diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 0a9407ae4025..0e0390ece122 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -2219,6 +2219,17 @@ void intel_crt_init(struct drm_device *dev)
 !Iinclude/drm/drm_flip_work.h
 !Edrivers/gpu/drm/drm_flip_work.c
     </sect2>
+    <sect2>
+      <title>HDMI Infoframes Helper Reference</title>
+      <para>
+	Strictly speaking this is not a DRM helper library but generally useable
+	by any driver interfacing with HDMI outputs like v4l or alsa drivers.
+	But it nicely fits into the overall topic of mode setting helper
+	libraries and hence is also included here.
+      </para>
+!Iinclude/linux/hdmi.h
+!Edrivers/video/hdmi.c
+    </sect2>
   </sect1>
 
   <!-- Internals: kms properties -->
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index 9231be9e90a2..11c0182a153b 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -262,6 +262,18 @@ union hdmi_vendor_any_infoframe {
 	struct hdmi_vendor_infoframe hdmi;
 };
 
+/**
+ * union hdmi_infoframe - overall union of all abstract infoframe representations
+ * @any: generic infoframe
+ * @avi: avi infoframe
+ * @spd: spd infoframe
+ * @vendor: union of all vendor infoframes
+ * @audio: audio infoframe
+ *
+ * This is used by the generic pack function. This works since all infoframes
+ * have the same header which also indicates which type of infoframe should be
+ * packed.
+ */
 union hdmi_infoframe {
 	struct hdmi_any_infoframe any;
 	struct hdmi_avi_infoframe avi;