diff --git a/drivers/isdn/i4l/isdn_common.h b/drivers/isdn/i4l/isdn_common.h
new file mode 100644
index 0000000..808135c
--- /dev/null
+++ b/drivers/isdn/i4l/isdn_common.h
@@ -0,0 +1,47 @@
+/* $Id: isdn_common.h,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
+ *
+ * header for Linux ISDN subsystem
+ * common used functions and debugging-switches (linklevel).
+ *
+ * Copyright 1994-1999  by Fritz Elfert (fritz@isdn4linux.de)
+ * Copyright 1995,96    by Thinking Objects Software GmbH Wuerzburg
+ * Copyright 1995,96    by Michael Hipp (Michael.Hipp@student.uni-tuebingen.de)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ */
+
+#undef  ISDN_DEBUG_MODEM_OPEN
+#undef  ISDN_DEBUG_MODEM_IOCTL
+#undef  ISDN_DEBUG_MODEM_WAITSENT
+#undef  ISDN_DEBUG_MODEM_HUP
+#undef  ISDN_DEBUG_MODEM_ICALL
+#undef  ISDN_DEBUG_MODEM_DUMP
+#undef  ISDN_DEBUG_MODEM_VOICE
+#undef  ISDN_DEBUG_AT
+#undef  ISDN_DEBUG_NET_DUMP
+#undef  ISDN_DEBUG_NET_DIAL
+#undef  ISDN_DEBUG_NET_ICALL
+
+/* Prototypes */
+extern void isdn_lock_drivers(void);
+extern void isdn_unlock_drivers(void);
+extern void isdn_free_channel(int di, int ch, int usage);
+extern void isdn_all_eaz(int di, int ch);
+extern int  isdn_command(isdn_ctrl *);
+extern int  isdn_dc2minor(int di, int ch);
+extern void isdn_info_update(void);
+extern char *isdn_map_eaz2msn(char *msn, int di);
+extern void isdn_timer_ctrl(int tf, int onoff);
+extern void isdn_unexclusive_channel(int di, int ch);
+extern int  isdn_getnum(char **);
+extern int  isdn_readbchan(int, int, u_char *, u_char *, int, wait_queue_head_t *);
+extern int  isdn_get_free_channel(int, int, int, int, int, char *);
+extern int  isdn_writebuf_skb_stub(int, int, int, struct sk_buff *);
+extern int  register_isdn(isdn_if * i);
+extern int  isdn_msncmp( const char *,  const char *);
+extern int  isdn_add_channels(isdn_driver_t *, int, int, int);
+#if defined(ISDN_DEBUG_NET_DUMP) || defined(ISDN_DEBUG_MODEM_DUMP)
+extern void isdn_dumppkt(char *, u_char *, int, int);
+#endif