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
 116 static int if_open(struct tty_struct *tty, struct file *filp)
 117 {
 118         struct cardstate *cs;
 119
 120         gig_dbg(DEBUG_IF, "%d+%d: %s()",
 121                 tty->driver->minor_start, tty->index, __func__);
 122
 123         cs = gigaset_get_cs_by_tty(tty);
 124         if (!cs || !try_module_get(cs->driver->owner))
 125                 return -ENODEV;
 126
 127         if (mutex_lock_interruptible(&cs->mutex)) {
 128                 module_put(cs->driver->owner);
 129                 return -ERESTARTSYS;
 130         }
 131         tty->driver_data = cs;
 132
 133         ++cs->port.count;
 134
 135         if (cs->port.count == 1) {
 136                 tty_port_tty_set(&cs->port, tty);
 137                 cs->port.low_latency = 1;
 138         }
 139
 140         mutex_unlock(&cs->mutex);
 141         return 0;
 142 }
 143
 144 static void if_close(struct tty_struct *tty, struct file *filp)
 145 {
 146         struct cardstate *cs = tty->driver_data;
 147
 148         if (!cs) { /* happens if we didn't find cs in open */
 149                 gig_dbg(DEBUG_IF, "%s: no cardstate", __func__);
 150                 return;
 151         }
 152
 153         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 154
 155         mutex_lock(&cs->mutex);
 156
 157         if (!cs->connected)
 158                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 159         else if (!cs->port.count)
 160                 dev_warn(cs->dev, "%s: device not opened\n", __func__);
 161         else if (!--cs->port.count)
 162                 tty_port_tty_set(&cs->port, NULL);
 163
 164         mutex_unlock(&cs->mutex);
 165
 166         module_put(cs->driver->owner);
 167 }
 168
 169 static int if_ioctl(struct tty_struct *tty,
 170                     unsigned int cmd, unsigned long arg)
 171 {
 172         struct cardstate *cs = tty->driver_data;
 173         int retval = -ENODEV;
 174         int int_arg;
 175         unsigned char buf[6];
 176         unsigned version[4];
 177
 178         gig_dbg(DEBUG_IF, "%u: %s(0x%x)", cs->minor_index, __func__, cmd);
 179
 180         if (mutex_lock_interruptible(&cs->mutex))
 181                 return -ERESTARTSYS;
 182
 183         if (!cs->connected) {
 184                 gig_dbg(DEBUG_IF, "not connected");
 185                 retval = -ENODEV;
 186         } else {
 187                 retval = 0;
 188                 switch (cmd) {
 189                 case GIGASET_REDIR:
 190                         retval = get_user(int_arg, (int __user *) arg);
 191                         if (retval >= 0)
 192                                 retval = if_lock(cs, &int_arg);
 193                         if (retval >= 0)
 194                                 retval = put_user(int_arg, (int __user *) arg);
 195                         break;
 196                 case GIGASET_CONFIG:
 197                         retval = get_user(int_arg, (int __user *) arg);
 198                         if (retval >= 0)
 199                                 retval = if_config(cs, &int_arg);
 200                         if (retval >= 0)
 201                                 retval = put_user(int_arg, (int __user *) arg);
 202                         break;
 203                 case GIGASET_BRKCHARS:
 204                         retval = copy_from_user(&buf,
 205                                                 (const unsigned char __user *) arg, 6)
 206                                 ? -EFAULT : 0;
 207                         if (retval >= 0) {
 208                                 gigaset_dbg_buffer(DEBUG_IF, "GIGASET_BRKCHARS",
 209                                                    6, buf);
 210                                 retval = cs->ops->brkchars(cs, buf);
 211                         }
 212                         break;
 213                 case GIGASET_VERSION:
 214                         retval = copy_from_user(version,
 215                                                 (unsigned __user *) arg, sizeof version)
 216                                 ? -EFAULT : 0;
 217                         if (retval >= 0)
 218                                 retval = if_version(cs, version);
 219                         if (retval >= 0)
 220                                 retval = copy_to_user((unsigned __user *) arg,
 221                                                       version, sizeof version)
 222                                         ? -EFAULT : 0;
 223                         break;
 224                 default:
 225                         gig_dbg(DEBUG_IF, "%s: arg not supported - 0x%04x",
 226                                 __func__, cmd);
 227                         retval = -ENOIOCTLCMD;
 228                 }
 229         }
 230
 231         mutex_unlock(&cs->mutex);
 232
 233         return retval;
 234 }
 235
 236 #ifdef CONFIG_COMPAT
 237 static long if_compat_ioctl(struct tty_struct *tty,
 238                     unsigned int cmd, unsigned long arg)
 239 {
 240         return if_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
 241 }
 242 #endif
 243
 244 static int if_tiocmget(struct tty_struct *tty)
 245 {
 246         struct cardstate *cs = tty->driver_data;
 247         int retval;
 248
 249         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 250
 251         if (mutex_lock_interruptible(&cs->mutex))
 252                 return -ERESTARTSYS;
 253
 254         retval = cs->control_state & (TIOCM_RTS | TIOCM_DTR);
 255
 256         mutex_unlock(&cs->mutex);
 257
 258         return retval;
 259 }
 260
 261 static int if_tiocmset(struct tty_struct *tty,
 262                        unsigned int set, unsigned int clear)
 263 {
 264         struct cardstate *cs = tty->driver_data;
 265         int retval;
 266         unsigned mc;
 267
 268         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 269                 cs->minor_index, __func__, set, clear);
 270
 271         if (mutex_lock_interruptible(&cs->mutex))
 272                 return -ERESTARTSYS;
 273
 274         if (!cs->connected) {
 275                 gig_dbg(DEBUG_IF, "not connected");
 276                 retval = -ENODEV;
 277         } else {
 278                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS | TIOCM_DTR);
 279                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 280                 cs->control_state = mc;
 281         }
 282
 283         mutex_unlock(&cs->mutex);
 284
 285         return retval;
 286 }
 287
 288 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 289 {
 290         struct cardstate *cs = tty->driver_data;
 291         struct cmdbuf_t *cb;
 292         int retval;
 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         if (!cs->connected) {
 300                 gig_dbg(DEBUG_IF, "not connected");
 301                 retval = -ENODEV;
 302                 goto done;
 303         }
 304         if (cs->mstate != MS_LOCKED) {
 305                 dev_warn(cs->dev, "can't write to unlocked device\n");
 306                 retval = -EBUSY;
 307                 goto done;
 308         }
 309         if (count <= 0) {
 310                 /* nothing to do */
 311                 retval = 0;
 312                 goto done;
 313         }
 314
 315         cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
 316         if (!cb) {
 317                 dev_err(cs->dev, "%s: out of memory\n", __func__);
 318                 retval = -ENOMEM;
 319                 goto done;
 320         }
 321
 322         memcpy(cb->buf, buf, count);
 323         cb->len = count;
 324         cb->offset = 0;
 325         cb->next = NULL;
 326         cb->wake_tasklet = &cs->if_wake_tasklet;
 327         retval = cs->ops->write_cmd(cs, cb);
 328 done:
 329         mutex_unlock(&cs->mutex);
 330         return retval;
 331 }
 332
 333 static int if_write_room(struct tty_struct *tty)
 334 {
 335         struct cardstate *cs = tty->driver_data;
 336         int retval;
 337
 338         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 339
 340         if (mutex_lock_interruptible(&cs->mutex))
 341                 return -ERESTARTSYS;
 342
 343         if (!cs->connected) {
 344                 gig_dbg(DEBUG_IF, "not connected");
 345                 retval = -ENODEV;
 346         } else if (cs->mstate != MS_LOCKED) {
 347                 dev_warn(cs->dev, "can't write to unlocked device\n");
 348                 retval = -EBUSY;
 349         } else
 350                 retval = cs->ops->write_room(cs);
 351
 352         mutex_unlock(&cs->mutex);
 353
 354         return retval;
 355 }
 356
 357 static int if_chars_in_buffer(struct tty_struct *tty)
 358 {
 359         struct cardstate *cs = tty->driver_data;
 360         int retval = 0;
 361
 362         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 363
 364         mutex_lock(&cs->mutex);
 365
 366         if (!cs->connected)
 367                 gig_dbg(DEBUG_IF, "not connected");
 368         else if (cs->mstate != MS_LOCKED)
 369                 dev_warn(cs->dev, "can't write to unlocked device\n");
 370         else
 371                 retval = cs->ops->chars_in_buffer(cs);
 372
 373         mutex_unlock(&cs->mutex);
 374
 375         return retval;
 376 }
 377
 378 static void if_throttle(struct tty_struct *tty)
 379 {
 380         struct cardstate *cs = tty->driver_data;
 381
 382         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 383
 384         mutex_lock(&cs->mutex);
 385
 386         if (!cs->connected)
 387                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 388         else
 389                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 390
 391         mutex_unlock(&cs->mutex);
 392 }
 393
 394 static void if_unthrottle(struct tty_struct *tty)
 395 {
 396         struct cardstate *cs = tty->driver_data;
 397
 398         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 399
 400         mutex_lock(&cs->mutex);
 401
 402         if (!cs->connected)
 403                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 404         else
 405                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 406
 407         mutex_unlock(&cs->mutex);
 408 }
 409
 410 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
 411 {
 412         struct cardstate *cs = tty->driver_data;
 413         unsigned int iflag;
 414         unsigned int cflag;
 415         unsigned int old_cflag;
 416         unsigned int control_state, new_state;
 417
 418         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 419
 420         mutex_lock(&cs->mutex);
 421
 422         if (!cs->connected) {
 423                 gig_dbg(DEBUG_IF, "not connected");
 424                 goto out;
 425         }
 426
 427         iflag = tty->termios.c_iflag;
 428         cflag = tty->termios.c_cflag;
 429         old_cflag = old ? old->c_cflag : cflag;
 430         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 431                 cs->minor_index, iflag, cflag, old_cflag);
 432
 433         /* get a local copy of the current port settings */
 434         control_state = cs->control_state;
 435
 436         /*
 437          * Update baud rate.
 438          * Do not attempt to cache old rates and skip settings,
 439          * disconnects screw such tricks up completely.
 440          * Premature optimization is the root of all evil.
 441          */
 442
 443         /* reassert DTR and (maybe) RTS on transition from B0 */
 444         if ((old_cflag & CBAUD) == B0) {
 445                 new_state = control_state | TIOCM_DTR;
 446                 /* don't set RTS if using hardware flow control */
 447                 if (!(old_cflag & CRTSCTS))
 448                         new_state |= TIOCM_RTS;
 449                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 450                         cs->minor_index,
 451                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 452                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 453                 control_state = new_state;
 454         }
 455
 456         cs->ops->baud_rate(cs, cflag & CBAUD);
 457
 458         if ((cflag & CBAUD) == B0) {
 459                 /* Drop RTS and DTR */
 460                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 461                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 462                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 463                 control_state = new_state;
 464         }
 465
 466         /*
 467          * Update line control register (LCR)
 468          */
 469
 470         cs->ops->set_line_ctrl(cs, cflag);
 471
 472         /* save off the modified port settings */
 473         cs->control_state = control_state;
 474
 475 out:
 476         mutex_unlock(&cs->mutex);
 477 }
 478
 479 static const struct tty_operations if_ops = {
 480         .open =                 if_open,
 481         .close =                if_close,
 482         .ioctl =                if_ioctl,
 483 #ifdef CONFIG_COMPAT
 484         .compat_ioctl =         if_compat_ioctl,
 485 #endif
 486         .write =                if_write,
 487         .write_room =           if_write_room,
 488         .chars_in_buffer =      if_chars_in_buffer,
 489         .set_termios =          if_set_termios,
 490         .throttle =             if_throttle,
 491         .unthrottle =           if_unthrottle,
 492         .tiocmget =             if_tiocmget,
 493         .tiocmset =             if_tiocmset,
 494 };
 495
 496
 497 /* wakeup tasklet for the write operation */
 498 static void if_wake(unsigned long data)
 499 {
 500         struct cardstate *cs = (struct cardstate *)data;
 501
 502         tty_port_tty_wakeup(&cs->port);
 503 }
 504
 505 /*** interface to common ***/
 506
 507 void gigaset_if_init(struct cardstate *cs)
 508 {
 509         struct gigaset_driver *drv;
 510
 511         drv = cs->driver;
 512         if (!drv->have_tty)
 513                 return;
 514
 515         tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
 516
 517         mutex_lock(&cs->mutex);
 518         cs->tty_dev = tty_port_register_device(&cs->port, drv->tty,
 519                         cs->minor_index, NULL);
 520
 521         if (!IS_ERR(cs->tty_dev))
 522                 dev_set_drvdata(cs->tty_dev, cs);
 523         else {
 524                 pr_warning("could not register device to the tty subsystem\n");
 525                 cs->tty_dev = NULL;
 526         }
 527         mutex_unlock(&cs->mutex);
 528 }
 529
 530 void gigaset_if_free(struct cardstate *cs)
 531 {
 532         struct gigaset_driver *drv;
 533
 534         drv = cs->driver;
 535         if (!drv->have_tty)
 536                 return;
 537
 538         tasklet_disable(&cs->if_wake_tasklet);
 539         tasklet_kill(&cs->if_wake_tasklet);
 540         cs->tty_dev = NULL;
 541         tty_unregister_device(drv->tty, cs->minor_index);
 542 }
 543
 544 /**
 545  * gigaset_if_receive() - pass a received block of data to the tty device
 546  * @cs:         device descriptor structure.
 547  * @buffer:     received data.
 548  * @len:        number of bytes received.
 549  *
 550  * Called by asyncdata/isocdata if a block of data received from the
 551  * device must be sent to userspace through the ttyG* device.
 552  */
 553 void gigaset_if_receive(struct cardstate *cs,
 554                         unsigned char *buffer, size_t len)
 555 {
 556         tty_insert_flip_string(&cs->port, buffer, len);
 557         tty_flip_buffer_push(&cs->port);
 558 }
 559 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 560
 561 /* gigaset_if_initdriver
 562  * Initialize tty interface.
 563  * parameters:
 564  *      drv             Driver
 565  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 566  *      devname         Name of the device files (prefix without minor number)
 567  */
 568 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 569                            const char *devname)
 570 {
 571         int ret;
 572         struct tty_driver *tty;
 573
 574         drv->have_tty = 0;
 575
 576         drv->tty = tty = alloc_tty_driver(drv->minors);
 577         if (tty == NULL)
 578                 goto enomem;
 579
 580         tty->type =             TTY_DRIVER_TYPE_SERIAL;
 581         tty->subtype =          SERIAL_TYPE_NORMAL;
 582         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 583
 584         tty->driver_name =      procname;
 585         tty->name =             devname;
 586         tty->minor_start =      drv->minor;
 587
 588         tty->init_termios          = tty_std_termios;
 589         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 590         tty_set_operations(tty, &if_ops);
 591
 592         ret = tty_register_driver(tty);
 593         if (ret < 0) {
 594                 pr_err("error %d registering tty driver\n", ret);
 595                 goto error;
 596         }
 597         gig_dbg(DEBUG_IF, "tty driver initialized");
 598         drv->have_tty = 1;
 599         return;
 600
 601 enomem:
 602         pr_err("out of memory\n");
 603 error:
 604         if (drv->tty)
 605                 put_tty_driver(drv->tty);
 606 }
 607
 608 void gigaset_if_freedriver(struct gigaset_driver *drv)
 609 {
 610         if (!drv->have_tty)
 611                 return;
 612
 613         drv->have_tty = 0;
 614         tty_unregister_driver(drv->tty);
 615         put_tty_driver(drv->tty);
 616 }