drm/i915: start adding dp mst audio

This patch adds support for DP MST audio in i915.

Enable audio codec when DP MST is enabled if has_audio flag is set.
Disable audio codec when DP MST is disabled if has_audio flag is set.

Another separated patches to support DP MST audio will be implemented
in audio driver.

Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Libin Yang <libin.yang@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449036584-105393-2-git-send-email-libin.yang@linux.intel.com
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index a8721fc..8698bd5 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2850,6 +2850,20 @@
 		intel_panel_info(m, &intel_connector->panel);
 }
 
+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)
 {
@@ -2893,6 +2907,8 @@
 			intel_hdmi_info(m, intel_connector);
 		else if (intel_encoder->type == INTEL_OUTPUT_LVDS)
 			intel_lvds_info(m, intel_connector);
+		else if (intel_encoder->type == INTEL_OUTPUT_DP_MST)
+			intel_dp_mst_info(m, intel_connector);
 	}
 
 	seq_printf(m, "\tmodes:\n");