drm/i915/debugfs: add dp mst info

Add the DP MST info dump in debugfs.

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Libin Yang <libin.yang@intel.com>
Reviewed-by: Lyude <cpaul@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480334827-112273-1-git-send-email-libin.yang@intel.com
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4a431d9..db53fd0 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2877,6 +2877,20 @@ static void intel_dp_info(struct seq_file *m,
 				&intel_dp->aux);
 }
 
+static void intel_dp_mst_info(struct seq_file *m,
+			  struct intel_connector *intel_connector)
+{
+	struct intel_encoder *intel_encoder = intel_connector->encoder;
+	struct intel_dp_mst_encoder *intel_mst =
+		enc_to_mst(&intel_encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	bool has_audio = drm_dp_mst_port_has_audio(&intel_dp->mst_mgr,
+					intel_connector->port);
+
+	seq_printf(m, "\taudio support: %s\n", yesno(has_audio));
+}
+
 static void intel_hdmi_info(struct seq_file *m,
 			    struct intel_connector *intel_connector)
 {
@@ -2919,7 +2933,10 @@ static void intel_connector_info(struct seq_file *m,
 	switch (connector->connector_type) {
 	case DRM_MODE_CONNECTOR_DisplayPort:
 	case DRM_MODE_CONNECTOR_eDP:
-		intel_dp_info(m, intel_connector);
+		if (intel_encoder->type == INTEL_OUTPUT_DP_MST)
+			intel_dp_mst_info(m, intel_connector);
+		else
+			intel_dp_info(m, intel_connector);
 		break;
 	case DRM_MODE_CONNECTOR_LVDS:
 		if (intel_encoder->type == INTEL_OUTPUT_LVDS)