diff --git a/common/hw-gfx-gma-pch-transcoder.ads b/common/hw-gfx-gma-pch-transcoder.ads
new file mode 100644
index 0000000..b1c5ca9
--- /dev/null
+++ b/common/hw-gfx-gma-pch-transcoder.ads
@@ -0,0 +1,24 @@
+--
+-- Copyright (C) 2015-2016 secunet Security Networks AG
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; version 2 of the License.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+
+package HW.GFX.GMA.PCH.Transcoder is
+
+   procedure On
+     (Port_Cfg : Port_Config;
+      Port     : FDI_Port_Type;
+      PLL      : Word32);
+
+   procedure Off
+     (Port  : FDI_Port_Type);
+
+end HW.GFX.GMA.PCH.Transcoder;