Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-jammy-kernel.git] / drivers / isdn / gigaset / ev-layer.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Stuff used by all variants of the driver
 *
 * Copyright (c) 2001 by Stefan Eilers,
 *                       Hansjoerg Lipp <hjlipp@web.de>,
 *                       Tilman Schmidt <tilman@imap.cc>.
 *
 * =====================================================================
 * =====================================================================
 */

#include <linux/export.h>
#include "gigaset.h"

/* ========================================================== */
/* bit masks for pending commands */
#define PC_DIAL		0x001
#define PC_HUP		0x002
#define PC_INIT		0x004
#define PC_DLE0		0x008
#define PC_DLE1		0x010
#define PC_SHUTDOWN	0x020
#define PC_ACCEPT	0x040
#define PC_CID		0x080
#define PC_NOCID	0x100
#define PC_CIDMODE	0x200
#define PC_UMMODE	0x400

/* types of modem responses */
#define RT_NOTHING	0
#define RT_ZSAU		1
#define RT_RING		2
#define RT_NUMBER	3
#define RT_STRING	4
#define RT_ZCAU		6

/* Possible ASCII responses */
#define RSP_OK		0
#define RSP_ERROR	1
#define RSP_ZGCI	3
#define RSP_RING	4
#define RSP_ZVLS	5
#define RSP_ZCAU	6

/* responses with values to store in at_state */
/* - numeric */
#define RSP_VAR		100
#define RSP_ZSAU	(RSP_VAR + VAR_ZSAU)
#define RSP_ZDLE	(RSP_VAR + VAR_ZDLE)
#define RSP_ZCTP	(RSP_VAR + VAR_ZCTP)
/* - string */
#define RSP_STR		(RSP_VAR + VAR_NUM)
#define RSP_NMBR	(RSP_STR + STR_NMBR)
#define RSP_ZCPN	(RSP_STR + STR_ZCPN)
#define RSP_ZCON	(RSP_STR + STR_ZCON)
#define RSP_ZBC		(RSP_STR + STR_ZBC)
#define RSP_ZHLC	(RSP_STR + STR_ZHLC)

#define RSP_WRONG_CID	-2	/* unknown cid in cmd */
#define RSP_INVAL	-6	/* invalid response   */
#define RSP_NODEV	-9	/* device not connected */

#define RSP_NONE	-19
#define RSP_STRING	-20
#define RSP_NULL	-21
#define RSP_INIT	-27
#define RSP_ANY		-26
#define RSP_LAST	-28

/* actions for process_response */
#define ACT_NOTHING		0
#define ACT_SETDLE1		1
#define ACT_SETDLE0		2
#define ACT_FAILINIT		3
#define ACT_HUPMODEM		4
#define ACT_CONFIGMODE		5
#define ACT_INIT		6
#define ACT_DLE0		7
#define ACT_DLE1		8
#define ACT_FAILDLE0		9
#define ACT_FAILDLE1		10
#define ACT_RING		11
#define ACT_CID			12
#define ACT_FAILCID		13
#define ACT_SDOWN		14
#define ACT_FAILSDOWN		15
#define ACT_DEBUG		16
#define ACT_WARN		17
#define ACT_DIALING		18
#define ACT_ABORTDIAL		19
#define ACT_DISCONNECT		20
#define ACT_CONNECT		21
#define ACT_REMOTEREJECT	22
#define ACT_CONNTIMEOUT		23
#define ACT_REMOTEHUP		24
#define ACT_ABORTHUP		25
#define ACT_ICALL		26
#define ACT_ACCEPTED		27
#define ACT_ABORTACCEPT		28
#define ACT_TIMEOUT		29
#define ACT_GETSTRING		30
#define ACT_SETVER		31
#define ACT_FAILVER		32
#define ACT_GOTVER		33
#define ACT_TEST		34
#define ACT_ERROR		35
#define ACT_ABORTCID		36
#define ACT_ZCAU		37
#define ACT_NOTIFY_BC_DOWN	38
#define ACT_NOTIFY_BC_UP	39
#define ACT_DIAL		40
#define ACT_ACCEPT		41
#define ACT_HUP			43
#define ACT_IF_LOCK		44
#define ACT_START		45
#define ACT_STOP		46
#define ACT_FAKEDLE0		47
#define ACT_FAKEHUP		48
#define ACT_FAKESDOWN		49
#define ACT_SHUTDOWN		50
#define ACT_PROC_CIDMODE	51
#define ACT_UMODESET		52
#define ACT_FAILUMODE		53
#define ACT_CMODESET		54
#define ACT_FAILCMODE		55
#define ACT_IF_VER		56
#define ACT_CMD			100

/* at command sequences */
#define SEQ_NONE	0
#define SEQ_INIT	100
#define SEQ_DLE0	200
#define SEQ_DLE1	250
#define SEQ_CID		300
#define SEQ_NOCID	350
#define SEQ_HUP		400
#define SEQ_DIAL	600
#define SEQ_ACCEPT	720
#define SEQ_SHUTDOWN	500
#define SEQ_CIDMODE	10
#define SEQ_UMMODE	11


/* 100: init, 200: dle0, 250:dle1, 300: get cid (dial), 350: "hup" (no cid),
 * 400: hup, 500: reset, 600: dial, 700: ring */
struct reply_t gigaset_tab_nocid[] =
{
/* resp_code, min_ConState, max_ConState, parameter, new_ConState, timeout,
 * action, command */

/* initialize device, set cid mode if possible */
	{RSP_INIT,	 -1,  -1, SEQ_INIT,	100,  1, {ACT_TIMEOUT} },

	{EV_TIMEOUT,	100, 100, -1,		101,  3, {0},	"Z\r"},
	{RSP_OK,	101, 103, -1,		120,  5, {ACT_GETSTRING},
								"+GMR\r"},

	{EV_TIMEOUT,	101, 101, -1,		102,  5, {0},	"Z\r"},
	{RSP_ERROR,	101, 101, -1,		102,  5, {0},	"Z\r"},

	{EV_TIMEOUT,	102, 102, -1,		108,  5, {ACT_SETDLE1},
								"^SDLE=0\r"},
	{RSP_OK,	108, 108, -1,		104, -1},
	{RSP_ZDLE,	104, 104,  0,		103,  5, {0},	"Z\r"},
	{EV_TIMEOUT,	104, 104, -1,		  0,  0, {ACT_FAILINIT} },
	{RSP_ERROR,	108, 108, -1,		  0,  0, {ACT_FAILINIT} },

	{EV_TIMEOUT,	108, 108, -1,		105,  2, {ACT_SETDLE0,
							  ACT_HUPMODEM,
							  ACT_TIMEOUT} },
	{EV_TIMEOUT,	105, 105, -1,		103,  5, {0},	"Z\r"},

	{RSP_ERROR,	102, 102, -1,		107,  5, {0},	"^GETPRE\r"},
	{RSP_OK,	107, 107, -1,		  0,  0, {ACT_CONFIGMODE} },
	{RSP_ERROR,	107, 107, -1,		  0,  0, {ACT_FAILINIT} },
	{EV_TIMEOUT,	107, 107, -1,		  0,  0, {ACT_FAILINIT} },

	{RSP_ERROR,	103, 103, -1,		  0,  0, {ACT_FAILINIT} },
	{EV_TIMEOUT,	103, 103, -1,		  0,  0, {ACT_FAILINIT} },

	{RSP_STRING,	120, 120, -1,		121, -1, {ACT_SETVER} },

	{EV_TIMEOUT,	120, 121, -1,		  0,  0, {ACT_FAILVER,
							  ACT_INIT} },
	{RSP_ERROR,	120, 121, -1,		  0,  0, {ACT_FAILVER,
							  ACT_INIT} },
	{RSP_OK,	121, 121, -1,		  0,  0, {ACT_GOTVER,
							  ACT_INIT} },
	{RSP_NONE,	121, 121, -1,		120,  0, {ACT_GETSTRING} },

/* leave dle mode */
	{RSP_INIT,	  0,   0, SEQ_DLE0,	201,  5, {0},	"^SDLE=0\r"},
	{RSP_OK,	201, 201, -1,		202, -1},
	{RSP_ZDLE,	202, 202,  0,		  0,  0, {ACT_DLE0} },
	{RSP_NODEV,	200, 249, -1,		  0,  0, {ACT_FAKEDLE0} },
	{RSP_ERROR,	200, 249, -1,		  0,  0, {ACT_FAILDLE0} },
	{EV_TIMEOUT,	200, 249, -1,		  0,  0, {ACT_FAILDLE0} },

/* enter dle mode */
	{RSP_INIT,	  0,   0, SEQ_DLE1,	251,  5, {0},	"^SDLE=1\r"},
	{RSP_OK,	251, 251, -1,		252, -1},
	{RSP_ZDLE,	252, 252,  1,		  0,  0, {ACT_DLE1} },
	{RSP_ERROR,	250, 299, -1,		  0,  0, {ACT_FAILDLE1} },
	{EV_TIMEOUT,	250, 299, -1,		  0,  0, {ACT_FAILDLE1} },

/* incoming call */
	{RSP_RING,	 -1,  -1, -1,		 -1, -1, {ACT_RING} },

/* get cid */
	{RSP_INIT,	  0,   0, SEQ_CID,	301,  5, {0},	"^SGCI?\r"},
	{RSP_OK,	301, 301, -1,		302, -1},
	{RSP_ZGCI,	302, 302, -1,		  0,  0, {ACT_CID} },
	{RSP_ERROR,	301, 349, -1,		  0,  0, {ACT_FAILCID} },
	{EV_TIMEOUT,	301, 349, -1,		  0,  0, {ACT_FAILCID} },

/* enter cid mode */
	{RSP_INIT,	  0,   0, SEQ_CIDMODE,	150,  5, {0},	"^SGCI=1\r"},
	{RSP_OK,	150, 150, -1,		  0,  0, {ACT_CMODESET} },
	{RSP_ERROR,	150, 150, -1,		  0,  0, {ACT_FAILCMODE} },
	{EV_TIMEOUT,	150, 150, -1,		  0,  0, {ACT_FAILCMODE} },

/* leave cid mode */
	{RSP_INIT,	  0,   0, SEQ_UMMODE,	160,  5, {0},	"Z\r"},
	{RSP_OK,	160, 160, -1,		  0,  0, {ACT_UMODESET} },
	{RSP_ERROR,	160, 160, -1,		  0,  0, {ACT_FAILUMODE} },
	{EV_TIMEOUT,	160, 160, -1,		  0,  0, {ACT_FAILUMODE} },

/* abort getting cid */
	{RSP_INIT,	  0,   0, SEQ_NOCID,	  0,  0, {ACT_ABORTCID} },

/* reset */
	{RSP_INIT,	  0,   0, SEQ_SHUTDOWN,	504,  5, {0},	"Z\r"},
	{RSP_OK,	504, 504, -1,		  0,  0, {ACT_SDOWN} },
	{RSP_ERROR,	501, 599, -1,		  0,  0, {ACT_FAILSDOWN} },
	{EV_TIMEOUT,	501, 599, -1,		  0,  0, {ACT_FAILSDOWN} },
	{RSP_NODEV,	501, 599, -1,		  0,  0, {ACT_FAKESDOWN} },

	{EV_PROC_CIDMODE, -1, -1, -1,		 -1, -1, {ACT_PROC_CIDMODE} },
	{EV_IF_LOCK,	 -1,  -1, -1,		 -1, -1, {ACT_IF_LOCK} },
	{EV_IF_VER,	 -1,  -1, -1,		 -1, -1, {ACT_IF_VER} },
	{EV_START,	 -1,  -1, -1,		 -1, -1, {ACT_START} },
	{EV_STOP,	 -1,  -1, -1,		 -1, -1, {ACT_STOP} },
	{EV_SHUTDOWN,	 -1,  -1, -1,		 -1, -1, {ACT_SHUTDOWN} },

/* misc. */
	{RSP_ERROR,	 -1,  -1, -1,		 -1, -1, {ACT_ERROR} },
	{RSP_ZCAU,	 -1,  -1, -1,		 -1, -1, {ACT_ZCAU} },
	{RSP_NONE,	 -1,  -1, -1,		 -1, -1, {ACT_DEBUG} },
	{RSP_ANY,	 -1,  -1, -1,		 -1, -1, {ACT_WARN} },
	{RSP_LAST}
};

/* 600: start dialing, 650: dial in progress, 800: connection is up, 700: ring,
 * 400: hup, 750: accepted icall */
struct reply_t gigaset_tab_cid[] =
{
/* resp_code, min_ConState, max_ConState, parameter, new_ConState, timeout,
 * action, command */

/* dial */
	{EV_DIAL,	 -1,  -1, -1,		 -1, -1, {ACT_DIAL} },
	{RSP_INIT,	  0,   0, SEQ_DIAL,	601,  5, {ACT_CMD + AT_BC} },
	{RSP_OK,	601, 601, -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_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,	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 */
	{RSP_ZSAU,	650, 650, ZSAU_ACTIVE,	800, -1, {ACT_CONNECT} },
	{RSP_ZSAU,	651, 651, ZSAU_ACTIVE,	800, -1, {ACT_CONNECT,
							  ACT_NOTIFY_BC_UP} },
	{RSP_ZSAU,	750, 750, ZSAU_ACTIVE,	800, -1, {ACT_CONNECT} },
	{RSP_ZSAU,	751, 751, ZSAU_ACTIVE,	800, -1, {ACT_CONNECT,
							  ACT_NOTIFY_BC_UP} },
	{EV_BC_OPEN,	800, 800, -1,		800, -1, {ACT_NOTIFY_BC_UP} },

/* remote hangup */
	{RSP_ZSAU,	650, 651, ZSAU_DISCONNECT_IND, 0, 0, {ACT_REMOTEREJECT} },
	{RSP_ZSAU,	750, 751, ZSAU_DISCONNECT_IND, 0, 0, {ACT_REMOTEHUP} },
	{RSP_ZSAU,	800, 800, ZSAU_DISCONNECT_IND, 0, 0, {ACT_REMOTEHUP} },

/* hangup */
	{EV_HUP,	 -1,  -1, -1,		 -1, -1, {ACT_HUP} },
	{RSP_INIT,	 -1,  -1, SEQ_HUP,	401,  5, {0},	"+VLS=0\r"},
	{RSP_OK,	401, 401, -1,		402,  5},
	{RSP_ZVLS,	402, 402,  0,		403,  5},
	{RSP_ZSAU,	403, 403, ZSAU_DISCONNECT_REQ, -1, -1, {ACT_DEBUG} },
	{RSP_ZSAU,	403, 403, ZSAU_NULL,	  0,  0, {ACT_DISCONNECT} },
	{RSP_NODEV,	401, 403, -1,		  0,  0, {ACT_FAKEHUP} },
	{RSP_ERROR,	401, 401, -1,		  0,  0, {ACT_ABORTHUP} },
	{EV_TIMEOUT,	401, 403, -1,		  0,  0, {ACT_ABORTHUP} },

	{EV_BC_CLOSED,	  0,   0, -1,		  0, -1, {ACT_NOTIFY_BC_DOWN} },

/* ring */
	{RSP_ZBC,	700, 700, -1,		 -1, -1, {0} },
	{RSP_ZHLC,	700, 700, -1,		 -1, -1, {0} },
	{RSP_NMBR,	700, 700, -1,		 -1, -1, {0} },
	{RSP_ZCPN,	700, 700, -1,		 -1, -1, {0} },
	{RSP_ZCTP,	700, 700, -1,		 -1, -1, {0} },
	{EV_TIMEOUT,	700, 700, -1,		720, 720, {ACT_ICALL} },
	{EV_BC_CLOSED,	720, 720, -1,		  0, -1, {ACT_NOTIFY_BC_DOWN} },

/*accept icall*/
	{EV_ACCEPT,	 -1,  -1, -1,		 -1, -1, {ACT_ACCEPT} },
	{RSP_INIT,	720, 720, SEQ_ACCEPT,	721,  5, {ACT_CMD + AT_PROTO} },
	{RSP_OK,	721, 721, -1,		722,  5, {ACT_CMD + AT_ISO} },
	{RSP_OK,	722, 722, -1,		723,  5, {0},	"+VLS=17\r"},
	{RSP_OK,	723, 723, -1,		724,  5, {0} },
	{RSP_ZVLS,	724, 724, 17,		750, 50, {ACT_ACCEPTED} },
	{RSP_ERROR,	721, 729, -1,		  0,  0, {ACT_ABORTACCEPT} },
	{EV_TIMEOUT,	721, 729, -1,		  0,  0, {ACT_ABORTACCEPT} },
	{RSP_ZSAU,	700, 729, ZSAU_NULL,	  0,  0, {ACT_ABORTACCEPT} },
	{RSP_ZSAU,	700, 729, ZSAU_ACTIVE,	  0,  0, {ACT_ABORTACCEPT} },
	{RSP_ZSAU,	700, 729, ZSAU_DISCONNECT_IND, 0, 0, {ACT_ABORTACCEPT} },

	{EV_BC_OPEN,	750, 750, -1,		751, -1},
	{EV_TIMEOUT,	750, 751, -1,		  0,  0, {ACT_CONNTIMEOUT} },

/* B channel closed (general case) */
	{EV_BC_CLOSED,	 -1,  -1, -1,		 -1, -1, {ACT_NOTIFY_BC_DOWN} },

/* misc. */
	{RSP_ZCON,	 -1,  -1, -1,		 -1, -1, {ACT_DEBUG} },
	{RSP_ZCAU,	 -1,  -1, -1,		 -1, -1, {ACT_ZCAU} },
	{RSP_NONE,	 -1,  -1, -1,		 -1, -1, {ACT_DEBUG} },
	{RSP_ANY,	 -1,  -1, -1,		 -1, -1, {ACT_WARN} },
	{RSP_LAST}
};


static const struct resp_type_t {
	char	*response;
	int	resp_code;
	int	type;
}
resp_type[] =
{
	{"OK",		RSP_OK,		RT_NOTHING},
	{"ERROR",	RSP_ERROR,	RT_NOTHING},
	{"ZSAU",	RSP_ZSAU,	RT_ZSAU},
	{"ZCAU",	RSP_ZCAU,	RT_ZCAU},
	{"RING",	RSP_RING,	RT_RING},
	{"ZGCI",	RSP_ZGCI,	RT_NUMBER},
	{"ZVLS",	RSP_ZVLS,	RT_NUMBER},
	{"ZCTP",	RSP_ZCTP,	RT_NUMBER},
	{"ZDLE",	RSP_ZDLE,	RT_NUMBER},
	{"ZHLC",	RSP_ZHLC,	RT_STRING},
	{"ZBC",		RSP_ZBC,	RT_STRING},
	{"NMBR",	RSP_NMBR,	RT_STRING},
	{"ZCPN",	RSP_ZCPN,	RT_STRING},
	{"ZCON",	RSP_ZCON,	RT_STRING},
	{NULL,		0,		0}
};

static const struct zsau_resp_t {
	char	*str;
	int	code;
}
zsau_resp[] =
{
	{"OUTGOING_CALL_PROCEEDING",	ZSAU_PROCEEDING},
	{"CALL_DELIVERED",		ZSAU_CALL_DELIVERED},
	{"ACTIVE",			ZSAU_ACTIVE},
	{"DISCONNECT_IND",		ZSAU_DISCONNECT_IND},
	{"NULL",			ZSAU_NULL},
	{"DISCONNECT_REQ",		ZSAU_DISCONNECT_REQ},
	{NULL,				ZSAU_UNKNOWN}
};

/* check for and remove fixed string prefix
 * If s starts with prefix terminated by a non-alphanumeric character,
 * return pointer to the first character after that, otherwise return NULL.
 */
static char *skip_prefix(char *s, const char *prefix)
{
	while (*prefix)
		if (*s++ != *prefix++)
			return NULL;
	if (isalnum(*s))
		return NULL;
	return s;
}

/* queue event with CID */
static void add_cid_event(struct cardstate *cs, int cid, int type,
			  void *ptr, int parameter)
{
	unsigned long flags;
	unsigned next, tail;
	struct event_t *event;

	gig_dbg(DEBUG_EVENT, "queueing event %d for cid %d", type, cid);

	spin_lock_irqsave(&cs->ev_lock, flags);

	tail = cs->ev_tail;
	next = (tail + 1) % MAX_EVENTS;
	if (unlikely(next == cs->ev_head)) {
		dev_err(cs->dev, "event queue full\n");
		kfree(ptr);
	} else {
		event = cs->events + tail;
		event->type = type;
		event->cid = cid;
		event->ptr = ptr;
		event->arg = NULL;
		event->parameter = parameter;
		event->at_state = NULL;
		cs->ev_tail = next;
	}

	spin_unlock_irqrestore(&cs->ev_lock, flags);
}

/**
 * gigaset_handle_modem_response() - process received modem response
 * @cs:		device descriptor structure.
 *
 * Called by asyncdata/isocdata if a block of data received from the
 * device must be processed as a modem command response. The data is
 * already in the cs structure.
 */
void gigaset_handle_modem_response(struct cardstate *cs)
{
	char *eoc, *psep, *ptr;
	const struct resp_type_t *rt;
	const struct zsau_resp_t *zr;
	int cid, parameter;
	u8 type, value;

	if (!cs->cbytes) {
		/* ignore additional LFs/CRs (M10x config mode or cx100) */
		gig_dbg(DEBUG_MCMD, "skipped EOL [%02X]", cs->respdata[0]);
		return;
	}
	cs->respdata[cs->cbytes] = 0;

	if (cs->at_state.getstring) {
		/* state machine wants next line verbatim */
		cs->at_state.getstring = 0;
		ptr = kstrdup(cs->respdata, GFP_ATOMIC);
		gig_dbg(DEBUG_EVENT, "string==%s", ptr ? ptr : "NULL");
		add_cid_event(cs, 0, RSP_STRING, ptr, 0);
		return;
	}

	/* look up response type */
	for (rt = resp_type; rt->response; ++rt) {
		eoc = skip_prefix(cs->respdata, rt->response);
		if (eoc)
			break;
	}
	if (!rt->response) {
		add_cid_event(cs, 0, RSP_NONE, NULL, 0);
		gig_dbg(DEBUG_EVENT, "unknown modem response: '%s'\n",
			cs->respdata);
		return;
	}

	/* check for CID */
	psep = strrchr(cs->respdata, ';');
	if (psep &&
	    !kstrtoint(psep + 1, 10, &cid) &&
	    cid >= 1 && cid <= 65535) {
		/* valid CID: chop it off */
		*psep = 0;
	} else {
		/* no valid CID: leave unchanged */
		cid = 0;
	}

	gig_dbg(DEBUG_EVENT, "CMD received: %s", cs->respdata);
	if (cid)
		gig_dbg(DEBUG_EVENT, "CID: %d", cid);

	switch (rt->type) {
	case RT_NOTHING:
		/* check parameter separator */
		if (*eoc)
			goto bad_param;	/* extra parameter */

		add_cid_event(cs, cid, rt->resp_code, NULL, 0);
		break;

	case RT_RING:
		/* check parameter separator */
		if (!*eoc)
			eoc = NULL;	/* no parameter */
		else if (*eoc++ != ',')
			goto bad_param;

		add_cid_event(cs, 0, rt->resp_code, NULL, cid);

		/* process parameters as individual responses */
		while (eoc) {
			/* look up parameter type */
			psep = NULL;
			for (rt = resp_type; rt->response; ++rt) {
				psep = skip_prefix(eoc, rt->response);
				if (psep)
					break;
			}

			/* all legal parameters are of type RT_STRING */
			if (!psep || rt->type != RT_STRING) {
				dev_warn(cs->dev,
					 "illegal RING parameter: '%s'\n",
					 eoc);
				return;
			}

			/* skip parameter value separator */
			if (*psep++ != '=')
				goto bad_param;

			/* look up end of parameter */
			eoc = strchr(psep, ',');
			if (eoc)
				*eoc++ = 0;

			/* retrieve parameter value */
			ptr = kstrdup(psep, GFP_ATOMIC);

			/* queue event */
			add_cid_event(cs, cid, rt->resp_code, ptr, 0);
		}
		break;

	case RT_ZSAU:
		/* check parameter separator */
		if (!*eoc) {
			/* no parameter */
			add_cid_event(cs, cid, rt->resp_code, NULL, ZSAU_NONE);
			break;
		}
		if (*eoc++ != '=')
			goto bad_param;

		/* look up parameter value */
		for (zr = zsau_resp; zr->str; ++zr)
			if (!strcmp(eoc, zr->str))
				break;
		if (!zr->str)
			goto bad_param;

		add_cid_event(cs, cid, rt->resp_code, NULL, zr->code);
		break;

	case RT_STRING:
		/* check parameter separator */
		if (*eoc++ != '=')
			goto bad_param;

		/* retrieve parameter value */
		ptr = kstrdup(eoc, GFP_ATOMIC);

		/* queue event */
		add_cid_event(cs, cid, rt->resp_code, ptr, 0);
		break;

	case RT_ZCAU:
		/* check parameter separators */
		if (*eoc++ != '=')
			goto bad_param;
		psep = strchr(eoc, ',');
		if (!psep)
			goto bad_param;
		*psep++ = 0;

		/* decode parameter values */
		if (kstrtou8(eoc, 16, &type) || kstrtou8(psep, 16, &value)) {
			*--psep = ',';
			goto bad_param;
		}
		parameter = (type << 8) | value;

		add_cid_event(cs, cid, rt->resp_code, NULL, parameter);
		break;

	case RT_NUMBER:
		/* check parameter separator */
		if (*eoc++ != '=')
			goto bad_param;

		/* decode parameter value */
		if (kstrtoint(eoc, 10, &parameter))
			goto bad_param;

		/* special case ZDLE: set flag before queueing event */
		if (rt->resp_code == RSP_ZDLE)
			cs->dle = parameter;

		add_cid_event(cs, cid, rt->resp_code, NULL, parameter);
		break;

bad_param:
		/* parameter unexpected, incomplete or malformed */
		dev_warn(cs->dev, "bad parameter in response '%s'\n",
			 cs->respdata);
		add_cid_event(cs, cid, rt->resp_code, NULL, -1);
		break;

	default:
		dev_err(cs->dev, "%s: internal error on '%s'\n",
			__func__, cs->respdata);
	}
}
EXPORT_SYMBOL_GPL(gigaset_handle_modem_response);

/* disconnect_nobc
 * process closing of connection associated with given AT state structure
 * without B channel
 */
static void disconnect_nobc(struct at_state_t **at_state_p,
			    struct cardstate *cs)
{
	unsigned long flags;

	spin_lock_irqsave(&cs->lock, flags);
	++(*at_state_p)->seq_index;

	/* revert to selected idle mode */
	if (!cs->cidmode) {
		cs->at_state.pending_commands |= PC_UMMODE;
		gig_dbg(DEBUG_EVENT, "Scheduling PC_UMMODE");
		cs->commands_pending = 1;
	}

	/* check for and deallocate temporary AT state */
	if (!list_empty(&(*at_state_p)->list)) {
		list_del(&(*at_state_p)->list);
		kfree(*at_state_p);
		*at_state_p = NULL;
	}

	spin_unlock_irqrestore(&cs->lock, flags);
}

/* disconnect_bc
 * process closing of connection associated with given AT state structure
 * and B channel
 */
static void disconnect_bc(struct at_state_t *at_state,
			  struct cardstate *cs, struct bc_state *bcs)
{
	unsigned long flags;

	spin_lock_irqsave(&cs->lock, flags);
	++at_state->seq_index;

	/* revert to selected idle mode */
	if (!cs->cidmode) {
		cs->at_state.pending_commands |= PC_UMMODE;
		gig_dbg(DEBUG_EVENT, "Scheduling PC_UMMODE");
		cs->commands_pending = 1;
	}
	spin_unlock_irqrestore(&cs->lock, flags);

	/* invoke hardware specific handler */
	cs->ops->close_bchannel(bcs);

	/* notify LL */
	if (bcs->chstate & (CHS_D_UP | CHS_NOTIFY_LL)) {
		bcs->chstate &= ~(CHS_D_UP | CHS_NOTIFY_LL);
		gigaset_isdn_hupD(bcs);
	}
}

/* get_free_channel
 * get a free AT state structure: either one of those associated with the
 * B channels of the Gigaset device, or if none of those is available,
 * a newly allocated one with bcs=NULL
 * The structure should be freed by calling disconnect_nobc() after use.
 */
static inline struct at_state_t *get_free_channel(struct cardstate *cs,
						  int cid)
/* cids: >0: siemens-cid
 *        0: without cid
 *       -1: no cid assigned yet
 */
{
	unsigned long flags;
	int i;
	struct at_state_t *ret;

	for (i = 0; i < cs->channels; ++i)
		if (gigaset_get_channel(cs->bcs + i) >= 0) {
			ret = &cs->bcs[i].at_state;
			ret->cid = cid;
			return ret;
		}

	spin_lock_irqsave(&cs->lock, flags);
	ret = kmalloc(sizeof(struct at_state_t), GFP_ATOMIC);
	if (ret) {
		gigaset_at_init(ret, NULL, cs, cid);
		list_add(&ret->list, &cs->temp_at_states);
	}
	spin_unlock_irqrestore(&cs->lock, flags);
	return ret;
}

static void init_failed(struct cardstate *cs, int mode)
{
	int i;
	struct at_state_t *at_state;

	cs->at_state.pending_commands &= ~PC_INIT;
	cs->mode = mode;
	cs->mstate = MS_UNINITIALIZED;
	gigaset_free_channels(cs);
	for (i = 0; i < cs->channels; ++i) {
		at_state = &cs->bcs[i].at_state;
		if (at_state->pending_commands & PC_CID) {
			at_state->pending_commands &= ~PC_CID;
			at_state->pending_commands |= PC_NOCID;
			cs->commands_pending = 1;
		}
	}
}

static void schedule_init(struct cardstate *cs, int state)
{
	if (cs->at_state.pending_commands & PC_INIT) {
		gig_dbg(DEBUG_EVENT, "not scheduling PC_INIT again");
		return;
	}
	cs->mstate = state;
	cs->mode = M_UNKNOWN;
	gigaset_block_channels(cs);
	cs->at_state.pending_commands |= PC_INIT;
	gig_dbg(DEBUG_EVENT, "Scheduling PC_INIT");
	cs->commands_pending = 1;
}

/* send an AT command
 * adding the "AT" prefix, cid and DLE encapsulation as appropriate
 */
static void send_command(struct cardstate *cs, const char *cmd,
			 struct at_state_t *at_state)
{
	int cid = at_state->cid;
	struct cmdbuf_t *cb;
	size_t buflen;

	buflen = strlen(cmd) + 12; /* DLE ( A T 1 2 3 4 5 <cmd> DLE ) \0 */
	cb = kmalloc(sizeof(struct cmdbuf_t) + buflen, GFP_ATOMIC);
	if (!cb) {
		dev_err(cs->dev, "%s: out of memory\n", __func__);
		return;
	}
	if (cid > 0 && cid <= 65535)
		cb->len = snprintf(cb->buf, buflen,
				   cs->dle ? "\020(AT%d%s\020)" : "AT%d%s",
				   cid, cmd);
	else
		cb->len = snprintf(cb->buf, buflen,
				   cs->dle ? "\020(AT%s\020)" : "AT%s",
				   cmd);
	cb->offset = 0;
	cb->next = NULL;
	cb->wake_tasklet = NULL;
	cs->ops->write_cmd(cs, cb);
}

static struct at_state_t *at_state_from_cid(struct cardstate *cs, int cid)
{
	struct at_state_t *at_state;
	int i;
	unsigned long flags;

	if (cid == 0)
		return &cs->at_state;

	for (i = 0; i < cs->channels; ++i)
		if (cid == cs->bcs[i].at_state.cid)
			return &cs->bcs[i].at_state;

	spin_lock_irqsave(&cs->lock, flags);

	list_for_each_entry(at_state, &cs->temp_at_states, list)
		if (cid == at_state->cid) {
			spin_unlock_irqrestore(&cs->lock, flags);
			return at_state;
		}

	spin_unlock_irqrestore(&cs->lock, flags);

	return NULL;
}

static void bchannel_down(struct bc_state *bcs)
{
	if (bcs->chstate & CHS_B_UP) {
		bcs->chstate &= ~CHS_B_UP;
		gigaset_isdn_hupB(bcs);
	}

	if (bcs->chstate & (CHS_D_UP | CHS_NOTIFY_LL)) {
		bcs->chstate &= ~(CHS_D_UP | CHS_NOTIFY_LL);
		gigaset_isdn_hupD(bcs);
	}

	gigaset_free_channel(bcs);

	gigaset_bcs_reinit(bcs);
}

static void bchannel_up(struct bc_state *bcs)
{
	if (bcs->chstate & CHS_B_UP) {
		dev_notice(bcs->cs->dev, "%s: B channel already up\n",
			   __func__);
		return;
	}

	bcs->chstate |= CHS_B_UP;
	gigaset_isdn_connB(bcs);
}

static void start_dial(struct at_state_t *at_state, void *data,
		       unsigned seq_index)
{
	struct bc_state *bcs = at_state->bcs;
	struct cardstate *cs = at_state->cs;
	char **commands = data;
	unsigned long flags;
	int i;

	bcs->chstate |= CHS_NOTIFY_LL;

	spin_lock_irqsave(&cs->lock, flags);
	if (at_state->seq_index != seq_index) {
		spin_unlock_irqrestore(&cs->lock, flags);
		goto error;
	}
	spin_unlock_irqrestore(&cs->lock, flags);

	for (i = 0; i < AT_NUM; ++i) {
		kfree(bcs->commands[i]);
		bcs->commands[i] = commands[i];
	}

	at_state->pending_commands |= PC_CID;
	gig_dbg(DEBUG_EVENT, "Scheduling PC_CID");
	cs->commands_pending = 1;
	return;

error:
	for (i = 0; i < AT_NUM; ++i) {
		kfree(commands[i]);
		commands[i] = NULL;
	}
	at_state->pending_commands |= PC_NOCID;
	gig_dbg(DEBUG_EVENT, "Scheduling PC_NOCID");
	cs->commands_pending = 1;
	return;
}

static void start_accept(struct at_state_t *at_state)
{
	struct cardstate *cs = at_state->cs;
	struct bc_state *bcs = at_state->bcs;
	int i;

	for (i = 0; i < AT_NUM; ++i) {
		kfree(bcs->commands[i]);
		bcs->commands[i] = NULL;
	}

	bcs->commands[AT_PROTO] = kmalloc(9, GFP_ATOMIC);
	bcs->commands[AT_ISO] = kmalloc(9, GFP_ATOMIC);
	if (!bcs->commands[AT_PROTO] || !bcs->commands[AT_ISO]) {
		dev_err(at_state->cs->dev, "out of memory\n");
		/* error reset */
		at_state->pending_commands |= PC_HUP;
		gig_dbg(DEBUG_EVENT, "Scheduling PC_HUP");
		cs->commands_pending = 1;
		return;
	}

	snprintf(bcs->commands[AT_PROTO], 9, "^SBPR=%u\r", bcs->proto2);
	snprintf(bcs->commands[AT_ISO], 9, "^SISO=%u\r", bcs->channel + 1);

	at_state->pending_commands |= PC_ACCEPT;
	gig_dbg(DEBUG_EVENT, "Scheduling PC_ACCEPT");
	cs->commands_pending = 1;
}

static void do_start(struct cardstate *cs)
{
	gigaset_free_channels(cs);

	if (cs->mstate != MS_LOCKED)
		schedule_init(cs, MS_INIT);

	cs->isdn_up = 1;
	gigaset_isdn_start(cs);

	cs->waiting = 0;
	wake_up(&cs->waitqueue);
}

static void finish_shutdown(struct cardstate *cs)
{
	if (cs->mstate != MS_LOCKED) {
		cs->mstate = MS_UNINITIALIZED;
		cs->mode = M_UNKNOWN;
	}

	/* Tell the LL that the device is not available .. */
	if (cs->isdn_up) {
		cs->isdn_up = 0;
		gigaset_isdn_stop(cs);
	}

	/* The rest is done by cleanup_cs() in process context. */

	cs->cmd_result = -ENODEV;
	cs->waiting = 0;
	wake_up(&cs->waitqueue);
}

static void do_shutdown(struct cardstate *cs)
{
	gigaset_block_channels(cs);

	if (cs->mstate == MS_READY) {
		cs->mstate = MS_SHUTDOWN;
		cs->at_state.pending_commands |= PC_SHUTDOWN;
		gig_dbg(DEBUG_EVENT, "Scheduling PC_SHUTDOWN");
		cs->commands_pending = 1;
	} else
		finish_shutdown(cs);
}

static void do_stop(struct cardstate *cs)
{
	unsigned long flags;

	spin_lock_irqsave(&cs->lock, flags);
	cs->connected = 0;
	spin_unlock_irqrestore(&cs->lock, flags);

	do_shutdown(cs);
}

/* Entering cid mode or getting a cid failed:
 * try to initialize the device and try again.
 *
 * channel >= 0: getting cid for the channel failed
 * channel < 0:  entering cid mode failed
 *
 * returns 0 on success, <0 on failure
 */
static int reinit_and_retry(struct cardstate *cs, int channel)
{
	int i;

	if (--cs->retry_count <= 0)
		return -EFAULT;

	for (i = 0; i < cs->channels; ++i)
		if (cs->bcs[i].at_state.cid > 0)
			return -EBUSY;

	if (channel < 0)
		dev_warn(cs->dev,
			 "Could not enter cid mode. Reinit device and try again.\n");
	else {
		dev_warn(cs->dev,
			 "Could not get a call id. Reinit device and try again.\n");
		cs->bcs[channel].at_state.pending_commands |= PC_CID;
	}
	schedule_init(cs, MS_INIT);
	return 0;
}

static int at_state_invalid(struct cardstate *cs,
			    struct at_state_t *test_ptr)
{
	unsigned long flags;
	unsigned channel;
	struct at_state_t *at_state;
	int retval = 0;

	spin_lock_irqsave(&cs->lock, flags);

	if (test_ptr == &cs->at_state)
		goto exit;

	list_for_each_entry(at_state, &cs->temp_at_states, list)
		if (at_state == test_ptr)
			goto exit;

	for (channel = 0; channel < cs->channels; ++channel)
		if (&cs->bcs[channel].at_state == test_ptr)
			goto exit;

	retval = 1;
exit:
	spin_unlock_irqrestore(&cs->lock, flags);
	return retval;
}

static void handle_icall(struct cardstate *cs, struct bc_state *bcs,
			 struct at_state_t *at_state)
{
	int retval;

	retval = gigaset_isdn_icall(at_state);
	switch (retval) {
	case ICALL_ACCEPT:
		break;
	default:
		dev_err(cs->dev, "internal error: disposition=%d\n", retval);
		/* fall through */
	case ICALL_IGNORE:
	case ICALL_REJECT:
		/* hang up actively
		 * Device doc says that would reject the call.
		 * In fact it doesn't.
		 */
		at_state->pending_commands |= PC_HUP;
		cs->commands_pending = 1;
		break;
	}
}

static int do_lock(struct cardstate *cs)
{
	int mode;
	int i;

	switch (cs->mstate) {
	case MS_UNINITIALIZED:
	case MS_READY:
		if (cs->cur_at_seq || !list_empty(&cs->temp_at_states) ||
		    cs->at_state.pending_commands)
			return -EBUSY;

		for (i = 0; i < cs->channels; ++i)
			if (cs->bcs[i].at_state.pending_commands)
				return -EBUSY;

		if (gigaset_get_channels(cs) < 0)
			return -EBUSY;

		break;
	case MS_LOCKED:
		break;
	default:
		return -EBUSY;
	}

	mode = cs->mode;
	cs->mstate = MS_LOCKED;
	cs->mode = M_UNKNOWN;

	return mode;
}

static int do_unlock(struct cardstate *cs)
{
	if (cs->mstate != MS_LOCKED)
		return -EINVAL;

	cs->mstate = MS_UNINITIALIZED;
	cs->mode = M_UNKNOWN;
	gigaset_free_channels(cs);
	if (cs->connected)
		schedule_init(cs, MS_INIT);

	return 0;
}

static void do_action(int action, struct cardstate *cs,
		      struct bc_state *bcs,
		      struct at_state_t **p_at_state, char **pp_command,
		      int *p_genresp, int *p_resp_code,
		      struct event_t *ev)
{
	struct at_state_t *at_state = *p_at_state;
	struct bc_state *bcs2;
	unsigned long flags;

	int channel;

	unsigned char *s, *e;
	int i;
	unsigned long val;

	switch (action) {
	case ACT_NOTHING:
		break;
	case ACT_TIMEOUT:
		at_state->waiting = 1;
		break;
	case ACT_INIT:
		cs->at_state.pending_commands &= ~PC_INIT;
		cs->cur_at_seq = SEQ_NONE;
		cs->mode = M_UNIMODEM;
		spin_lock_irqsave(&cs->lock, flags);
		if (!cs->cidmode) {
			spin_unlock_irqrestore(&cs->lock, flags);
			gigaset_free_channels(cs);
			cs->mstate = MS_READY;
			break;
		}
		spin_unlock_irqrestore(&cs->lock, flags);
		cs->at_state.pending_commands |= PC_CIDMODE;
		gig_dbg(DEBUG_EVENT, "Scheduling PC_CIDMODE");
		cs->commands_pending = 1;
		break;
	case ACT_FAILINIT:
		dev_warn(cs->dev, "Could not initialize the device.\n");
		cs->dle = 0;
		init_failed(cs, M_UNKNOWN);
		cs->cur_at_seq = SEQ_NONE;
		break;
	case ACT_CONFIGMODE:
		init_failed(cs, M_CONFIG);
		cs->cur_at_seq = SEQ_NONE;
		break;
	case ACT_SETDLE1:
		cs->dle = 1;
		/* cs->inbuf[0].inputstate |= INS_command | INS_DLE_command; */
		cs->inbuf[0].inputstate &=
			~(INS_command | INS_DLE_command);
		break;
	case ACT_SETDLE0:
		cs->dle = 0;
		cs->inbuf[0].inputstate =
			(cs->inbuf[0].inputstate & ~INS_DLE_command)
			| INS_command;
		break;
	case ACT_CMODESET:
		if (cs->mstate == MS_INIT || cs->mstate == MS_RECOVER) {
			gigaset_free_channels(cs);
			cs->mstate = MS_READY;
		}
		cs->mode = M_CID;
		cs->cur_at_seq = SEQ_NONE;
		break;
	case ACT_UMODESET:
		cs->mode = M_UNIMODEM;
		cs->cur_at_seq = SEQ_NONE;
		break;
	case ACT_FAILCMODE:
		cs->cur_at_seq = SEQ_NONE;
		if (cs->mstate == MS_INIT || cs->mstate == MS_RECOVER) {
			init_failed(cs, M_UNKNOWN);
			break;
		}
		if (reinit_and_retry(cs, -1) < 0)
			schedule_init(cs, MS_RECOVER);
		break;
	case ACT_FAILUMODE:
		cs->cur_at_seq = SEQ_NONE;
		schedule_init(cs, MS_RECOVER);
		break;
	case ACT_HUPMODEM:
		/* send "+++" (hangup in unimodem mode) */
		if (cs->connected) {
			struct cmdbuf_t *cb;

			cb = kmalloc(sizeof(struct cmdbuf_t) + 3, GFP_ATOMIC);
			if (!cb) {
				dev_err(cs->dev, "%s: out of memory\n",
					__func__);
				return;
			}
			memcpy(cb->buf, "+++", 3);
			cb->len = 3;
			cb->offset = 0;
			cb->next = NULL;
			cb->wake_tasklet = NULL;
			cs->ops->write_cmd(cs, cb);
		}
		break;
	case ACT_RING:
		/* get fresh AT state structure for new CID */
		at_state = get_free_channel(cs, ev->parameter);
		if (!at_state) {
			dev_warn(cs->dev,
				 "RING ignored: could not allocate channel structure\n");
			break;
		}

		/* initialize AT state structure
		 * note that bcs may be NULL if no B channel is free
		 */
		at_state->ConState = 700;
		for (i = 0; i < STR_NUM; ++i) {
			kfree(at_state->str_var[i]);
			at_state->str_var[i] = NULL;
		}
		at_state->int_var[VAR_ZCTP] = -1;

		spin_lock_irqsave(&cs->lock, flags);
		at_state->timer_expires = RING_TIMEOUT;
		at_state->timer_active = 1;
		spin_unlock_irqrestore(&cs->lock, flags);
		break;
	case ACT_ICALL:
		handle_icall(cs, bcs, at_state);
		break;
	case ACT_FAILSDOWN:
		dev_warn(cs->dev, "Could not shut down the device.\n");
		/* fall through */
	case ACT_FAKESDOWN:
	case ACT_SDOWN:
		cs->cur_at_seq = SEQ_NONE;
		finish_shutdown(cs);
		break;
	case ACT_CONNECT:
		if (cs->onechannel) {
			at_state->pending_commands |= PC_DLE1;
			cs->commands_pending = 1;
			break;
		}
		bcs->chstate |= CHS_D_UP;
		gigaset_isdn_connD(bcs);
		cs->ops->init_bchannel(bcs);
		break;
	case ACT_DLE1:
		cs->cur_at_seq = SEQ_NONE;
		bcs = cs->bcs + cs->curchannel;

		bcs->chstate |= CHS_D_UP;
		gigaset_isdn_connD(bcs);
		cs->ops->init_bchannel(bcs);
		break;
	case ACT_FAKEHUP:
		at_state->int_var[VAR_ZSAU] = ZSAU_NULL;
		/* fall through */
	case ACT_DISCONNECT:
		cs->cur_at_seq = SEQ_NONE;
		at_state->cid = -1;
		if (!bcs) {
			disconnect_nobc(p_at_state, cs);
		} else if (cs->onechannel && cs->dle) {
			/* Check for other open channels not needed:
			 * DLE only used for M10x with one B channel.
			 */
			at_state->pending_commands |= PC_DLE0;
			cs->commands_pending = 1;
		} else {
			disconnect_bc(at_state, cs, bcs);
		}
		break;
	case ACT_FAKEDLE0:
		at_state->int_var[VAR_ZDLE] = 0;
		cs->dle = 0;
		/* fall through */
	case ACT_DLE0:
		cs->cur_at_seq = SEQ_NONE;
		bcs2 = cs->bcs + cs->curchannel;
		disconnect_bc(&bcs2->at_state, cs, bcs2);
		break;
	case ACT_ABORTHUP:
		cs->cur_at_seq = SEQ_NONE;
		dev_warn(cs->dev, "Could not hang up.\n");
		at_state->cid = -1;
		if (!bcs)
			disconnect_nobc(p_at_state, cs);
		else if (cs->onechannel)
			at_state->pending_commands |= PC_DLE0;
		else
			disconnect_bc(at_state, cs, bcs);
		schedule_init(cs, MS_RECOVER);
		break;
	case ACT_FAILDLE0:
		cs->cur_at_seq = SEQ_NONE;
		dev_warn(cs->dev, "Error leaving DLE mode.\n");
		cs->dle = 0;
		bcs2 = cs->bcs + cs->curchannel;
		disconnect_bc(&bcs2->at_state, cs, bcs2);
		schedule_init(cs, MS_RECOVER);
		break;
	case ACT_FAILDLE1:
		cs->cur_at_seq = SEQ_NONE;
		dev_warn(cs->dev,
			 "Could not enter DLE mode. Trying to hang up.\n");
		channel = cs->curchannel;
		cs->bcs[channel].at_state.pending_commands |= PC_HUP;
		cs->commands_pending = 1;
		break;

	case ACT_CID: /* got cid; start dialing */
		cs->cur_at_seq = SEQ_NONE;
		channel = cs->curchannel;
		if (ev->parameter > 0 && ev->parameter <= 65535) {
			cs->bcs[channel].at_state.cid = ev->parameter;
			cs->bcs[channel].at_state.pending_commands |=
				PC_DIAL;
			cs->commands_pending = 1;
			break;
		}
		/* fall through - bad cid */
	case ACT_FAILCID:
		cs->cur_at_seq = SEQ_NONE;
		channel = cs->curchannel;
		if (reinit_and_retry(cs, channel) < 0) {
			dev_warn(cs->dev,
				 "Could not get a call ID. Cannot dial.\n");
			bcs2 = cs->bcs + channel;
			disconnect_bc(&bcs2->at_state, cs, bcs2);
		}
		break;
	case ACT_ABORTCID:
		cs->cur_at_seq = SEQ_NONE;
		bcs2 = cs->bcs + cs->curchannel;
		disconnect_bc(&bcs2->at_state, cs, bcs2);
		break;

	case ACT_DIALING:
	case ACT_ACCEPTED:
		cs->cur_at_seq = SEQ_NONE;
		break;

	case ACT_ABORTACCEPT:	/* hangup/error/timeout during ICALL procssng */
		if (bcs)
			disconnect_bc(at_state, cs, bcs);
		else
			disconnect_nobc(p_at_state, cs);
		break;

	case ACT_ABORTDIAL:	/* error/timeout during dial preparation */
		cs->cur_at_seq = SEQ_NONE;
		at_state->pending_commands |= PC_HUP;
		cs->commands_pending = 1;
		break;

	case ACT_REMOTEREJECT:	/* DISCONNECT_IND after dialling */
	case ACT_CONNTIMEOUT:	/* timeout waiting for ZSAU=ACTIVE */
	case ACT_REMOTEHUP:	/* DISCONNECT_IND with established connection */
		at_state->pending_commands |= PC_HUP;
		cs->commands_pending = 1;
		break;
	case ACT_GETSTRING: /* warning: RING, ZDLE, ...
			       are not handled properly anymore */
		at_state->getstring = 1;
		break;
	case ACT_SETVER:
		if (!ev->ptr) {
			*p_genresp = 1;
			*p_resp_code = RSP_ERROR;
			break;
		}
		s = ev->ptr;

		if (!strcmp(s, "OK")) {
			/* OK without version string: assume old response */
			*p_genresp = 1;
			*p_resp_code = RSP_NONE;
			break;
		}

		for (i = 0; i < 4; ++i) {
			val = simple_strtoul(s, (char **) &e, 10);
			if (val > INT_MAX || e == s)
				break;
			if (i == 3) {
				if (*e)
					break;
			} else if (*e != '.')
				break;
			else
				s = e + 1;
			cs->fwver[i] = val;
		}
		if (i != 4) {
			*p_genresp = 1;
			*p_resp_code = RSP_ERROR;
			break;
		}
		cs->gotfwver = 0;
		break;
	case ACT_GOTVER:
		if (cs->gotfwver == 0) {
			cs->gotfwver = 1;
			gig_dbg(DEBUG_EVENT,
				"firmware version %02d.%03d.%02d.%02d",
				cs->fwver[0], cs->fwver[1],
				cs->fwver[2], cs->fwver[3]);
			break;
		}
		/* fall through */
	case ACT_FAILVER:
		cs->gotfwver = -1;
		dev_err(cs->dev, "could not read firmware version.\n");
		break;
	case ACT_ERROR:
		gig_dbg(DEBUG_ANY, "%s: ERROR response in ConState %d",
			__func__, at_state->ConState);
		cs->cur_at_seq = SEQ_NONE;
		break;
	case ACT_DEBUG:
		gig_dbg(DEBUG_ANY, "%s: resp_code %d in ConState %d",
			__func__, ev->type, at_state->ConState);
		break;
	case ACT_WARN:
		dev_warn(cs->dev, "%s: resp_code %d in ConState %d!\n",
			 __func__, ev->type, at_state->ConState);
		break;
	case ACT_ZCAU:
		dev_warn(cs->dev, "cause code %04x in connection state %d.\n",
			 ev->parameter, at_state->ConState);
		break;

	/* events from the LL */

	case ACT_DIAL:
		if (!ev->ptr) {
			*p_genresp = 1;
			*p_resp_code = RSP_ERROR;
			break;
		}
		start_dial(at_state, ev->ptr, ev->parameter);
		break;
	case ACT_ACCEPT:
		start_accept(at_state);
		break;
	case ACT_HUP:
		at_state->pending_commands |= PC_HUP;
		gig_dbg(DEBUG_EVENT, "Scheduling PC_HUP");
		cs->commands_pending = 1;
		break;

	/* hotplug events */

	case ACT_STOP:
		do_stop(cs);
		break;
	case ACT_START:
		do_start(cs);
		break;

	/* events from the interface */

	case ACT_IF_LOCK:
		cs->cmd_result = ev->parameter ? do_lock(cs) : do_unlock(cs);
		cs->waiting = 0;
		wake_up(&cs->waitqueue);
		break;
	case ACT_IF_VER:
		if (ev->parameter != 0)
			cs->cmd_result = -EINVAL;
		else if (cs->gotfwver != 1) {
			cs->cmd_result = -ENOENT;
		} else {
			memcpy(ev->arg, cs->fwver, sizeof cs->fwver);
			cs->cmd_result = 0;
		}
		cs->waiting = 0;
		wake_up(&cs->waitqueue);
		break;

	/* events from the proc file system */

	case ACT_PROC_CIDMODE:
		spin_lock_irqsave(&cs->lock, flags);
		if (ev->parameter != cs->cidmode) {
			cs->cidmode = ev->parameter;
			if (ev->parameter) {
				cs->at_state.pending_commands |= PC_CIDMODE;
				gig_dbg(DEBUG_EVENT, "Scheduling PC_CIDMODE");
			} else {
				cs->at_state.pending_commands |= PC_UMMODE;
				gig_dbg(DEBUG_EVENT, "Scheduling PC_UMMODE");
			}
			cs->commands_pending = 1;
		}
		spin_unlock_irqrestore(&cs->lock, flags);
		cs->waiting = 0;
		wake_up(&cs->waitqueue);
		break;

	/* events from the hardware drivers */

	case ACT_NOTIFY_BC_DOWN:
		bchannel_down(bcs);
		break;
	case ACT_NOTIFY_BC_UP:
		bchannel_up(bcs);
		break;
	case ACT_SHUTDOWN:
		do_shutdown(cs);
		break;


	default:
		if (action >= ACT_CMD && action < ACT_CMD + AT_NUM) {
			*pp_command = at_state->bcs->commands[action - ACT_CMD];
			if (!*pp_command) {
				*p_genresp = 1;
				*p_resp_code = RSP_NULL;
			}
		} else
			dev_err(cs->dev, "%s: action==%d!\n", __func__, action);
	}
}

/* State machine to do the calling and hangup procedure */
static void process_event(struct cardstate *cs, struct event_t *ev)
{
	struct bc_state *bcs;
	char *p_command = NULL;
	struct reply_t *rep;
	int rcode;
	int genresp = 0;
	int resp_code = RSP_ERROR;
	struct at_state_t *at_state;
	int index;
	int curact;
	unsigned long flags;

	if (ev->cid >= 0) {
		at_state = at_state_from_cid(cs, ev->cid);
		if (!at_state) {
			gig_dbg(DEBUG_EVENT, "event %d for invalid cid %d",
				ev->type, ev->cid);
			gigaset_add_event(cs, &cs->at_state, RSP_WRONG_CID,
					  NULL, 0, NULL);
			return;
		}
	} else {
		at_state = ev->at_state;
		if (at_state_invalid(cs, at_state)) {
			gig_dbg(DEBUG_EVENT, "event for invalid at_state %p",
				at_state);
			return;
		}
	}

	gig_dbg(DEBUG_EVENT, "connection state %d, event %d",
		at_state->ConState, ev->type);

	bcs = at_state->bcs;

	/* Setting the pointer to the dial array */
	rep = at_state->replystruct;

	spin_lock_irqsave(&cs->lock, flags);
	if (ev->type == EV_TIMEOUT) {
		if (ev->parameter != at_state->timer_index
		    || !at_state->timer_active) {
			ev->type = RSP_NONE; /* old timeout */
			gig_dbg(DEBUG_EVENT, "old timeout");
		} else {
			if (at_state->waiting)
				gig_dbg(DEBUG_EVENT, "stopped waiting");
			else
				gig_dbg(DEBUG_EVENT, "timeout occurred");
		}
	}
	spin_unlock_irqrestore(&cs->lock, flags);

	/* if the response belongs to a variable in at_state->int_var[VAR_XXXX]
	   or at_state->str_var[STR_XXXX], set it */
	if (ev->type >= RSP_VAR && ev->type < RSP_VAR + VAR_NUM) {
		index = ev->type - RSP_VAR;
		at_state->int_var[index] = ev->parameter;
	} else if (ev->type >= RSP_STR && ev->type < RSP_STR + STR_NUM) {
		index = ev->type - RSP_STR;
		kfree(at_state->str_var[index]);
		at_state->str_var[index] = ev->ptr;
		ev->ptr = NULL; /* prevent process_events() from
				   deallocating ptr */
	}

	if (ev->type == EV_TIMEOUT || ev->type == RSP_STRING)
		at_state->getstring = 0;

	/* Search row in dial array which matches modem response and current
	   constate */
	for (;; rep++) {
		rcode = rep->resp_code;
		if (rcode == RSP_LAST) {
			/* found nothing...*/
			dev_warn(cs->dev, "%s: rcode=RSP_LAST: "
				 "resp_code %d in ConState %d!\n",
				 __func__, ev->type, at_state->ConState);
			return;
		}
		if ((rcode == RSP_ANY || rcode == ev->type)
		    && ((int) at_state->ConState >= rep->min_ConState)
		    && (rep->max_ConState < 0
			|| (int) at_state->ConState <= rep->max_ConState)
		    && (rep->parameter < 0 || rep->parameter == ev->parameter))
			break;
	}

	p_command = rep->command;

	at_state->waiting = 0;
	for (curact = 0; curact < MAXACT; ++curact) {
		/* The row tells us what we should do  ..
		 */
		do_action(rep->action[curact], cs, bcs, &at_state, &p_command,
			  &genresp, &resp_code, ev);
		if (!at_state)
			/* at_state destroyed by disconnect */
			return;
	}

	/* Jump to the next con-state regarding the array */
	if (rep->new_ConState >= 0)
		at_state->ConState = rep->new_ConState;

	if (genresp) {
		spin_lock_irqsave(&cs->lock, flags);
		at_state->timer_expires = 0;
		at_state->timer_active = 0;
		spin_unlock_irqrestore(&cs->lock, flags);
		gigaset_add_event(cs, at_state, resp_code, NULL, 0, NULL);
	} else {
		/* Send command to modem if not NULL... */
		if (p_command) {
			if (cs->connected)
				send_command(cs, p_command, at_state);
			else
				gigaset_add_event(cs, at_state, RSP_NODEV,
						  NULL, 0, NULL);
		}

		spin_lock_irqsave(&cs->lock, flags);
		if (!rep->timeout) {
			at_state->timer_expires = 0;
			at_state->timer_active = 0;
		} else if (rep->timeout > 0) { /* new timeout */
			at_state->timer_expires = rep->timeout * 10;
			at_state->timer_active = 1;
			++at_state->timer_index;
		}
		spin_unlock_irqrestore(&cs->lock, flags);
	}
}

static void schedule_sequence(struct cardstate *cs,
			      struct at_state_t *at_state, int sequence)
{
	cs->cur_at_seq = sequence;
	gigaset_add_event(cs, at_state, RSP_INIT, NULL, sequence, NULL);
}

static void process_command_flags(struct cardstate *cs)
{
	struct at_state_t *at_state = NULL;
	struct bc_state *bcs;
	int i;
	int sequence;
	unsigned long flags;

	cs->commands_pending = 0;

	if (cs->cur_at_seq) {
		gig_dbg(DEBUG_EVENT, "not searching scheduled commands: busy");
		return;
	}

	gig_dbg(DEBUG_EVENT, "searching scheduled commands");

	sequence = SEQ_NONE;

	/* clear pending_commands and hangup channels on shutdown */
	if (cs->at_state.pending_commands & PC_SHUTDOWN) {
		cs->at_state.pending_commands &= ~PC_CIDMODE;
		for (i = 0; i < cs->channels; ++i) {
			bcs = cs->bcs + i;
			at_state = &bcs->at_state;
			at_state->pending_commands &=
				~(PC_DLE1 | PC_ACCEPT | PC_DIAL);
			if (at_state->cid > 0)
				at_state->pending_commands |= PC_HUP;
			if (at_state->pending_commands & PC_CID) {
				at_state->pending_commands |= PC_NOCID;
				at_state->pending_commands &= ~PC_CID;
			}
		}
	}

	/* clear pending_commands and hangup channels on reset */
	if (cs->at_state.pending_commands & PC_INIT) {
		cs->at_state.pending_commands &= ~PC_CIDMODE;
		for (i = 0; i < cs->channels; ++i) {
			bcs = cs->bcs + i;
			at_state = &bcs->at_state;
			at_state->pending_commands &=
				~(PC_DLE1 | PC_ACCEPT | PC_DIAL);
			if (at_state->cid > 0)
				at_state->pending_commands |= PC_HUP;
			if (cs->mstate == MS_RECOVER) {
				if (at_state->pending_commands & PC_CID) {
					at_state->pending_commands |= PC_NOCID;
					at_state->pending_commands &= ~PC_CID;
				}
			}
		}
	}

	/* only switch back to unimodem mode if no commands are pending and
	 * no channels are up */
	spin_lock_irqsave(&cs->lock, flags);
	if (cs->at_state.pending_commands == PC_UMMODE
	    && !cs->cidmode
	    && list_empty(&cs->temp_at_states)
	    && cs->mode == M_CID) {
		sequence = SEQ_UMMODE;
		at_state = &cs->at_state;
		for (i = 0; i < cs->channels; ++i) {
			bcs = cs->bcs + i;
			if (bcs->at_state.pending_commands ||
			    bcs->at_state.cid > 0) {
				sequence = SEQ_NONE;
				break;
			}
		}
	}
	spin_unlock_irqrestore(&cs->lock, flags);
	cs->at_state.pending_commands &= ~PC_UMMODE;
	if (sequence != SEQ_NONE) {
		schedule_sequence(cs, at_state, sequence);
		return;
	}

	for (i = 0; i < cs->channels; ++i) {
		bcs = cs->bcs + i;
		if (bcs->at_state.pending_commands & PC_HUP) {
			if (cs->dle) {
				cs->curchannel = bcs->channel;
				schedule_sequence(cs, &cs->at_state, SEQ_DLE0);
				return;
			}
			bcs->at_state.pending_commands &= ~PC_HUP;
			if (bcs->at_state.pending_commands & PC_CID) {
				/* not yet dialing: PC_NOCID is sufficient */
				bcs->at_state.pending_commands |= PC_NOCID;
				bcs->at_state.pending_commands &= ~PC_CID;
			} else {
				schedule_sequence(cs, &bcs->at_state, SEQ_HUP);
				return;
			}
		}
		if (bcs->at_state.pending_commands & PC_NOCID) {
			bcs->at_state.pending_commands &= ~PC_NOCID;
			cs->curchannel = bcs->channel;
			schedule_sequence(cs, &cs->at_state, SEQ_NOCID);
			return;
		} else if (bcs->at_state.pending_commands & PC_DLE0) {
			bcs->at_state.pending_commands &= ~PC_DLE0;
			cs->curchannel = bcs->channel;
			schedule_sequence(cs, &cs->at_state, SEQ_DLE0);
			return;
		}
	}

	list_for_each_entry(at_state, &cs->temp_at_states, list)
		if (at_state->pending_commands & PC_HUP) {
			at_state->pending_commands &= ~PC_HUP;
			schedule_sequence(cs, at_state, SEQ_HUP);
			return;
		}

	if (cs->at_state.pending_commands & PC_INIT) {
		cs->at_state.pending_commands &= ~PC_INIT;
		cs->dle = 0;
		cs->inbuf->inputstate = INS_command;
		schedule_sequence(cs, &cs->at_state, SEQ_INIT);
		return;
	}
	if (cs->at_state.pending_commands & PC_SHUTDOWN) {
		cs->at_state.pending_commands &= ~PC_SHUTDOWN;
		schedule_sequence(cs, &cs->at_state, SEQ_SHUTDOWN);
		return;
	}
	if (cs->at_state.pending_commands & PC_CIDMODE) {
		cs->at_state.pending_commands &= ~PC_CIDMODE;
		if (cs->mode == M_UNIMODEM) {
			cs->retry_count = 1;
			schedule_sequence(cs, &cs->at_state, SEQ_CIDMODE);
			return;
		}
	}

	for (i = 0; i < cs->channels; ++i) {
		bcs = cs->bcs + i;
		if (bcs->at_state.pending_commands & PC_DLE1) {
			bcs->at_state.pending_commands &= ~PC_DLE1;
			cs->curchannel = bcs->channel;
			schedule_sequence(cs, &cs->at_state, SEQ_DLE1);
			return;
		}
		if (bcs->at_state.pending_commands & PC_ACCEPT) {
			bcs->at_state.pending_commands &= ~PC_ACCEPT;
			schedule_sequence(cs, &bcs->at_state, SEQ_ACCEPT);
			return;
		}
		if (bcs->at_state.pending_commands & PC_DIAL) {
			bcs->at_state.pending_commands &= ~PC_DIAL;
			schedule_sequence(cs, &bcs->at_state, SEQ_DIAL);
			return;
		}
		if (bcs->at_state.pending_commands & PC_CID) {
			switch (cs->mode) {
			case M_UNIMODEM:
				cs->at_state.pending_commands |= PC_CIDMODE;
				gig_dbg(DEBUG_EVENT, "Scheduling PC_CIDMODE");
				cs->commands_pending = 1;
				return;
			case M_UNKNOWN:
				schedule_init(cs, MS_INIT);
				return;
			}
			bcs->at_state.pending_commands &= ~PC_CID;
			cs->curchannel = bcs->channel;
			cs->retry_count = 2;
			schedule_sequence(cs, &cs->at_state, SEQ_CID);
			return;
		}
	}
}

static void process_events(struct cardstate *cs)
{
	struct event_t *ev;
	unsigned head, tail;
	int i;
	int check_flags = 0;
	int was_busy;
	unsigned long flags;

	spin_lock_irqsave(&cs->ev_lock, flags);
	head = cs->ev_head;

	for (i = 0; i < 2 * MAX_EVENTS; ++i) {
		tail = cs->ev_tail;
		if (tail == head) {
			if (!check_flags && !cs->commands_pending)
				break;
			check_flags = 0;
			spin_unlock_irqrestore(&cs->ev_lock, flags);
			process_command_flags(cs);
			spin_lock_irqsave(&cs->ev_lock, flags);
			tail = cs->ev_tail;
			if (tail == head) {
				if (!cs->commands_pending)
					break;
				continue;
			}
		}

		ev = cs->events + head;
		was_busy = cs->cur_at_seq != SEQ_NONE;
		spin_unlock_irqrestore(&cs->ev_lock, flags);
		process_event(cs, ev);
		spin_lock_irqsave(&cs->ev_lock, flags);
		kfree(ev->ptr);
		ev->ptr = NULL;
		if (was_busy && cs->cur_at_seq == SEQ_NONE)
			check_flags = 1;

		head = (head + 1) % MAX_EVENTS;
		cs->ev_head = head;
	}

	spin_unlock_irqrestore(&cs->ev_lock, flags);

	if (i == 2 * MAX_EVENTS) {
		dev_err(cs->dev,
			"infinite loop in process_events; aborting.\n");
	}
}

/* tasklet scheduled on any event received from the Gigaset device
 * parameter:
 *	data	ISDN controller state structure
 */
void gigaset_handle_event(unsigned long data)
{
	struct cardstate *cs = (struct cardstate *) data;

	/* handle incoming data on control/common channel */
	if (cs->inbuf->head != cs->inbuf->tail) {
		gig_dbg(DEBUG_INTR, "processing new data");
		cs->ops->handle_input(cs->inbuf);
	}

	process_events(cs);
}