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.h>
  17 #include <linux/tty_flip.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 = atomic_read(&cs->mstate) == MS_LOCKED; //FIXME remove?
  32                 return 0;
  33         }
  34
  35         if (!cmd && atomic_read(&cs->mstate) == MS_LOCKED
  36             && atomic_read(&cs->connected)) {
  37                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
  38                 cs->ops->baud_rate(cs, B115200);
  39                 cs->ops->set_line_ctrl(cs, CS8);
  40                 cs->control_state = TIOCM_DTR|TIOCM_RTS;
  41         }
  42
  43         cs->waiting = 1;
  44         if (!gigaset_add_event(cs, &cs->at_state, EV_IF_LOCK,
  45                                NULL, cmd, NULL)) {
  46                 cs->waiting = 0;
  47                 return -ENOMEM;
  48         }
  49
  50         gig_dbg(DEBUG_CMD, "scheduling IF_LOCK");
  51         gigaset_schedule_event(cs);
  52
  53         wait_event(cs->waitqueue, !cs->waiting);
  54
  55         if (cs->cmd_result >= 0) {
  56                 *arg = cs->cmd_result;
  57                 return 0;
  58         }
  59
  60         return cs->cmd_result;
  61 }
  62
  63 static int if_version(struct cardstate *cs, unsigned arg[4])
  64 {
  65         static const unsigned version[4] = GIG_VERSION;
  66         static const unsigned compat[4] = GIG_COMPAT;
  67         unsigned cmd = arg[0];
  68
  69         gig_dbg(DEBUG_IF, "%u: if_version (%d)", cs->minor_index, cmd);
  70
  71         switch (cmd) {
  72         case GIGVER_DRIVER:
  73                 memcpy(arg, version, sizeof version);
  74                 return 0;
  75         case GIGVER_COMPAT:
  76                 memcpy(arg, compat, sizeof compat);
  77                 return 0;
  78         case GIGVER_FWBASE:
  79                 cs->waiting = 1;
  80                 if (!gigaset_add_event(cs, &cs->at_state, EV_IF_VER,
  81                                        NULL, 0, arg)) {
  82                         cs->waiting = 0;
  83                         return -ENOMEM;
  84                 }
  85
  86                 gig_dbg(DEBUG_CMD, "scheduling IF_VER");
  87                 gigaset_schedule_event(cs);
  88
  89                 wait_event(cs->waitqueue, !cs->waiting);
  90
  91                 if (cs->cmd_result >= 0)
  92                         return 0;
  93
  94                 return cs->cmd_result;
  95         default:
  96                 return -EINVAL;
  97         }
  98 }
  99
 100 static int if_config(struct cardstate *cs, int *arg)
 101 {
 102         gig_dbg(DEBUG_IF, "%u: if_config (%d)", cs->minor_index, *arg);
 103
 104         if (*arg != 1)
 105                 return -EINVAL;
 106
 107         if (atomic_read(&cs->mstate) != MS_LOCKED)
 108                 return -EBUSY;
 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, struct file *file,
 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 termios *old);
 126 static int  if_tiocmget(struct tty_struct *tty, struct file *file);
 127 static int  if_tiocmset(struct tty_struct *tty, struct file *file,
 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 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 #if 0
 143         .break_ctl =            serial_break,
 144 #endif
 145         .tiocmget =             if_tiocmget,
 146         .tiocmset =             if_tiocmset,
 147 };
 148
 149 static int if_open(struct tty_struct *tty, struct file *filp)
 150 {
 151         struct cardstate *cs;
 152         unsigned long flags;
 153
 154         gig_dbg(DEBUG_IF, "%d+%d: %s()",
 155                 tty->driver->minor_start, tty->index, __func__);
 156
 157         tty->driver_data = NULL;
 158
 159         cs = gigaset_get_cs_by_tty(tty);
 160         if (!cs)
 161                 return -ENODEV;
 162
 163         if (down_interruptible(&cs->sem))
 164                 return -ERESTARTSYS; // FIXME -EINTR?
 165         tty->driver_data = cs;
 166
 167         ++cs->open_count;
 168
 169         if (cs->open_count == 1) {
 170                 spin_lock_irqsave(&cs->lock, flags);
 171                 cs->tty = tty;
 172                 spin_unlock_irqrestore(&cs->lock, flags);
 173                 tty->low_latency = 1; //FIXME test
 174         }
 175
 176         up(&cs->sem);
 177         return 0;
 178 }
 179
 180 static void if_close(struct tty_struct *tty, struct file *filp)
 181 {
 182         struct cardstate *cs;
 183         unsigned long flags;
 184
 185         cs = (struct cardstate *) tty->driver_data;
 186         if (!cs) {
 187                 err("cs==NULL in %s", __func__);
 188                 return;
 189         }
 190
 191         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 192
 193         down(&cs->sem);
 194
 195         if (!cs->open_count)
 196                 warn("%s: device not opened", __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         up(&cs->sem);
 206 }
 207
 208 static int if_ioctl(struct tty_struct *tty, struct file *file,
 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                 err("cs==NULL in %s", __func__);
 220                 return -ENODEV;
 221         }
 222
 223         gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 224
 225         if (down_interruptible(&cs->sem))
 226                 return -ERESTARTSYS; // FIXME -EINTR?
 227
 228         if (!cs->open_count)
 229                 warn("%s: device not opened", __func__);
 230         else {
 231                 retval = 0;
 232                 switch (cmd) {
 233                 case GIGASET_REDIR:
 234                         retval = get_user(int_arg, (int __user *) arg);
 235                         if (retval >= 0)
 236                                 retval = if_lock(cs, &int_arg);
 237                         if (retval >= 0)
 238                                 retval = put_user(int_arg, (int __user *) arg);
 239                         break;
 240                 case GIGASET_CONFIG:
 241                         retval = get_user(int_arg, (int __user *) arg);
 242                         if (retval >= 0)
 243                                 retval = if_config(cs, &int_arg);
 244                         if (retval >= 0)
 245                                 retval = put_user(int_arg, (int __user *) arg);
 246                         break;
 247                 case GIGASET_BRKCHARS:
 248                         //FIXME test if MS_LOCKED
 249                         if (!atomic_read(&cs->connected)) {
 250                                 gig_dbg(DEBUG_ANY,
 251                                     "can't communicate with unplugged device");
 252                                 retval = -ENODEV;
 253                                 break;
 254                         }
 255                         retval = copy_from_user(&buf,
 256                                         (const unsigned char __user *) arg, 6)
 257                                 ? -EFAULT : 0;
 258                         if (retval >= 0) {
 259                                 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
 260                                                 6, (const unsigned char *) arg);
 261                                 retval = cs->ops->brkchars(cs, buf);
 262                         }
 263                         break;
 264                 case GIGASET_VERSION:
 265                         retval = copy_from_user(version,
 266                                         (unsigned __user *) arg, sizeof version)
 267                                 ? -EFAULT : 0;
 268                         if (retval >= 0)
 269                                 retval = if_version(cs, version);
 270                         if (retval >= 0)
 271                                 retval = copy_to_user((unsigned __user *) arg,
 272                                                       version, sizeof version)
 273                                         ? -EFAULT : 0;
 274                         break;
 275                 default:
 276                         gig_dbg(DEBUG_ANY, "%s: arg not supported - 0x%04x",
 277                                 __func__, cmd);
 278                         retval = -ENOIOCTLCMD;
 279                 }
 280         }
 281
 282         up(&cs->sem);
 283
 284         return retval;
 285 }
 286
 287 static int if_tiocmget(struct tty_struct *tty, struct file *file)
 288 {
 289         struct cardstate *cs;
 290         int retval;
 291
 292         cs = (struct cardstate *) tty->driver_data;
 293         if (!cs) {
 294                 err("cs==NULL in %s", __func__);
 295                 return -ENODEV;
 296         }
 297
 298         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 299
 300         if (down_interruptible(&cs->sem))
 301                 return -ERESTARTSYS; // FIXME -EINTR?
 302
 303         // FIXME read from device?
 304         retval = cs->control_state & (TIOCM_RTS|TIOCM_DTR);
 305
 306         up(&cs->sem);
 307
 308         return retval;
 309 }
 310
 311 static int if_tiocmset(struct tty_struct *tty, struct file *file,
 312                        unsigned int set, unsigned int clear)
 313 {
 314         struct cardstate *cs;
 315         int retval;
 316         unsigned mc;
 317
 318         cs = (struct cardstate *) tty->driver_data;
 319         if (!cs) {
 320                 err("cs==NULL in %s", __func__);
 321                 return -ENODEV;
 322         }
 323
 324         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 325                 cs->minor_index, __func__, set, clear);
 326
 327         if (down_interruptible(&cs->sem))
 328                 return -ERESTARTSYS; // FIXME -EINTR?
 329
 330         if (!atomic_read(&cs->connected)) {
 331                 gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
 332                 retval = -ENODEV;
 333         } else {
 334                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS|TIOCM_DTR);
 335                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 336                 cs->control_state = mc;
 337         }
 338
 339         up(&cs->sem);
 340
 341         return retval;
 342 }
 343
 344 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 345 {
 346         struct cardstate *cs;
 347         int retval = -ENODEV;
 348
 349         cs = (struct cardstate *) tty->driver_data;
 350         if (!cs) {
 351                 err("cs==NULL in %s", __func__);
 352                 return -ENODEV;
 353         }
 354
 355         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 356
 357         if (down_interruptible(&cs->sem))
 358                 return -ERESTARTSYS; // FIXME -EINTR?
 359
 360         if (!cs->open_count)
 361                 warn("%s: device not opened", __func__);
 362         else if (atomic_read(&cs->mstate) != MS_LOCKED) {
 363                 warn("can't write to unlocked device");
 364                 retval = -EBUSY;
 365         } else if (!atomic_read(&cs->connected)) {
 366                 gig_dbg(DEBUG_ANY, "can't write to unplugged device");
 367                 retval = -EBUSY; //FIXME
 368         } else {
 369                 retval = cs->ops->write_cmd(cs, buf, count,
 370                                             &cs->if_wake_tasklet);
 371         }
 372
 373         up(&cs->sem);
 374
 375         return retval;
 376 }
 377
 378 static int if_write_room(struct tty_struct *tty)
 379 {
 380         struct cardstate *cs;
 381         int retval = -ENODEV;
 382
 383         cs = (struct cardstate *) tty->driver_data;
 384         if (!cs) {
 385                 err("cs==NULL in %s", __func__);
 386                 return -ENODEV;
 387         }
 388
 389         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 390
 391         if (down_interruptible(&cs->sem))
 392                 return -ERESTARTSYS; // FIXME -EINTR?
 393
 394         if (!cs->open_count)
 395                 warn("%s: device not opened", __func__);
 396         else if (atomic_read(&cs->mstate) != MS_LOCKED) {
 397                 warn("can't write to unlocked device");
 398                 retval = -EBUSY; //FIXME
 399         } else if (!atomic_read(&cs->connected)) {
 400                 gig_dbg(DEBUG_ANY, "can't write to unplugged device");
 401                 retval = -EBUSY; //FIXME
 402         } else
 403                 retval = cs->ops->write_room(cs);
 404
 405         up(&cs->sem);
 406
 407         return retval;
 408 }
 409
 410 static int if_chars_in_buffer(struct tty_struct *tty)
 411 {
 412         struct cardstate *cs;
 413         int retval = -ENODEV;
 414
 415         cs = (struct cardstate *) tty->driver_data;
 416         if (!cs) {
 417                 err("cs==NULL in %s", __func__);
 418                 return -ENODEV;
 419         }
 420
 421         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 422
 423         if (down_interruptible(&cs->sem))
 424                 return -ERESTARTSYS; // FIXME -EINTR?
 425
 426         if (!cs->open_count)
 427                 warn("%s: device not opened", __func__);
 428         else if (atomic_read(&cs->mstate) != MS_LOCKED) {
 429                 warn("can't write to unlocked device");
 430                 retval = -EBUSY;
 431         } else if (!atomic_read(&cs->connected)) {
 432                 gig_dbg(DEBUG_ANY, "can't write to unplugged device");
 433                 retval = -EBUSY; //FIXME
 434         } else
 435                 retval = cs->ops->chars_in_buffer(cs);
 436
 437         up(&cs->sem);
 438
 439         return retval;
 440 }
 441
 442 static void if_throttle(struct tty_struct *tty)
 443 {
 444         struct cardstate *cs;
 445
 446         cs = (struct cardstate *) tty->driver_data;
 447         if (!cs) {
 448                 err("cs==NULL in %s", __func__);
 449                 return;
 450         }
 451
 452         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 453
 454         down(&cs->sem);
 455
 456         if (!cs->open_count)
 457                 warn("%s: device not opened", __func__);
 458         else {
 459                 //FIXME
 460         }
 461
 462         up(&cs->sem);
 463 }
 464
 465 static void if_unthrottle(struct tty_struct *tty)
 466 {
 467         struct cardstate *cs;
 468
 469         cs = (struct cardstate *) tty->driver_data;
 470         if (!cs) {
 471                 err("cs==NULL in %s", __func__);
 472                 return;
 473         }
 474
 475         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 476
 477         down(&cs->sem);
 478
 479         if (!cs->open_count)
 480                 warn("%s: device not opened", __func__);
 481         else {
 482                 //FIXME
 483         }
 484
 485         up(&cs->sem);
 486 }
 487
 488 static void if_set_termios(struct tty_struct *tty, struct termios *old)
 489 {
 490         struct cardstate *cs;
 491         unsigned int iflag;
 492         unsigned int cflag;
 493         unsigned int old_cflag;
 494         unsigned int control_state, new_state;
 495
 496         cs = (struct cardstate *) tty->driver_data;
 497         if (!cs) {
 498                 err("cs==NULL in %s", __func__);
 499                 return;
 500         }
 501
 502         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 503
 504         down(&cs->sem);
 505
 506         if (!cs->open_count) {
 507                 warn("%s: device not opened", __func__);
 508                 goto out;
 509         }
 510
 511         if (!atomic_read(&cs->connected)) {
 512                 gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
 513                 goto out;
 514         }
 515
 516         // stolen from mct_u232.c
 517         iflag = tty->termios->c_iflag;
 518         cflag = tty->termios->c_cflag;
 519         old_cflag = old ? old->c_cflag : cflag; //FIXME?
 520         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 521                 cs->minor_index, iflag, cflag, old_cflag);
 522
 523         /* get a local copy of the current port settings */
 524         control_state = cs->control_state;
 525
 526         /*
 527          * Update baud rate.
 528          * Do not attempt to cache old rates and skip settings,
 529          * disconnects screw such tricks up completely.
 530          * Premature optimization is the root of all evil.
 531          */
 532
 533         /* reassert DTR and (maybe) RTS on transition from B0 */
 534         if ((old_cflag & CBAUD) == B0) {
 535                 new_state = control_state | TIOCM_DTR;
 536                 /* don't set RTS if using hardware flow control */
 537                 if (!(old_cflag & CRTSCTS))
 538                         new_state |= TIOCM_RTS;
 539                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 540                         cs->minor_index,
 541                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 542                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 543                 control_state = new_state;
 544         }
 545
 546         cs->ops->baud_rate(cs, cflag & CBAUD);
 547
 548         if ((cflag & CBAUD) == B0) {
 549                 /* Drop RTS and DTR */
 550                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 551                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 552                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 553                 control_state = new_state;
 554         }
 555
 556         /*
 557          * Update line control register (LCR)
 558          */
 559
 560         cs->ops->set_line_ctrl(cs, cflag);
 561
 562 #if 0
 563         //FIXME this hangs M101 [ts 2005-03-09]
 564         //FIXME do we need this?
 565         /*
 566          * Set flow control: well, I do not really now how to handle DTR/RTS.
 567          * Just do what we have seen with SniffUSB on Win98.
 568          */
 569         /* Drop DTR/RTS if no flow control otherwise assert */
 570         gig_dbg(DEBUG_IF, "%u: control_state %x",
 571                 cs->minor_index, control_state);
 572         new_state = control_state;
 573         if ((iflag & IXOFF) || (iflag & IXON) || (cflag & CRTSCTS))
 574                 new_state |= TIOCM_DTR | TIOCM_RTS;
 575         else
 576                 new_state &= ~(TIOCM_DTR | TIOCM_RTS);
 577         if (new_state != control_state) {
 578                 gig_dbg(DEBUG_IF, "%u: new_state %x",
 579                         cs->minor_index, new_state);
 580                 gigaset_set_modem_ctrl(cs, control_state, new_state);
 581                 control_state = new_state;
 582         }
 583 #endif
 584
 585         /* save off the modified port settings */
 586         cs->control_state = control_state;
 587
 588 out:
 589         up(&cs->sem);
 590 }
 591
 592
 593 /* wakeup tasklet for the write operation */
 594 static void if_wake(unsigned long data)
 595 {
 596         struct cardstate *cs = (struct cardstate *) data;
 597         struct tty_struct *tty;
 598
 599         tty = cs->tty;
 600         if (!tty)
 601                 return;
 602
 603         if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 604             tty->ldisc.write_wakeup) {
 605                 gig_dbg(DEBUG_IF, "write wakeup call");
 606                 tty->ldisc.write_wakeup(tty);
 607         }
 608
 609         wake_up_interruptible(&tty->write_wait);
 610 }
 611
 612 /*** interface to common ***/
 613
 614 void gigaset_if_init(struct cardstate *cs)
 615 {
 616         struct gigaset_driver *drv;
 617
 618         drv = cs->driver;
 619         if (!drv->have_tty)
 620                 return;
 621
 622         tasklet_init(&cs->if_wake_tasklet, &if_wake, (unsigned long) cs);
 623         tty_register_device(drv->tty, cs->minor_index, NULL);
 624 }
 625
 626 void gigaset_if_free(struct cardstate *cs)
 627 {
 628         struct gigaset_driver *drv;
 629
 630         drv = cs->driver;
 631         if (!drv->have_tty)
 632                 return;
 633
 634         tasklet_disable(&cs->if_wake_tasklet);
 635         tasklet_kill(&cs->if_wake_tasklet);
 636         tty_unregister_device(drv->tty, cs->minor_index);
 637 }
 638
 639 void gigaset_if_receive(struct cardstate *cs,
 640                         unsigned char *buffer, size_t len)
 641 {
 642         unsigned long flags;
 643         struct tty_struct *tty;
 644
 645         spin_lock_irqsave(&cs->lock, flags);
 646         if ((tty = cs->tty) == NULL)
 647                 gig_dbg(DEBUG_ANY, "receive on closed device");
 648         else {
 649                 tty_buffer_request_room(tty, len);
 650                 tty_insert_flip_string(tty, buffer, len);
 651                 tty_flip_buffer_push(tty);
 652         }
 653         spin_unlock_irqrestore(&cs->lock, flags);
 654 }
 655 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 656
 657 /* gigaset_if_initdriver
 658  * Initialize tty interface.
 659  * parameters:
 660  *      drv             Driver
 661  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 662  *      devname         Name of the device files (prefix without minor number)
 663  *      devfsname       Devfs name of the device files without %d
 664  */
 665 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 666                            const char *devname, const char *devfsname)
 667 {
 668         unsigned minors = drv->minors;
 669         int ret;
 670         struct tty_driver *tty;
 671
 672         drv->have_tty = 0;
 673
 674         if ((drv->tty = alloc_tty_driver(minors)) == NULL)
 675                 goto enomem;
 676         tty = drv->tty;
 677
 678         tty->magic =            TTY_DRIVER_MAGIC,
 679         tty->major =            GIG_MAJOR,
 680         tty->type =             TTY_DRIVER_TYPE_SERIAL,
 681         tty->subtype =          SERIAL_TYPE_NORMAL,
 682         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,
 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         tty->devfs_name =       devfsname;
 691
 692         tty->init_termios          = tty_std_termios; //FIXME
 693         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL; //FIXME
 694         tty_set_operations(tty, &if_ops);
 695
 696         ret = tty_register_driver(tty);
 697         if (ret < 0) {
 698                 warn("failed to register tty driver (error %d)", ret);
 699                 goto error;
 700         }
 701         gig_dbg(DEBUG_IF, "tty driver initialized");
 702         drv->have_tty = 1;
 703         return;
 704
 705 enomem:
 706         warn("could not allocate tty structures");
 707 error:
 708         if (drv->tty)
 709                 put_tty_driver(drv->tty);
 710 }
 711
 712 void gigaset_if_freedriver(struct gigaset_driver *drv)
 713 {
 714         if (!drv->have_tty)
 715                 return;
 716
 717         drv->have_tty = 0;
 718         tty_unregister_driver(drv->tty);
 719         put_tty_driver(drv->tty);
 720 }