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                 return -ERESTARTSYS;
 161         tty->driver_data = cs;
 162
 163         ++cs->open_count;
 164
 165         if (cs->open_count == 1) {
 166                 spin_lock_irqsave(&cs->lock, flags);
 167                 cs->tty = tty;
 168                 spin_unlock_irqrestore(&cs->lock, flags);
 169                 tty->low_latency = 1;
 170         }
 171
 172         mutex_unlock(&cs->mutex);
 173         return 0;
 174 }
 175
 176 static void if_close(struct tty_struct *tty, struct file *filp)
 177 {
 178         struct cardstate *cs;
 179         unsigned long flags;
 180
 181         cs = (struct cardstate *) tty->driver_data;
 182         if (!cs) {
 183                 pr_err("%s: no cardstate\n", __func__);
 184                 return;
 185         }
 186
 187         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 188
 189         mutex_lock(&cs->mutex);
 190
 191         if (!cs->connected)
 192                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 193         else if (!cs->open_count)
 194                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 195         else {
 196                 if (!--cs->open_count) {
 197                         spin_lock_irqsave(&cs->lock, flags);
 198                         cs->tty = NULL;
 199                         spin_unlock_irqrestore(&cs->lock, flags);
 200                 }
 201         }
 202
 203         mutex_unlock(&cs->mutex);
 204
 205         module_put(cs->driver->owner);
 206 }
 207
 208 static int if_ioctl(struct tty_struct *tty,
 209                     unsigned int cmd, unsigned long arg)
 210 {
 211         struct cardstate *cs;
 212         int retval = -ENODEV;
 213         int int_arg;
 214         unsigned char buf[6];
 215         unsigned version[4];
 216
 217         cs = (struct cardstate *) tty->driver_data;
 218         if (!cs) {
 219                 pr_err("%s: no cardstate\n", __func__);
 220                 return -ENODEV;
 221         }
 222
 223         gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 224
 225         if (mutex_lock_interruptible(&cs->mutex))
 226                 return -ERESTARTSYS;
 227
 228         if (!cs->connected) {
 229                 gig_dbg(DEBUG_IF, "not connected");
 230                 retval = -ENODEV;
 231         } else if (!cs->open_count)
 232                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 233         else {
 234                 retval = 0;
 235                 switch (cmd) {
 236                 case GIGASET_REDIR:
 237                         retval = get_user(int_arg, (int __user *) arg);
 238                         if (retval >= 0)
 239                                 retval = if_lock(cs, &int_arg);
 240                         if (retval >= 0)
 241                                 retval = put_user(int_arg, (int __user *) arg);
 242                         break;
 243                 case GIGASET_CONFIG:
 244                         retval = get_user(int_arg, (int __user *) arg);
 245                         if (retval >= 0)
 246                                 retval = if_config(cs, &int_arg);
 247                         if (retval >= 0)
 248                                 retval = put_user(int_arg, (int __user *) arg);
 249                         break;
 250                 case GIGASET_BRKCHARS:
 251                         retval = copy_from_user(&buf,
 252                                         (const unsigned char __user *) arg, 6)
 253                                 ? -EFAULT : 0;
 254                         if (retval >= 0) {
 255                                 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
 256                                                 6, (const unsigned char *) arg);
 257                                 retval = cs->ops->brkchars(cs, buf);
 258                         }
 259                         break;
 260                 case GIGASET_VERSION:
 261                         retval = copy_from_user(version,
 262                                         (unsigned __user *) arg, sizeof version)
 263                                 ? -EFAULT : 0;
 264                         if (retval >= 0)
 265                                 retval = if_version(cs, version);
 266                         if (retval >= 0)
 267                                 retval = copy_to_user((unsigned __user *) arg,
 268                                                       version, sizeof version)
 269                                         ? -EFAULT : 0;
 270                         break;
 271                 default:
 272                         gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
 273                                 __func__, cmd);
 274                         retval = -ENOIOCTLCMD;
 275                 }
 276         }
 277
 278         mutex_unlock(&cs->mutex);
 279
 280         return retval;
 281 }
 282
 283 static int if_tiocmget(struct tty_struct *tty)
 284 {
 285         struct cardstate *cs;
 286         int retval;
 287
 288         cs = (struct cardstate *) tty->driver_data;
 289         if (!cs) {
 290                 pr_err("%s: no cardstate\n", __func__);
 291                 return -ENODEV;
 292         }
 293
 294         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 295
 296         if (mutex_lock_interruptible(&cs->mutex))
 297                 return -ERESTARTSYS;
 298
 299         retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
 300
 301         mutex_unlock(&cs->mutex);
 302
 303         return retval;
 304 }
 305
 306 static int if_tiocmset(struct tty_struct *tty,
 307                        unsigned int set, unsigned int clear)
 308 {
 309         struct cardstate *cs;
 310         int retval;
 311         unsigned mc;
 312
 313         cs = (struct cardstate *) tty->driver_data;
 314         if (!cs) {
 315                 pr_err("%s: no cardstate\n", __func__);
 316                 return -ENODEV;
 317         }
 318
 319         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 320                 cs->minor_index, __func__, set, clear);
 321
 322         if (mutex_lock_interruptible(&cs->mutex))
 323                 return -ERESTARTSYS;
 324
 325         if (!cs->connected) {
 326                 gig_dbg(DEBUG_IF, "not connected");
 327                 retval = -ENODEV;
 328         } else {
 329                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
 330                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 331                 cs->control_state = mc;
 332         }
 333
 334         mutex_unlock(&cs->mutex);
 335
 336         return retval;
 337 }
 338
 339 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 340 {
 341         struct cardstate *cs;
 342         struct cmdbuf_t *cb;
 343         int retval;
 344
 345         cs = (struct cardstate *) tty->driver_data;
 346         if (!cs) {
 347                 pr_err("%s: no cardstate\n", __func__);
 348                 return -ENODEV;
 349         }
 350
 351         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 352
 353         if (mutex_lock_interruptible(&cs->mutex))
 354                 return -ERESTARTSYS;
 355
 356         if (!cs->connected) {
 357                 gig_dbg(DEBUG_IF, "not connected");
 358                 retval = -ENODEV;
 359                 goto done;
 360         }
 361         if (!cs->open_count) {
 362                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 363                 retval = -ENODEV;
 364                 goto done;
 365         }
 366         if (cs->mstate != MS_LOCKED) {
 367                 dev_warn(cs->dev, "can't write to unlocked device\n");
 368                 retval = -EBUSY;
 369                 goto done;
 370         }
 371         if (count <= 0) {
 372                 /* nothing to do */
 373                 retval = 0;
 374                 goto done;
 375         }
 376
 377         cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
 378         if (!cb) {
 379                 dev_err(cs->dev, "%s: out of memory\n", __func__);
 380                 retval = -ENOMEM;
 381                 goto done;
 382         }
 383
 384         memcpy(cb->buf, buf, count);
 385         cb->len = count;
 386         cb->offset = 0;
 387         cb->next = NULL;
 388         cb->wake_tasklet = &cs->if_wake_tasklet;
 389         retval = cs->ops->write_cmd(cs, cb);
 390 done:
 391         mutex_unlock(&cs->mutex);
 392         return retval;
 393 }
 394
 395 static int if_write_room(struct tty_struct *tty)
 396 {
 397         struct cardstate *cs;
 398         int retval = -ENODEV;
 399
 400         cs = (struct cardstate *) tty->driver_data;
 401         if (!cs) {
 402                 pr_err("%s: no cardstate\n", __func__);
 403                 return -ENODEV;
 404         }
 405
 406         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 407
 408         if (mutex_lock_interruptible(&cs->mutex))
 409                 return -ERESTARTSYS;
 410
 411         if (!cs->connected) {
 412                 gig_dbg(DEBUG_IF, "not connected");
 413                 retval = -ENODEV;
 414         } else if (!cs->open_count)
 415                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 416         else if (cs->mstate != MS_LOCKED) {
 417                 dev_warn(cs->dev, "can't write to unlocked device\n");
 418                 retval = -EBUSY;
 419         } else
 420                 retval = cs->ops->write_room(cs);
 421
 422         mutex_unlock(&cs->mutex);
 423
 424         return retval;
 425 }
 426
 427 static int if_chars_in_buffer(struct tty_struct *tty)
 428 {
 429         struct cardstate *cs;
 430         int retval = 0;
 431
 432         cs = (struct cardstate *) tty->driver_data;
 433         if (!cs) {
 434                 pr_err("%s: no cardstate\n", __func__);
 435                 return 0;
 436         }
 437
 438         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 439
 440         mutex_lock(&cs->mutex);
 441
 442         if (!cs->connected)
 443                 gig_dbg(DEBUG_IF, "not connected");
 444         else if (!cs->open_count)
 445                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 446         else if (cs->mstate != MS_LOCKED)
 447                 dev_warn(cs->dev, "can't write to unlocked device\n");
 448         else
 449                 retval = cs->ops->chars_in_buffer(cs);
 450
 451         mutex_unlock(&cs->mutex);
 452
 453         return retval;
 454 }
 455
 456 static void if_throttle(struct tty_struct *tty)
 457 {
 458         struct cardstate *cs;
 459
 460         cs = (struct cardstate *) tty->driver_data;
 461         if (!cs) {
 462                 pr_err("%s: no cardstate\n", __func__);
 463                 return;
 464         }
 465
 466         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 467
 468         mutex_lock(&cs->mutex);
 469
 470         if (!cs->connected)
 471                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 472         else if (!cs->open_count)
 473                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 474         else
 475                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 476
 477         mutex_unlock(&cs->mutex);
 478 }
 479
 480 static void if_unthrottle(struct tty_struct *tty)
 481 {
 482         struct cardstate *cs;
 483
 484         cs = (struct cardstate *) tty->driver_data;
 485         if (!cs) {
 486                 pr_err("%s: no cardstate\n", __func__);
 487                 return;
 488         }
 489
 490         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 491
 492         mutex_lock(&cs->mutex);
 493
 494         if (!cs->connected)
 495                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 496         else if (!cs->open_count)
 497                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 498         else
 499                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 500
 501         mutex_unlock(&cs->mutex);
 502 }
 503
 504 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
 505 {
 506         struct cardstate *cs;
 507         unsigned int iflag;
 508         unsigned int cflag;
 509         unsigned int old_cflag;
 510         unsigned int control_state, new_state;
 511
 512         cs = (struct cardstate *) tty->driver_data;
 513         if (!cs) {
 514                 pr_err("%s: no cardstate\n", __func__);
 515                 return;
 516         }
 517
 518         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 519
 520         mutex_lock(&cs->mutex);
 521
 522         if (!cs->connected) {
 523                 gig_dbg(DEBUG_IF, "not connected");
 524                 goto out;
 525         }
 526
 527         if (!cs->open_count) {
 528                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 529                 goto out;
 530         }
 531
 532         iflag = tty->termios->c_iflag;
 533         cflag = tty->termios->c_cflag;
 534         old_cflag = old ? old->c_cflag : cflag;
 535         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 536                 cs->minor_index, iflag, cflag, old_cflag);
 537
 538         /* get a local copy of the current port settings */
 539         control_state = cs->control_state;
 540
 541         /*
 542          * Update baud rate.
 543          * Do not attempt to cache old rates and skip settings,
 544          * disconnects screw such tricks up completely.
 545          * Premature optimization is the root of all evil.
 546          */
 547
 548         /* reassert DTR and (maybe) RTS on transition from B0 */
 549         if ((old_cflag & CBAUD) == B0) {
 550                 new_state = control_state | TIOCM_DTR;
 551                 /* don't set RTS if using hardware flow control */
 552                 if (!(old_cflag & CRTSCTS))
 553                         new_state |= TIOCM_RTS;
 554                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 555                         cs->minor_index,
 556                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 557                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 558                 control_state = new_state;
 559         }
 560
 561         cs->ops->baud_rate(cs, cflag & CBAUD);
 562
 563         if ((cflag & CBAUD) == B0) {
 564                 /* Drop RTS and DTR */
 565                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 566                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 567                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 568                 control_state = new_state;
 569         }
 570
 571         /*
 572          * Update line control register (LCR)
 573          */
 574
 575         cs->ops->set_line_ctrl(cs, cflag);
 576
 577         /* save off the modified port settings */
 578         cs->control_state = control_state;
 579
 580 out:
 581         mutex_unlock(&cs->mutex);
 582 }
 583
 584
 585 /* wakeup tasklet for the write operation */
 586 static void if_wake(unsigned long data)
 587 {
 588         struct cardstate *cs = (struct cardstate *) data;
 589
 590         if (cs->tty)
 591                 tty_wakeup(cs->tty);
 592 }
 593
 594 /*** interface to common ***/
 595
 596 void gigaset_if_init(struct cardstate *cs)
 597 {
 598         struct gigaset_driver *drv;
 599
 600         drv = cs->driver;
 601         if (!drv->have_tty)
 602                 return;
 603
 604         tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
 605
 606         mutex_lock(&cs->mutex);
 607         cs->tty_dev = tty_register_device(drv->tty, cs->minor_index, NULL);
 608
 609         if (!IS_ERR(cs->tty_dev))
 610                 dev_set_drvdata(cs->tty_dev, cs);
 611         else {
 612                 pr_warning("could not register device to the tty subsystem\n");
 613                 cs->tty_dev = NULL;
 614         }
 615         mutex_unlock(&cs->mutex);
 616 }
 617
 618 void gigaset_if_free(struct cardstate *cs)
 619 {
 620         struct gigaset_driver *drv;
 621
 622         drv = cs->driver;
 623         if (!drv->have_tty)
 624                 return;
 625
 626         tasklet_disable(&cs->if_wake_tasklet);
 627         tasklet_kill(&cs->if_wake_tasklet);
 628         cs->tty_dev = NULL;
 629         tty_unregister_device(drv->tty, cs->minor_index);
 630 }
 631
 632 /**
 633  * gigaset_if_receive() - pass a received block of data to the tty device
 634  * @cs:         device descriptor structure.
 635  * @buffer:     received data.
 636  * @len:        number of bytes received.
 637  *
 638  * Called by asyncdata/isocdata if a block of data received from the
 639  * device must be sent to userspace through the ttyG* device.
 640  */
 641 void gigaset_if_receive(struct cardstate *cs,
 642                         unsigned char *buffer, size_t len)
 643 {
 644         unsigned long flags;
 645         struct tty_struct *tty;
 646
 647         spin_lock_irqsave(&cs->lock, flags);
 648         tty = cs->tty;
 649         if (tty == NULL)
 650                 gig_dbg(DEBUG_IF, "receive on closed device");
 651         else {
 652                 tty_insert_flip_string(tty, buffer, len);
 653                 tty_flip_buffer_push(tty);
 654         }
 655         spin_unlock_irqrestore(&cs->lock, flags);
 656 }
 657 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 658
 659 /* gigaset_if_initdriver
 660  * Initialize tty interface.
 661  * parameters:
 662  *      drv             Driver
 663  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 664  *      devname         Name of the device files (prefix without minor number)
 665  */
 666 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 667                            const char *devname)
 668 {
 669         unsigned minors = drv->minors;
 670         int ret;
 671         struct tty_driver *tty;
 672
 673         drv->have_tty = 0;
 674
 675         drv->tty = tty = alloc_tty_driver(minors);
 676         if (tty == NULL)
 677                 goto enomem;
 678
 679         tty->magic =            TTY_DRIVER_MAGIC,
 680         tty->type =             TTY_DRIVER_TYPE_SERIAL,
 681         tty->subtype =          SERIAL_TYPE_NORMAL,
 682         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 683
 684         tty->driver_name =      procname;
 685         tty->name =             devname;
 686         tty->minor_start =      drv->minor;
 687         tty->num =              drv->minors;
 688
 689         tty->owner =            THIS_MODULE;
 690
 691         tty->init_termios          = tty_std_termios;
 692         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 693         tty_set_operations(tty, &if_ops);
 694
 695         ret = tty_register_driver(tty);
 696         if (ret < 0) {
 697                 pr_err("error %d registering tty driver\n", ret);
 698                 goto error;
 699         }
 700         gig_dbg(DEBUG_IF, "tty driver initialized");
 701         drv->have_tty = 1;
 702         return;
 703
 704 enomem:
 705         pr_err("out of memory\n");
 706 error:
 707         if (drv->tty)
 708                 put_tty_driver(drv->tty);
 709 }
 710
 711 void gigaset_if_freedriver(struct gigaset_driver *drv)
 712 {
 713         if (!drv->have_tty)
 714                 return;
 715
 716         drv->have_tty = 0;
 717         tty_unregister_driver(drv->tty);
 718         put_tty_driver(drv->tty);
 719 }