SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/isdn/gigaset/i4l.c

   1 /*
   2  * Stuff used by all variants of the driver
   3  *
   4  * Copyright (c) 2001 by Stefan Eilers,
   5  *                       Hansjoerg Lipp <hjlipp@web.de>,
   6  *                       Tilman Schmidt <tilman@imap.cc>.
   7  *
   8  * =====================================================================
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License as
  11  *      published by the Free Software Foundation; either version 2 of
  12  *      the License, or (at your option) any later version.
  13  * =====================================================================
  14  */
  15
  16 #include "gigaset.h"
  17
  18 /* == Handling of I4L IO =====================================================*/
  19
  20 /* writebuf_from_LL
  21  * called by LL to transmit data on an open channel
  22  * inserts the buffer data into the send queue and starts the transmission
  23  * Note that this operation must not sleep!
  24  * When the buffer is processed completely, gigaset_skb_sent() should be called.
  25  * parameters:
  26  *      driverID        driver ID as assigned by LL
  27  *      channel         channel number
  28  *      ack             if != 0 LL wants to be notified on completion via
  29  *                      statcallb(ISDN_STAT_BSENT)
  30  *      skb             skb containing data to send
  31  * return value:
  32  *      number of accepted bytes
  33  *      0 if temporarily unable to accept data (out of buffer space)
  34  *      <0 on error (eg. -EINVAL)
  35  */
  36 static int writebuf_from_LL(int driverID, int channel, int ack,
  37                             struct sk_buff *skb)
  38 {
  39         struct cardstate *cs;
  40         struct bc_state *bcs;
  41         unsigned len;
  42         unsigned skblen;
  43
  44         if (!(cs = gigaset_get_cs_by_id(driverID))) {
  45                 err("%s: invalid driver ID (%d)", __func__, driverID);
  46                 return -ENODEV;
  47         }
  48         if (channel < 0 || channel >= cs->channels) {
  49                 err("%s: invalid channel ID (%d)", __func__, channel);
  50                 return -ENODEV;
  51         }
  52         bcs = &cs->bcs[channel];
  53         len = skb->len;
  54
  55         gig_dbg(DEBUG_LLDATA,
  56                 "Receiving data from LL (id: %d, ch: %d, ack: %d, sz: %d)",
  57                 driverID, channel, ack, len);
  58
  59         if (!len) {
  60                 if (ack)
  61                         notice("%s: not ACKing empty packet", __func__);
  62                 return 0;
  63         }
  64         if (len > MAX_BUF_SIZE) {
  65                 err("%s: packet too large (%d bytes)", __func__, len);
  66                 return -EINVAL;
  67         }
  68
  69         skblen = ack ? len : 0;
  70         skb->head[0] = skblen & 0xff;
  71         skb->head[1] = skblen >> 8;
  72         gig_dbg(DEBUG_MCMD, "skb: len=%u, skblen=%u: %02x %02x",
  73                 len, skblen, (unsigned) skb->head[0], (unsigned) skb->head[1]);
  74
  75         /* pass to device-specific module */
  76         return cs->ops->send_skb(bcs, skb);
  77 }
  78
  79 void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb)
  80 {
  81         unsigned len;
  82         isdn_ctrl response;
  83
  84         ++bcs->trans_up;
  85
  86         if (skb->len)
  87                 dev_warn(bcs->cs->dev, "%s: skb->len==%d\n",
  88                          __func__, skb->len);
  89
  90         len = (unsigned char) skb->head[0] |
  91               (unsigned) (unsigned char) skb->head[1] << 8;
  92         if (len) {
  93                 gig_dbg(DEBUG_MCMD, "ACKing to LL (id: %d, ch: %d, sz: %u)",
  94                         bcs->cs->myid, bcs->channel, len);
  95
  96                 response.driver = bcs->cs->myid;
  97                 response.command = ISDN_STAT_BSENT;
  98                 response.arg = bcs->channel;
  99                 response.parm.length = len;
 100                 bcs->cs->iif.statcallb(&response);
 101         }
 102 }
 103 EXPORT_SYMBOL_GPL(gigaset_skb_sent);
 104
 105 /* This function will be called by LL to send commands
 106  * NOTE: LL ignores the returned value, for commands other than ISDN_CMD_IOCTL,
 107  * so don't put too much effort into it.
 108  */
 109 static int command_from_LL(isdn_ctrl *cntrl)
 110 {
 111         struct cardstate *cs = gigaset_get_cs_by_id(cntrl->driver);
 112         struct bc_state *bcs;
 113         int retval = 0;
 114         struct setup_parm *sp;
 115
 116         gigaset_debugdrivers();
 117
 118         if (!cs) {
 119                 warn("LL tried to access unknown device with nr. %d",
 120                      cntrl->driver);
 121                 return -ENODEV;
 122         }
 123
 124         switch (cntrl->command) {
 125         case ISDN_CMD_IOCTL:
 126                 gig_dbg(DEBUG_ANY, "ISDN_CMD_IOCTL (driver: %d, arg: %ld)",
 127                         cntrl->driver, cntrl->arg);
 128
 129                 warn("ISDN_CMD_IOCTL is not supported.");
 130                 return -EINVAL;
 131
 132         case ISDN_CMD_DIAL:
 133                 gig_dbg(DEBUG_ANY,
 134                         "ISDN_CMD_DIAL (driver: %d, ch: %ld, "
 135                         "phone: %s, ownmsn: %s, si1: %d, si2: %d)",
 136                         cntrl->driver, cntrl->arg,
 137                         cntrl->parm.setup.phone, cntrl->parm.setup.eazmsn,
 138                         cntrl->parm.setup.si1, cntrl->parm.setup.si2);
 139
 140                 if (cntrl->arg >= cs->channels) {
 141                         err("ISDN_CMD_DIAL: invalid channel (%d)",
 142                             (int) cntrl->arg);
 143                         return -EINVAL;
 144                 }
 145
 146                 bcs = cs->bcs + cntrl->arg;
 147
 148                 if (!gigaset_get_channel(bcs)) {
 149                         err("ISDN_CMD_DIAL: channel not free");
 150                         return -EBUSY;
 151                 }
 152
 153                 sp = kmalloc(sizeof *sp, GFP_ATOMIC);
 154                 if (!sp) {
 155                         gigaset_free_channel(bcs);
 156                         err("ISDN_CMD_DIAL: out of memory");
 157                         return -ENOMEM;
 158                 }
 159                 *sp = cntrl->parm.setup;
 160
 161                 if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, sp,
 162                                        bcs->at_state.seq_index, NULL)) {
 163                         //FIXME what should we do?
 164                         kfree(sp);
 165                         gigaset_free_channel(bcs);
 166                         return -ENOMEM;
 167                 }
 168
 169                 gig_dbg(DEBUG_CMD, "scheduling DIAL");
 170                 gigaset_schedule_event(cs);
 171                 break;
 172         case ISDN_CMD_ACCEPTD: //FIXME
 173                 gig_dbg(DEBUG_ANY, "ISDN_CMD_ACCEPTD");
 174
 175                 if (cntrl->arg >= cs->channels) {
 176                         err("ISDN_CMD_ACCEPTD: invalid channel (%d)",
 177                             (int) cntrl->arg);
 178                         return -EINVAL;
 179                 }
 180
 181                 if (!gigaset_add_event(cs, &cs->bcs[cntrl->arg].at_state,
 182                                        EV_ACCEPT, NULL, 0, NULL)) {
 183                         //FIXME what should we do?
 184                         return -ENOMEM;
 185                 }
 186
 187                 gig_dbg(DEBUG_CMD, "scheduling ACCEPT");
 188                 gigaset_schedule_event(cs);
 189
 190                 break;
 191         case ISDN_CMD_ACCEPTB:
 192                 gig_dbg(DEBUG_ANY, "ISDN_CMD_ACCEPTB");
 193                 break;
 194         case ISDN_CMD_HANGUP:
 195                 gig_dbg(DEBUG_ANY, "ISDN_CMD_HANGUP (ch: %d)",
 196                         (int) cntrl->arg);
 197
 198                 if (cntrl->arg >= cs->channels) {
 199                         err("ISDN_CMD_HANGUP: invalid channel (%u)",
 200                             (unsigned) cntrl->arg);
 201                         return -EINVAL;
 202                 }
 203
 204                 if (!gigaset_add_event(cs, &cs->bcs[cntrl->arg].at_state,
 205                                        EV_HUP, NULL, 0, NULL)) {
 206                         //FIXME what should we do?
 207                         return -ENOMEM;
 208                 }
 209
 210                 gig_dbg(DEBUG_CMD, "scheduling HUP");
 211                 gigaset_schedule_event(cs);
 212
 213                 break;
 214         case ISDN_CMD_CLREAZ: /* Do not signal incoming signals */ //FIXME
 215                 gig_dbg(DEBUG_ANY, "ISDN_CMD_CLREAZ");
 216                 break;
 217         case ISDN_CMD_SETEAZ: /* Signal incoming calls for given MSN */ //FIXME
 218                 gig_dbg(DEBUG_ANY,
 219                         "ISDN_CMD_SETEAZ (id: %d, ch: %ld, number: %s)",
 220                         cntrl->driver, cntrl->arg, cntrl->parm.num);
 221                 break;
 222         case ISDN_CMD_SETL2: /* Set L2 to given protocol */
 223                 gig_dbg(DEBUG_ANY, "ISDN_CMD_SETL2 (ch: %ld, proto: %lx)",
 224                         cntrl->arg & 0xff, (cntrl->arg >> 8));
 225
 226                 if ((cntrl->arg & 0xff) >= cs->channels) {
 227                         err("ISDN_CMD_SETL2: invalid channel (%u)",
 228                             (unsigned) cntrl->arg & 0xff);
 229                         return -EINVAL;
 230                 }
 231
 232                 if (!gigaset_add_event(cs, &cs->bcs[cntrl->arg & 0xff].at_state,
 233                                        EV_PROTO_L2, NULL, cntrl->arg >> 8,
 234                                        NULL)) {
 235                         //FIXME what should we do?
 236                         return -ENOMEM;
 237                 }
 238
 239                 gig_dbg(DEBUG_CMD, "scheduling PROTO_L2");
 240                 gigaset_schedule_event(cs);
 241                 break;
 242         case ISDN_CMD_SETL3: /* Set L3 to given protocol */
 243                 gig_dbg(DEBUG_ANY, "ISDN_CMD_SETL3 (ch: %ld, proto: %lx)",
 244                         cntrl->arg & 0xff, (cntrl->arg >> 8));
 245
 246                 if ((cntrl->arg & 0xff) >= cs->channels) {
 247                         err("ISDN_CMD_SETL3: invalid channel (%u)",
 248                             (unsigned) cntrl->arg & 0xff);
 249                         return -EINVAL;
 250                 }
 251
 252                 if (cntrl->arg >> 8 != ISDN_PROTO_L3_TRANS) {
 253                         err("ISDN_CMD_SETL3: invalid protocol %lu",
 254                             cntrl->arg >> 8);
 255                         return -EINVAL;
 256                 }
 257
 258                 break;
 259         case ISDN_CMD_PROCEED:
 260                 gig_dbg(DEBUG_ANY, "ISDN_CMD_PROCEED"); //FIXME
 261                 break;
 262         case ISDN_CMD_ALERT:
 263                 gig_dbg(DEBUG_ANY, "ISDN_CMD_ALERT"); //FIXME
 264                 if (cntrl->arg >= cs->channels) {
 265                         err("ISDN_CMD_ALERT: invalid channel (%d)",
 266                             (int) cntrl->arg);
 267                         return -EINVAL;
 268                 }
 269                 //bcs = cs->bcs + cntrl->arg;
 270                 //bcs->proto2 = -1;
 271                 // FIXME
 272                 break;
 273         case ISDN_CMD_REDIR:
 274                 gig_dbg(DEBUG_ANY, "ISDN_CMD_REDIR"); //FIXME
 275                 break;
 276         case ISDN_CMD_PROT_IO:
 277                 gig_dbg(DEBUG_ANY, "ISDN_CMD_PROT_IO");
 278                 break;
 279         case ISDN_CMD_FAXCMD:
 280                 gig_dbg(DEBUG_ANY, "ISDN_CMD_FAXCMD");
 281                 break;
 282         case ISDN_CMD_GETL2:
 283                 gig_dbg(DEBUG_ANY, "ISDN_CMD_GETL2");
 284                 break;
 285         case ISDN_CMD_GETL3:
 286                 gig_dbg(DEBUG_ANY, "ISDN_CMD_GETL3");
 287                 break;
 288         case ISDN_CMD_GETEAZ:
 289                 gig_dbg(DEBUG_ANY, "ISDN_CMD_GETEAZ");
 290                 break;
 291         case ISDN_CMD_SETSIL:
 292                 gig_dbg(DEBUG_ANY, "ISDN_CMD_SETSIL");
 293                 break;
 294         case ISDN_CMD_GETSIL:
 295                 gig_dbg(DEBUG_ANY, "ISDN_CMD_GETSIL");
 296                 break;
 297         default:
 298                 err("unknown command %d from LL", cntrl->command);
 299                 return -EINVAL;
 300         }
 301
 302         return retval;
 303 }
 304
 305 void gigaset_i4l_cmd(struct cardstate *cs, int cmd)
 306 {
 307         isdn_ctrl command;
 308
 309         command.driver = cs->myid;
 310         command.command = cmd;
 311         command.arg = 0;
 312         cs->iif.statcallb(&command);
 313 }
 314
 315 void gigaset_i4l_channel_cmd(struct bc_state *bcs, int cmd)
 316 {
 317         isdn_ctrl command;
 318
 319         command.driver = bcs->cs->myid;
 320         command.command = cmd;
 321         command.arg = bcs->channel;
 322         bcs->cs->iif.statcallb(&command);
 323 }
 324
 325 int gigaset_isdn_setup_dial(struct at_state_t *at_state, void *data)
 326 {
 327         struct bc_state *bcs = at_state->bcs;
 328         unsigned proto;
 329         const char *bc;
 330         size_t length[AT_NUM];
 331         size_t l;
 332         int i;
 333         struct setup_parm *sp = data;
 334
 335         switch (bcs->proto2) {
 336         case ISDN_PROTO_L2_HDLC:
 337                 proto = 1; /* 0: Bitsynchron, 1: HDLC, 2: voice */
 338                 break;
 339         case ISDN_PROTO_L2_TRANS:
 340                 proto = 2; /* 0: Bitsynchron, 1: HDLC, 2: voice */
 341                 break;
 342         default:
 343                 dev_err(bcs->cs->dev, "%s: invalid L2 protocol: %u\n",
 344                         __func__, bcs->proto2);
 345                 return -EINVAL;
 346         }
 347
 348         switch (sp->si1) {
 349         case 1:         /* audio */
 350                 bc = "9090A3";  /* 3.1 kHz audio, A-law */
 351                 break;
 352         case 7:         /* data */
 353         default:        /* hope the app knows what it is doing */
 354                 bc = "8890";    /* unrestricted digital information */
 355         }
 356         //FIXME add missing si1 values from 1TR6, inspect si2, set HLC/LLC
 357
 358         length[AT_DIAL ] = 1 + strlen(sp->phone) + 1 + 1;
 359         l = strlen(sp->eazmsn);
 360         length[AT_MSN  ] = l ? 6 + l + 1 + 1 : 0;
 361         length[AT_BC   ] = 5 + strlen(bc) + 1 + 1;
 362         length[AT_PROTO] = 6 + 1 + 1 + 1; /* proto: 1 character */
 363         length[AT_ISO  ] = 6 + 1 + 1 + 1; /* channel: 1 character */
 364         length[AT_TYPE ] = 6 + 1 + 1 + 1; /* call type: 1 character */
 365         length[AT_HLC  ] = 0;
 366
 367         for (i = 0; i < AT_NUM; ++i) {
 368                 kfree(bcs->commands[i]);
 369                 bcs->commands[i] = NULL;
 370                 if (length[i] &&
 371                     !(bcs->commands[i] = kmalloc(length[i], GFP_ATOMIC))) {
 372                         dev_err(bcs->cs->dev, "out of memory\n");
 373                         return -ENOMEM;
 374                 }
 375         }
 376
 377         /* type = 1: extern, 0: intern, 2: recall, 3: door, 4: centrex */
 378         if (sp->phone[0] == '*' && sp->phone[1] == '*') {
 379                 /* internal call: translate ** prefix to CTP value */
 380                 snprintf(bcs->commands[AT_DIAL], length[AT_DIAL],
 381                          "D%s\r", sp->phone+2);
 382                 strncpy(bcs->commands[AT_TYPE], "^SCTP=0\r", length[AT_TYPE]);
 383         } else {
 384                 snprintf(bcs->commands[AT_DIAL], length[AT_DIAL],
 385                          "D%s\r", sp->phone);
 386                 strncpy(bcs->commands[AT_TYPE], "^SCTP=1\r", length[AT_TYPE]);
 387         }
 388
 389         if (bcs->commands[AT_MSN])
 390                 snprintf(bcs->commands[AT_MSN], length[AT_MSN],
 391                          "^SMSN=%s\r", sp->eazmsn);
 392         snprintf(bcs->commands[AT_BC   ], length[AT_BC   ],
 393                  "^SBC=%s\r", bc);
 394         snprintf(bcs->commands[AT_PROTO], length[AT_PROTO],
 395                  "^SBPR=%u\r", proto);
 396         snprintf(bcs->commands[AT_ISO  ], length[AT_ISO  ],
 397                  "^SISO=%u\r", (unsigned)bcs->channel + 1);
 398
 399         return 0;
 400 }
 401
 402 int gigaset_isdn_setup_accept(struct at_state_t *at_state)
 403 {
 404         unsigned proto;
 405         size_t length[AT_NUM];
 406         int i;
 407         struct bc_state *bcs = at_state->bcs;
 408
 409         switch (bcs->proto2) {
 410         case ISDN_PROTO_L2_HDLC:
 411                 proto = 1; /* 0: Bitsynchron, 1: HDLC, 2: voice */
 412                 break;
 413         case ISDN_PROTO_L2_TRANS:
 414                 proto = 2; /* 0: Bitsynchron, 1: HDLC, 2: voice */
 415                 break;
 416         default:
 417                 dev_err(at_state->cs->dev, "%s: invalid protocol: %u\n",
 418                         __func__, bcs->proto2);
 419                 return -EINVAL;
 420         }
 421
 422         length[AT_DIAL ] = 0;
 423         length[AT_MSN  ] = 0;
 424         length[AT_BC   ] = 0;
 425         length[AT_PROTO] = 6 + 1 + 1 + 1; /* proto: 1 character */
 426         length[AT_ISO  ] = 6 + 1 + 1 + 1; /* channel: 1 character */
 427         length[AT_TYPE ] = 0;
 428         length[AT_HLC  ] = 0;
 429
 430         for (i = 0; i < AT_NUM; ++i) {
 431                 kfree(bcs->commands[i]);
 432                 bcs->commands[i] = NULL;
 433                 if (length[i] &&
 434                     !(bcs->commands[i] = kmalloc(length[i], GFP_ATOMIC))) {
 435                         dev_err(at_state->cs->dev, "out of memory\n");
 436                         return -ENOMEM;
 437                 }
 438         }
 439
 440         snprintf(bcs->commands[AT_PROTO], length[AT_PROTO],
 441                  "^SBPR=%u\r", proto);
 442         snprintf(bcs->commands[AT_ISO  ], length[AT_ISO  ],
 443                  "^SISO=%u\r", (unsigned) bcs->channel + 1);
 444
 445         return 0;
 446 }
 447
 448 int gigaset_isdn_icall(struct at_state_t *at_state)
 449 {
 450         struct cardstate *cs = at_state->cs;
 451         struct bc_state *bcs = at_state->bcs;
 452         isdn_ctrl response;
 453         int retval;
 454
 455         /* fill ICALL structure */
 456         response.parm.setup.si1 = 0;    /* default: unknown */
 457         response.parm.setup.si2 = 0;
 458         response.parm.setup.screen = 0; //FIXME how to set these?
 459         response.parm.setup.plan = 0;
 460         if (!at_state->str_var[STR_ZBC]) {
 461                 /* no BC (internal call): assume speech, A-law */
 462                 response.parm.setup.si1 = 1;
 463         } else if (!strcmp(at_state->str_var[STR_ZBC], "8890")) {
 464                 /* unrestricted digital information */
 465                 response.parm.setup.si1 = 7;
 466         } else if (!strcmp(at_state->str_var[STR_ZBC], "8090A3")) {
 467                 /* speech, A-law */
 468                 response.parm.setup.si1 = 1;
 469         } else if (!strcmp(at_state->str_var[STR_ZBC], "9090A3")) {
 470                 /* 3,1 kHz audio, A-law */
 471                 response.parm.setup.si1 = 1;
 472                 response.parm.setup.si2 = 2;
 473         } else {
 474                 dev_warn(cs->dev, "RING ignored - unsupported BC %s\n",
 475                      at_state->str_var[STR_ZBC]);
 476                 return ICALL_IGNORE;
 477         }
 478         if (at_state->str_var[STR_NMBR]) {
 479                 strncpy(response.parm.setup.phone, at_state->str_var[STR_NMBR],
 480                         sizeof response.parm.setup.phone - 1);
 481                 response.parm.setup.phone[sizeof response.parm.setup.phone - 1] = 0;
 482         } else
 483                 response.parm.setup.phone[0] = 0;
 484         if (at_state->str_var[STR_ZCPN]) {
 485                 strncpy(response.parm.setup.eazmsn, at_state->str_var[STR_ZCPN],
 486                         sizeof response.parm.setup.eazmsn - 1);
 487                 response.parm.setup.eazmsn[sizeof response.parm.setup.eazmsn - 1] = 0;
 488         } else
 489                 response.parm.setup.eazmsn[0] = 0;
 490
 491         if (!bcs) {
 492                 dev_notice(cs->dev, "no channel for incoming call\n");
 493                 response.command = ISDN_STAT_ICALLW;
 494                 response.arg = 0; //FIXME
 495         } else {
 496                 gig_dbg(DEBUG_CMD, "Sending ICALL");
 497                 response.command = ISDN_STAT_ICALL;
 498                 response.arg = bcs->channel; //FIXME
 499         }
 500         response.driver = cs->myid;
 501         retval = cs->iif.statcallb(&response);
 502         gig_dbg(DEBUG_CMD, "Response: %d", retval);
 503         switch (retval) {
 504         case 0: /* no takers */
 505                 return ICALL_IGNORE;
 506         case 1: /* alerting */
 507                 bcs->chstate |= CHS_NOTIFY_LL;
 508                 return ICALL_ACCEPT;
 509         case 2: /* reject */
 510                 return ICALL_REJECT;
 511         case 3: /* incomplete */
 512                 dev_warn(cs->dev,
 513                        "LL requested unsupported feature: Incomplete Number\n");
 514                 return ICALL_IGNORE;
 515         case 4: /* proceeding */
 516                 /* Gigaset will send ALERTING anyway.
 517                  * There doesn't seem to be a way to avoid this.
 518                  */
 519                 return ICALL_ACCEPT;
 520         case 5: /* deflect */
 521                 dev_warn(cs->dev,
 522                          "LL requested unsupported feature: Call Deflection\n");
 523                 return ICALL_IGNORE;
 524         default:
 525                 dev_err(cs->dev, "LL error %d on ICALL\n", retval);
 526                 return ICALL_IGNORE;
 527         }
 528 }
 529
 530 /* Set Callback function pointer */
 531 int gigaset_register_to_LL(struct cardstate *cs, const char *isdnid)
 532 {
 533         isdn_if *iif = &cs->iif;
 534
 535         gig_dbg(DEBUG_ANY, "Register driver capabilities to LL");
 536
 537         //iif->id[sizeof(iif->id) - 1]=0;
 538         //strncpy(iif->id, isdnid, sizeof(iif->id) - 1);
 539         if (snprintf(iif->id, sizeof iif->id, "%s_%u", isdnid, cs->minor_index)
 540             >= sizeof iif->id)
 541                 return -ENOMEM; //FIXME EINVAL/...??
 542
 543         iif->owner = THIS_MODULE;
 544         iif->channels = cs->channels;
 545         iif->maxbufsize = MAX_BUF_SIZE;
 546         iif->features = ISDN_FEATURE_L2_TRANS |
 547                 ISDN_FEATURE_L2_HDLC |
 548 #ifdef GIG_X75
 549                 ISDN_FEATURE_L2_X75I |
 550 #endif
 551                 ISDN_FEATURE_L3_TRANS |
 552                 ISDN_FEATURE_P_EURO;
 553         iif->hl_hdrlen = HW_HDR_LEN;            /* Area for storing ack */
 554         iif->command = command_from_LL;
 555         iif->writebuf_skb = writebuf_from_LL;
 556         iif->writecmd = NULL;                   /* Don't support isdnctrl */
 557         iif->readstat = NULL;                   /* Don't support isdnctrl */
 558         iif->rcvcallb_skb = NULL;               /* Will be set by LL */
 559         iif->statcallb = NULL;                  /* Will be set by LL */
 560
 561         if (!register_isdn(iif))
 562                 return 0;
 563
 564         cs->myid = iif->channels;               /* Set my device id */
 565         return 1;
 566 }