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 #include <linux/isdnif.h>
  18
  19 #define SBUFSIZE        4096    /* sk_buff payload size */
  20 #define TRANSBUFSIZE    768     /* bytes per skb for transparent receive */
  21 #define HW_HDR_LEN      2       /* Header size used to store ack info */
  22 #define MAX_BUF_SIZE    (SBUFSIZE - HW_HDR_LEN) /* max data packet from LL */
  23
  24 /* == Handling of I4L IO =====================================================*/
  25
  26 /* writebuf_from_LL
  27  * called by LL to transmit data on an open channel
  28  * inserts the buffer data into the send queue and starts the transmission
  29  * Note that this operation must not sleep!
  30  * When the buffer is processed completely, gigaset_skb_sent() should be called.
  31  * parameters:
  32  *      driverID        driver ID as assigned by LL
  33  *      channel         channel number
  34  *      ack             if != 0 LL wants to be notified on completion via
  35  *                      statcallb(ISDN_STAT_BSENT)
  36  *      skb             skb containing data to send
  37  * return value:
  38  *      number of accepted bytes
  39  *      0 if temporarily unable to accept data (out of buffer space)
  40  *      <0 on error (eg. -EINVAL)
  41  */
  42 static int writebuf_from_LL(int driverID, int channel, int ack,
  43                             struct sk_buff *skb)
  44 {
  45         struct cardstate *cs = gigaset_get_cs_by_id(driverID);
  46         struct bc_state *bcs;
  47         unsigned char *ack_header;
  48         unsigned len;
  49
  50         if (!cs) {
  51                 pr_err("%s: invalid driver ID (%d)\n", __func__, driverID);
  52                 return -ENODEV;
  53         }
  54         if (channel < 0 || channel >= cs->channels) {
  55                 dev_err(cs->dev, "%s: invalid channel ID (%d)\n",
  56                         __func__, channel);
  57                 return -ENODEV;
  58         }
  59         bcs = &cs->bcs[channel];
  60
  61         /* can only handle linear sk_buffs */
  62         if (skb_linearize(skb) < 0) {
  63                 dev_err(cs->dev, "%s: skb_linearize failed\n", __func__);
  64                 return -ENOMEM;
  65         }
  66         len = skb->len;
  67
  68         gig_dbg(DEBUG_LLDATA,
  69                 "Receiving data from LL (id: %d, ch: %d, ack: %d, sz: %d)",
  70                 driverID, channel, ack, len);
  71
  72         if (!len) {
  73                 if (ack)
  74                         dev_notice(cs->dev, "%s: not ACKing empty packet\n",
  75                                    __func__);
  76                 return 0;
  77         }
  78         if (len > MAX_BUF_SIZE) {
  79                 dev_err(cs->dev, "%s: packet too large (%d bytes)\n",
  80                         __func__, len);
  81                 return -EINVAL;
  82         }
  83
  84         /* set up acknowledgement header */
  85         if (skb_headroom(skb) < HW_HDR_LEN) {
  86                 /* should never happen */
  87                 dev_err(cs->dev, "%s: insufficient skb headroom\n", __func__);
  88                 return -ENOMEM;
  89         }
  90         skb_set_mac_header(skb, -HW_HDR_LEN);
  91         skb->mac_len = HW_HDR_LEN;
  92         ack_header = skb_mac_header(skb);
  93         if (ack) {
  94                 ack_header[0] = len & 0xff;
  95                 ack_header[1] = len >> 8;
  96         } else {
  97                 ack_header[0] = ack_header[1] = 0;
  98         }
  99         gig_dbg(DEBUG_MCMD, "skb: len=%u, ack=%d: %02x %02x",
 100                 len, ack, ack_header[0], ack_header[1]);
 101
 102         /* pass to device-specific module */
 103         return cs->ops->send_skb(bcs, skb);
 104 }
 105
 106 /**
 107  * gigaset_skb_sent() - acknowledge sending an skb
 108  * @bcs:        B channel descriptor structure.
 109  * @skb:        sent data.
 110  *
 111  * Called by hardware module {bas,ser,usb}_gigaset when the data in a
 112  * skb has been successfully sent, for signalling completion to the LL.
 113  */
 114 void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb)
 115 {
 116         isdn_if *iif = bcs->cs->iif;
 117         unsigned char *ack_header = skb_mac_header(skb);
 118         unsigned len;
 119         isdn_ctrl response;
 120
 121         ++bcs->trans_up;
 122
 123         if (skb->len)
 124                 dev_warn(bcs->cs->dev, "%s: skb->len==%d\n",
 125                          __func__, skb->len);
 126
 127         len = ack_header[0] + ((unsigned) ack_header[1] << 8);
 128         if (len) {
 129                 gig_dbg(DEBUG_MCMD, "ACKing to LL (id: %d, ch: %d, sz: %u)",
 130                         bcs->cs->myid, bcs->channel, len);
 131
 132                 response.driver = bcs->cs->myid;
 133                 response.command = ISDN_STAT_BSENT;
 134                 response.arg = bcs->channel;
 135                 response.parm.length = len;
 136                 iif->statcallb(&response);
 137         }
 138 }
 139 EXPORT_SYMBOL_GPL(gigaset_skb_sent);
 140
 141 /**
 142  * gigaset_skb_rcvd() - pass received skb to LL
 143  * @bcs:        B channel descriptor structure.
 144  * @skb:        received data.
 145  *
 146  * Called by hardware module {bas,ser,usb}_gigaset when user data has
 147  * been successfully received, for passing to the LL.
 148  * Warning: skb must not be accessed anymore!
 149  */
 150 void gigaset_skb_rcvd(struct bc_state *bcs, struct sk_buff *skb)
 151 {
 152         isdn_if *iif = bcs->cs->iif;
 153
 154         iif->rcvcallb_skb(bcs->cs->myid, bcs->channel, skb);
 155         bcs->trans_down++;
 156 }
 157 EXPORT_SYMBOL_GPL(gigaset_skb_rcvd);
 158
 159 /**
 160  * gigaset_isdn_rcv_err() - signal receive error
 161  * @bcs:        B channel descriptor structure.
 162  *
 163  * Called by hardware module {bas,ser,usb}_gigaset when a receive error
 164  * has occurred, for signalling to the LL.
 165  */
 166 void gigaset_isdn_rcv_err(struct bc_state *bcs)
 167 {
 168         isdn_if *iif = bcs->cs->iif;
 169         isdn_ctrl response;
 170
 171         /* if currently ignoring packets, just count down */
 172         if (bcs->ignore) {
 173                 bcs->ignore--;
 174                 return;
 175         }
 176
 177         /* update statistics */
 178         bcs->corrupted++;
 179
 180         /* error -> LL */
 181         gig_dbg(DEBUG_CMD, "sending L1ERR");
 182         response.driver = bcs->cs->myid;
 183         response.command = ISDN_STAT_L1ERR;
 184         response.arg = bcs->channel;
 185         response.parm.errcode = ISDN_STAT_L1ERR_RECV;
 186         iif->statcallb(&response);
 187 }
 188 EXPORT_SYMBOL_GPL(gigaset_isdn_rcv_err);
 189
 190 /* This function will be called by LL to send commands
 191  * NOTE: LL ignores the returned value, for commands other than ISDN_CMD_IOCTL,
 192  * so don't put too much effort into it.
 193  */
 194 static int command_from_LL(isdn_ctrl *cntrl)
 195 {
 196         struct cardstate *cs;
 197         struct bc_state *bcs;
 198         int retval = 0;
 199         char **commands;
 200         int ch;
 201         int i;
 202         size_t l;
 203
 204         gigaset_debugdrivers();
 205
 206         gig_dbg(DEBUG_CMD, "driver: %d, command: %d, arg: 0x%lx",
 207                 cntrl->driver, cntrl->command, cntrl->arg);
 208
 209         cs = gigaset_get_cs_by_id(cntrl->driver);
 210         if (cs == NULL) {
 211                 pr_err("%s: invalid driver ID (%d)\n", __func__, cntrl->driver);
 212                 return -ENODEV;
 213         }
 214         ch = cntrl->arg & 0xff;
 215
 216         switch (cntrl->command) {
 217         case ISDN_CMD_IOCTL:
 218                 dev_warn(cs->dev, "ISDN_CMD_IOCTL not supported\n");
 219                 return -EINVAL;
 220
 221         case ISDN_CMD_DIAL:
 222                 gig_dbg(DEBUG_CMD,
 223                         "ISDN_CMD_DIAL (phone: %s, msn: %s, si1: %d, si2: %d)",
 224                         cntrl->parm.setup.phone, cntrl->parm.setup.eazmsn,
 225                         cntrl->parm.setup.si1, cntrl->parm.setup.si2);
 226
 227                 if (ch >= cs->channels) {
 228                         dev_err(cs->dev,
 229                                 "ISDN_CMD_DIAL: invalid channel (%d)\n", ch);
 230                         return -EINVAL;
 231                 }
 232                 bcs = cs->bcs + ch;
 233                 if (!gigaset_get_channel(bcs)) {
 234                         dev_err(cs->dev, "ISDN_CMD_DIAL: channel not free\n");
 235                         return -EBUSY;
 236                 }
 237                 switch (bcs->proto2) {
 238                 case L2_HDLC:
 239                         bcs->rx_bufsize = SBUFSIZE;
 240                         break;
 241                 default:                        /* assume transparent */
 242                         bcs->rx_bufsize = TRANSBUFSIZE;
 243                 }
 244                 dev_kfree_skb(bcs->rx_skb);
 245                 gigaset_new_rx_skb(bcs);
 246
 247                 commands = kzalloc(AT_NUM*(sizeof *commands), GFP_ATOMIC);
 248                 if (!commands) {
 249                         gigaset_free_channel(bcs);
 250                         dev_err(cs->dev, "ISDN_CMD_DIAL: out of memory\n");
 251                         return -ENOMEM;
 252                 }
 253
 254                 l = 3 + strlen(cntrl->parm.setup.phone);
 255                 commands[AT_DIAL] = kmalloc(l, GFP_ATOMIC);
 256                 if (!commands[AT_DIAL])
 257                         goto oom;
 258                 if (cntrl->parm.setup.phone[0] == '*' &&
 259                     cntrl->parm.setup.phone[1] == '*') {
 260                         /* internal call: translate ** prefix to CTP value */
 261                         commands[AT_TYPE] = kstrdup("^SCTP=0\r", GFP_ATOMIC);
 262                         if (!commands[AT_TYPE])
 263                                 goto oom;
 264                         snprintf(commands[AT_DIAL], l,
 265                                  "D%s\r", cntrl->parm.setup.phone+2);
 266                 } else {
 267                         commands[AT_TYPE] = kstrdup("^SCTP=1\r", GFP_ATOMIC);
 268                         if (!commands[AT_TYPE])
 269                                 goto oom;
 270                         snprintf(commands[AT_DIAL], l,
 271                                  "D%s\r", cntrl->parm.setup.phone);
 272                 }
 273
 274                 l = strlen(cntrl->parm.setup.eazmsn);
 275                 if (l) {
 276                         l += 8;
 277                         commands[AT_MSN] = kmalloc(l, GFP_ATOMIC);
 278                         if (!commands[AT_MSN])
 279                                 goto oom;
 280                         snprintf(commands[AT_MSN], l, "^SMSN=%s\r",
 281                                  cntrl->parm.setup.eazmsn);
 282                 }
 283
 284                 switch (cntrl->parm.setup.si1) {
 285                 case 1:         /* audio */
 286                         /* BC = 9090A3: 3.1 kHz audio, A-law */
 287                         commands[AT_BC] = kstrdup("^SBC=9090A3\r", GFP_ATOMIC);
 288                         if (!commands[AT_BC])
 289                                 goto oom;
 290                         break;
 291                 case 7:         /* data */
 292                 default:        /* hope the app knows what it is doing */
 293                         /* BC = 8890: unrestricted digital information */
 294                         commands[AT_BC] = kstrdup("^SBC=8890\r", GFP_ATOMIC);
 295                         if (!commands[AT_BC])
 296                                 goto oom;
 297                 }
 298                 /* ToDo: other si1 values, inspect si2, set HLC/LLC */
 299
 300                 commands[AT_PROTO] = kmalloc(9, GFP_ATOMIC);
 301                 if (!commands[AT_PROTO])
 302                         goto oom;
 303                 snprintf(commands[AT_PROTO], 9, "^SBPR=%u\r", bcs->proto2);
 304
 305                 commands[AT_ISO] = kmalloc(9, GFP_ATOMIC);
 306                 if (!commands[AT_ISO])
 307                         goto oom;
 308                 snprintf(commands[AT_ISO], 9, "^SISO=%u\r",
 309                          (unsigned) bcs->channel + 1);
 310
 311                 if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, commands,
 312                                        bcs->at_state.seq_index, NULL)) {
 313                         for (i = 0; i < AT_NUM; ++i)
 314                                 kfree(commands[i]);
 315                         kfree(commands);
 316                         gigaset_free_channel(bcs);
 317                         return -ENOMEM;
 318                 }
 319                 gigaset_schedule_event(cs);
 320                 break;
 321         case ISDN_CMD_ACCEPTD:
 322                 gig_dbg(DEBUG_CMD, "ISDN_CMD_ACCEPTD");
 323                 if (ch >= cs->channels) {
 324                         dev_err(cs->dev,
 325                                 "ISDN_CMD_ACCEPTD: invalid channel (%d)\n", ch);
 326                         return -EINVAL;
 327                 }
 328                 bcs = cs->bcs + ch;
 329                 switch (bcs->proto2) {
 330                 case L2_HDLC:
 331                         bcs->rx_bufsize = SBUFSIZE;
 332                         break;
 333                 default:                        /* assume transparent */
 334                         bcs->rx_bufsize = TRANSBUFSIZE;
 335                 }
 336                 dev_kfree_skb(bcs->rx_skb);
 337                 gigaset_new_rx_skb(bcs);
 338                 if (!gigaset_add_event(cs, &bcs->at_state,
 339                                        EV_ACCEPT, NULL, 0, NULL))
 340                         return -ENOMEM;
 341                 gigaset_schedule_event(cs);
 342
 343                 break;
 344         case ISDN_CMD_HANGUP:
 345                 gig_dbg(DEBUG_CMD, "ISDN_CMD_HANGUP");
 346                 if (ch >= cs->channels) {
 347                         dev_err(cs->dev,
 348                                 "ISDN_CMD_HANGUP: invalid channel (%d)\n", ch);
 349                         return -EINVAL;
 350                 }
 351                 bcs = cs->bcs + ch;
 352                 if (!gigaset_add_event(cs, &bcs->at_state,
 353                                        EV_HUP, NULL, 0, NULL))
 354                         return -ENOMEM;
 355                 gigaset_schedule_event(cs);
 356
 357                 break;
 358         case ISDN_CMD_CLREAZ: /* Do not signal incoming signals */
 359                 dev_info(cs->dev, "ignoring ISDN_CMD_CLREAZ\n");
 360                 break;
 361         case ISDN_CMD_SETEAZ: /* Signal incoming calls for given MSN */
 362                 dev_info(cs->dev, "ignoring ISDN_CMD_SETEAZ (%s)\n",
 363                          cntrl->parm.num);
 364                 break;
 365         case ISDN_CMD_SETL2: /* Set L2 to given protocol */
 366                 if (ch >= cs->channels) {
 367                         dev_err(cs->dev,
 368                                 "ISDN_CMD_SETL2: invalid channel (%d)\n", ch);
 369                         return -EINVAL;
 370                 }
 371                 bcs = cs->bcs + ch;
 372                 if (bcs->chstate & CHS_D_UP) {
 373                         dev_err(cs->dev,
 374                                 "ISDN_CMD_SETL2: channel active (%d)\n", ch);
 375                         return -EINVAL;
 376                 }
 377                 switch (cntrl->arg >> 8) {
 378                 case ISDN_PROTO_L2_HDLC:
 379                         gig_dbg(DEBUG_CMD, "ISDN_CMD_SETL2: setting L2_HDLC");
 380                         bcs->proto2 = L2_HDLC;
 381                         break;
 382                 case ISDN_PROTO_L2_TRANS:
 383                         gig_dbg(DEBUG_CMD, "ISDN_CMD_SETL2: setting L2_VOICE");
 384                         bcs->proto2 = L2_VOICE;
 385                         break;
 386                 default:
 387                         dev_err(cs->dev,
 388                                 "ISDN_CMD_SETL2: unsupported protocol (%lu)\n",
 389                                 cntrl->arg >> 8);
 390                         return -EINVAL;
 391                 }
 392                 break;
 393         case ISDN_CMD_SETL3: /* Set L3 to given protocol */
 394                 gig_dbg(DEBUG_CMD, "ISDN_CMD_SETL3");
 395                 if (ch >= cs->channels) {
 396                         dev_err(cs->dev,
 397                                 "ISDN_CMD_SETL3: invalid channel (%d)\n", ch);
 398                         return -EINVAL;
 399                 }
 400
 401                 if (cntrl->arg >> 8 != ISDN_PROTO_L3_TRANS) {
 402                         dev_err(cs->dev,
 403                                 "ISDN_CMD_SETL3: unsupported protocol (%lu)\n",
 404                                 cntrl->arg >> 8);
 405                         return -EINVAL;
 406                 }
 407
 408                 break;
 409
 410         default:
 411                 gig_dbg(DEBUG_CMD, "unknown command %d from LL",
 412                         cntrl->command);
 413                 return -EINVAL;
 414         }
 415
 416         return retval;
 417
 418 oom:
 419         dev_err(bcs->cs->dev, "out of memory\n");
 420         for (i = 0; i < AT_NUM; ++i)
 421                 kfree(commands[i]);
 422         kfree(commands);
 423         gigaset_free_channel(bcs);
 424         return -ENOMEM;
 425 }
 426
 427 static void gigaset_i4l_cmd(struct cardstate *cs, int cmd)
 428 {
 429         isdn_if *iif = cs->iif;
 430         isdn_ctrl command;
 431
 432         command.driver = cs->myid;
 433         command.command = cmd;
 434         command.arg = 0;
 435         iif->statcallb(&command);
 436 }
 437
 438 static void gigaset_i4l_channel_cmd(struct bc_state *bcs, int cmd)
 439 {
 440         isdn_if *iif = bcs->cs->iif;
 441         isdn_ctrl command;
 442
 443         command.driver = bcs->cs->myid;
 444         command.command = cmd;
 445         command.arg = bcs->channel;
 446         iif->statcallb(&command);
 447 }
 448
 449 /**
 450  * gigaset_isdn_icall() - signal incoming call
 451  * @at_state:   connection state structure.
 452  *
 453  * Called by main module to notify the LL that an incoming call has been
 454  * received. @at_state contains the parameters of the call.
 455  *
 456  * Return value: call disposition (ICALL_*)
 457  */
 458 int gigaset_isdn_icall(struct at_state_t *at_state)
 459 {
 460         struct cardstate *cs = at_state->cs;
 461         struct bc_state *bcs = at_state->bcs;
 462         isdn_if *iif = cs->iif;
 463         isdn_ctrl response;
 464         int retval;
 465
 466         /* fill ICALL structure */
 467         response.parm.setup.si1 = 0;    /* default: unknown */
 468         response.parm.setup.si2 = 0;
 469         response.parm.setup.screen = 0;
 470         response.parm.setup.plan = 0;
 471         if (!at_state->str_var[STR_ZBC]) {
 472                 /* no BC (internal call): assume speech, A-law */
 473                 response.parm.setup.si1 = 1;
 474         } else if (!strcmp(at_state->str_var[STR_ZBC], "8890")) {
 475                 /* unrestricted digital information */
 476                 response.parm.setup.si1 = 7;
 477         } else if (!strcmp(at_state->str_var[STR_ZBC], "8090A3")) {
 478                 /* speech, A-law */
 479                 response.parm.setup.si1 = 1;
 480         } else if (!strcmp(at_state->str_var[STR_ZBC], "9090A3")) {
 481                 /* 3,1 kHz audio, A-law */
 482                 response.parm.setup.si1 = 1;
 483                 response.parm.setup.si2 = 2;
 484         } else {
 485                 dev_warn(cs->dev, "RING ignored - unsupported BC %s\n",
 486                      at_state->str_var[STR_ZBC]);
 487                 return ICALL_IGNORE;
 488         }
 489         if (at_state->str_var[STR_NMBR]) {
 490                 strlcpy(response.parm.setup.phone, at_state->str_var[STR_NMBR],
 491                         sizeof response.parm.setup.phone);
 492         } else
 493                 response.parm.setup.phone[0] = 0;
 494         if (at_state->str_var[STR_ZCPN]) {
 495                 strlcpy(response.parm.setup.eazmsn, at_state->str_var[STR_ZCPN],
 496                         sizeof response.parm.setup.eazmsn);
 497         } else
 498                 response.parm.setup.eazmsn[0] = 0;
 499
 500         if (!bcs) {
 501                 dev_notice(cs->dev, "no channel for incoming call\n");
 502                 response.command = ISDN_STAT_ICALLW;
 503                 response.arg = 0;
 504         } else {
 505                 gig_dbg(DEBUG_CMD, "Sending ICALL");
 506                 response.command = ISDN_STAT_ICALL;
 507                 response.arg = bcs->channel;
 508         }
 509         response.driver = cs->myid;
 510         retval = iif->statcallb(&response);
 511         gig_dbg(DEBUG_CMD, "Response: %d", retval);
 512         switch (retval) {
 513         case 0: /* no takers */
 514                 return ICALL_IGNORE;
 515         case 1: /* alerting */
 516                 bcs->chstate |= CHS_NOTIFY_LL;
 517                 return ICALL_ACCEPT;
 518         case 2: /* reject */
 519                 return ICALL_REJECT;
 520         case 3: /* incomplete */
 521                 dev_warn(cs->dev,
 522                        "LL requested unsupported feature: Incomplete Number\n");
 523                 return ICALL_IGNORE;
 524         case 4: /* proceeding */
 525                 /* Gigaset will send ALERTING anyway.
 526                  * There doesn't seem to be a way to avoid this.
 527                  */
 528                 return ICALL_ACCEPT;
 529         case 5: /* deflect */
 530                 dev_warn(cs->dev,
 531                          "LL requested unsupported feature: Call Deflection\n");
 532                 return ICALL_IGNORE;
 533         default:
 534                 dev_err(cs->dev, "LL error %d on ICALL\n", retval);
 535                 return ICALL_IGNORE;
 536         }
 537 }
 538
 539 /**
 540  * gigaset_isdn_connD() - signal D channel connect
 541  * @bcs:        B channel descriptor structure.
 542  *
 543  * Called by main module to notify the LL that the D channel connection has
 544  * been established.
 545  */
 546 void gigaset_isdn_connD(struct bc_state *bcs)
 547 {
 548         gig_dbg(DEBUG_CMD, "sending DCONN");
 549         gigaset_i4l_channel_cmd(bcs, ISDN_STAT_DCONN);
 550 }
 551
 552 /**
 553  * gigaset_isdn_hupD() - signal D channel hangup
 554  * @bcs:        B channel descriptor structure.
 555  *
 556  * Called by main module to notify the LL that the D channel connection has
 557  * been shut down.
 558  */
 559 void gigaset_isdn_hupD(struct bc_state *bcs)
 560 {
 561         gig_dbg(DEBUG_CMD, "sending DHUP");
 562         gigaset_i4l_channel_cmd(bcs, ISDN_STAT_DHUP);
 563 }
 564
 565 /**
 566  * gigaset_isdn_connB() - signal B channel connect
 567  * @bcs:        B channel descriptor structure.
 568  *
 569  * Called by main module to notify the LL that the B channel connection has
 570  * been established.
 571  */
 572 void gigaset_isdn_connB(struct bc_state *bcs)
 573 {
 574         gig_dbg(DEBUG_CMD, "sending BCONN");
 575         gigaset_i4l_channel_cmd(bcs, ISDN_STAT_BCONN);
 576 }
 577
 578 /**
 579  * gigaset_isdn_hupB() - signal B channel hangup
 580  * @bcs:        B channel descriptor structure.
 581  *
 582  * Called by main module to notify the LL that the B channel connection has
 583  * been shut down.
 584  */
 585 void gigaset_isdn_hupB(struct bc_state *bcs)
 586 {
 587         gig_dbg(DEBUG_CMD, "sending BHUP");
 588         gigaset_i4l_channel_cmd(bcs, ISDN_STAT_BHUP);
 589 }
 590
 591 /**
 592  * gigaset_isdn_start() - signal device availability
 593  * @cs:         device descriptor structure.
 594  *
 595  * Called by main module to notify the LL that the device is available for
 596  * use.
 597  */
 598 void gigaset_isdn_start(struct cardstate *cs)
 599 {
 600         gig_dbg(DEBUG_CMD, "sending RUN");
 601         gigaset_i4l_cmd(cs, ISDN_STAT_RUN);
 602 }
 603
 604 /**
 605  * gigaset_isdn_stop() - signal device unavailability
 606  * @cs:         device descriptor structure.
 607  *
 608  * Called by main module to notify the LL that the device is no longer
 609  * available for use.
 610  */
 611 void gigaset_isdn_stop(struct cardstate *cs)
 612 {
 613         gig_dbg(DEBUG_CMD, "sending STOP");
 614         gigaset_i4l_cmd(cs, ISDN_STAT_STOP);
 615 }
 616
 617 /**
 618  * gigaset_isdn_regdev() - register to LL
 619  * @cs:         device descriptor structure.
 620  * @isdnid:     device name.
 621  *
 622  * Return value: 1 for success, 0 for failure
 623  */
 624 int gigaset_isdn_regdev(struct cardstate *cs, const char *isdnid)
 625 {
 626         isdn_if *iif;
 627
 628         pr_info("ISDN4Linux interface\n");
 629
 630         iif = kmalloc(sizeof *iif, GFP_KERNEL);
 631         if (!iif) {
 632                 pr_err("out of memory\n");
 633                 return 0;
 634         }
 635
 636         if (snprintf(iif->id, sizeof iif->id, "%s_%u", isdnid, cs->minor_index)
 637             >= sizeof iif->id) {
 638                 pr_err("ID too long: %s\n", isdnid);
 639                 kfree(iif);
 640                 return 0;
 641         }
 642
 643         iif->owner = THIS_MODULE;
 644         iif->channels = cs->channels;
 645         iif->maxbufsize = MAX_BUF_SIZE;
 646         iif->features = ISDN_FEATURE_L2_TRANS |
 647                 ISDN_FEATURE_L2_HDLC |
 648                 ISDN_FEATURE_L2_X75I |
 649                 ISDN_FEATURE_L3_TRANS |
 650                 ISDN_FEATURE_P_EURO;
 651         iif->hl_hdrlen = HW_HDR_LEN;            /* Area for storing ack */
 652         iif->command = command_from_LL;
 653         iif->writebuf_skb = writebuf_from_LL;
 654         iif->writecmd = NULL;                   /* Don't support isdnctrl */
 655         iif->readstat = NULL;                   /* Don't support isdnctrl */
 656         iif->rcvcallb_skb = NULL;               /* Will be set by LL */
 657         iif->statcallb = NULL;                  /* Will be set by LL */
 658
 659         if (!register_isdn(iif)) {
 660                 pr_err("register_isdn failed\n");
 661                 kfree(iif);
 662                 return 0;
 663         }
 664
 665         cs->iif = iif;
 666         cs->myid = iif->channels;               /* Set my device id */
 667         cs->hw_hdr_len = HW_HDR_LEN;
 668         return 1;
 669 }
 670
 671 /**
 672  * gigaset_isdn_unregdev() - unregister device from LL
 673  * @cs:         device descriptor structure.
 674  */
 675 void gigaset_isdn_unregdev(struct cardstate *cs)
 676 {
 677         gig_dbg(DEBUG_CMD, "sending UNLOAD");
 678         gigaset_i4l_cmd(cs, ISDN_STAT_UNLOAD);
 679         kfree(cs->iif);
 680         cs->iif = NULL;
 681 }
 682
 683 /**
 684  * gigaset_isdn_regdrv() - register driver to LL
 685  */
 686 void gigaset_isdn_regdrv(void)
 687 {
 688         /* nothing to do */
 689 }
 690
 691 /**
 692  * gigaset_isdn_unregdrv() - unregister driver from LL
 693  */
 694 void gigaset_isdn_unregdrv(void)
 695 {
 696         /* nothing to do */
 697 }