drm/i915: mst topology dumper in debugfs (v0.2)

use the mst helper code to dump the topology in debugfs.

v0.2: drop is_mst check - as we want to dump other info
Reviewed-by: Todd Previte <tprevite@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -2405,6 +2405,28 @@ struct pipe_crc_info {
 	enum pipe pipe;
 };
 
+static int i915_dp_mst_info(struct seq_file *m, void *unused)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_encoder *encoder;
+	struct intel_encoder *intel_encoder;
+	struct intel_digital_port *intel_dig_port;
+	drm_modeset_lock_all(dev);
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+		intel_encoder = to_intel_encoder(encoder);
+		if (intel_encoder->type != INTEL_OUTPUT_DISPLAYPORT)
+			continue;
+		intel_dig_port = enc_to_dig_port(encoder);
+		if (!intel_dig_port->dp.can_mst)
+			continue;
+
+		drm_dp_mst_dump_topology(m, &intel_dig_port->dp.mst_mgr);
+	}
+	drm_modeset_unlock_all(dev);
+	return 0;
+}
+
 static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
 {
 	struct pipe_crc_info *info = inode->i_private;
@@ -3906,6 +3928,7 @@ static const struct drm_info_list i915_debugfs_list[] = {
 	{"i915_display_info", i915_display_info, 0},
 	{"i915_semaphore_status", i915_semaphore_status, 0},
 	{"i915_shared_dplls_info", i915_shared_dplls_info, 0},
+	{"i915_dp_mst_info", i915_dp_mst_info, 0},
 };
 #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)