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>

6 files changed, 2335 insertions, 16 deletions

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);
+				/* To