gigaset: add Kernel CAPI interface (v3)

Add a Kernel CAPI interface to the Gigaset driver.

Impact: optional new functionality
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 2356 insertions, 29 deletions

diff --git a/Documentation/isdn/README.gigaset b/Documentation/isdn/README.gigaset
index f9963103ae3d..0fc9831d7ecb 100644
--- a/Documentation/isdn/README.gigaset
+++ b/Documentation/isdn/README.gigaset
@@ -5,7 +5,7 @@ GigaSet 307x Device Driver
      ------------
 1.1. Hardware
      --------
-     This release supports the connection of the Gigaset 307x/417x family of
+     This driver supports the connection of the Gigaset 307x/417x family of
      ISDN DECT bases via Gigaset M101 Data, Gigaset M105 Data or direct USB
      connection. The following devices are reported to be compatible:
 
@@ -33,7 +33,7 @@ GigaSet 307x Device Driver
               http://gigaset307x.sourceforge.net/
 
      We had also reports from users of Gigaset M105 who could use the drivers
-     with SX 100 and CX 100 ISDN bases (only in unimodem mode, see section 2.4.)
+     with SX 100 and CX 100 ISDN bases (only in unimodem mode, see section 2.5.)
      If you have another device that works with our driver, please let us know.
 
      Chances of getting an USB device to work are good if the output of
@@ -49,7 +49,7 @@ GigaSet 307x Device Driver
      --------
      The driver works with ISDN4linux and so can be used with any software
      which is able to use ISDN4linux for ISDN connections (voice or data).
-     CAPI4Linux support is planned but not yet available.
+     Experimental Kernel CAPI support is available as a compilation option.
 
      There are some user space tools available at
      http://sourceforge.net/projects/gigaset307x/
@@ -102,20 +102,28 @@ GigaSet 307x Device Driver
 2.3. ISDN4linux
      ----------
      This is the "normal" mode of operation. After loading the module you can
-     set up the ISDN system just as you'd do with any ISDN card.
-     Your distribution should provide some configuration utility.
-     If not, you can use some HOWTOs like
+     set up the ISDN system just as you'd do with any ISDN card supported by
+     the ISDN4Linux subsystem. Most distributions provide some configuration
+     utility. If not, you can use some HOWTOs like
          http://www.linuxhaven.de/dlhp/HOWTO/DE-ISDN-HOWTO-5.html
-     If this doesn't work, because you have some recent device like SX100 where
+     If this doesn't work, because you have some device like SX100 where
      debug output (see section 3.2.) shows something like this when dialing
          CMD Received: ERROR
          Available Params: 0
          Connection State: 0, Response: -1
          gigaset_process_response: resp_code -1 in ConState 0 !
          Timeout occurred
-     you might need to use unimodem mode:
+     you might need to use unimodem mode. (see section 2.5.)
 
-2.4. Unimodem mode
+2.4. CAPI
+     ----
+     If the driver is compiled with CAPI support (kernel configuration option
+     GIGASET_CAPI, experimental) it can also be used with CAPI 2.0 kernel and
+     user space applications.  ISDN4Linux is supported in this configuration
+     via the capidrv compatibility driver. The kernel module capidrv.ko must
+     be loaded explicitly ("modprobe capidrv") if needed.
+
+2.5. Unimodem mode
      -------------
      This is needed for some devices [e.g. SX100] as they have problems with
      the "normal" commands.
@@ -160,7 +168,7 @@ GigaSet 307x Device Driver
      configuration file like /etc/modprobe.conf.local,
      using that should be preferred.
 
-2.5. Call-ID (CID) mode
+2.6. Call-ID (CID) mode
      ------------------
      Call-IDs are numbers used to tag commands to, and responses from, the
      Gigaset base in order to support the simultaneous handling of multiple
@@ -188,7 +196,7 @@ GigaSet 307x Device Driver
      You can also use /sys/class/tty/ttyGxy/cidmode for changing the CID mode
      setting (ttyGxy is ttyGU0 or ttyGB0).
 
-2.6. Unregistered Wireless Devices (M101/M105)
+2.7. Unregistered Wireless Devices (M101/M105)
      -----------------------------------------
      The main purpose of the ser_gigaset and usb_gigaset drivers is to allow
      the M101 and M105 wireless devices to be used as ISDN devices for ISDN
@@ -228,7 +236,7 @@ GigaSet 307x Device Driver
         You have two or more DECT data adapters (M101/M105) and only the
         first one you turn on works.
      Solution:
-        Select Unimodem mode for all DECT data adapters. (see section 2.4.)
+        Select Unimodem mode for all DECT data adapters. (see section 2.5.)
 
      Problem:
 	Messages like this:
@@ -236,7 +244,7 @@ GigaSet 307x Device Driver
 	appear in your syslog.
      Solution:
 	Check whether your M10x wireless device is correctly registered to the
-	Gigaset base. (see section 2.6.)
+	Gigaset base. (see section 2.7.)
 
 3.2. Telling the driver to provide more information
      ----------------------------------------------
diff --git a/drivers/isdn/gigaset/Kconfig b/drivers/isdn/gigaset/Kconfig
index 6fd2dc1e97fb..dcefedc7044a 100644
--- a/drivers/isdn/gigaset/Kconfig
+++ b/drivers/isdn/gigaset/Kconfig
@@ -10,20 +10,32 @@ menuconfig ISDN_DRV_GIGASET
 	  If you have one of these devices, say M here and for at least
 	  one of the connection specific parts that follow.
 	  This will build a module called "gigaset".
-	  Note: If you build the ISDN4Linux subsystem (ISDN_I4L)
+	  Note: If you build your ISDN subsystem (ISDN_CAPI or ISDN_I4L)
 	  as a module, you have to build this driver as a module too,
 	  otherwise the Gigaset device won't show up as an ISDN device.
 
 if ISDN_DRV_GIGASET
 
+config GIGASET_CAPI
+	bool "Gigaset CAPI support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	depends on ISDN_CAPI='y'||(ISDN_CAPI='m'&&ISDN_DRV_GIGASET='m')
+	default ISDN_I4L='n'
+	help
+	  Build the Gigaset driver as a CAPI 2.0 driver interfacing with
+	  the Kernel CAPI subsystem. To use it with the old ISDN4Linux
+	  subsystem you'll have to enable the capidrv glue driver.
+	  (select ISDN_CAPI_CAPIDRV.)
+	  Say N to build the old native ISDN4Linux variant.
+
 config GIGASET_I4L
 	bool
 	depends on ISDN_I4L='y'||(ISDN_I4L='m'&&ISDN_DRV_GIGASET='m')
-	default y
+	default !GIGASET_CAPI
 
 config GIGASET_DUMMYLL
 	bool
-	default !GIGASET_I4L
+	default !GIGASET_CAPI&&!GIGASET_I4L
 
 config GIGASET_BASE
 	tristate "Gigaset base station support"
diff --git a/drivers/isdn/gigaset/Makefile b/drivers/isdn/gigaset/Makefile
index d429202ba8ef..c453b72272a0 100644
--- a/drivers/isdn/gigaset/Makefile
+++ b/drivers/isdn/gigaset/Makefile
@@ -1,4 +1,5 @@
 gigaset-y := common.o interface.o proc.o ev-layer.o asyncdata.o
+gigaset-$(CONFIG_GIGASET_CAPI) += capi.o
 gigaset-$(CONFIG_GIGASET_I4L) += i4l.o
 gigaset-$(CONFIG_GIGASET_DUMMYLL) += dummyll.o
 usb_gigaset-y := usb-gigaset.o
diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c
new file mode 100644
index 000000000000..c276a925b36f
--- /dev/null
+++ b/drivers/isdn/gigaset/capi.c
@@ -0,0 +1,2273 @@
+/*
+ * Kernel CAPI interface for the Gigaset driver
+ *
+ * Copyright (c) 2009 by Tilman Schmidt <tilman@imap.cc>.
+ *
+ * =====================================================================
+ *	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; either version 2 of
+ *	the License, or (at your option) any later version.
+ * =====================================================================
+ */
+
+#include "gigaset.h"
+#include <linux/ctype.h>
+#include <linux/isdn/capilli.h>
+#include <linux/isdn/capicmd.h>
+#include <linux/isdn/capiutil.h>
+
+/* missing from kernelcapi.h */
+#define CapiNcpiNotSupportedByProtocol	0x0001
+#define CapiFlagsNotSupportedByProtocol	0x0002
+#define CapiAlertAlreadySent		0x0003
+#define CapiFacilitySpecificFunctionNotSupported	0x3011
+
+/* missing from capicmd.h */
+#define CAPI_CONNECT_IND_BASELEN	(CAPI_MSG_BASELEN+4+2+8*1)
+#define CAPI_CONNECT_ACTIVE_IND_BASELEN	(CAPI_MSG_BASELEN+4+3*1)
+#define CAPI_CONNECT_B3_IND_BASELEN	(CAPI_MSG_BASELEN+4+1)
+#define CAPI_CONNECT_B3_ACTIVE_IND_BASELEN	(CAPI_MSG_BASELEN+4+1)
+#define CAPI_DATA_B3_REQ_LEN64		(CAPI_MSG_BASELEN+4+4+2+2+2+8)
+#define CAPI_DATA_B3_CONF_LEN		(CAPI_MSG_BASELEN+4+2+2)
+#define CAPI_DISCONNECT_IND_LEN		(CAPI_MSG_BASELEN+4+2)
+#define CAPI_DISCONNECT_B3_IND_BASELEN	(CAPI_MSG_BASELEN+4+2+1)
+#define CAPI_FACILITY_CONF_BASELEN	(CAPI_MSG_BASELEN+4+2+2+1)
+/* most _CONF messages contain only Controller/PLCI/NCCI and Info parameters */
+#define CAPI_STDCONF_LEN		(CAPI_MSG_BASELEN+4+2)
+
+#define CAPI_FACILITY_HANDSET	0x0000
+#define CAPI_FACILITY_DTMF	0x0001
+#define CAPI_FACILITY_V42BIS	0x0002
+#define CAPI_FACILITY_SUPPSVC	0x0003
+#define CAPI_FACILITY_WAKEUP	0x0004
+#define CAPI_FACILITY_LI	0x0005
+
+#define CAPI_SUPPSVC_GETSUPPORTED	0x0000
+
+/* missing from capiutil.h */
+#define CAPIMSG_PLCI_PART(m)	CAPIMSG_U8(m, 9)
+#define CAPIMSG_NCCI_PART(m)	CAPIMSG_U16(m, 10)
+#define CAPIMSG_HANDLE_REQ(m)	CAPIMSG_U16(m, 18) /* DATA_B3_REQ/_IND only! */
+#define CAPIMSG_FLAGS(m)	CAPIMSG_U16(m, 20)
+#define CAPIMSG_SETCONTROLLER(m, contr)	capimsg_setu8(m, 8, contr)
+#define CAPIMSG_SETPLCI_PART(m, plci)	capimsg_setu8(m, 9, plci)
+#define CAPIMSG_SETNCCI_PART(m, ncci)	capimsg_setu16(m, 10, ncci)
+#define CAPIMSG_SETFLAGS(m, flags)	capimsg_setu16(m, 20, flags)
+
+/* parameters with differing location in DATA_B3_CONF/_RESP: */
+#define CAPIMSG_SETHANDLE_CONF(m, handle)	capimsg_setu16(m, 12, handle)
+#define	CAPIMSG_SETINFO_CONF(m, info)		capimsg_setu16(m, 14, info)
+
+/* Flags (DATA_B3_REQ/_IND) */
+#define CAPI_FLAGS_DELIVERY_CONFIRMATION	0x04
+#define CAPI_FLAGS_RESERVED			(~0x1f)
+
+/* buffer sizes */
+#define MAX_BC_OCTETS 11
+#define MAX_HLC_OCTETS 3
+#define MAX_NUMBER_DIGITS 20
+#define MAX_FMT_IE_LEN 20
+
+/* values for gigaset_capi_appl.connected */
+#define APCONN_NONE	0	/* inactive/listening */
+#define APCONN_SETUP	1	/* connecting */
+#define APCONN_ACTIVE	2	/* B channel up */
+
+/* registered application data structure */
+struct gigaset_capi_appl {
+	struct list_head ctrlist;
+	struct gigaset_capi_appl *bcnext;
+	u16 id;
+	u16 nextMessageNumber;
+	u32 listenInfoMask;
+	u32 listenCIPmask;
+	int connected;
+};
+
+/* CAPI specific controller data structure */
+struct gigaset_capi_ctr {
+	struct capi_ctr ctr;
+	struct list_head appls;
+	struct sk_buff_head sendqueue;
+	atomic_t sendqlen;
+	/* two _cmsg structures possibly used concurrently: */
+	_cmsg hcmsg;	/* for message composition triggered from hardware */
+	_cmsg acmsg;	/* for dissection of messages sent from application */
+	u8 bc_buf[MAX_BC_OCTETS+1];
+	u8 hlc_buf[MAX_HLC_OCTETS+1];
+	u8 cgpty_buf[MAX_NUMBER_DIGITS+3];
+	u8 cdpty_buf[MAX_NUMBER_DIGITS+2];
+};
+
+/* CIP Value table (from CAPI 2.0 standard, ch. 6.1) */
+static struct {
+	u8 *bc;
+	u8 *hlc;
+} cip2bchlc[] = {
+	[1] = { "8090A3", NULL },
+		/* Speech (A-law) */
+	[2] = { "8890", NULL },
+		/* Unrestricted digital information */
+	[3] = { "8990", NULL },
+		/* Restricted digital information */
+	[4] = { "9090A3", NULL },
+		/* 3,1 kHz audio (A-law) */
+	[5] = { "9190", NULL },
+		/* 7 kHz audio */
+	[6] = { "9890", NULL },
+		/* Video */
+	[7] = { "88C0C6E6", NULL },
+		/* Packet mode */
+	[8] = { "8890218F", NULL },
+		/* 56 kbit/s rate adaptation */
+	[9] = { "9190A5", NULL },
+		/* Unrestricted digital information with tones/announcements */
+	[16] = { "8090A3", "9181" },
+		/* Telephony */
+	[17] = { "9090A3", "9184" },
+		/* Group 2/3 facsimile */
+	[18] = { "8890", "91A1" },
+		/* Group 4 facsimile Class 1 */
+	[19] = { "8890", "91A4" },
+		/* Teletex service basic and mixed mode
+		   and Group 4 facsimile service Classes II and III */
+	[20] = { "8890", "91A8" },
+		/* Teletex service basic and processable mode */
+	[21] = { "8890", "91B1" },
+		/* Teletex service basic mode */
+	[22] = { "8890", "91B2" },
+		/* International interworking for Videotex */
+	[23] = { "8890", "91B5" },
+		/* Telex */
+	[24] = { "8890", "91B8" },
+		/* Message Handling Systems in accordance with X.400 */
+	[25] = { "8890", "91C1" },
+		/* OSI application in accordance with X.200 */
+	[26] = { "9190A5", "9181" },
+		/* 7 kHz telephony */
+	[27] = { "9190A5", "916001" },
+		/* Video telephony, first connection */
+	[28] = { "8890", "916002" },
+		/* Video telephony, second connection */
+};
+
+/*
+ * helper functions
+ * ================
+ */
+
+/*
+ * emit unsupported parameter warning
+ */
+static inline void ignore_cstruct_param(struct cardstate *cs, _cstruct param,
+				       char *msgname, char *paramname)
+{
+	if (param && *param)
+		dev_warn(cs->dev, "%s: ignoring unsupported parameter: %s\n",
+			 msgname, paramname);
+}
+
+static inline void ignore_cmstruct_param(struct cardstate *cs, _cmstruct param,
+				       char *msgname, char *paramname)
+{
+	if (param != CAPI_DEFAULT)
+		dev_warn(cs->dev, "%s: ignoring unsupported parameter: %s\n",
+			 msgname, paramname);
+}
+
+/*
+ * check for legal hex digit
+ */
+static inline int ishexdigit(char c)
+{
+	if (c >= '0' && c <= '9')
+		return 1;
+	if (c >= 'A' && c <= 'F')
+		return 1;
+	if (c >= 'a' && c <= 'f')
+		return 1;
+	return 0;
+}
+
+/*
+ * convert hex to binary
+ */
+static inline u8 hex2bin(char c)
+{
+	int result = c & 0x0f;
+	if (c & 0x40)
+		result += 9;
+	return result;
+}
+
+/*
+ * convert an IE from Gigaset hex string to ETSI binary representation
+ * including length byte
+ * return value: result length, -1 on error
+ */
+static int encode_ie(char *in, u8 *out, int maxlen)
+{
+	int l = 0;
+	while (*in) {
+		if (!ishexdigit(in[0]) || !ishexdigit(in[1]) || l >= maxlen)
+			return -1;
+		out[++l] = (hex2bin(in[0]) << 4) + hex2bin(in[1]);
+		in += 2;
+	}
+	out[0] = l;
+	return l;
+}
+
+/*
+ * convert an IE from ETSI binary representation including length byte
+ * to Gigaset hex string
+ */
+static void decode_ie(u8 *in, char *out)
+{
+	int i = *in;
+	while (i-- > 0) {
+		/* ToDo: conversion to upper case necessary? */
+		*out++ = toupper(hex_asc_hi(*++in));
+		*out++ = toupper(hex_asc_lo(*in));
+	}
+}
+
+/*
+ * retrieve application data structure for an application ID
+ */
+static inline struct gigaset_capi_appl *
+get_appl(struct gigaset_capi_ctr *iif, u16 appl)
+{
+	struct gigaset_capi_appl *ap;
+
+	list_for_each_entry(ap, &iif->appls, ctrlist)
+		if (ap->id == appl)
+			return ap;
+	return NULL;
+}
+
+/*
+ * dump CAPI message to kernel messages for debugging
+ */
+static inline void dump_cmsg(enum debuglevel level, const char *tag, _cmsg *p)
+{
+#ifdef CONFIG_GIGASET_DEBUG
+	_cdebbuf *cdb;
+
+	if (!(gigaset_debuglevel & level))
+		return;
+
+	cdb = capi_cmsg2str(p);
+	if (cdb) {
+		gig_dbg(level, "%s: [%d] %s", tag, p->ApplId, cdb->buf);
+		cdebbuf_free(cdb);
+	} else {
+		gig_dbg(level, "%s: [%d] %s", tag, p->ApplId,
+			capi_cmd2str(p->Command, p->Subcommand));
+	}
+#endif
+}
+
+static inline void dump_rawmsg(enum debuglevel level, const char *tag,
+			       unsigned char *data)
+{
+#ifdef CONFIG_GIGASET_DEBUG
+	char *dbgline;
+	int i, l;
+
+	if (!(gigaset_debuglevel & level))
+		return;
+
+	l = CAPIMSG_LEN(data);
+	if (l < 12) {
+		gig_dbg(level, "%s: ??? LEN=%04d", tag, l);
+		return;
+	}
+	gig_dbg(level, "%s: 0x%02x:0x%02x: ID=%03d #0x%04x LEN=%04d NCCI=0x%x",
+		tag, CAPIMSG_COMMAND(data), CAPIMSG_SUBCOMMAND(data),
+		CAPIMSG_APPID(data), CAPIMSG_MSGID(data), l,
+		CAPIMSG_CONTROL(data));
+	l -= 12;
+	dbgline = kmalloc(3*l, GFP_ATOMIC);
+	if (!dbgline)
+		return;
+	for (i = 0; i < l; i++) {
+		dbgline[3*i] = hex_asc_hi(data[12+i]);
+		dbgline[3*i+1] = hex_asc_lo(data[12+i]);
+		dbgline[3*i+2] = ' ';
+	}
+	dbgline[3*l-1] = '\0';
+	gig_dbg(level, "  %s", dbgline);
+	kfree(dbgline);
+	if (CAPIMSG_COMMAND(data) == CAPI_DATA_B3 &&
+	    (CAPIMSG_SUBCOMMAND(data) == CAPI_REQ ||
+	     CAPIMSG_SUBCOMMAND(data) == CAPI_IND) &&
+	    CAPIMSG_DATALEN(data) > 0) {
+		l = CAPIMSG_DATALEN(data);
+		dbgline = kmalloc(3*l, GFP_ATOMIC);
+		if (!dbgline)
+			return;
+		data += CAPIMSG_LEN(data);
+		for (i = 0; i < l; i++) {
+			dbgline[3*i] = hex_asc_hi(data[i]);
+			dbgline[3*i+1] = hex_asc_lo(data[i]);
+			dbgline[3*i+2] = ' ';
+		}
+		dbgline[3*l-1] = '\0';
+		gig_dbg(level, "  %s", dbgline);
+		kfree(dbgline);
+	}
+#endif
+}
+
+/*
+ * format CAPI IE as string
+ */
+
+static const char *format_ie(const char *ie)
+{
+	static char result[3*MAX_FMT_IE_LEN];
+	int len, count;
+	char *pout = result;
+
+	if (!ie)
+		return "NULL";
+
+	count = len = ie[0];
+	if (count > MAX_FMT_IE_LEN)
+		count = MAX_FMT_IE_LEN-1;
+	while (count--) {
+		*pout++ = hex_asc_hi(*++ie);
+		*pout++ = hex_asc_lo(*ie);
+		*pout++ = ' ';
+	}
+	if (len > MAX_FMT_IE_LEN) {
+		*pout++ = '.';
+		*pout++ = '.';
+		*pout++ = '.';
+	}
+	*--pout = 0;
+	return result;
+}
+
+
+/*
+ * driver interface functions
+ * ==========================
+ */
+
+/**
+ * gigaset_skb_sent() - acknowledge transmission of outgoing skb
+ * @bcs:	B channel descriptor structure.
+ * @skb:	sent data.
+ *
+ * Called by hardware module {bas,ser,usb}_gigaset when the data in a
+ * skb has been successfully sent, for signalling completion to the LL.
+ */
+void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *dskb)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct gigaset_capi_appl *ap = bcs->ap;
+	struct sk_buff *cskb;
+	u16 flags;
+
+	/* update statistics */
+	++bcs->trans_up;
+
+	if (!ap) {
+		dev_err(cs->dev, "%s: no application\n", __func__);
+		return;
+	}
+
+	/* don't send further B3 messages if disconnected */
+	if (ap->connected < APCONN_ACTIVE) {
+		gig_dbg(DEBUG_LLDATA, "disconnected, discarding ack");
+		return;
+	}
+
+	/* ToDo: honor unset "delivery confirmation" bit */
+	flags = CAPIMSG_FLAGS(dskb->head);
+
+	/* build DATA_B3_CONF message */
+	cskb = alloc_skb(CAPI_DATA_B3_CONF_LEN, GFP_ATOMIC);
+	if (!cskb) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	/* frequent message, avoid _cmsg overhead */
+	CAPIMSG_SETLEN(cskb->data, CAPI_DATA_B3_CONF_LEN);
+	CAPIMSG_SETAPPID(cskb->data, ap->id);
+	CAPIMSG_SETCOMMAND(cskb->data, CAPI_DATA_B3);
+	CAPIMSG_SETSUBCOMMAND(cskb->data,  CAPI_CONF);
+	CAPIMSG_SETMSGID(cskb->data, CAPIMSG_MSGID(dskb->head));
+	CAPIMSG_SETCONTROLLER(cskb->data, iif->ctr.cnr);
+	CAPIMSG_SETPLCI_PART(cskb->data, bcs->channel + 1);
+	CAPIMSG_SETNCCI_PART(cskb->data, 1);
+	CAPIMSG_SETHANDLE_CONF(cskb->data, CAPIMSG_HANDLE_REQ(dskb->head));
+	if (flags & ~CAPI_FLAGS_DELIVERY_CONFIRMATION)
+		CAPIMSG_SETINFO_CONF(cskb->data,
+				     CapiFlagsNotSupportedByProtocol);
+	else
+		CAPIMSG_SETINFO_CONF(cskb->data, CAPI_NOERROR);
+
+	/* emit message */
+	dump_rawmsg(DEBUG_LLDATA, "DATA_B3_CONF", cskb->data);
+	capi_ctr_handle_message(&iif->ctr, ap->id, cskb);
+}
+EXPORT_SYMBOL_GPL(gigaset_skb_sent);
+
+/**
+ * gigaset_skb_rcvd() - pass received skb to LL
+ * @bcs:	B channel descriptor structure.
+ * @skb:	received data.
+ *
+ * Called by hardware module {bas,ser,usb}_gigaset when user data has
+ * been successfully received, for passing to the LL.
+ * Warning: skb must not be accessed anymore!
+ */
+void gigaset_skb_rcvd(struct bc_state *bcs, struct sk_buff *skb)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct gigaset_capi_appl *ap = bcs->ap;
+	int len = skb->len;
+
+	/* update statistics */
+	bcs->trans_down++;
+
+	if (!ap) {
+		dev_err(cs->dev, "%s: no application\n", __func__);
+		return;
+	}
+
+	/* don't send further B3 messages if disconnected */
+	if (ap->connected < APCONN_ACTIVE) {
+		gig_dbg(DEBUG_LLDATA, "disconnected, discarding data");
+		dev_kfree_skb(skb);
+		return;
+	}
+
+	/*
+	 * prepend DATA_B3_IND message to payload
+	 * Parameters: NCCI = 1, all others 0/unused
+	 * frequent message, avoid _cmsg overhead
+	 */
+	skb_push(skb, CAPI_DATA_B3_REQ_LEN);
+	CAPIMSG_SETLEN(skb->data, CAPI_DATA_B3_REQ_LEN);
+	CAPIMSG_SETAPPID(skb->data, ap->id);
+	CAPIMSG_SETCOMMAND(skb->data, CAPI_DATA_B3);
+	CAPIMSG_SETSUBCOMMAND(skb->data,  CAPI_IND);
+	CAPIMSG_SETMSGID(skb->data, ap->nextMessageNumber++);
+	CAPIMSG_SETCONTROLLER(skb->data, iif->ctr.cnr);
+	CAPIMSG_SETPLCI_PART(skb->data, bcs->channel + 1);
+	CAPIMSG_SETNCCI_PART(skb->data, 1);
+	/* Data parameter not used */
+	CAPIMSG_SETDATALEN(skb->data, len);
+	/* Data handle parameter not used */
+	CAPIMSG_SETFLAGS(skb->data, 0);
+	/* Data64 parameter not present */
+
+	/* emit message */
+	dump_rawmsg(DEBUG_LLDATA, "DATA_B3_IND", skb->data);
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+EXPORT_SYMBOL_GPL(gigaset_skb_rcvd);
+
+/**
+ * gigaset_isdn_rcv_err() - signal receive error
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by hardware module {bas,ser,usb}_gigaset when a receive error
+ * has occurred, for signalling to the LL.
+ */
+void gigaset_isdn_rcv_err(struct bc_state *bcs)
+{
+	/* if currently ignoring packets, just count down */
+	if (bcs->ignore) {
+		bcs->ignore--;
+		return;
+	}
+
+	/* update statistics */
+	bcs->corrupted++;
+
+	/* ToDo: signal error -> LL */
+}
+EXPORT_SYMBOL_GPL(gigaset_isdn_rcv_err);
+
+/**
+ * gigaset_isdn_icall() - signal incoming call
+ * @at_state:	connection state structure.
+ *
+ * Called by main module at tasklet level to notify the LL that an incoming
+ * call has been received. @at_state contains the parameters of the call.
+ *
+ * Return value: call disposition (ICALL_*)
+ */
+int gigaset_isdn_icall(struct at_state_t *at_state)
+{
+	struct cardstate *cs = at_state->cs;
+	struct bc_state *bcs = at_state->bcs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct gigaset_capi_appl *ap;
+	u32 actCIPmask;
+	struct sk_buff *skb;
+	unsigned int msgsize;
+	int i;
+
+	/*
+	 * ToDo: signal calls without a free B channel, too
+	 * (requires a u8 handle for the at_state structure that can
+	 * be stored in the PLCI and used in the CONNECT_RESP message
+	 * handler to retrieve it)
+	 */
+	if (!bcs)
+		return ICALL_IGNORE;
+
+	/* prepare CONNECT_IND message, using B channel number as PLCI */
+	capi_cmsg_header(&iif->hcmsg, 0, CAPI_CONNECT, CAPI_IND, 0,
+			 iif->ctr.cnr | ((bcs->channel + 1) << 8));
+
+	/* minimum size, all structs empty */
+	msgsize = CAPI_CONNECT_IND_BASELEN;
+
+	/* Bearer Capability (mandatory) */
+	if (at_state->str_var[STR_ZBC]) {
+		/* pass on BC from Gigaset */
+		if (encode_ie(at_state->str_var[STR_ZBC], iif->bc_buf,
+			      MAX_BC_OCTETS) < 0) {
+			dev_warn(cs->dev, "RING ignored - bad BC %s\n",
+				 at_state->str_var[STR_ZBC]);
+			return ICALL_IGNORE;
+		}
+
+		/* look up corresponding CIP value */
+		iif->hcmsg.CIPValue = 0;	/* default if nothing found */
+		for (i = 0; i < ARRAY_SIZE(cip2bchlc); i++)
+			if (cip2bchlc[i].bc != NULL &&
+			    cip2bchlc[i].hlc == NULL &&
+			    !strcmp(cip2bchlc[i].bc,
+				    at_state->str_var[STR_ZBC])) {
+				iif->hcmsg.CIPValue = i;
+				break;
+			}
+	} else {
+		/* no BC (internal call): assume CIP 1 (speech, A-law) */
+		iif->hcmsg.CIPValue = 1;
+		encode_ie(cip2bchlc[1].bc, iif->bc_buf, MAX_BC_OCTETS);
+	}
+	iif->hcmsg.BC = iif->bc_buf;
+	msgsize += iif->hcmsg.BC[0];
+
+	/* High Layer Compatibility (optional) */
+	if (at_state->str_var[STR_ZHLC]) {
+		/* pass on HLC from Gigaset */
+		if (encode_ie(at_state->str_var[STR_ZHLC], iif->hlc_buf,
+			      MAX_HLC_OCTETS) < 0) {
+			dev_warn(cs->dev, "RING ignored - bad HLC %s\n",
+				 at_state->str_var[STR_ZHLC]);
+			return ICALL_IGNORE;
+		}
+		iif->hcmsg.HLC = iif->hlc_buf;
+		msgsize += iif->hcmsg.HLC[0];
+
+		/* look up corresponding CIP value */
+		/* keep BC based CIP value if none found */
+		if (at_state->str_var[STR_ZBC])
+			for (i = 0; i < ARRAY_SIZE(cip2bchlc); i++)
+				if (cip2bchlc[i].hlc != NULL &&
+				    !strcmp(cip2bchlc[i].hlc,
+					    at_state->str_var[STR_ZHLC]) &&
+				    !strcmp(cip2bchlc[i].bc,
+					    at_state->str_var[STR_ZBC])) {
+					iif->hcmsg.CIPValue = i;
+					break;
+				}
+	}
+
+	/* Called Party Number (optional) */
+	if (at_state->str_var[STR_ZCPN]) {
+		i = strlen(at_state->str_var[STR_ZCPN]);
+		if (i > MAX_NUMBER_DIGITS) {
+			dev_warn(cs->dev, "RING ignored - bad number %s\n",
+				 at_state->str_var[STR_ZBC]);
+			return ICALL_IGNORE;
+		}
+		iif->cdpty_buf[0] = i + 1;
+		iif->cdpty_buf[1] = 0x80; /* type / numbering plan unknown */
+		memcpy(iif->cdpty_buf+2, at_state->str_var[STR_ZCPN], i);
+		iif->hcmsg.CalledPartyNumber = iif->cdpty_buf;
+		msgsize += iif->hcmsg.CalledPartyNumber[0];
+	}
+
+	/* Calling Party Number (optional) */
+	if (at_state->str_var[STR_NMBR]) {
+		i = strlen(at_state->str_var[STR_NMBR]);
+		if (i > MAX_NUMBER_DIGITS) {
+			dev_warn(cs->dev, "RING ignored - bad number %s\n",
+				 at_state->str_var[STR_ZBC]);
+			return ICALL_IGNORE;
+		}
+		iif->cgpty_buf[0] = i + 2;
+		iif->cgpty_buf[1] = 0x00; /* type / numbering plan unknown */
+		iif->cgpty_buf[2] = 0x80; /* pres. allowed, not screened */
+		memcpy(iif->cgpty_buf+3, at_state->str_var[STR_NMBR], i);
+		iif->hcmsg.CallingPartyNumber = iif->cgpty_buf;
+		msgsize += iif->hcmsg.CallingPartyNumber[0];
+	}
+
+	/* remaining parameters (not supported, always left NULL):
+	 * - CalledPartySubaddress
+	 * - CallingPartySubaddress
+	 * - AdditionalInfo
+	 *   - BChannelinformation
+	 *   - Keypadfacility
+	 *   - Useruserdata
+	 *   - Facilitydataarray
+	 */
+
+	gig_dbg(DEBUG_CMD, "icall: PLCI %x CIP %d BC %s",
+		iif->hcmsg.adr.adrPLCI, iif->hcmsg.CIPValue,
+		format_ie(iif->hcmsg.BC));
+	gig_dbg(DEBUG_CMD, "icall: HLC %s",
+		format_ie(iif->hcmsg.HLC));
+	gig_dbg(DEBUG_CMD, "icall: CgPty %s",
+		format_ie(iif->hcmsg.CallingPartyNumber));
+	gig_dbg(DEBUG_CMD, "icall: CdPty %s",
+		format_ie(iif->hcmsg.CalledPartyNumber));
+
+	/* scan application list for matching listeners */
+	bcs->ap = NULL;
+	actCIPmask = 1 | (1 << iif->hcmsg.CIPValue);
+	list_for_each_entry(ap, &iif->appls, ctrlist)
+		if (actCIPmask & ap->listenCIPmask) {
+			/* build CONNECT_IND message for this application */
+			iif->hcmsg.ApplId = ap->id;
+			iif->hcmsg.Messagenumber = ap->nextMessageNumber++;
+
+			skb = alloc_skb(msgsize, GFP_ATOMIC);
+			if (!skb) {
+				dev_err(cs->dev, "%s: out of memory\n",
+					__func__);
+				break;
+			}
+			capi_cmsg2message(&iif->hcmsg, __skb_put(skb, msgsize));
+			dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
+
+			/* add to listeners on this B channel, update state */
+			ap->bcnext = bcs->ap;
+			bcs->ap = ap;
+			bcs->chstate |= CHS_NOTIFY_LL;
+			ap->connected = APCONN_SETUP;
+
+			/* emit message */
+			capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+		}
+
+	/*
+	 * Return "accept" if any listeners.
+	 * Gigaset will send ALERTING.
+	 * There doesn't seem to be a way to avoid this.
+	 */
+	return bcs->ap ? ICALL_ACCEPT : ICALL_IGNORE;
+}
+
+/*
+ * send a DISCONNECT_IND message to an application
+ * does not sleep, clobbers the controller's hcmsg structure
+ */
+static void send_disconnect_ind(struct bc_state *bcs,
+				struct gigaset_capi_appl *ap, u16 reason)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct sk_buff *skb;
+
+	if (ap->connected == APCONN_NONE)
+		return;
+
+	capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_DISCONNECT, CAPI_IND,
+			 ap->nextMessageNumber++,
+			 iif->ctr.cnr | ((bcs->channel + 1) << 8));
+	iif->hcmsg.Reason = reason;
+	skb = alloc_skb(CAPI_DISCONNECT_IND_LEN, GFP_ATOMIC);
+	if (!skb) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	capi_cmsg2message(&iif->hcmsg, __skb_put(skb, CAPI_DISCONNECT_IND_LEN));
+	dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
+	ap->connected = APCONN_NONE;
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+
+/*
+ * send a DISCONNECT_B3_IND message to an application
+ * Parameters: NCCI = 1, NCPI empty, Reason_B3 = 0
+ * does not sleep, clobbers the controller's hcmsg structure
+ */
+static void send_disconnect_b3_ind(struct bc_state *bcs,
+				   struct gigaset_capi_appl *ap)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct sk_buff *skb;
+
+	/* nothing to do if no logical connection active */
+	if (ap->connected < APCONN_ACTIVE)
+		return;
+	ap->connected = APCONN_SETUP;
+
+	capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_DISCONNECT_B3, CAPI_IND,
+			 ap->nextMessageNumber++,
+			 iif->ctr.cnr | ((bcs->channel + 1) << 8) | (1 << 16));
+	skb = alloc_skb(CAPI_DISCONNECT_B3_IND_BASELEN, GFP_ATOMIC);
+	if (!skb) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	capi_cmsg2message(&iif->hcmsg,
+			  __skb_put(skb, CAPI_DISCONNECT_B3_IND_BASELEN));
+	dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+
+/**
+ * gigaset_isdn_connD() - signal D channel connect
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module at tasklet level to notify the LL that the D channel
+ * connection has been established.
+ */
+void gigaset_isdn_connD(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct gigaset_capi_appl *ap = bcs->ap;
+	struct sk_buff *skb;
+	unsigned int msgsize;
+
+	if (!ap) {
+		dev_err(cs->dev, "%s: no application\n", __func__);
+		return;
+	}
+	while (ap->bcnext) {
+		/* this should never happen */
+		dev_warn(cs->dev, "%s: dropping extra application %u\n",
+			 __func__, ap->bcnext->id);
+		send_disconnect_ind(bcs, ap->bcnext,
+				    CapiCallGivenToOtherApplication);
+		ap->bcnext = ap->bcnext->bcnext;
+	}
+	if (ap->connected == APCONN_NONE) {
+		dev_warn(cs->dev, "%s: application %u not connected\n",
+			 __func__, ap->id);
+		return;
+	}
+
+	/* prepare CONNECT_ACTIVE_IND message
+	 * Note: LLC not supported by device
+	 */
+	capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_CONNECT_ACTIVE, CAPI_IND,
+			 ap->nextMessageNumber++,
+			 iif->ctr.cnr | ((bcs->channel + 1) << 8));
+
+	/* minimum size, all structs empty */
+	msgsize = CAPI_CONNECT_ACTIVE_IND_BASELEN;
+
+	/* ToDo: set parameter: Connected number
+	 * (requires ev-layer state machine extension to collect
+	 * ZCON device reply)
+	 */
+
+	/* build and emit CONNECT_ACTIVE_IND message */
+	skb = alloc_skb(msgsize, GFP_ATOMIC);
+	if (!skb) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	capi_cmsg2message(&iif->hcmsg, __skb_put(skb, msgsize));
+	dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+
+/**
+ * gigaset_isdn_hupD() - signal D channel hangup
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module at tasklet level to notify the LL that the D channel
+ * connection has been shut down.
+ */
+void gigaset_isdn_hupD(struct bc_state *bcs)
+{
+	struct gigaset_capi_appl *ap;
+
+	/*
+	 * ToDo: pass on reason code reported by device
+	 * (requires ev-layer state machine extension to collect
+	 * ZCAU device reply)
+	 */
+	for (ap = bcs->ap; ap != NULL; ap = ap->bcnext) {
+		send_disconnect_b3_ind(bcs, ap);
+		send_disconnect_ind(bcs, ap, 0);
+	}
+	bcs->ap = NULL;
+}
+
+/**
+ * gigaset_isdn_connB() - signal B channel connect
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module at tasklet level to notify the LL that the B channel
+ * connection has been established.
+ */
+void gigaset_isdn_connB(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_ctr *iif = cs->iif;
+	struct gigaset_capi_appl *ap = bcs->ap;
+	struct sk_buff *skb;
+	unsigned int msgsize;
+	u8 command;
+
+	if (!ap) {
+		dev_err(cs->dev, "%s: no application\n", __func__);
+		return;
+	}
+	while (ap->bcnext) {
+		/* this should never happen */
+		dev_warn(cs->dev, "%s: dropping extra application %u\n",
+			 __func__, ap->bcnext->id);
+		send_disconnect_ind(bcs, ap->bcnext,
+				    CapiCallGivenToOtherApplication);
+		ap->bcnext = ap->bcnext->bcnext;
+	}
+	if (!ap->connected) {
+		dev_warn(cs->dev, "%s: application %u not connected\n",
+			 __func__, ap->id);
+		return;
+	}
+
+	/*
+	 * emit CONNECT_B3_ACTIVE_IND if we already got CONNECT_B3_REQ;
+	 * otherwise we have to emit CONNECT_B3_IND first, and follow up with
+	 * CONNECT_B3_ACTIVE_IND in reply to CONNECT_B3_RESP
+	 * Parameters in both cases always: NCCI = 1, NCPI empty
+	 */
+	if (ap->connected >= APCONN_ACTIVE) {
+		command = CAPI_CONNECT_B3_ACTIVE;
+		msgsize = CAPI_CONNECT_B3_ACTIVE_IND_BASELEN;
+	} else {
+		command = CAPI_CONNECT_B3;
+		msgsize = CAPI_CONNECT_B3_IND_BASELEN;
+	}
+	capi_cmsg_header(&iif->hcmsg, ap->id, command, CAPI_IND,
+			 ap->nextMessageNumber++,
+			 iif->ctr.cnr | ((bcs->channel + 1) << 8) | (1 << 16));
+	skb = alloc_skb(msgsize, GFP_ATOMIC);
+	if (!skb) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	capi_cmsg2message(&iif->hcmsg, __skb_put(skb, msgsize));
+	dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
+	ap->connected = APCONN_ACTIVE;
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+
+/**
+ * gigaset_isdn_hupB() - signal B channel hangup
+ * @bcs:	B channel descriptor structure.
+ *
+ * Called by main module to notify the LL that the B channel connection has
+ * been shut down.
+ */
+void gigaset_isdn_hupB(struct bc_state *bcs)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_appl *ap = bcs->ap;
+
+	/* ToDo: assure order of DISCONNECT_B3_IND and DISCONNECT_IND ? */
+
+	if (!ap) {
+		dev_err(cs->dev, "%s: no application\n", __func__);
+		return;
+	}
+
+	send_disconnect_b3_ind(bcs, ap);
+}
+
+/**
+ * gigaset_isdn_start() - signal device availability
+ * @cs:		device descriptor structure.
+ *
+ * Called by main module to notify the LL that the device is available for
+ * use.
+ */
+void gigaset_isdn_start(struct cardstate *cs)
+{
+	struct gigaset_capi_ctr *iif = cs->iif;
+
+	/* fill profile data: manufacturer name */
+	strcpy(iif->ctr.manu, "Siemens");
+	/* CAPI and device version */
+	iif->ctr.version.majorversion = 2;		/* CAPI 2.0 */
+	iif->ctr.version.minorversion = 0;
+	/* ToDo: check/assert cs->gotfwver? */
+	iif->ctr.version.majormanuversion = cs->fwver[0];
+	iif->ctr.version.minormanuversion = cs->fwver[1];
+	/* number of B channels supported */
+	iif->ctr.profile.nbchannel = cs->channels;
+	/* global options: internal controller, supplementary services */
+	iif->ctr.profile.goptions = 0x11;
+	/* B1 protocols: 64 kbit/s HDLC or transparent */
+	iif->ctr.profile.support1 =  0x03;
+	/* B2 protocols: transparent only */
+	/* ToDo: X.75 SLP ? */
+	iif->ctr.profile.support2 =  0x02;
+	/* B3 protocols: transparent only */
+	iif->ctr.profile.support3 =  0x01;
+	/* no serial number */
+	strcpy(iif->ctr.serial, "0");
+	capi_ctr_ready(&iif->ctr);
+}
+
+/**
+ * gigaset_isdn_stop() - signal device unavailability
+ * @cs:		device descriptor structure.
+ *
+ * Called by main module to notify the LL that the device is no longer
+ * available for use.
+ */
+void gigaset_isdn_stop(struct cardstate *cs)
+{
+	struct gigaset_capi_ctr *iif = cs->iif;
+	capi_ctr_down(&iif->ctr);
+}
+
+/*
+ * kernel CAPI callback methods
+ * ============================
+ */
+
+/*
+ * load firmware
+ */
+static int gigaset_load_firmware(struct capi_ctr *ctr, capiloaddata *data)
+{
+	struct cardstate *cs = ctr->driverdata;
+
+	/* AVM specific operation, not needed for Gigaset -- ignore */
+	dev_notice(cs->dev, "load_firmware ignored\n");
+
+	return 0;
+}
+
+/*
+ * reset (deactivate) controller
+ */
+static void gigaset_reset_ctr(struct capi_ctr *ctr)
+{
+	struct cardstate *cs = ctr->driverdata;
+
+	/* AVM specific operation, not needed for Gigaset -- ignore */
+	dev_notice(cs->dev, "reset_ctr ignored\n");
+}
+
+/*
+ * register CAPI application
+ */
+static void gigaset_register_appl(struct capi_ctr *ctr, u16 appl,
+			   capi_register_params *rp)
+{
+	struct gigaset_capi_ctr *iif
+		= container_of(ctr, struct gigaset_capi_ctr, ctr);
+	struct cardstate *cs = ctr->driverdata;
+	struct gigaset_capi_appl *ap;
+
+	list_for_each_entry(ap, &iif->appls, ctrlist)
+		if (ap->id == appl) {
+			dev_notice(cs->dev,
+				   "application %u already registered\n", appl);
+			return;
+		}
+
+	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
+	if (!ap) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	ap->id = appl;
+
+	list_add(&ap->ctrlist, &iif->appls);
+}
+
+/*
+ * release CAPI application
+ */
+static void gigaset_release_appl(struct capi_ctr *ctr, u16 appl)
+{
+	struct gigaset_capi_ctr *iif
+		= container_of(ctr, struct gigaset_capi_ctr, ctr);
+	struct cardstate *cs = iif->ctr.driverdata;
+	struct gigaset_capi_appl *ap, *tmp;
+
+	list_for_each_entry_safe(ap, tmp, &iif->appls, ctrlist)
+		if (ap->id == appl) {
+			if (ap->connected != APCONN_NONE) {
+				dev_err(cs->dev,
+					"%s: application %u still connected\n",
+					__func__, ap->id);
+				/* ToDo: clear active connection */
+			}
+			list_del(&ap->ctrlist);
+			kfree(ap);
+		}
+
+}
+
+/*
+ * =====================================================================
+ * outgoing CAPI message handler
+ * =====================================================================
+ */
+
+/*
+ * helper function: emit reply message with given Info value
+ */
+static void send_conf(struct gigaset_capi_ctr *iif,
+		      struct gigaset_capi_appl *ap,
+		      struct sk_buff *skb,
+		      u16 info)
+{
+	/*
+	 * _CONF replies always only have NCCI and Info parameters
+	 * so they'll fit into the _REQ message skb
+	 */
+	capi_cmsg_answer(&iif->acmsg);
+	iif->acmsg.Info = info;
+	capi_cmsg2message(&iif->acmsg, skb->data);
+	__skb_trim(skb, CAPI_STDCONF_LEN);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+
+/*
+ * process FACILITY_REQ message
+ */
+static void do_facility_req(struct gigaset_capi_ctr *iif,
+			    struct gigaset_capi_appl *ap,
+			    struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	struct sk_buff *cskb;
+	u8 *pparam;
+	unsigned int msgsize = CAPI_FACILITY_CONF_BASELEN;
+	u16 function, info;
+	static u8 confparam[10];	/* max. 9 octets + length byte */
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/*
+	 * Facility Request Parameter is not decoded by capi_message2cmsg()
+	 * encoding depends on Facility Selector
+	 */
+	switch (iif->acmsg.FacilitySelector) {
+	case CAPI_FACILITY_DTMF:	/* ToDo */
+		info = CapiFacilityNotSupported;
+		confparam[0] = 2;	/* length */
+		/* DTMF information: Unknown DTMF request */
+		capimsg_setu16(confparam, 1, 2);
+		break;
+
+	case CAPI_FACILITY_V42BIS:	/* not supported */
+		info = CapiFacilityNotSupported;
+		confparam[0] = 2;	/* length */
+		/* V.42 bis information: not available */
+		capimsg_setu16(confparam, 1, 1);
+		break;
+
+	case CAPI_FACILITY_SUPPSVC:
+		/* decode Function parameter */
+		pparam = iif->acmsg.FacilityRequestParameter;
+		if (pparam == NULL || *pparam < 2) {
+			dev_notice(cs->dev, "%s: %s missing\n", "FACILITY_REQ",
+				   "Facility Request Parameter");
+			send_conf(iif, ap, skb, CapiIllMessageParmCoding);
+			return;
+		}
+		function = CAPIMSG_U16(pparam, 1);
+		switch (function) {
+		case CAPI_SUPPSVC_GETSUPPORTED:
+			info = CapiSuccess;
+			/* Supplementary Service specific parameter */
+			confparam[3] = 6;	/* length */
+			/* Supplementary services info: Success */
+			capimsg_setu16(confparam, 4, CapiSuccess);
+			/* Supported Services: none */
+			capimsg_setu32(confparam, 6, 0);
+			break;
+		/* ToDo: add supported services */
+		default:
+			info = CapiFacilitySpecificFunctionNotSupported;
+			/* Supplementary Service specific parameter */
+			confparam[3] = 2;	/* length */
+			/* Supplementary services info: not supported */
+			capimsg_setu16(confparam, 4,
+				       CapiSupplementaryServiceNotSupported);
+		}
+
+		/* Facility confirmation parameter */
+		confparam[0] = confparam[3] + 3;	/* total length */
+		/* Function: copy from _REQ message */
+		capimsg_setu16(confparam, 1, function);
+		/* Supplementary Service specific parameter already set above */
+		break;
+
+	case CAPI_FACILITY_WAKEUP:	/* ToDo */
+		info = CapiFacilityNotSupported;
+		confparam[0] = 2;	/* length */
+		/* Number of accepted awake request parameters: 0 */
+		capimsg_setu16(confparam, 1, 0);
+		break;
+
+	default:
+		info = CapiFacilityNotSupported;
+		confparam[0] = 0;	/* empty struct */
+	}
+
+	/* send FACILITY_CONF with given Info and confirmation parameter */
+	capi_cmsg_answer(&iif->acmsg);
+	iif->acmsg.Info = info;
+	iif->acmsg.FacilityConfirmationParameter = confparam;
+	msgsize += confparam[0];	/* length */
+	cskb = alloc_skb(msgsize, GFP_ATOMIC);
+	if (!cskb) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		return;
+	}
+	capi_cmsg2message(&iif->acmsg, __skb_put(cskb, msgsize));
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+		capi_ctr_handle_message(&iif->ctr, ap->id, cskb);
+}
+
+
+/*
+ * process LISTEN_REQ message
+ * just store the masks in the application data structure
+ */
+static void do_listen_req(struct gigaset_capi_ctr *iif,
+			  struct gigaset_capi_appl *ap,
+			  struct sk_buff *skb)
+{
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/* store listening parameters */
+	ap->listenInfoMask = iif->acmsg.InfoMask;
+	ap->listenCIPmask = iif->acmsg.CIPmask;
+	send_conf(iif, ap, skb, CapiSuccess);
+}
+
+/*
+ * process ALERT_REQ message
+ * nothing to do, Gigaset always alerts anyway
+ */
+static void do_alert_req(struct gigaset_capi_ctr *iif,
+			 struct gigaset_capi_appl *ap,
+			 struct sk_buff *skb)
+{
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	send_conf(iif, ap, skb, CapiAlertAlreadySent);
+}
+
+/*
+ * process CONNECT_REQ message
+ * allocate a B channel, prepare dial commands, queue a DIAL event,
+ * emit CONNECT_CONF reply
+ */
+static void do_connect_req(struct gigaset_capi_ctr *iif,
+			   struct gigaset_capi_appl *ap,
+			   struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	_cmsg *cmsg = &iif->acmsg;
+	struct bc_state *bcs;
+	char **commands;
+	char *s;
+	u8 *pp;
+	int i, l;
+	u16 info;
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/* get free B channel & construct PLCI */
+	bcs = gigaset_get_free_channel(cs);
+	if (!bcs) {
+		dev_notice(cs->dev, "%s: no B channel available\n",
+			   "CONNECT_REQ");
+		send_conf(iif, ap, skb, CapiNoPlciAvailable);
+		return;
+	}
+	ap->bcnext = NULL;
+	bcs->ap = ap;
+	cmsg->adr.adrPLCI |= (bcs->channel + 1) << 8;
+
+	/* build command table */
+	commands = kzalloc(AT_NUM*(sizeof *commands), GFP_KERNEL);
+	if (!commands)
+		goto oom;
+
+	/* encode parameter: Called party number */
+	pp = cmsg->CalledPartyNumber;
+	if (pp == NULL || *pp == 0) {
+		dev_notice(cs->dev, "%s: %s missing\n",
+			   "CONNECT_REQ", "Called party number");
+		info = CapiIllMessageParmCoding;
+		goto error;
+	}
+	l = *pp++;
+	/* check type of number/numbering plan byte */
+	switch (*pp) {
+	case 0x80:	/* unknown type / unknown numbering plan */
+	case 0x81:	/* unknown type / ISDN/Telephony numbering plan */
+		break;
+	default:	/* others: warn about potential misinterpretation */
+		dev_notice(cs->dev, "%s: %s type/plan 0x%02x unsupported\n",
+			   "CONNECT_REQ", "Called party number", *pp);
+	}
+	pp++;
+	l--;
+	/* translate "**" internal call prefix to CTP value */
+	if (l >= 2 && pp[0] == '*' && pp[1] == '*') {
+		s = "^SCTP=0\r";
+		pp += 2;
+		l -= 2;
+	} else {
+		s = "^SCTP=1\r";
+	}
+	commands[AT_TYPE] = kstrdup(s, GFP_KERNEL);
+	if (!commands[AT_TYPE])
+		goto oom;
+	commands[AT_DIAL] = kmalloc(l+3, GFP_KERNEL);
+	if (!commands[AT_DIAL])
+		goto oom;
+	snprintf(commands[AT_DIAL], l+3, "D%*s\r", l, pp);
+
+	/* encode parameter: Calling party number */
+	pp = cmsg->CallingPartyNumber;
+	if (pp != NULL && *pp > 0) {
+		l = *pp++;
+
+		/* check type of number/numbering plan byte */
+		/* ToDo: allow for/handle Ext=1? */
+		switch (*pp) {
+		case 0x00:	/* unknown type / unknown numbering plan */
+		case 0x01:	/* unknown type / ISDN/Telephony num. plan */
+			break;
+		default:
+			dev_notice(cs->dev,
+				   "%s: %s type/plan 0x%02x unsupported\n",
+				   "CONNECT_REQ", "Calling party number", *pp);
+		}
+		pp++;
+		l--;
+
+		/* check presentation indicator */
+		if (!l) {
+			dev_notice(cs->dev, "%s: %s IE truncated\n",
+				   "CONNECT_REQ", "Calling party number");
+			info = CapiIllMessageParmCoding;
+			goto error;
+		}
+		switch (*pp & 0xfc) { /* ignore Screening indicator */
+		case 0x80:	/* Presentation allowed */
+			s = "^SCLIP=1\r";
+			break;
+		case 0xa0:	/* Presentation restricted */
+			s = "^SCLIP=0\r";
+			break;
+		default:
+			dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+				   "CONNECT_REQ",
+				   "Presentation/Screening indicator",
+				   *pp);
+			s = "^SCLIP=1\r";
+		}
+		commands[AT_CLIP] = kstrdup(s, GFP_KERNEL);
+		if (!commands[AT_CLIP])
+			goto oom;
+		pp++;
+		l--;
+
+		if (l) {
+			/* number */
+			commands[AT_MSN] = kmalloc(l+8, GFP_KERNEL);
+			if (!commands[AT_MSN])
+				goto oom;
+			snprintf(commands[AT_MSN], l+8, "^SMSN=%*s\r", l, pp);
+		}
+	}
+
+	/* check parameter: CIP Value */
+	if (cmsg->CIPValue > ARRAY_SIZE(cip2bchlc) ||
+	    (cmsg->CIPValue > 0 && cip2bchlc[cmsg->CIPValue].bc == NULL)) {
+		dev_notice(cs->dev, "%s: unknown CIP value %d\n",
+			   "CONNECT_REQ", cmsg->CIPValue);
+		info = CapiCipValueUnknown;
+		goto error;
+	}
+
+	/* check/encode parameter: BC */
+	if (cmsg->BC && cmsg->BC[0]) {
+		/* explicit BC overrides CIP */
+		l = 2*cmsg->BC[0] + 7;
+		commands[AT_BC] = kmalloc(l, GFP_KERNEL);
+		if (!commands[AT_BC])
+			goto oom;
+		strcpy(commands[AT_BC], "^SBC=");
+		decode_ie(cmsg->BC, commands[AT_BC]+5);
+		strcpy(commands[AT_BC] + l - 2, "\r");
+	} else if (cip2bchlc[cmsg->CIPValue].bc) {
+		l = strlen(cip2bchlc[cmsg->CIPValue].bc) + 7;
+		commands[AT_BC] = kmalloc(l, GFP_KERNEL);
+		if (!commands[AT_BC])
+			goto oom;
+		snprintf(commands[AT_BC], l, "^SBC=%s\r",
+			 cip2bchlc[cmsg->CIPValue].bc);
+	}
+
+	/* check/encode parameter: HLC */
+	if (cmsg->HLC && cmsg->HLC[0]) {
+		/* explicit HLC overrides CIP */
+		l = 2*cmsg->HLC[0] + 7;
+		commands[AT_HLC] = kmalloc(l, GFP_KERNEL);
+		if (!commands[AT_HLC])
+			goto oom;
+		strcpy(commands[AT_HLC], "^SHLC=");
+		decode_ie(cmsg->HLC, commands[AT_HLC]+5);
+		strcpy(commands[AT_HLC] + l - 2, "\r");
+	} else if (cip2bchlc[cmsg->CIPValue].hlc) {
+		l = strlen(cip2bchlc[cmsg->CIPValue].hlc) + 7;
+		commands[AT_HLC] = kmalloc(l, GFP_KERNEL);
+		if (!commands[AT_HLC])
+			goto oom;
+		snprintf(commands[AT_HLC], l, "^SHLC=%s\r",
+			 cip2bchlc[cmsg->CIPValue].hlc);
+	}
+
+	/* check/encode parameter: B Protocol */
+	if (cmsg->BProtocol == CAPI_DEFAULT) {
+		bcs->proto2 = L2_HDLC;
+		dev_warn(cs->dev,
+		    "B2 Protocol X.75 SLP unsupported, using Transparent\n");
+	} else {
+		switch (cmsg->B1protocol) {
+		case 0:
+			bcs->proto2 = L2_HDLC;
+			break;
+		case 1:
+			bcs->proto2 = L2_BITSYNC;
+			break;
+		default:
+			dev_warn(cs->dev,
+			    "B1 Protocol %u unsupported, using Transparent\n",
+				 cmsg->B1protocol);
+			bcs->proto2 = L2_BITSYNC;
+		}
+		if (cmsg->B2protocol != 1)
+			dev_warn(cs->dev,
+			    "B2 Protocol %u unsupported, using Transparent\n",
+				 cmsg->B2protocol);
+		if (cmsg->B3protocol != 0)
+			dev_warn(cs->dev,
+			    "B3 Protocol %u unsupported, using Transparent\n",
+				 cmsg->B3protocol);
+		ignore_cstruct_param(cs, cmsg->B1configuration,
+					"CONNECT_REQ", "B1 Configuration");
+		ignore_cstruct_param(cs, cmsg->B2configuration,
+					"CONNECT_REQ", "B2 Configuration");
+		ignore_cstruct_param(cs, cmsg->B3configuration,
+					"CONNECT_REQ", "B3 Configuration");
+	}
+	commands[AT_PROTO] = kmalloc(9, GFP_KERNEL);
+	if (!commands[AT_PROTO])
+		goto oom;
+	snprintf(commands[AT_PROTO], 9, "^SBPR=%u\r", bcs->proto2);
+
+	/* ToDo: check/encode remaining parameters */
+	ignore_cstruct_param(cs, cmsg->CalledPartySubaddress,
+					"CONNECT_REQ", "Called pty subaddr");
+	ignore_cstruct_param(cs, cmsg->CallingPartySubaddress,
+					"CONNECT_REQ", "Calling pty subaddr");
+	ignore_cstruct_param(cs, cmsg->LLC,
+					"CONNECT_REQ", "LLC");
+	ignore_cmstruct_param(cs, cmsg->AdditionalInfo,
+					"CONNECT_REQ", "Additional Info");
+
+	/* encode parameter: B channel to use */
+	commands[AT_ISO] = kmalloc(9, GFP_KERNEL);
+	if (!commands[AT_ISO])
+		goto oom;
+	snprintf(commands[AT_ISO], 9, "^SISO=%u\r",
+		 (unsigned) bcs->channel + 1);
+
+	/* queue & schedule EV_DIAL event */
+	if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, commands,
+			       bcs->at_state.seq_index, NULL))
+		goto oom;
+	gig_dbg(DEBUG_CMD, "scheduling DIAL");
+	gigaset_schedule_event(cs);
+	ap->connected = APCONN_SETUP;
+	send_conf(iif, ap, skb, CapiSuccess);
+	return;
+
+oom:
+	dev_err(cs->dev, "%s: out of memory\n", __func__);
+	info = CAPI_MSGOSRESOURCEERR;
+error:
+	if (commands)
+		for (i = 0; i < AT_NUM; i++)
+			kfree(commands[i]);
+	kfree(commands);
+	gigaset_free_channel(bcs);
+	send_conf(iif, ap, skb, info);
+}
+
+/*
+ * process CONNECT_RESP message
+ * checks protocol parameters and queues an ACCEPT or HUP event
+ */
+static void do_connect_resp(struct gigaset_capi_ctr *iif,
+			    struct gigaset_capi_appl *ap,
+			    struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	_cmsg *cmsg = &iif->acmsg;
+	struct bc_state *bcs;
+	struct gigaset_capi_appl *oap;
+	int channel;
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	dev_kfree_skb(skb);
+
+	/* extract and check channel number from PLCI */
+	channel = (cmsg->adr.adrPLCI >> 8) & 0xff;
+	if (!channel || channel > cs->channels) {
+		dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+			   "CONNECT_RESP", "PLCI", cmsg->adr.adrPLCI);
+		return;
+	}
+	bcs = cs->bcs + channel - 1;
+
+	switch (cmsg->Reject) {
+	case 0:		/* Accept */
+		/* drop all competing applications, keep only this one */
+		for (oap = bcs->ap; oap != NULL; oap = oap->bcnext)
+			if (oap != ap)
+				send_disconnect_ind(bcs, oap,
+					CapiCallGivenToOtherApplication);
+		ap->bcnext = NULL;
+		bcs->ap = ap;
+		bcs->chstate |= CHS_NOTIFY_LL;
+
+		/* check/encode B channel protocol */
+		if (cmsg->BProtocol == CAPI_DEFAULT) {
+			bcs->proto2 = L2_HDLC;
+			dev_warn(cs->dev,
+		"B2 Protocol X.75 SLP unsupported, using Transparent\n");
+		} else {
+			switch (cmsg->B1protocol) {
+			case 0:
+				bcs->proto2 = L2_HDLC;
+				break;
+			case 1:
+				bcs->proto2 = L2_BITSYNC;
+				break;
+			default:
+				dev_warn(cs->dev,
+			"B1 Protocol %u unsupported, using Transparent\n",
+					 cmsg->B1protocol);
+				bcs->proto2 = L2_BITSYNC;
+			}
+			if (cmsg->B2protocol != 1)
+				dev_warn(cs->dev,
+			"B2 Protocol %u unsupported, using Transparent\n",
+					 cmsg->B2protocol);
+			if (cmsg->B3protocol != 0)
+				dev_warn(cs->dev,
+			"B3 Protocol %u unsupported, using Transparent\n",
+					 cmsg->B3protocol);
+			ignore_cstruct_param(cs, cmsg->B1configuration,
+					"CONNECT_RESP", "B1 Configuration");
+			ignore_cstruct_param(cs, cmsg->B2configuration,
+					"CONNECT_RESP", "B2 Configuration");
+			ignore_cstruct_param(cs, cmsg->B3configuration,
+					"CONNECT_RESP", "B3 Configuration");
+		}
+
+		/* ToDo: check/encode remaining parameters */
+		ignore_cstruct_param(cs, cmsg->ConnectedNumber,
+					"CONNECT_RESP", "Connected Number");
+		ignore_cstruct_param(cs, cmsg->ConnectedSubaddress,
+					"CONNECT_RESP", "Connected Subaddress");
+		ignore_cstruct_param(cs, cmsg->LLC,
+					"CONNECT_RESP", "LLC");
+		ignore_cmstruct_param(cs, cmsg->AdditionalInfo,
+					"CONNECT_RESP", "Additional Info");
+
+		/* Accept call */
+		if (!gigaset_add_event(cs, &cs->bcs[channel-1].at_state,
+				       EV_ACCEPT, NULL, 0, NULL))
+			return;
+		gig_dbg(DEBUG_CMD, "scheduling ACCEPT");
+		gigaset_schedule_event(cs);
+		return;
+
+	case 1:			/* Ignore */
+		/* send DISCONNECT_IND to this application */
+		send_disconnect_ind(bcs, ap, 0);
+
+		/* remove it from the list of listening apps */
+		if (bcs->ap == ap) {
+			bcs->ap = ap->bcnext;
+			if (bcs->ap == NULL)
+				/* last one: stop ev-layer hupD notifications */
+				bcs->chstate &= ~CHS_NOTIFY_LL;
+			return;
+		}
+		for (oap = bcs->ap; oap != NULL; oap = oap->bcnext) {
+			if (oap->bcnext == ap) {
+				oap->bcnext = oap->bcnext->bcnext;
+				return;
+			}
+		}
+		dev_err(cs->dev, "%s: application %u not found\n",
+			__func__, ap->id);
+		return;
+
+	default:		/* Reject */
+		/* drop all competing applications, keep only this one */
+		for (oap = bcs->ap; oap != NULL; oap = oap->bcnext)
+			if (oap != ap)
+				send_disconnect_ind(bcs, oap,
+					CapiCallGivenToOtherApplication);
+		ap->bcnext = NULL;
+		bcs->ap = ap;
+
+		/* reject call - will trigger DISCONNECT_IND for this app */
+		dev_info(cs->dev, "%s: Reject=%x\n",
+			 "CONNECT_RESP", cmsg->Reject);
+		if (!gigaset_add_event(cs, &cs->bcs[channel-1].at_state,
+				       EV_HUP, NULL, 0, NULL))
+			return;
+		gig_dbg(DEBUG_CMD, "scheduling HUP");
+		gigaset_schedule_event(cs);
+		return;
+	}
+}
+
+/*
+ * process CONNECT_B3_REQ message
+ * build NCCI and emit CONNECT_B3_CONF reply
+ */
+static void do_connect_b3_req(struct gigaset_capi_ctr *iif,
+			      struct gigaset_capi_appl *ap,
+			      struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	int channel;
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/* extract and check channel number from PLCI */
+	channel = (iif->acmsg.adr.adrPLCI >> 8) & 0xff;
+	if (!channel || channel > cs->channels) {
+		dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+			   "CONNECT_B3_REQ", "PLCI", iif->acmsg.adr.adrPLCI);
+		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
+		return;
+	}
+
+	/* mark logical connection active */
+	ap->connected = APCONN_ACTIVE;
+
+	/* build NCCI: always 1 (one B3 connection only) */
+	iif->acmsg.adr.adrNCCI |= 1 << 16;
+
+	/* NCPI parameter: not applicable for B3 Transparent */
+	ignore_cstruct_param(cs, iif->acmsg.NCPI,
+				"CONNECT_B3_REQ", "NCPI");
+	send_conf(iif, ap, skb,
+		  (iif->acmsg.NCPI && iif->acmsg.NCPI[0]) ?
+			CapiNcpiNotSupportedByProtocol : CapiSuccess);
+}
+
+/*
+ * process CONNECT_B3_RESP message
+ * Depending on the Reject parameter, either emit CONNECT_B3_ACTIVE_IND
+ * or queue EV_HUP and emit DISCONNECT_B3_IND.
+ * The emitted message is always shorter than the received one,
+ * allowing to reuse the skb.
+ */
+static void do_connect_b3_resp(struct gigaset_capi_ctr *iif,
+			       struct gigaset_capi_appl *ap,
+			       struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	struct bc_state *bcs = NULL;
+	int channel;
+	unsigned int msgsize;
+	u8 command;
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/* extract and check channel number and NCCI */
+	channel = (iif->acmsg.adr.adrNCCI >> 8) & 0xff;
+	if (!channel || channel > cs->channels ||
+	    ((iif->acmsg.adr.adrNCCI >> 16) & 0xffff) != 1) {
+		dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+			   "CONNECT_B3_RESP", "NCCI", iif->acmsg.adr.adrNCCI);
+		dev_kfree_skb(skb);
+		return;
+	}
+	bcs = &cs->bcs[channel-1];
+
+	if (iif->acmsg.Reject) {
+		/* Reject: clear B3 connect received flag */
+		ap->connected = APCONN_SETUP;
+
+		/* trigger hangup, causing eventual DISCONNECT_IND */
+		if (!gigaset_add_event(cs, &bcs->at_state,
+				       EV_HUP, NULL, 0, NULL)) {
+			dev_err(cs->dev, "%s: out of memory\n", __func__);
+			dev_kfree_skb(skb);
+			return;
+		}
+		gig_dbg(DEBUG_CMD, "scheduling HUP");
+		gigaset_schedule_event(cs);
+
+		/* emit DISCONNECT_B3_IND */
+		command = CAPI_DISCONNECT_B3;
+		msgsize = CAPI_DISCONNECT_B3_IND_BASELEN;
+	} else {
+		/*
+		 * Accept: emit CONNECT_B3_ACTIVE_IND immediately, as
+		 * we only send CONNECT_B3_IND if the B channel is up
+		 */
+		command = CAPI_CONNECT_B3_ACTIVE;
+		msgsize = CAPI_CONNECT_B3_ACTIVE_IND_BASELEN;
+	}
+	capi_cmsg_header(&iif->acmsg, ap->id, command, CAPI_IND,
+			 ap->nextMessageNumber++, iif->acmsg.adr.adrNCCI);
+	__skb_trim(skb, msgsize);
+	capi_cmsg2message(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
+}
+
+/*
+ * process DISCONNECT_REQ message
+ * schedule EV_HUP and emit DISCONNECT_B3_IND if necessary,
+ * emit DISCONNECT_CONF reply
+ */
+static void do_disconnect_req(struct gigaset_capi_ctr *iif,
+			      struct gigaset_capi_appl *ap,
+			      struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	struct bc_state *bcs;
+	_cmsg *b3cmsg;
+	struct sk_buff *b3skb;
+	int channel;
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/* extract and check channel number from PLCI */
+	channel = (iif->acmsg.adr.adrPLCI >> 8) & 0xff;
+	if (!channel || channel > cs->channels) {
+		dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+			   "DISCONNECT_REQ", "PLCI", iif->acmsg.adr.adrPLCI);
+		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
+		return;
+	}
+	bcs = cs->bcs + channel - 1;
+
+	/* ToDo: process parameter: Additional info */
+	ignore_cmstruct_param(cs, iif->acmsg.AdditionalInfo,
+			      "DISCONNECT_REQ", "Additional Info");
+
+	/* skip if DISCONNECT_IND already sent */
+	if (!ap->connected)
+		return;
+
+	/* check for active logical connection */
+	if (ap->connected >= APCONN_ACTIVE) {
+		/*
+		 * emit DISCONNECT_B3_IND with cause 0x3301
+		 * use separate cmsg structure, as the content of iif->acmsg
+		 * is still needed for creating the _CONF message
+		 */
+		b3cmsg = kmalloc(sizeof(*b3cmsg), GFP_KERNEL);
+		if (!b3cmsg) {
+			dev_err(cs->dev, "%s: out of memory\n", __func__);
+			send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
+			return;
+		}
+		capi_cmsg_header(b3cmsg, ap->id, CAPI_DISCONNECT_B3, CAPI_IND,
+				 ap->nextMessageNumber++,
+				 iif->acmsg.adr.adrPLCI | (1 << 16));
+		b3cmsg->Reason_B3 = CapiProtocolErrorLayer1;
+		b3skb = alloc_skb(CAPI_DISCONNECT_B3_IND_BASELEN, GFP_KERNEL);
+		if (b3skb == NULL) {
+			dev_err(cs->dev, "%s: out of memory\n", __func__);
+			send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
+			return;
+		}
+		capi_cmsg2message(b3cmsg,
+			__skb_put(b3skb, CAPI_DISCONNECT_B3_IND_BASELEN));
+		kfree(b3cmsg);
+		capi_ctr_handle_message(&iif->ctr, ap->id, b3skb);
+	}
+
+	/* trigger hangup, causing eventual DISCONNECT_IND */
+	if (!gigaset_add_event(cs, &bcs->at_state, EV_HUP, NULL, 0, NULL)) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
+		return;
+	}
+	gig_dbg(DEBUG_CMD, "scheduling HUP");
+	gigaset_schedule_event(cs);
+
+	/* emit reply */
+	send_conf(iif, ap, skb, CapiSuccess);
+}
+
+/*
+ * process DISCONNECT_B3_REQ message
+ * schedule EV_HUP and emit DISCONNECT_B3_CONF reply
+ */
+static void do_disconnect_b3_req(struct gigaset_capi_ctr *iif,
+				 struct gigaset_capi_appl *ap,
+				 struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	int channel;
+
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+
+	/* extract and check channel number and NCCI */
+	channel = (iif->acmsg.adr.adrNCCI >> 8) & 0xff;
+	if (!channel || channel > cs->channels ||
+	    ((iif->acmsg.adr.adrNCCI >> 16) & 0xffff) != 1) {
+		dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+			   "DISCONNECT_B3_REQ", "NCCI", iif->acmsg.adr.adrNCCI);
+		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
+		return;
+	}
+
+	/* reject if logical connection not active */
+	if (ap->connected < APCONN_ACTIVE) {
+		send_conf(iif, ap, skb,
+			  CapiMessageNotSupportedInCurrentState);
+		return;
+	}
+
+	/* trigger hangup, causing eventual DISCONNECT_B3_IND */
+	if (!gigaset_add_event(cs, &cs->bcs[channel-1].at_state,
+			       EV_HUP, NULL, 0, NULL)) {
+		dev_err(cs->dev, "%s: out of memory\n", __func__);
+		send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
+		return;
+	}
+	gig_dbg(DEBUG_CMD, "scheduling HUP");
+	gigaset_schedule_event(cs);
+
+	/* NCPI parameter: not applicable for B3 Transparent */
+	ignore_cstruct_param(cs, iif->acmsg.NCPI,
+				"DISCONNECT_B3_REQ", "NCPI");
+	send_conf(iif, ap, skb,
+		  (iif->acmsg.NCPI && iif->acmsg.NCPI[0]) ?
+			CapiNcpiNotSupportedByProtocol : CapiSuccess);
+}
+
+/*
+ * process DATA_B3_REQ message
+ */
+static void do_data_b3_req(struct gigaset_capi_ctr *iif,
+			   struct gigaset_capi_appl *ap,
+			   struct sk_buff *skb)
+{
+	struct cardstate *cs = iif->ctr.driverdata;
+	int channel = CAPIMSG_PLCI_PART(skb->data);
+	u16 ncci = CAPIMSG_NCCI_PART(skb->data);
+	u16 msglen = CAPIMSG_LEN(skb->data);
+	u16 datalen = CAPIMSG_DATALEN(skb->data);
+	u16 flags = CAPIMSG_FLAGS(skb->data);
+
+	/* frequent message, avoid _cmsg overhead */
+	dump_rawmsg(DEBUG_LLDATA, "DATA_B3_REQ", skb->data);
+
+	gig_dbg(DEBUG_LLDATA,
+		"Receiving data from LL (ch: %d, flg: %x, sz: %d|%d)",
+		channel, flags, msglen, datalen);
+
+	/* check parameters */
+	if (channel == 0 || channel > cs->channels || ncci != 1) {
+		dev_notice(cs->dev, "%s: invalid %s 0x%02x\n",
+			   "DATA_B3_REQ", "NCCI", CAPIMSG_NCCI(skb->data));
+		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
+		return;
+	}
+	if (msglen != CAPI_DATA_B3_REQ_LEN && msglen != CAPI_DATA_B3_REQ_LEN64)
+		dev_notice(cs->dev, "%s: unexpected length %d\n",
+			   "DATA_B3_REQ", msglen);
+	if (msglen + datalen != skb->len)
+		dev_notice(cs->dev, "%s: length mismatch (%d+%d!=%d)\n",
+			   "DATA_B3_REQ", msglen, datalen, skb->len);
+	if (msglen + datalen > skb->len) {
+		/* message too short for announced data length */
+		send_conf(iif, ap, skb, CapiIllMessageParmCoding); /* ? */
+		return;
+	}
+	if (flags & CAPI_FLAGS_RESERVED) {
+		dev_notice(cs->dev, "%s: reserved flags set (%x)\n",
+			   "DATA_B3_REQ", flags);
+		send_conf(iif, ap, skb, CapiIllMessageParmCoding);
+		return;
+	}
+
+	/* reject if logical connection not active */
+	if (ap->connected < APCONN_ACTIVE) {
+		send_conf(iif, ap, skb, CapiMessageNotSupportedInCurrentState);
+		return;
+	}
+
+	/*
+	 * pull CAPI message from skb,
+	 * pass payload data to device-specific module
+	 * CAPI message will be preserved in headroom
+	 */
+	skb_pull(skb, msglen);
+	if (cs->ops->send_skb(&cs->bcs[channel-1], skb) < 0) {
+		send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
+		return;
+	}
+
+	/* DATA_B3_CONF reply will be sent by gigaset_skb_sent() */
+
+	/*
+	 * ToDo: honor unset "delivery confirmation" bit
+	 * (send DATA_B3_CONF immediately?)
+	 */
+}
+
+/*
+ * process RESET_B3_REQ message
+ * just always reply "not supported by current protocol"
+ */
+static void do_reset_b3_req(struct gigaset_capi_ctr *iif,
+			    struct gigaset_capi_appl *ap,
+			    struct sk_buff *skb)
+{
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	send_conf(iif, ap, skb,
+		  CapiResetProcedureNotSupportedByCurrentProtocol);
+}
+
+/*
+ * dump unsupported/ignored messages at most twice per minute,
+ * some apps send those very frequently
+ */
+static unsigned long ignored_msg_dump_time;
+
+/*
+ * unsupported CAPI message handler
+ */
+static void do_unsupported(struct gigaset_capi_ctr *iif,
+			   struct gigaset_capi_appl *ap,
+			   struct sk_buff *skb)
+{
+	/* decode message */
+	capi_message2cmsg(&iif->acmsg, skb->data);
+	if (printk_timed_ratelimit(&ignored_msg_dump_time, 30 * 1000))
+		dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	send_conf(iif, ap, skb, CapiMessageNotSupportedInCurrentState);
+}
+
+/*
+ * CAPI message handler: no-op
+ */
+static void do_nothing(struct gigaset_capi_ctr *iif,
+		       struct gigaset_capi_appl *ap,
+		       struct sk_buff *skb)
+{
+	if (printk_timed_ratelimit(&ignored_msg_dump_time, 30 * 1000)) {
+		/* decode message */
+		capi_message2cmsg(&iif->acmsg, skb->data);
+		dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+	}
+	dev_kfree_skb(skb);
+}
+
+static void do_data_b3_resp(struct gigaset_capi_ctr *iif,
+			    struct gigaset_capi_appl *ap,
+			    struct sk_buff *skb)
+{
+	dump_rawmsg(DEBUG_LLDATA, __func__, skb->data);
+	dev_kfree_skb(skb);
+}
+
+/* table of outgoing CAPI message handlers with lookup function */
+typedef void (*capi_send_handler_t)(struct gigaset_capi_ctr *,
+				    struct gigaset_capi_appl *,
+				    struct sk_buff *);
+
+static struct {
+	u16 cmd;
+	capi_send_handler_t handler;
+} capi_send_handler_table[] = {
+	/* most frequent messages first for faster lookup */
+	{ CAPI_DATA_B3_REQ, do_data_b3_req },
+	{ CAPI_DATA_B3_RESP, do_data_b3_resp },
+
+	{ CAPI_ALERT_REQ, do_alert_req },
+	{ CAPI_CONNECT_ACTIVE_RESP, do_nothing },
+	{ CAPI_CONNECT_B3_ACTIVE_RESP, do_nothing },
+	{ CAPI_CONNECT_B3_REQ, do_connect_b3_req },
+	{ CAPI_CONNECT_B3_RESP, do_connect_b3_resp },
+	{ CAPI_CONNECT_B3_T90_ACTIVE_RESP, do_nothing },
+	{ CAPI_CONNECT_REQ, do_connect_req },
+	{ CAPI_CONNECT_RESP, do_connect_resp },
+	{ CAPI_DISCONNECT_B3_REQ, do_disconnect_b3_req },
+	{ CAPI_DISCONNECT_B3_RESP, do_nothing },
+	{ CAPI_DISCONNECT_REQ, do_disconnect_req },
+	{ CAPI_DISCONNECT_RESP, do_nothing },
+	{ CAPI_FACILITY_REQ, do_facility_req },
+	{ CAPI_FACILITY_RESP, do_nothing },
+	{ CAPI_LISTEN_REQ, do_listen_req },
+	{ CAPI_SELECT_B_PROTOCOL_REQ, do_unsupported },
+	{ CAPI_RESET_B3_REQ, do_reset_b3_req },
+	{ CAPI_RESET_B3_RESP, do_nothing },
+
+	/*
+	 * ToDo: support overlap sending (requires ev-layer state
+	 * machine extension to generate additional ATD commands)
+	 */
+	{ CAPI_INFO_REQ, do_unsupported },
+	{ CAPI_INFO_RESP, do_nothing },
+
+	/*
+	 * ToDo: what's the proper response for these?
+	 */
+	{ CAPI_MANUFACTURER_REQ, do_nothing },
+	{ CAPI_MANUFACTURER_RESP, do_nothing },
+};
+
+/* look up handler */
+static inline capi_send_handler_t lookup_capi_send_handler(const u16 cmd)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(capi_send_handler_table); i++)
+		if (capi_send_handler_table[i].cmd == cmd)
+			return capi_send_handler_table[i].handler;
+	return NULL;
+}
+
+
+/**
+ * gigaset_send_message() - accept a CAPI message from an application
+ * @ctr:	controller descriptor structure.
+ * @skb:	CAPI message.
+ *
+ * Return value: CAPI error code
+ * Note: capidrv (and probably others, too) only uses the return value to
+ * decide whether it has to free the skb (only if result != CAPI_NOERROR (0))
+ */
+static u16 gigaset_send_message(struct capi_ctr *ctr, struct sk_buff *skb)
+{
+	struct gigaset_capi_ctr *iif
+		= container_of(ctr, struct gigaset_capi_ctr, ctr);
+	struct cardstate *cs = ctr->driverdata;
+	struct gigaset_capi_appl *ap;
+	capi_send_handler_t handler;
+
+	/* can only handle linear sk_buffs */
+	if (skb_linearize(skb) < 0) {
+		dev_warn(cs->dev, "%s: skb_linearize failed\n", __func__);
+		return CAPI_MSGOSRESOURCEERR;
+	}
+
+	/* retrieve application data structure */
+	ap = get_appl(iif, CAPIMSG_APPID(skb->data));
+	if (!ap) {
+		dev_notice(cs->dev, "%s: application %u not registered\n",
+			   __func__, CAPIMSG_APPID(skb->data));
+		return CAPI_ILLAPPNR;
+	}
+
+	/* look up command */
+	handler = lookup_capi_send_handler(CAPIMSG_CMD(skb->data));
+	if (!handler) {
+		/* unknown/unsupported message type */
+		if (printk_ratelimit())
+			dev_notice(cs->dev, "%s: unsupported message %u\n",
+				   __func__, CAPIMSG_CMD(skb->data));
+		return CAPI_ILLCMDORSUBCMDORMSGTOSMALL;
+	}
+
+	/* serialize */
+	if (atomic_add_return(1, &iif->sendqlen) > 1) {
+		/* queue behind other messages */
+		skb_queue_tail(&iif->sendqueue, skb);
+		return CAPI_NOERROR;
+	}
+
+	/* process message */
+	handler(iif, ap, skb);
+
+	/* process other messages arrived in the meantime */
+	while (atomic_sub_return(1, &iif->sendqlen) > 0) {
+		skb = skb_dequeue(&iif->sendqueue);
+		if (!skb) {
+			/* should never happen */
+			dev_err(cs->dev, "%s: send queue empty\n", __func__);
+			continue;
+		}
+		ap = get_appl(iif, CAPIMSG_APPID(skb->data));
+		if (!ap) {
+			/* could that happen? */
+			dev_warn(cs->dev, "%s: application %u vanished\n",
+				 __func__, CAPIMSG_APPID(skb->data));
+			continue;
+		}
+		handler = lookup_capi_send_handler(CAPIMSG_CMD(skb->data));
+		if (!handler) {
+			/* should never happen */
+			dev_err(cs->dev, "%s: handler %x vanished\n",
+				__func__, CAPIMSG_CMD(skb->data));
+			continue;
+		}
+		handler(iif, ap, skb);
+	}
+
+	return CAPI_NOERROR;
+}
+
+/**
+ * gigaset_procinfo() - build single line description for controller
+ * @ctr:	controller descriptor structure.
+ *
+ * Return value: pointer to generated string (null terminated)
+ */
+static char *gigaset_procinfo(struct capi_ctr *ctr)
+{
+	return ctr->name;	/* ToDo: more? */
+}
+
+/**
+ * gigaset_ctr_read_proc() - build controller proc file entry
+ * @page:	buffer of PAGE_SIZE bytes for receiving the entry.
+ * @start:	unused.
+ * @off:	unused.
+ * @count:	unused.
+ * @eof:	unused.
+ * @ctr:	controller descriptor structure.
+ *
+ * Return value: length of generated entry
+ */
+static int gigaset_ctr_read_proc(char *page, char **start, off_t off,
+			  int count, int *eof, struct capi_ctr *ctr)
+{
+	struct cardstate *cs = ctr->driverdata;
+	char *s;
+	int i;
+	int len = 0;
+	len += sprintf(page+len, "%-16s %s\n", "name", ctr->name);
+	len += sprintf(page+len, "%-16s %s %s\n", "dev",
+			dev_driver_string(cs->dev), dev_name(cs->dev));
+	len += sprintf(page+len, "%-16s %d\n", "id", cs->myid);
+	if (cs->gotfwver)
+		len += sprintf(page+len, "%-16s %d.%d.%d.%d\n", "firmware",
+			cs->fwver[0], cs->fwver[1], cs->fwver[2], cs->fwver[3]);
+	len += sprintf(page+len, "%-16s %d\n", "channels",
+			cs->channels);
+	len += sprintf(page+len, "%-16s %s\n", "onechannel",
+			cs->onechannel ? "yes" : "no");
+
+	switch (cs->mode) {
+	case M_UNKNOWN:
+		s = "unknown";
+		break;
+	case M_CONFIG:
+		s = "config";
+		break;
+	case M_UNIMODEM:
+		s = "Unimodem";
+		break;
+	case M_CID:
+		s = "CID";
+		break;
+	default:
+		s = "??";
+	}
+	len += sprintf(page+len, "%-16s %s\n", "mode", s);
+
+	switch (cs->mstate) {
+	case MS_UNINITIALIZED:
+		s = "uninitialized";
+		break;
+	case MS_INIT:
+		s = "init";
+		break;
+	case MS_LOCKED:
+		s = "locked";
+		break;
+	case MS_SHUTDOWN:
+		s = "shutdown";
+		break;
+	case MS_RECOVER:
+		s = "recover";
+		break;
+	case MS_READY:
+		s = "ready";
+		break;
+	default:
+		s = "??";
+	}
+	len += sprintf(page+len, "%-16s %s\n", "mstate", s);
+
+	len += sprintf(page+len, "%-16s %s\n", "running",
+			cs->running ? "yes" : "no");
+	len += sprintf(page+len, "%-16s %s\n", "connected",
+			cs->connected ? "yes" : "no");
+	len += sprintf(page+len, "%-16s %s\n", "isdn_up",
+			cs->isdn_up ? "yes" : "no");
+	len += sprintf(page+len, "%-16s %s\n", "cidmode",
+			cs->cidmode ? "yes" : "no");
+
+	for (i = 0; i < cs->channels; i++) {
+		len += sprintf(page+len, "[%d]%-13s %d\n", i, "corrupted",
+				cs->bcs[i].corrupted);
+		len += sprintf(page+len, "[%d]%-13s %d\n", i, "trans_down",
+				cs->bcs[i].trans_down);
+		len += sprintf(page+len, "[%d]%-13s %d\n", i, "trans_up",
+				cs->bcs[i].trans_up);
+		len += sprintf(page+len, "[%d]%-13s %d\n", i, "chstate",
+				cs->bcs[i].chstate);
+		switch (cs->bcs[i].proto2) {
+		case L2_BITSYNC:
+			s = "bitsync";
+			break;
+		case L2_HDLC:
+			s = "HDLC";
+			break;
+		case L2_VOICE:
+			s = "voice";
+			break;
+		default:
+			s = "??";
+		}
+		len += sprintf(page+len, "[%d]%-13s %s\n", i, "proto2", s);
+	}
+	return len;
+}
+
+
+static struct capi_driver capi_driver_gigaset = {
+	.name		= "gigaset",
+	.revision	= "1.0",
+};
+
+/**
+ * gigaset_isdn_register() - register to LL
+ * @cs:		device descriptor structure.
+ * @isdnid:	device name.
+ *
+ * Called by main module to register the device with the LL.
+ *
+ * Return value: 1 for success, 0 for failure
+ */
+int gigaset_isdn_register(struct cardstate *cs, const char *isdnid)
+{
+	struct gigaset_capi_ctr *iif;
+	int rc;
+
+	pr_info("Kernel CAPI interface\n");
+
+	iif = kmalloc(sizeof(*iif), GFP_KERNEL);
+	if (!iif) {
+		pr_err("%s: out of memory\n", __func__);
+		return 0;
+	}
+
+	/* register driver with CAPI (ToDo: what for?) */
+	register_capi_driver(&capi_driver_gigaset);
+
+	/* prepare controller structure */
+	iif->ctr.owner         = THIS_MODULE;
+	iif->ctr.driverdata    = cs;
+	strncpy(iif->ctr.name, isdnid, sizeof(iif->ctr.name));
+	iif->ctr.driver_name   = "gigaset";
+	iif->ctr.load_firmware = gigaset_load_firmware;
+	iif->ctr.reset_ctr     = gigaset_reset_ctr;
+	iif->ctr.register_appl = gigaset_register_appl;
+	iif->ctr.release_appl  = gigaset_release_appl;
+	iif->ctr.send_message  = gigaset_send_message;
+	iif->ctr.procinfo      = gigaset_procinfo;
+	iif->ctr.ctr_read_proc = gigaset_ctr_read_proc;
+	INIT_LIST_HEAD(&iif->appls);
+	skb_queue_head_init(&iif->sendqueue);
+	atomic_set(&iif->sendqlen, 0);
+
+	/* register controller with CAPI */
+	rc = attach_capi_ctr(&iif->ctr);
+	if (rc) {
+		pr_err("attach_capi_ctr failed (%d)\n", rc);
+		unregister_capi_driver(&capi_driver_gigaset);
+		kfree(iif);
+		return 0;
+	}
+
+	cs->iif = iif;
+	cs->hw_hdr_len = CAPI_DATA_B3_REQ_LEN;
+	return 1;
+}
+
+/**
+ * gigaset_isdn_unregister() - unregister from LL
+ * @cs:		device descriptor structure.
+ *
+ * Called by main module to unregister the device from the LL.
+ */
+void gigaset_isdn_unregister(struct cardstate *cs)
+{
+	struct gigaset_capi_ctr *iif = cs->iif;
+
+	detach_capi_ctr(&iif->ctr);
+	kfree(iif);
+	cs->iif = NULL;
+	unregister_capi_driver(&capi_driver_gigaset);
+}
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 15dc0fc28a96..1d2ae2e05e0b 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -207,6 +207,32 @@ int gigaset_get_channel(struct bc_state *bcs)
 	return 1;
 }
 
+struct bc_state *gigaset_get_free_channel(struct cardstate *cs)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&cs->lock, flags);
+	if (!try_module_get(cs->driver->owner)) {
+		gig_dbg(DEBUG_ANY,
+			"could not get module for allocating channel");
+		spin_unlock_irqrestore(&cs->lock, flags);
+		return NULL;
+	}
+	for (i = 0; i < cs->channels; ++i)
+		if (!cs->bcs[i].use_count) {
+			++cs->bcs[i].use_count;
+			cs->bcs[i].busy = 1;
+			spin_unlock_irqrestore(&cs->lock, flags);
+			gig_dbg(DEBUG_ANY, "allocated channel %d", i);
+			return cs->bcs + i;
+		}
+	module_put(cs->driver->owner);
+	spin_unlock_irqrestore(&cs->lock, flags);
+	gig_dbg(DEBUG_ANY, "no free channel");
+	return NULL;
+}
+
 void gigaset_free_channel(struct bc_state *bcs)
 {
 	unsigned long flags;
diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/isdn/gigaset/ev-layer.c
index cb25d2b834b9..369927f90729 100644
--- a/drivers/isdn/gigaset/ev-layer.c
+++ b/drivers/isdn/gigaset/ev-layer.c
@@ -291,21 +291,23 @@ struct reply_t gigaset_tab_cid[] =
 	{RSP_OK,      602,602, -1,                603, 5, {ACT_CMD+AT_PROTO}},
 	{RSP_OK,      603,603, -1,                604, 5, {ACT_CMD+AT_TYPE}},
 	{RSP_OK,      604,604, -1,                605, 5, {ACT_CMD+AT_MSN}},
-	{RSP_OK,      605,605, -1,                606, 5, {ACT_CMD+AT_ISO}},
-	{RSP_NULL,    605,605, -1,                606, 5, {ACT_CMD+AT_ISO}},
-	{RSP_OK,      606,606, -1,                607, 5, {0}, "+VLS=17\r"},
-	{RSP_OK,      607,607, -1,                608,-1},
-	{RSP_ZSAU,    608,608,ZSAU_PROCEEDING,    609, 5, {ACT_CMD+AT_DIAL}},
-	{RSP_OK,      609,609, -1,                650, 0, {ACT_DIALING}},
-
-	{RSP_ERROR,   601,609, -1,                  0, 0, {ACT_ABORTDIAL}},
-	{EV_TIMEOUT,  601,609, -1,                  0, 0, {ACT_ABORTDIAL}},
+	{RSP_NULL,    605, 605, -1,               606, 5, {ACT_CMD+AT_CLIP} },
+	{RSP_OK,      605, 605, -1,               606, 5, {ACT_CMD+AT_CLIP} },
+	{RSP_NULL,    606, 606, -1,               607, 5, {ACT_CMD+AT_ISO} },
+	{RSP_OK,      606, 606, -1,               607, 5, {ACT_CMD+AT_ISO} },
+	{RSP_OK,      607, 607, -1,               608, 5, {0}, "+VLS=17\r"},
+	{RSP_OK,      608, 608, -1,               609, -1},
+	{RSP_ZSAU,    609, 609, ZSAU_PROCEEDING,  610, 5, {ACT_CMD+AT_DIAL} },
+	{RSP_OK,      610, 610, -1,               650, 0, {ACT_DIALING} },
+
+	{RSP_ERROR,   601, 610, -1,                 0, 0, {ACT_ABORTDIAL} },
+	{EV_TIMEOUT,  601, 610, -1,                 0, 0, {ACT_ABORTDIAL} },
 
 	/* optional dialing responses */
 	{EV_BC_OPEN,  650,650, -1,                651,-1},
-	{RSP_ZVLS,    608,651, 17,                 -1,-1, {ACT_DEBUG}},
-	{RSP_ZCTP,    609,651, -1,                 -1,-1, {ACT_DEBUG}},
-	{RSP_ZCPN,    609,651, -1,                 -1,-1, {ACT_DEBUG}},
+	{RSP_ZVLS,    609, 651, 17,                -1, -1, {ACT_DEBUG} },
+	{RSP_ZCTP,    610, 651, -1,                -1, -1, {ACT_DEBUG} },
+	{RSP_ZCPN,    610, 651, -1,                -1, -1, {ACT_DEBUG} },
 	{RSP_ZSAU,    650,651,ZSAU_CALL_DELIVERED, -1,-1, {ACT_DEBUG}},
 
 	/* connect */
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index 1185da2dbf61..4749ef100fd3 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -191,7 +191,9 @@ void gigaset_dbg_buffer(enum debuglevel level, const unsigned char *msg,
 #define AT_PROTO	4
 #define AT_TYPE		5
 #define AT_HLC		6
-#define AT_NUM		7
+#define AT_CLIP		7
+/* total number */
+#define AT_NUM		8
 
 /* variables in struct at_state_t */
 #define VAR_ZSAU	0
@@ -412,6 +414,8 @@ struct bc_state {
 		struct usb_bc_state *usb;	/* usb hardware driver (m105) */
 		struct bas_bc_state *bas;	/* usb hardware driver (base) */
 	} hw;
+
+	void *ap;			/* LL application structure */
 };
 
 struct cardstate {
@@ -725,6 +729,7 @@ void gigaset_bcs_reinit(struct bc_state *bcs);
 void gigaset_at_init(struct at_state_t *at_state, struct bc_state *bcs,
 		     struct cardstate *cs, int cid);
 int gigaset_get_channel(struct bc_state *bcs);
+struct bc_state *gigaset_get_free_channel(struct cardstate *cs);
 void gigaset_free_channel(struct bc_state *bcs);
 int gigaset_get_channels(struct cardstate *cs);
 void gigaset_free_channels(struct cardstate *cs);