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