_get_next_avail_link_enc(link->ctx->dc);
-		}
-
+		link->link_enc = dp_get_link_enc(link);
+		ASSERT(link->link_enc);
 		if (link->link_enc)
 			aconnector->base.ycbcr_420_allowed =
 			link->link_enc->features.dp_ycbcr420_supported ? true : false;

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

@@ -6174,6 +6174,23 @@ void dp_set_fec_enable(struct dc_link *link, bool enable)
 	}
 }
 
+struct link_encoder *dp_get_link_enc(struct dc_link *link)
+{
+	struct link_encoder *link_enc;
+
+	link_enc = link->link_enc;
+	if (link->is_dig_mapping_flexible &&
+	    link->dc->res_pool->funcs->link_encs_assign) {
+		link_enc = link_enc_cfg_get_link_enc_used_by_link(link->ctx->dc,
+								  link);
+		if (!link->link_enc)
+			link_enc = link_enc_cfg_get_next_avail_link_enc(
+				link->ctx->dc);
+	}
+
+	return link_enc;
+}
+
 void dpcd_set_source_specific_data(struct dc_link *link)
 {
 	if (!link->dc->vendor_signature.is_valid) {

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

@@ -170,6 +170,7 @@ uint8_t dc_dp_initialize_scrambling_data_symbols(
 
 enum dc_status dp_set_fec_ready(struct dc_link *link, bool ready);
 void dp_set_fec_enable(struct dc_link *link, bool enable);
+struct link_encoder *dp_get_link_enc(struct dc_link *link);
 bool dp_set_dsc_enable(struct pipe_ctx *pipe_ctx, bool enable);
 bool dp_set_dsc_pps_sdp(struct pipe_ctx *pipe_ctx, bool enable, bool immediate_update);
 void dp_set_dsc_on_stream(struct pipe_ctx *pipe_ctx, bool enable);