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 #include <linux/module.h>
  18
  19 /*** our ioctls ***/
  20
  21 static int if_lock(struct cardstate *cs, int *arg)
  22 {
  23         int cmd = *arg;
  24
  25         gig_dbg(DEBUG_IF, "%u: if_lock (%d)", cs->minor_index, cmd);
  26
  27         if (cmd > 1)
  28                 return -EINVAL;
  29
  30         if (cmd < 0) {
  31                 *arg = cs->mstate == MS_LOCKED;
  32                 return 0;
  33         }
  34
  35         if (!cmd && cs->mstate == MS_LOCKED && cs->connected) {
  36                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
  37                 cs->ops->baud_rate(cs, B115200);
  38                 cs->ops->set_line_ctrl(cs, CS8);
  39                 cs->control_state = TIOCM_DTR|TIOCM_RTS;
  40         }
  41
  42         cs->waiting = 1;
  43         if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
  44                                NULL, cmd, NULL)) {
  45                 cs->waiting = 0;
  46                 return -ENOMEM;
  47         }
  48         gigaset_schedule_event(cs);
  49
  50         wait_event(cs->waitqueue, !cs->waiting);
  51
  52         if (cs->cmd_result >= 0) {
  53                 *arg = cs->cmd_result;
  54                 return 0;
  55         }
  56
  57         return cs->cmd_result;
  58 }
  59
  60 static int if_version(struct cardstate *cs, unsigned arg[4])
  61 {
  62         static const unsigned version[4] = GIG_VERSION;
  63         static const unsigned compat[4] = GIG_COMPAT;
  64         unsigned cmd = arg[0];
  65
  66         gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
  67
  68         switch (cmd) {
  69         case GIGVER_DRIVER:
  70                 memcpy(arg, version, sizeof version);
  71                 return 0;
  72         case GIGVER_COMPAT:
  73                 memcpy(arg, compat, sizeof compat);
  74                 return 0;
  75         case GIGVER_FWBASE:
  76                 cs->waiting = 1;
  77                 if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
  78                                        NULL, 0, arg)) {
  79                         cs->waiting = 0;
  80                         return -ENOMEM;
  81                 }
  82                 gigaset_schedule_event(cs);
  83
  84                 wait_event(cs->waitqueue, !cs->waiting);
  85
  86                 if (cs->cmd_result >= 0)
  87                         return 0;
  88
  89                 return cs->cmd_result;
  90         default:
  91                 return -EINVAL;
  92         }
  93 }
  94
  95 static int if_config(struct cardstate *cs, int *arg)
  96 {
  97         gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
  98
  99         if (*arg != 1)
 100                 return -EINVAL;
 101
 102         if (cs->mstate != MS_LOCKED)
 103                 return -EBUSY;
 104
 105         if (!cs->connected) {
 106                 pr_err("%s: not connected\n", __func__);
 107                 return -ENODEV;
 108         }
 109
 110         *arg = 0;
 111         return gigaset_enterconfigmode(cs);
 112 }
 113
 114 /*** the terminal driver ***/
 115 /* stolen from usbserial and some other tty drivers */
 116
 117 static int  if_open(struct tty_struct *tty, struct file *filp);
 118 static void if_close(struct tty_struct *tty, struct file *filp);
 119 static int  if_ioctl(struct tty_struct *tty,
 120                      unsigned int cmd, unsigned long arg);
 121 static int  if_write_room(struct tty_struct *tty);
 122 static int  if_chars_in_buffer(struct tty_struct *tty);
 123 static void if_throttle(struct tty_struct *tty);
 124 static void if_unthrottle(struct tty_struct *tty);
 125 static void if_set_termios(struct tty_struct *tty, struct ktermios *old);
 126 static int  if_tiocmget(struct tty_struct *tty);
 127 static int  if_tiocmset(struct tty_struct *tty,
 128                         unsigned int set, unsigned int clear);
 129 static int  if_write(struct tty_struct *tty,
 130                      const unsigned char *buf, int count);
 131
 132 static const struct tty_operations if_ops = {
 133         .open =                 if_open,
 134         .close =                if_close,
 135         .ioctl =                if_ioctl,
 136         .write =                if_write,
 137         .write_room =           if_write_room,
 138         .chars_in_buffer =      if_chars_in_buffer,
 139         .set_termios =          if_set_termios,
 140         .throttle =             if_throttle,
 141         .unthrottle =           if_unthrottle,
 142         .tiocmget =             if_tiocmget,
 143         .tiocmset =             if_tiocmset,
 144 };
 145
 146 static int if_open(struct tty_struct *tty, struct file *filp)
 147 {
 148         struct cardstate *cs;
 149         unsigned long flags;
 150
 151         gig_dbg(DEBUG_IF, "%d+%d: %s()",
 152                 tty->driver->minor_start, tty->index, __func__);
 153
 154         tty->driver_data = NULL;
 155
 156         cs = gigaset_get_cs_by_tty(tty);
 157         if (!cs || !try_module_get(cs->driver->owner))
 158                 return -ENODEV;
 159
 160         if (mutex_lock_interruptible(&cs->mutex)) {
 161                 module_put(cs->driver->owner);
 162                 return -ERESTARTSYS;
 163         }
 164         tty->driver_data = cs;
 165
 166         ++cs->open_count;
 167
 168         if (cs->open_count == 1) {
 169                 spin_lock_irqsave(&cs->lock, flags);
 170                 cs->tty = tty;
 171                 spin_unlock_irqrestore(&cs->lock, flags);
 172                 tty->low_latency = 1;
 173         }
 174
 175         mutex_unlock(&cs->mutex);
 176         return 0;
 177 }
 178
 179 static void if_close(struct tty_struct *tty, struct file *filp)
 180 {
 181         struct cardstate *cs;
 182         unsigned long flags;
 183
 184         cs = (struct cardstate *) tty->driver_data;
 185         if (!cs) {
 186                 pr_err("%s: no cardstate\n", __func__);
 187                 return;
 188         }
 189
 190         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 191
 192         mutex_lock(&cs->mutex);
 193
 194         if (!cs->connected)
 195                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 196         else if (!cs->open_count)
 197                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 198         else {
 199                 if (!--cs->open_count) {
 200                         spin_lock_irqsave(&cs->lock, flags);
 201                         cs->tty = NULL;
 202                         spin_unlock_irqrestore(&cs->lock, flags);
 203                 }
 204         }
 205
 206         mutex_unlock(&cs->mutex);
 207
 208         module_put(cs->driver->owner);
 209 }
 210
 211 static int if_ioctl(struct tty_struct *tty,
 212                     unsigned int cmd, unsigned long arg)
 213 {
 214         struct cardstate *cs;
 215         int retval = -ENODEV;
 216         int int_arg;
 217         unsigned char buf[6];
 218         unsigned version[4];
 219
 220         cs = (struct cardstate *) tty->driver_data;
 221         if (!cs) {
 222                 pr_err("%s: no cardstate\n", __func__);
 223                 return -ENODEV;
 224         }
 225
 226         gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 227
 228         if (mutex_lock_interruptible(&cs->mutex))
 229                 return -ERESTARTSYS;
 230
 231         if (!cs->connected) {
 232                 gig_dbg(DEBUG_IF, "not connected");
 233                 retval = -ENODEV;
 234         } else if (!cs->open_count)
 235                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 236         else {
 237                 retval = 0;
 238                 switch (cmd) {
 239                 case GIGASET_REDIR:
 240                         retval = get_user(int_arg, (int __user *) arg);
 241                         if (retval >= 0)
 242                                 retval = if_lock(cs, &int_arg);
 243                         if (retval >= 0)
 244                                 retval = put_user(int_arg, (int __user *) arg);
 245                         break;
 246                 case GIGASET_CONFIG:
 247                         retval = get_user(int_arg, (int __user *) arg);
 248                         if (retval >= 0)
 249                                 retval = if_config(cs, &int_arg);
 250                         if (retval >= 0)
 251                                 retval = put_user(int_arg, (int __user *) arg);
 252                         break;
 253                 case GIGASET_BRKCHARS:
 254                         retval = copy_from_user(&buf,
 255                                         (const unsigned char __user *) arg, 6)
 256                                 ? -EFAULT : 0;
 257                         if (retval >= 0) {
 258                                 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
 259                                                 6, (const unsigned char *) arg);
 260                                 retval = cs->ops->brkchars(cs, buf);
 261                         }
 262                         break;
 263                 case GIGASET_VERSION:
 264                         retval = copy_from_user(version,
 265                                         (unsigned __user *) arg, sizeof version)
 266                                 ? -EFAULT : 0;
 267                         if (retval >= 0)
 268                                 retval = if_version(cs, version);
 269                         if (retval >= 0)
 270                                 retval = copy_to_user((unsigned __user *) arg,
 271                                                       version, sizeof version)
 272                                         ? -EFAULT : 0;
 273                         break;
 274                 default:
 275                         gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
 276                                 __func__, cmd);
 277                         retval = -ENOIOCTLCMD;
 278                 }
 279         }
 280
 281         mutex_unlock(&cs->mutex);
 282
 283         return retval;
 284 }
 285
 286 static int if_tiocmget(struct tty_struct *tty)
 287 {
 288         struct cardstate *cs;
 289         int retval;
 290
 291         cs = (struct cardstate *) tty->driver_data;
 292         if (!cs) {
 293                 pr_err("%s: no cardstate\n", __func__);
 294                 return -ENODEV;
 295         }
 296
 297         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 298
 299         if (mutex_lock_interruptible(&cs->mutex))
 300                 return -ERESTARTSYS;
 301
 302         retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
 303
 304         mutex_unlock(&cs->mutex);
 305
 306         return retval;
 307 }
 308
 309 static int if_tiocmset(struct tty_struct *tty,
 310                        unsigned int set, unsigned int clear)
 311 {
 312         struct cardstate *cs;
 313         int retval;
 314         unsigned mc;
 315
 316         cs = (struct cardstate *) tty->driver_data;
 317         if (!cs) {
 318                 pr_err("%s: no cardstate\n", __func__);
 319                 return -ENODEV;
 320         }
 321
 322         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 323                 cs->minor_index, __func__, set, clear);
 324
 325         if (mutex_lock_interruptible(&cs->mutex))
 326                 return -ERESTARTSYS;
 327
 328         if (!cs->connected) {
 329                 gig_dbg(DEBUG_IF, "not connected");
 330                 retval = -ENODEV;
 331         } else {
 332                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
 333                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 334                 cs->control_state = mc;
 335         }
 336
 337         mutex_unlock(&cs->mutex);
 338
 339         return retval;
 340 }
 341
 342 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 343 {
 344         struct cardstate *cs;
 345         struct cmdbuf_t *cb;
 346         int retval;
 347
 348         cs = (struct cardstate *) tty->driver_data;
 349         if (!cs) {
 350                 pr_err("%s: no cardstate\n", __func__);
 351                 return -ENODEV;
 352         }
 353
 354         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 355
 356         if (mutex_lock_interruptible(&cs->mutex))
 357                 return -ERESTARTSYS;
 358
 359         if (!cs->connected) {
 360                 gig_dbg(DEBUG_IF, "not connected");
 361                 retval = -ENODEV;
 362                 goto done;
 363         }
 364         if (!cs->open_count) {
 365                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 366                 retval = -ENODEV;
 367                 goto done;
 368         }
 369         if (cs->mstate != MS_LOCKED) {
 370                 dev_warn(cs->dev, "can't write to unlocked device\n");
 371                 retval = -EBUSY;
 372                 goto done;
 373         }
 374         if (count <= 0) {
 375                 /* nothing to do */
 376                 retval = 0;
 377                 goto done;
 378         }
 379
 380         cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
 381         if (!cb) {
 382                 dev_err(cs->dev, "%s: out of memory\n", __func__);
 383                 retval = -ENOMEM;
 384                 goto done;
 385         }
 386
 387         memcpy(cb->buf, buf, count);
 388         cb->len = count;
 389         cb->offset = 0;
 390         cb->next = NULL;
 391         cb->wake_tasklet = &cs->if_wake_tasklet;
 392         retval = cs->ops->write_cmd(cs, cb);
 393 done:
 394         mutex_unlock(&cs->mutex);
 395         return retval;
 396 }
 397
 398 static int if_write_room(struct tty_struct *tty)
 399 {
 400         struct cardstate *cs;
 401         int retval = -ENODEV;
 402
 403         cs = (struct cardstate *) tty->driver_data;
 404         if (!cs) {
 405                 pr_err("%s: no cardstate\n", __func__);
 406                 return -ENODEV;
 407         }
 408
 409         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 410
 411         if (mutex_lock_interruptible(&cs->mutex))
 412                 return -ERESTARTSYS;
 413
 414         if (!cs->connected) {
 415                 gig_dbg(DEBUG_IF, "not connected");
 416                 retval = -ENODEV;
 417         } else if (!cs->open_count)
 418                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 419         else if (cs->mstate != MS_LOCKED) {
 420                 dev_warn(cs->dev, "can't write to unlocked device\n");
 421                 retval = -EBUSY;
 422         } else
 423                 retval = cs->ops->write_room(cs);
 424
 425         mutex_unlock(&cs->mutex);
 426
 427         return retval;
 428 }
 429
 430 static int if_chars_in_buffer(struct tty_struct *tty)
 431 {
 432         struct cardstate *cs;
 433         int retval = 0;
 434
 435         cs = (struct cardstate *) tty->driver_data;
 436         if (!cs) {
 437                 pr_err("%s: no cardstate\n", __func__);
 438                 return 0;
 439         }
 440
 441         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 442
 443         mutex_lock(&cs->mutex);
 444
 445         if (!cs->connected)
 446                 gig_dbg(DEBUG_IF, "not connected");
 447         else if (!cs->open_count)
 448                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 449         else if (cs->mstate != MS_LOCKED)
 450                 dev_warn(cs->dev, "can't write to unlocked device\n");
 451         else
 452                 retval = cs->ops->chars_in_buffer(cs);
 453
 454         mutex_unlock(&cs->mutex);
 455
 456         return retval;
 457 }
 458
 459 static void if_throttle(struct tty_struct *tty)
 460 {
 461         struct cardstate *cs;
 462
 463         cs = (struct cardstate *) tty->driver_data;
 464         if (!cs) {
 465                 pr_err("%s: no cardstate\n", __func__);
 466                 return;
 467         }
 468
 469         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 470
 471         mutex_lock(&cs->mutex);
 472
 473         if (!cs->connected)
 474                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 475         else if (!cs->open_count)
 476                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 477         else
 478                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 479
 480         mutex_unlock(&cs->mutex);
 481 }
 482
 483 static void if_unthrottle(struct tty_struct *tty)
 484 {
 485         struct cardstate *cs;
 486
 487         cs = (struct cardstate *) tty->driver_data;
 488         if (!cs) {
 489                 pr_err("%s: no cardstate\n", __func__);
 490                 return;
 491         }
 492
 493         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 494
 495         mutex_lock(&cs->mutex);
 496
 497         if (!cs->connected)
 498                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 499         else if (!cs->open_count)
 500                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 501         else
 502                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 503
 504         mutex_unlock(&cs->mutex);
 505 }
 506
 507 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
 508 {
 509         struct cardstate *cs;
 510         unsigned int iflag;
 511         unsigned int cflag;
 512         unsigned int old_cflag;
 513         unsigned int control_state, new_state;
 514
 515         cs = (struct cardstate *) tty->driver_data;
 516         if (!cs) {
 517                 pr_err("%s: no cardstate\n", __func__);
 518                 return;
 519         }
 520
 521         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 522
 523         mutex_lock(&cs->mutex);
 524
 525         if (!cs->connected) {
 526                 gig_dbg(DEBUG_IF, "not connected");
 527                 goto out;
 528         }
 529
 530         if (!cs->open_count) {
 531                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 532                 goto out;
 533         }
 534
 535         iflag = tty->termios->c_iflag;
 536         cflag = tty->termios->c_cflag;
 537         old_cflag = old ? old->c_cflag : cflag;
 538         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 539                 cs->minor_index, iflag, cflag, old_cflag);
 540
 541         /* get a local copy of the current port settings */
 542         control_state = cs->control_state;
 543
 544         /*
 545          * Update baud rate.
 546          * Do not attempt to cache old rates and skip settings,
 547          * disconnects screw such tricks up completely.
 548          * Premature optimization is the root of all evil.
 549          */
 550
 551         /* reassert DTR and (maybe) RTS on transition from B0 */
 552         if ((old_cflag & CBAUD) == B0) {
 553                 new_state = control_state | TIOCM_DTR;
 554                 /* don't set RTS if using hardware flow control */
 555                 if (!(old_cflag & CRTSCTS))
 556                         new_state |= TIOCM_RTS;
 557                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 558                         cs->minor_index,
 559                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 560                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 561                 control_state = new_state;
 562         }
 563
 564         cs->ops->baud_rate(cs, cflag & CBAUD);
 565
 566         if ((cflag & CBAUD) == B0) {
 567                 /* Drop RTS and DTR */
 568                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 569                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 570                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 571                 control_state = new_state;
 572         }
 573
 574         /*
 575          * Update line control register (LCR)
 576          */
 577
 578         cs->ops->set_line_ctrl(cs, cflag);
 579
 580         /* save off the modified port settings */
 581         cs->control_state = control_state;
 582
 583 out:
 584         mutex_unlock(&cs->mutex);
 585 }
 586
 587
 588 /* wakeup tasklet for the write operation */
 589 static void if_wake(unsigned long data)
 590 {
 591         struct cardstate *cs = (struct cardstate *) data;
 592
 593         if (cs->tty)
 594                 tty_wakeup(cs->tty);
 595 }
 596
 597 /*** interface to common ***/
 598
 599 void gigaset_if_init(struct cardstate *cs)
 600 {
 601         struct gigaset_driver *drv;
 602
 603         drv = cs->driver;
 604         if (!drv->have_tty)
 605                 return;
 606
 607         tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
 608
 609         mutex_lock(&cs->mutex);
 610         cs->tty_dev = tty_register_device(drv->tty, cs->minor_index, NULL);
 611
 612         if (!IS_ERR(cs->tty_dev))
 613                 dev_set_drvdata(cs->tty_dev, cs);
 614         else {
 615                 pr_warning("could not register device to the tty subsystem\n");
 616                 cs->tty_dev = NULL;
 617         }
 618         mutex_unlock(&cs->mutex);
 619 }
 620
 621 void gigaset_if_free(struct cardstate *cs)
 622 {
 623         struct gigaset_driver *drv;
 624
 625         drv = cs->driver;
 626         if (!drv->have_tty)
 627                 return;
 628
 629         tasklet_disable(&cs->if_wake_tasklet);
 630         tasklet_kill(&cs->if_wake_tasklet);
 631         cs->tty_dev = NULL;
 632         tty_unregister_device(drv->tty, cs->minor_index);
 633 }
 634
 635 /**
 636  * gigaset_if_receive() - pass a received block of data to the tty device
 637  * @cs:         device descriptor structure.
 638  * @buffer:     received data.
 639  * @len:        number of bytes received.
 640  *
 641  * Called by asyncdata/isocdata if a block of data received from the
 642  * device must be sent to userspace through the ttyG* device.
 643  */
 644 void gigaset_if_receive(struct cardstate *cs,
 645                         unsigned char *buffer, size_t len)
 646 {
 647         unsigned long flags;
 648         struct tty_struct *tty;
 649
 650         spin_lock_irqsave(&cs->lock, flags);
 651         tty = cs->tty;
 652         if (tty == NULL)
 653                 gig_dbg(DEBUG_IF, "receive on closed device");
 654         else {
 655                 tty_insert_flip_string(tty, buffer, len);
 656                 tty_flip_buffer_push(tty);
 657         }
 658         spin_unlock_irqrestore(&cs->lock, flags);
 659 }
 660 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 661
 662 /* gigaset_if_initdriver
 663  * Initialize tty interface.
 664  * parameters:
 665  *      drv             Driver
 666  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 667  *      devname         Name of the device files (prefix without minor number)
 668  */
 669 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 670                            const char *devname)
 671 {
 672         unsigned minors = drv->minors;
 673         int ret;
 674         struct tty_driver *tty;
 675
 676         drv->have_tty = 0;
 677
 678         drv->tty = tty = alloc_tty_driver(minors);
 679         if (tty == NULL)
 680                 goto enomem;
 681
 682         tty->magic =            TTY_DRIVER_MAGIC,
 683         tty->type =             TTY_DRIVER_TYPE_SERIAL,
 684         tty->subtype =          SERIAL_TYPE_NORMAL,
 685         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 686
 687         tty->driver_name =      procname;
 688         tty->name =             devname;
 689         tty->minor_start =      drv->minor;
 690         tty->num =              drv->minors;
 691
 692         tty->owner =            THIS_MODULE;
 693
 694         tty->init_termios          = tty_std_termios;
 695         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 696         tty_set_operations(tty, &if_ops);
 697
 698         ret = tty_register_driver(tty);
 699         if (ret < 0) {
 700                 pr_err("error %d registering tty driver\n", ret);
 701                 goto error;
 702         }
 703         gig_dbg(DEBUG_IF, "tty driver initialized");
 704         drv->have_tty = 1;
 705         return;
 706
 707 enomem:
 708         pr_err("out of memory\n");
 709 error:
 710         if (drv->tty)
 711                 put_tty_driver(drv->tty);
 712 }
 713
 714 void gigaset_if_freedriver(struct gigaset_driver *drv)
 715 {
 716         if (!drv->have_tty)
 717                 return;
 718
 719         drv->have_tty = 0;
 720         tty_unregister_driver(drv->tty);
 721         put_tty_driver(drv->tty);
 722 }