drivers/isdn/gigaset/interface.c

   1 /*
   2  * interface to user space for the gigaset driver
   3  *
   4  * Copyright (c) 2004 by Hansjoerg Lipp <hjlipp@web.de>
   5  *
   6  * =====================================================================
   7  *    This program is free software; you can redistribute it and/or
   8  *    modify it under the terms of the GNU General Public License as
   9  *    published by the Free Software Foundation; either version 2 of
  10  *    the License, or (at your option) any later version.
  11  * =====================================================================
  12  */
  13
  14 #include "gigaset.h"
  15 #include <linux/gigaset_dev.h>
  16 #include <linux/tty_flip.h>
  17
  18 /*** our ioctls ***/
  19
  20 static int if_lock(struct cardstate *cs, int *arg)
  21 {
  22         int cmd = *arg;
  23
  24         gig_dbg(DEBUG_IF, "%u: if_lock (%d)", cs->minor_index, cmd);
  25
  26         if (cmd > 1)
  27                 return -EINVAL;
  28
  29         if (cmd < 0) {
  30                 *arg = cs->mstate == MS_LOCKED;
  31                 return 0;
  32         }
  33
  34         if (!cmd && cs->mstate == MS_LOCKED && cs->connected) {
  35                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
  36                 cs->ops->baud_rate(cs, B115200);
  37                 cs->ops->set_line_ctrl(cs, CS8);
  38                 cs->control_state = TIOCM_DTR|TIOCM_RTS;
  39         }
  40
  41         cs->waiting = 1;
  42         if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
  43                                NULL, cmd, NULL)) {
  44                 cs->waiting = 0;
  45                 return -ENOMEM;
  46         }
  47         gigaset_schedule_event(cs);
  48
  49         wait_event(cs->waitqueue, !cs->waiting);
  50
  51         if (cs->cmd_result >= 0) {
  52                 *arg = cs->cmd_result;
  53                 return 0;
  54         }
  55
  56         return cs->cmd_result;
  57 }
  58
  59 static int if_version(struct cardstate *cs, unsigned arg[4])
  60 {
  61         static const unsigned version[4] = GIG_VERSION;
  62         static const unsigned compat[4] = GIG_COMPAT;
  63         unsigned cmd = arg[0];
  64
  65         gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
  66
  67         switch (cmd) {
  68         case GIGVER_DRIVER:
  69                 memcpy(arg, version, sizeof version);
  70                 return 0;
  71         case GIGVER_COMPAT:
  72                 memcpy(arg, compat, sizeof compat);
  73                 return 0;
  74         case GIGVER_FWBASE:
  75                 cs->waiting = 1;
  76                 if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
  77                                        NULL, 0, arg)) {
  78                         cs->waiting = 0;
  79                         return -ENOMEM;
  80                 }
  81                 gigaset_schedule_event(cs);
  82
  83                 wait_event(cs->waitqueue, !cs->waiting);
  84
  85                 if (cs->cmd_result >= 0)
  86                         return 0;
  87
  88                 return cs->cmd_result;
  89         default:
  90                 return -EINVAL;
  91         }
  92 }
  93
  94 static int if_config(struct cardstate *cs, int *arg)
  95 {
  96         gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
  97
  98         if (*arg != 1)
  99                 return -EINVAL;
 100
 101         if (cs->mstate != MS_LOCKED)
 102                 return -EBUSY;
 103
 104         if (!cs->connected) {
 105                 pr_err("%s: not connected\n", __func__);
 106                 return -ENODEV;
 107         }
 108
 109         *arg = 0;
 110         return gigaset_enterconfigmode(cs);
 111 }
 112
 113 /*** the terminal driver ***/
 114 /* stolen from usbserial and some other tty drivers */
 115
 116 static int  if_open(struct tty_struct *tty, struct file *filp);
 117 static void if_close(struct tty_struct *tty, struct file *filp);
 118 static int  if_ioctl(struct tty_struct *tty,
 119                      unsigned int cmd, unsigned long arg);
 120 static int  if_write_room(struct tty_struct *tty);
 121 static int  if_chars_in_buffer(struct tty_struct *tty);
 122 static void if_throttle(struct tty_struct *tty);
 123 static void if_unthrottle(struct tty_struct *tty);
 124 static void if_set_termios(struct tty_struct *tty, struct ktermios *old);
 125 static int  if_tiocmget(struct tty_struct *tty);
 126 static int  if_tiocmset(struct tty_struct *tty,
 127                         unsigned int set, unsigned int clear);
 128 static int  if_write(struct tty_struct *tty,
 129                      const unsigned char *buf, int count);
 130
 131 static const struct tty_operations if_ops = {
 132         .open =                 if_open,
 133         .close =                if_close,
 134         .ioctl =                if_ioctl,
 135         .write =                if_write,
 136         .write_room =           if_write_room,
 137         .chars_in_buffer =      if_chars_in_buffer,
 138         .set_termios =          if_set_termios,
 139         .throttle =             if_throttle,
 140         .unthrottle =           if_unthrottle,
 141         .tiocmget =             if_tiocmget,
 142         .tiocmset =             if_tiocmset,
 143 };
 144
 145 static int if_open(struct tty_struct *tty, struct file *filp)
 146 {
 147         struct cardstate *cs;
 148         unsigned long flags;
 149
 150         gig_dbg(DEBUG_IF, "%d+%d: %s()",
 151                 tty->driver->minor_start, tty->index, __func__);
 152
 153         tty->driver_data = NULL;
 154
 155         cs = gigaset_get_cs_by_tty(tty);
 156         if (!cs || !try_module_get(cs->driver->owner))
 157                 return -ENODEV;
 158
 159         if (mutex_lock_interruptible(&cs->mutex)) {
 160                 module_put(cs->driver->owner);
 161                 return -ERESTARTSYS;
 162         }
 163         tty->driver_data = cs;
 164
 165         ++cs->open_count;
 166
 167         if (cs->open_count == 1) {
 168                 spin_lock_irqsave(&cs->lock, flags);
 169                 cs->tty = tty;
 170                 spin_unlock_irqrestore(&cs->lock, flags);
 171                 tty->low_latency = 1;
 172         }
 173
 174         mutex_unlock(&cs->mutex);
 175         return 0;
 176 }
 177
 178 static void if_close(struct tty_struct *tty, struct file *filp)
 179 {
 180         struct cardstate *cs;
 181         unsigned long flags;
 182
 183         cs = (struct cardstate *) tty->driver_data;
 184         if (!cs) {
 185                 pr_err("%s: no cardstate\n", __func__);
 186                 return;
 187         }
 188
 189         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 190
 191         mutex_lock(&cs->mutex);
 192
 193         if (!cs->connected)
 194                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 195         else if (!cs->open_count)
 196                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 197         else {
 198                 if (!--cs->open_count) {
 199                         spin_lock_irqsave(&cs->lock, flags);
 200                         cs->tty = NULL;
 201                         spin_unlock_irqrestore(&cs->lock, flags);
 202                 }
 203         }
 204
 205         mutex_unlock(&cs->mutex);
 206
 207         module_put(cs->driver->owner);
 208 }
 209
 210 static int if_ioctl(struct tty_struct *tty,
 211                     unsigned int cmd, unsigned long arg)
 212 {
 213         struct cardstate *cs;
 214         int retval = -ENODEV;
 215         int int_arg;
 216         unsigned char buf[6];
 217         unsigned version[4];
 218
 219         cs = (struct cardstate *) tty->driver_data;
 220         if (!cs) {
 221                 pr_err("%s: no cardstate\n", __func__);
 222                 return -ENODEV;
 223         }
 224
 225         gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 226
 227         if (mutex_lock_interruptible(&cs->mutex))
 228                 return -ERESTARTSYS;
 229
 230         if (!cs->connected) {
 231                 gig_dbg(DEBUG_IF, "not connected");
 232                 retval = -ENODEV;
 233         } else if (!cs->open_count)
 234                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 235         else {
 236                 retval = 0;
 237                 switch (cmd) {
 238                 case GIGASET_REDIR:
 239                         retval = get_user(int_arg, (int __user *) arg);
 240                         if (retval >= 0)
 241                                 retval = if_lock(cs, &int_arg);
 242                         if (retval >= 0)
 243                                 retval = put_user(int_arg, (int __user *) arg);
 244                         break;
 245                 case GIGASET_CONFIG:
 246                         retval = get_user(int_arg, (int __user *) arg);
 247                         if (retval >= 0)
 248                                 retval = if_config(cs, &int_arg);
 249                         if (retval >= 0)
 250                                 retval = put_user(int_arg, (int __user *) arg);
 251                         break;
 252                 case GIGASET_BRKCHARS:
 253                         retval = copy_from_user(&buf,
 254                                         (const unsigned char __user *) arg, 6)
 255                                 ? -EFAULT : 0;
 256                         if (retval >= 0) {
 257                                 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
 258                                                 6, (const unsigned char *) arg);
 259                                 retval = cs->ops->brkchars(cs, buf);
 260                         }
 261                         break;
 262                 case GIGASET_VERSION:
 263                         retval = copy_from_user(version,
 264                                         (unsigned __user *) arg, sizeof version)
 265                                 ? -EFAULT : 0;
 266                         if (retval >= 0)
 267                                 retval = if_version(cs, version);
 268                         if (retval >= 0)
 269                                 retval = copy_to_user((unsigned __user *) arg,
 270                                                       version, sizeof version)
 271                                         ? -EFAULT : 0;
 272                         break;
 273                 default:
 274                         gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
 275                                 __func__, cmd);
 276                         retval = -ENOIOCTLCMD;
 277                 }
 278         }
 279
 280         mutex_unlock(&cs->mutex);
 281
 282         return retval;
 283 }
 284
 285 static int if_tiocmget(struct tty_struct *tty)
 286 {
 287         struct cardstate *cs;
 288         int retval;
 289
 290         cs = (struct cardstate *) tty->driver_data;
 291         if (!cs) {
 292                 pr_err("%s: no cardstate\n", __func__);
 293                 return -ENODEV;
 294         }
 295
 296         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 297
 298         if (mutex_lock_interruptible(&cs->mutex))
 299                 return -ERESTARTSYS;
 300
 301         retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
 302
 303         mutex_unlock(&cs->mutex);
 304
 305         return retval;
 306 }
 307
 308 static int if_tiocmset(struct tty_struct *tty,
 309                        unsigned int set, unsigned int clear)
 310 {
 311         struct cardstate *cs;
 312         int retval;
 313         unsigned mc;
 314
 315         cs = (struct cardstate *) tty->driver_data;
 316         if (!cs) {
 317                 pr_err("%s: no cardstate\n", __func__);
 318                 return -ENODEV;
 319         }
 320
 321         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 322                 cs->minor_index, __func__, set, clear);
 323
 324         if (mutex_lock_interruptible(&cs->mutex))
 325                 return -ERESTARTSYS;
 326
 327         if (!cs->connected) {
 328                 gig_dbg(DEBUG_IF, "not connected");
 329                 retval = -ENODEV;
 330         } else {
 331                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
 332                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 333                 cs->control_state = mc;
 334         }
 335
 336         mutex_unlock(&cs->mutex);
 337
 338         return retval;
 339 }
 340
 341 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 342 {
 343         struct cardstate *cs;
 344         struct cmdbuf_t *cb;
 345         int retval;
 346
 347         cs = (struct cardstate *) tty->driver_data;
 348         if (!cs) {
 349                 pr_err("%s: no cardstate\n", __func__);
 350                 return -ENODEV;
 351         }
 352
 353         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 354
 355         if (mutex_lock_interruptible(&cs->mutex))
 356                 return -ERESTARTSYS;
 357
 358         if (!cs->connected) {
 359                 gig_dbg(DEBUG_IF, "not connected");
 360                 retval = -ENODEV;
 361                 goto done;
 362         }
 363         if (!cs->open_count) {
 364                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 365                 retval = -ENODEV;
 366                 goto done;
 367         }
 368         if (cs->mstate != MS_LOCKED) {
 369                 dev_warn(cs->dev, "can't write to unlocked device\n");
 370                 retval = -EBUSY;
 371                 goto done;
 372         }
 373         if (count <= 0) {
 374                 /* nothing to do */
 375                 retval = 0;
 376                 goto done;
 377         }
 378
 379         cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
 380         if (!cb) {
 381                 dev_err(cs->dev, "%s: out of memory\n", __func__);
 382                 retval = -ENOMEM;
 383                 goto done;
 384         }
 385
 386         memcpy(cb->buf, buf, count);
 387         cb->len = count;
 388         cb->offset = 0;
 389         cb->next = NULL;
 390         cb->wake_tasklet = &cs->if_wake_tasklet;
 391         retval = cs->ops->write_cmd(cs, cb);
 392 done:
 393         mutex_unlock(&cs->mutex);
 394         return retval;
 395 }
 396
 397 static int if_write_room(struct tty_struct *tty)
 398 {
 399         struct cardstate *cs;
 400         int retval = -ENODEV;
 401
 402         cs = (struct cardstate *) tty->driver_data;
 403         if (!cs) {
 404                 pr_err("%s: no cardstate\n", __func__);
 405                 return -ENODEV;
 406         }
 407
 408         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 409
 410         if (mutex_lock_interruptible(&cs->mutex))
 411                 return -ERESTARTSYS;
 412
 413         if (!cs->connected) {
 414                 gig_dbg(DEBUG_IF, "not connected");
 415                 retval = -ENODEV;
 416         } else if (!cs->open_count)
 417                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 418         else if (cs->mstate != MS_LOCKED) {
 419                 dev_warn(cs->dev, "can't write to unlocked device\n");
 420                 retval = -EBUSY;
 421         } else
 422                 retval = cs->ops->write_room(cs);
 423
 424         mutex_unlock(&cs->mutex);
 425
 426         return retval;
 427 }
 428
 429 static int if_chars_in_buffer(struct tty_struct *tty)
 430 {
 431         struct cardstate *cs;
 432         int retval = 0;
 433
 434         cs = (struct cardstate *) tty->driver_data;
 435         if (!cs) {
 436                 pr_err("%s: no cardstate\n", __func__);
 437                 return 0;
 438         }
 439
 440         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 441
 442         mutex_lock(&cs->mutex);
 443
 444         if (!cs->connected)
 445                 gig_dbg(DEBUG_IF, "not connected");
 446         else if (!cs->open_count)
 447                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 448         else if (cs->mstate != MS_LOCKED)
 449                 dev_warn(cs->dev, "can't write to unlocked device\n");
 450         else
 451                 retval = cs->ops->chars_in_buffer(cs);
 452
 453         mutex_unlock(&cs->mutex);
 454
 455         return retval;
 456 }
 457
 458 static void if_throttle(struct tty_struct *tty)
 459 {
 460         struct cardstate *cs;
 461
 462         cs = (struct cardstate *) tty->driver_data;
 463         if (!cs) {
 464                 pr_err("%s: no cardstate\n", __func__);
 465                 return;
 466         }
 467
 468         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 469
 470         mutex_lock(&cs->mutex);
 471
 472         if (!cs->connected)
 473                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 474         else if (!cs->open_count)
 475                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 476         else
 477                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 478
 479         mutex_unlock(&cs->mutex);
 480 }
 481
 482 static void if_unthrottle(struct tty_struct *tty)
 483 {
 484         struct cardstate *cs;
 485
 486         cs = (struct cardstate *) tty->driver_data;
 487         if (!cs) {
 488                 pr_err("%s: no cardstate\n", __func__);
 489                 return;
 490         }
 491
 492         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 493
 494         mutex_lock(&cs->mutex);
 495
 496         if (!cs->connected)
 497                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 498         else if (!cs->open_count)
 499                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 500         else
 501                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 502
 503         mutex_unlock(&cs->mutex);
 504 }
 505
 506 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
 507 {
 508         struct cardstate *cs;
 509         unsigned int iflag;
 510         unsigned int cflag;
 511         unsigned int old_cflag;
 512         unsigned int control_state, new_state;
 513
 514         cs = (struct cardstate *) tty->driver_data;
 515         if (!cs) {
 516                 pr_err("%s: no cardstate\n", __func__);
 517                 return;
 518         }
 519
 520         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 521
 522         mutex_lock(&cs->mutex);
 523
 524         if (!cs->connected) {
 525                 gig_dbg(DEBUG_IF, "not connected");
 526                 goto out;
 527         }
 528
 529         if (!cs->open_count) {
 530                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 531                 goto out;
 532         }
 533
 534         iflag = tty->termios->c_iflag;
 535         cflag = tty->termios->c_cflag;
 536         old_cflag = old ? old->c_cflag : cflag;
 537         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 538                 cs->minor_index, iflag, cflag, old_cflag);
 539
 540         /* get a local copy of the current port settings */
 541         control_state = cs->control_state;
 542
 543         /*
 544          * Update baud rate.
 545          * Do not attempt to cache old rates and skip settings,
 546          * disconnects screw such tricks up completely.
 547          * Premature optimization is the root of all evil.
 548          */
 549
 550         /* reassert DTR and (maybe) RTS on transition from B0 */
 551         if ((old_cflag & CBAUD) == B0) {
 552                 new_state = control_state | TIOCM_DTR;
 553                 /* don't set RTS if using hardware flow control */
 554                 if (!(old_cflag & CRTSCTS))
 555                         new_state |= TIOCM_RTS;
 556                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 557                         cs->minor_index,
 558                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 559                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 560                 control_state = new_state;
 561         }
 562
 563         cs->ops->baud_rate(cs, cflag & CBAUD);
 564
 565         if ((cflag & CBAUD) == B0) {
 566                 /* Drop RTS and DTR */
 567                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 568                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 569                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 570                 control_state = new_state;
 571         }
 572
 573         /*
 574          * Update line control register (LCR)
 575          */
 576
 577         cs->ops->set_line_ctrl(cs, cflag);
 578
 579         /* save off the modified port settings */
 580         cs->control_state = control_state;
 581
 582 out:
 583         mutex_unlock(&cs->mutex);
 584 }
 585
 586
 587 /* wakeup tasklet for the write operation */
 588 static void if_wake(unsigned long data)
 589 {
 590         struct cardstate *cs = (struct cardstate *) data;
 591
 592         if (cs->tty)
 593                 tty_wakeup(cs->tty);
 594 }
 595
 596 /*** interface to common ***/
 597
 598 void gigaset_if_init(struct cardstate *cs)
 599 {
 600         struct gigaset_driver *drv;
 601
 602         drv = cs->driver;
 603         if (!drv->have_tty)
 604                 return;
 605
 606         tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
 607
 608         mutex_lock(&cs->mutex);
 609         cs->tty_dev = tty_register_device(drv->tty, cs->minor_index, NULL);
 610
 611         if (!IS_ERR(cs->tty_dev))
 612                 dev_set_drvdata(cs->tty_dev, cs);
 613         else {
 614                 pr_warning("could not register device to the tty subsystem\n");
 615                 cs->tty_dev = NULL;
 616         }
 617         mutex_unlock(&cs->mutex);
 618 }
 619
 620 void gigaset_if_free(struct cardstate *cs)
 621 {
 622         struct gigaset_driver *drv;
 623
 624         drv = cs->driver;
 625         if (!drv->have_tty)
 626                 return;
 627
 628         tasklet_disable(&cs->if_wake_tasklet);
 629         tasklet_kill(&cs->if_wake_tasklet);
 630         cs->tty_dev = NULL;
 631         tty_unregister_device(drv->tty, cs->minor_index);
 632 }
 633
 634 /**
 635  * gigaset_if_receive() - pass a received block of data to the tty device
 636  * @cs:         device descriptor structure.
 637  * @buffer:     received data.
 638  * @len:        number of bytes received.
 639  *
 640  * Called by asyncdata/isocdata if a block of data received from the
 641  * device must be sent to userspace through the ttyG* device.
 642  */
 643 void gigaset_if_receive(struct cardstate *cs,
 644                         unsigned char *buffer, size_t len)
 645 {
 646         unsigned long flags;
 647         struct tty_struct *tty;
 648
 649         spin_lock_irqsave(&cs->lock, flags);
 650         tty = cs->tty;
 651         if (tty == NULL)
 652                 gig_dbg(DEBUG_IF, "receive on closed device");
 653         else {
 654                 tty_insert_flip_string(tty, buffer, len);
 655                 tty_flip_buffer_push(tty);
 656         }
 657         spin_unlock_irqrestore(&cs->lock, flags);
 658 }
 659 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 660
 661 /* gigaset_if_initdriver
 662  * Initialize tty interface.
 663  * parameters:
 664  *      drv             Driver
 665  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 666  *      devname         Name of the device files (prefix without minor number)
 667  */
 668 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 669                            const char *devname)
 670 {
 671         unsigned minors = drv->minors;
 672         int ret;
 673         struct tty_driver *tty;
 674
 675         drv->have_tty = 0;
 676
 677         drv->tty = tty = alloc_tty_driver(minors);
 678         if (tty == NULL)
 679                 goto enomem;
 680
 681         tty->magic =            TTY_DRIVER_MAGIC,
 682         tty->type =             TTY_DRIVER_TYPE_SERIAL,
 683         tty->subtype =          SERIAL_TYPE_NORMAL,
 684         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 685
 686         tty->driver_name =      procname;
 687         tty->name =             devname;
 688         tty->minor_start =      drv->minor;
 689         tty->num =              drv->minors;
 690
 691         tty->owner =            THIS_MODULE;
 692
 693         tty->init_termios          = tty_std_termios;
 694         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 695         tty_set_operations(tty, &if_ops);
 696
 697         ret = tty_register_driver(tty);
 698         if (ret < 0) {
 699                 pr_err("error %d registering tty driver\n", ret);
 700                 goto error;
 701         }
 702         gig_dbg(DEBUG_IF, "tty driver initialized");
 703         drv->have_tty = 1;
 704         return;
 705
 706 enomem:
 707         pr_err("out of memory\n");
 708 error:
 709         if (drv->tty)
 710                 put_tty_driver(drv->tty);
 711 }
 712
 713 void gigaset_if_freedriver(struct gigaset_driver *drv)
 714 {
 715         if (!drv->have_tty)
 716                 return;
 717
 718         drv->have_tty = 0;
 719         tty_unregister_driver(drv->tty);
 720         put_tty_driver(drv->tty);
 721 }