drm/amd/display: Add DP 2.0 MST DM Support

[Why]
Add DP2 MST and debugfs support

[How]
Update the slot info based on the link encoding format
Reviewed-by: "Lin, Wayne" <Wayne.Lin@amd.com>
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211025223825.301703-5-lyude@redhat.com

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

@@ -10684,6 +10684,8 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	struct dsc_mst_fairness_vars vars[MAX_PIPES];
 #endif
+	struct drm_dp_mst_topology_state *mst_state;
+	struct drm_dp_mst_topology_mgr *mgr;
 
 	trace_amdgpu_dm_atomic_check_begin(state);
 
@@ -10891,6 +10893,33 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 		lock_and_validation_needed = true;
 	}
 
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+	/* set the slot info for each mst_state based on the link encoding format */
+	for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
+		struct amdgpu_dm_connector *aconnector;
+		struct drm_connector *connector;
+		struct drm_connector_list_iter iter;
+		u8 link_coding_cap;
+
+		if (!mgr->mst_state )
+			continue;
+
+		drm_connector_list_iter_begin(dev, &iter);
+		drm_for_each_connector_iter(connector, &iter) {
+			int id = connector->index;
+
+			if (id == mst_state->mgr->conn_base_id) {
+				aconnector = to_amdgpu_dm_connector(connector);
+				link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(aconnector->dc_link);
+				drm_dp_mst_update_slots(mst_state, link_coding_cap);
+
+				break;
+			}
+		}
+		drm_connector_list_iter_end(&iter);
+
+	}
+#endif
 	/**
 	 * Streams and planes are reset when there are changes that affect
 	 * bandwidth. Anything that affects bandwidth needs to go through

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

@@ -294,6 +294,9 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
 	case LINK_RATE_RBR2:
 	case LINK_RATE_HIGH2:
 	case LINK_RATE_HIGH3:
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+	case LINK_RATE_UHBR10:
+#endif
 		break;
 	default:
 		valid_input = false;

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

@@ -219,6 +219,7 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
 	struct drm_dp_mst_topology_mgr *mst_mgr;
 	struct drm_dp_mst_port *mst_port;
 	bool ret;
+	u8 link_coding_cap;
 
 	aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
 	/* Accessing the connector state is required for vcpi_slots allocation
@@ -238,6 +239,8 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
 
 	mst_port = aconnector->port;
 
+	link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(aconnector->dc_link);
+
 	if (enable) {
 
 		ret = drm_dp_mst_allocate_vcpi(mst_mgr, mst_port,
@@ -251,7 +254,7 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
 	}
 
 	/* It's OK for this to fail */
-	drm_dp_update_payload_part1(mst_mgr, 1);
+	drm_dp_update_payload_part1(mst_mgr, (link_coding_cap == DP_CAP_ANSI_128B132B) ? 0:1);
 
 	/* mst_mgr->->payloads are VC payload notify MST branch using DPCD or
 	 * AUX message. The sequence is slot 1-63 allocated sequence for each