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
 150         gig_dbg(DEBUG_IF, "%d+%d: %s()",
 151                 tty->driver->minor_start, tty->index, __func__);
 152
 153         cs = gigaset_get_cs_by_tty(tty);
 154         if (!cs || !try_module_get(cs->driver->owner))
 155                 return -ENODEV;
 156
 157         if (mutex_lock_interruptible(&cs->mutex)) {
 158                 module_put(cs->driver->owner);
 159                 return -ERESTARTSYS;
 160         }
 161         tty->driver_data = cs;
 162
 163         ++cs->port.count;
 164
 165         if (cs->port.count == 1) {
 166                 tty_port_tty_set(&cs->port, tty);
 167                 tty->low_latency = 1;
 168         }
 169
 170         mutex_unlock(&cs->mutex);
 171         return 0;
 172 }
 173
 174 static void if_close(struct tty_struct *tty, struct file *filp)
 175 {
 176         struct cardstate *cs = tty->driver_data;
 177
 178         if (!cs) { /* happens if we didn't find cs in open */
 179                 gig_dbg(DEBUG_IF, "%s: no cardstate", __func__);
 180                 return;
 181         }
 182
 183         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 184
 185         mutex_lock(&cs->mutex);
 186
 187         if (!cs->connected)
 188                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 189         else if (!cs->port.count)
 190                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 191         else if (!--cs->port.count)
 192                 tty_port_tty_set(&cs->port, NULL);
 193
 194         mutex_unlock(&cs->mutex);
 195
 196         module_put(cs->driver->owner);
 197 }
 198
 199 static int if_ioctl(struct tty_struct *tty,
 200                     unsigned int cmd, unsigned long arg)
 201 {
 202         struct cardstate *cs = tty->driver_data;
 203         int retval = -ENODEV;
 204         int int_arg;
 205         unsigned char buf[6];
 206         unsigned version[4];
 207
 208         gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 209
 210         if (mutex_lock_interruptible(&cs->mutex))
 211                 return -ERESTARTSYS;
 212
 213         if (!cs->connected) {
 214                 gig_dbg(DEBUG_IF, "not connected");
 215                 retval = -ENODEV;
 216         } else {
 217                 retval = 0;
 218                 switch (cmd) {
 219                 case GIGASET_REDIR:
 220                         retval = get_user(int_arg, (int __user *) arg);
 221                         if (retval >= 0)
 222                                 retval = if_lock(cs, &int_arg);
 223                         if (retval >= 0)
 224                                 retval = put_user(int_arg, (int __user *) arg);
 225                         break;
 226                 case GIGASET_CONFIG:
 227                         retval = get_user(int_arg, (int __user *) arg);
 228                         if (retval >= 0)
 229                                 retval = if_config(cs, &int_arg);
 230                         if (retval >= 0)
 231                                 retval = put_user(int_arg, (int __user *) arg);
 232                         break;
 233                 case GIGASET_BRKCHARS:
 234                         retval = copy_from_user(&buf,
 235                                                 (const unsigned char __user *) arg, 6)
 236                                 ? -EFAULT : 0;
 237                         if (retval >= 0) {
 238                                 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
 239                                                    6, (const unsigned char *) arg);
 240                                 retval = cs->ops->brkchars(cs, buf);
 241                         }
 242                         break;
 243                 case GIGASET_VERSION:
 244                         retval = copy_from_user(version,
 245                                                 (unsigned __user *) arg, sizeof version)
 246                                 ? -EFAULT : 0;
 247                         if (retval >= 0)
 248                                 retval = if_version(cs, version);
 249                         if (retval >= 0)
 250                                 retval = copy_to_user((unsigned __user *) arg,
 251                                                       version, sizeof version)
 252                                         ? -EFAULT : 0;
 253                         break;
 254                 default:
 255                         gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
 256                                 __func__, cmd);
 257                         retval = -ENOIOCTLCMD;
 258                 }
 259         }
 260
 261         mutex_unlock(&cs->mutex);
 262
 263         return retval;
 264 }
 265
 266 static int if_tiocmget(struct tty_struct *tty)
 267 {
 268         struct cardstate *cs = tty->driver_data;
 269         int retval;
 270
 271         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 272
 273         if (mutex_lock_interruptible(&cs->mutex))
 274                 return -ERESTARTSYS;
 275
 276         retval = cs->control_state & (TIOCM_RTS | TIOCM_DTR);
 277
 278         mutex_unlock(&cs->mutex);
 279
 280         return retval;
 281 }
 282
 283 static int if_tiocmset(struct tty_struct *tty,
 284                        unsigned int set, unsigned int clear)
 285 {
 286         struct cardstate *cs = tty->driver_data;
 287         int retval;
 288         unsigned mc;
 289
 290         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 291                 cs->minor_index, __func__, set, clear);
 292
 293         if (mutex_lock_interruptible(&cs->mutex))
 294                 return -ERESTARTSYS;
 295
 296         if (!cs->connected) {
 297                 gig_dbg(DEBUG_IF, "not connected");
 298                 retval = -ENODEV;
 299         } else {
 300                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS | TIOCM_DTR);
 301                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 302                 cs->control_state = mc;
 303         }
 304
 305         mutex_unlock(&cs->mutex);
 306
 307         return retval;
 308 }
 309
 310 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 311 {
 312         struct cardstate *cs = tty->driver_data;
 313         struct cmdbuf_t *cb;
 314         int retval;
 315
 316         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 317
 318         if (mutex_lock_interruptible(&cs->mutex))
 319                 return -ERESTARTSYS;
 320
 321         if (!cs->connected) {
 322                 gig_dbg(DEBUG_IF, "not connected");
 323                 retval = -ENODEV;
 324                 goto done;
 325         }
 326         if (cs->mstate != MS_LOCKED) {
 327                 dev_warn(cs->dev, "can't write to unlocked device\n");
 328                 retval = -EBUSY;
 329                 goto done;
 330         }
 331         if (count <= 0) {
 332                 /* nothing to do */
 333                 retval = 0;
 334                 goto done;
 335         }
 336
 337         cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
 338         if (!cb) {
 339                 dev_err(cs->dev, "%s: out of memory\n", __func__);
 340                 retval = -ENOMEM;
 341                 goto done;
 342         }
 343
 344         memcpy(cb->buf, buf, count);
 345         cb->len = count;
 346         cb->offset = 0;
 347         cb->next = NULL;
 348         cb->wake_tasklet = &cs->if_wake_tasklet;
 349         retval = cs->ops->write_cmd(cs, cb);
 350 done:
 351         mutex_unlock(&cs->mutex);
 352         return retval;
 353 }
 354
 355 static int if_write_room(struct tty_struct *tty)
 356 {
 357         struct cardstate *cs = tty->driver_data;
 358         int retval = -ENODEV;
 359
 360         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 361
 362         if (mutex_lock_interruptible(&cs->mutex))
 363                 return -ERESTARTSYS;
 364
 365         if (!cs->connected) {
 366                 gig_dbg(DEBUG_IF, "not connected");
 367                 retval = -ENODEV;
 368         } else if (cs->mstate != MS_LOCKED) {
 369                 dev_warn(cs->dev, "can't write to unlocked device\n");
 370                 retval = -EBUSY;
 371         } else
 372                 retval = cs->ops->write_room(cs);
 373
 374         mutex_unlock(&cs->mutex);
 375
 376         return retval;
 377 }
 378
 379 static int if_chars_in_buffer(struct tty_struct *tty)
 380 {
 381         struct cardstate *cs = tty->driver_data;
 382         int retval = 0;
 383
 384         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 385
 386         mutex_lock(&cs->mutex);
 387
 388         if (!cs->connected)
 389                 gig_dbg(DEBUG_IF, "not connected");
 390         else if (cs->mstate != MS_LOCKED)
 391                 dev_warn(cs->dev, "can't write to unlocked device\n");
 392         else
 393                 retval = cs->ops->chars_in_buffer(cs);
 394
 395         mutex_unlock(&cs->mutex);
 396
 397         return retval;
 398 }
 399
 400 static void if_throttle(struct tty_struct *tty)
 401 {
 402         struct cardstate *cs = tty->driver_data;
 403
 404         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 405
 406         mutex_lock(&cs->mutex);
 407
 408         if (!cs->connected)
 409                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 410         else
 411                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 412
 413         mutex_unlock(&cs->mutex);
 414 }
 415
 416 static void if_unthrottle(struct tty_struct *tty)
 417 {
 418         struct cardstate *cs = tty->driver_data;
 419
 420         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 421
 422         mutex_lock(&cs->mutex);
 423
 424         if (!cs->connected)
 425                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 426         else
 427                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 428
 429         mutex_unlock(&cs->mutex);
 430 }
 431
 432 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
 433 {
 434         struct cardstate *cs = tty->driver_data;
 435         unsigned int iflag;
 436         unsigned int cflag;
 437         unsigned int old_cflag;
 438         unsigned int control_state, new_state;
 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                 goto out;
 447         }
 448
 449         iflag = tty->termios.c_iflag;
 450         cflag = tty->termios.c_cflag;
 451         old_cflag = old ? old->c_cflag : cflag;
 452         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 453                 cs->minor_index, iflag, cflag, old_cflag);
 454
 455         /* get a local copy of the current port settings */
 456         control_state = cs->control_state;
 457
 458         /*
 459          * Update baud rate.
 460          * Do not attempt to cache old rates and skip settings,
 461          * disconnects screw such tricks up completely.
 462          * Premature optimization is the root of all evil.
 463          */
 464
 465         /* reassert DTR and (maybe) RTS on transition from B0 */
 466         if ((old_cflag & CBAUD) == B0) {
 467                 new_state = control_state | TIOCM_DTR;
 468                 /* don't set RTS if using hardware flow control */
 469                 if (!(old_cflag & CRTSCTS))
 470                         new_state |= TIOCM_RTS;
 471                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 472                         cs->minor_index,
 473                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 474                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 475                 control_state = new_state;
 476         }
 477
 478         cs->ops->baud_rate(cs, cflag & CBAUD);
 479
 480         if ((cflag & CBAUD) == B0) {
 481                 /* Drop RTS and DTR */
 482                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 483                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 484                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 485                 control_state = new_state;
 486         }
 487
 488         /*
 489          * Update line control register (LCR)
 490          */
 491
 492         cs->ops->set_line_ctrl(cs, cflag);
 493
 494         /* save off the modified port settings */
 495         cs->control_state = control_state;
 496
 497 out:
 498         mutex_unlock(&cs->mutex);
 499 }
 500
 501
 502 /* wakeup tasklet for the write operation */
 503 static void if_wake(unsigned long data)
 504 {
 505         struct cardstate *cs = (struct cardstate *)data;
 506         struct tty_struct *tty = tty_port_tty_get(&cs->port);
 507
 508         if (tty) {
 509                 tty_wakeup(tty);
 510                 tty_kref_put(tty);
 511         }
 512 }
 513
 514 /*** interface to common ***/
 515
 516 void gigaset_if_init(struct cardstate *cs)
 517 {
 518         struct gigaset_driver *drv;
 519
 520         drv = cs->driver;
 521         if (!drv->have_tty)
 522                 return;
 523
 524         tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
 525
 526         mutex_lock(&cs->mutex);
 527         cs->tty_dev = tty_register_device(drv->tty, cs->minor_index, NULL);
 528
 529         if (!IS_ERR(cs->tty_dev))
 530                 dev_set_drvdata(cs->tty_dev, cs);
 531         else {
 532                 pr_warning("could not register device to the tty subsystem\n");
 533                 cs->tty_dev = NULL;
 534         }
 535         mutex_unlock(&cs->mutex);
 536 }
 537
 538 void gigaset_if_free(struct cardstate *cs)
 539 {
 540         struct gigaset_driver *drv;
 541
 542         drv = cs->driver;
 543         if (!drv->have_tty)
 544                 return;
 545
 546         tasklet_disable(&cs->if_wake_tasklet);
 547         tasklet_kill(&cs->if_wake_tasklet);
 548         cs->tty_dev = NULL;
 549         tty_unregister_device(drv->tty, cs->minor_index);
 550 }
 551
 552 /**
 553  * gigaset_if_receive() - pass a received block of data to the tty device
 554  * @cs:         device descriptor structure.
 555  * @buffer:     received data.
 556  * @len:        number of bytes received.
 557  *
 558  * Called by asyncdata/isocdata if a block of data received from the
 559  * device must be sent to userspace through the ttyG* device.
 560  */
 561 void gigaset_if_receive(struct cardstate *cs,
 562                         unsigned char *buffer, size_t len)
 563 {
 564         struct tty_struct *tty = tty_port_tty_get(&cs->port);
 565
 566         if (tty == NULL) {
 567                 gig_dbg(DEBUG_IF, "receive on closed device");
 568                 return;
 569         }
 570
 571         tty_insert_flip_string(tty, buffer, len);
 572         tty_flip_buffer_push(tty);
 573         tty_kref_put(tty);
 574 }
 575 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 576
 577 /* gigaset_if_initdriver
 578  * Initialize tty interface.
 579  * parameters:
 580  *      drv             Driver
 581  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 582  *      devname         Name of the device files (prefix without minor number)
 583  */
 584 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 585                            const char *devname)
 586 {
 587         int ret;
 588         struct tty_driver *tty;
 589
 590         drv->have_tty = 0;
 591
 592         drv->tty = tty = alloc_tty_driver(drv->minors);
 593         if (tty == NULL)
 594                 goto enomem;
 595
 596         tty->type =             TTY_DRIVER_TYPE_SERIAL;
 597         tty->subtype =          SERIAL_TYPE_NORMAL;
 598         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 599
 600         tty->driver_name =      procname;
 601         tty->name =             devname;
 602         tty->minor_start =      drv->minor;
 603
 604         tty->init_termios          = tty_std_termios;
 605         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 606         tty_set_operations(tty, &if_ops);
 607
 608         ret = tty_register_driver(tty);
 609         if (ret < 0) {
 610                 pr_err("error %d registering tty driver\n", ret);
 611                 goto error;
 612         }
 613         gig_dbg(DEBUG_IF, "tty driver initialized");
 614         drv->have_tty = 1;
 615         return;
 616
 617 enomem:
 618         pr_err("out of memory\n");
 619 error:
 620         if (drv->tty)
 621                 put_tty_driver(drv->tty);
 622 }
 623
 624 void gigaset_if_freedriver(struct gigaset_driver *drv)
 625 {
 626         if (!drv->have_tty)
 627                 return;
 628
 629         drv->have_tty = 0;
 630         tty_unregister_driver(drv->tty);
 631         put_tty_driver(drv->tty);
 632 }