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, (const unsigned char *) arg);
 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 static int if_tiocmget(struct tty_struct *tty)
 237 {
 238         struct cardstate *cs = tty->driver_data;
 239         int retval;
 240
 241         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 242
 243         if (mutex_lock_interruptible(&cs->mutex))
 244                 return -ERESTARTSYS;
 245
 246         retval = cs->control_state & (TIOCM_RTS | TIOCM_DTR);
 247
 248         mutex_unlock(&cs->mutex);
 249
 250         return retval;
 251 }
 252
 253 static int if_tiocmset(struct tty_struct *tty,
 254                        unsigned int set, unsigned int clear)
 255 {
 256         struct cardstate *cs = tty->driver_data;
 257         int retval;
 258         unsigned mc;
 259
 260         gig_dbg(DEBUG_IF, "%u: %s(0x%x, 0x%x)",
 261                 cs->minor_index, __func__, set, clear);
 262
 263         if (mutex_lock_interruptible(&cs->mutex))
 264                 return -ERESTARTSYS;
 265
 266         if (!cs->connected) {
 267                 gig_dbg(DEBUG_IF, "not connected");
 268                 retval = -ENODEV;
 269         } else {
 270                 mc = (cs->control_state | set) & ~clear & (TIOCM_RTS | TIOCM_DTR);
 271                 retval = cs->ops->set_modem_ctrl(cs, cs->control_state, mc);
 272                 cs->control_state = mc;
 273         }
 274
 275         mutex_unlock(&cs->mutex);
 276
 277         return retval;
 278 }
 279
 280 static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
 281 {
 282         struct cardstate *cs = tty->driver_data;
 283         struct cmdbuf_t *cb;
 284         int retval;
 285
 286         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 287
 288         if (mutex_lock_interruptible(&cs->mutex))
 289                 return -ERESTARTSYS;
 290
 291         if (!cs->connected) {
 292                 gig_dbg(DEBUG_IF, "not connected");
 293                 retval = -ENODEV;
 294                 goto done;
 295         }
 296         if (cs->mstate != MS_LOCKED) {
 297                 dev_warn(cs->dev, "can't write to unlocked device\n");
 298                 retval = -EBUSY;
 299                 goto done;
 300         }
 301         if (count <= 0) {
 302                 /* nothing to do */
 303                 retval = 0;
 304                 goto done;
 305         }
 306
 307         cb = kmalloc(sizeof(struct cmdbuf_t) + count, GFP_KERNEL);
 308         if (!cb) {
 309                 dev_err(cs->dev, "%s: out of memory\n", __func__);
 310                 retval = -ENOMEM;
 311                 goto done;
 312         }
 313
 314         memcpy(cb->buf, buf, count);
 315         cb->len = count;
 316         cb->offset = 0;
 317         cb->next = NULL;
 318         cb->wake_tasklet = &cs->if_wake_tasklet;
 319         retval = cs->ops->write_cmd(cs, cb);
 320 done:
 321         mutex_unlock(&cs->mutex);
 322         return retval;
 323 }
 324
 325 static int if_write_room(struct tty_struct *tty)
 326 {
 327         struct cardstate *cs = tty->driver_data;
 328         int retval;
 329
 330         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 331
 332         if (mutex_lock_interruptible(&cs->mutex))
 333                 return -ERESTARTSYS;
 334
 335         if (!cs->connected) {
 336                 gig_dbg(DEBUG_IF, "not connected");
 337                 retval = -ENODEV;
 338         } else if (cs->mstate != MS_LOCKED) {
 339                 dev_warn(cs->dev, "can't write to unlocked device\n");
 340                 retval = -EBUSY;
 341         } else
 342                 retval = cs->ops->write_room(cs);
 343
 344         mutex_unlock(&cs->mutex);
 345
 346         return retval;
 347 }
 348
 349 static int if_chars_in_buffer(struct tty_struct *tty)
 350 {
 351         struct cardstate *cs = tty->driver_data;
 352         int retval = 0;
 353
 354         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 355
 356         mutex_lock(&cs->mutex);
 357
 358         if (!cs->connected)
 359                 gig_dbg(DEBUG_IF, "not connected");
 360         else if (cs->mstate != MS_LOCKED)
 361                 dev_warn(cs->dev, "can't write to unlocked device\n");
 362         else
 363                 retval = cs->ops->chars_in_buffer(cs);
 364
 365         mutex_unlock(&cs->mutex);
 366
 367         return retval;
 368 }
 369
 370 static void if_throttle(struct tty_struct *tty)
 371 {
 372         struct cardstate *cs = tty->driver_data;
 373
 374         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 375
 376         mutex_lock(&cs->mutex);
 377
 378         if (!cs->connected)
 379                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 380         else
 381                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 382
 383         mutex_unlock(&cs->mutex);
 384 }
 385
 386 static void if_unthrottle(struct tty_struct *tty)
 387 {
 388         struct cardstate *cs = tty->driver_data;
 389
 390         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 391
 392         mutex_lock(&cs->mutex);
 393
 394         if (!cs->connected)
 395                 gig_dbg(DEBUG_IF, "not connected");     /* nothing to do */
 396         else
 397                 gig_dbg(DEBUG_IF, "%s: not implemented\n", __func__);
 398
 399         mutex_unlock(&cs->mutex);
 400 }
 401
 402 static void if_set_termios(struct tty_struct *tty, struct ktermios *old)
 403 {
 404         struct cardstate *cs = tty->driver_data;
 405         unsigned int iflag;
 406         unsigned int cflag;
 407         unsigned int old_cflag;
 408         unsigned int control_state, new_state;
 409
 410         gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
 411
 412         mutex_lock(&cs->mutex);
 413
 414         if (!cs->connected) {
 415                 gig_dbg(DEBUG_IF, "not connected");
 416                 goto out;
 417         }
 418
 419         iflag = tty->termios.c_iflag;
 420         cflag = tty->termios.c_cflag;
 421         old_cflag = old ? old->c_cflag : cflag;
 422         gig_dbg(DEBUG_IF, "%u: iflag %x cflag %x old %x",
 423                 cs->minor_index, iflag, cflag, old_cflag);
 424
 425         /* get a local copy of the current port settings */
 426         control_state = cs->control_state;
 427
 428         /*
 429          * Update baud rate.
 430          * Do not attempt to cache old rates and skip settings,
 431          * disconnects screw such tricks up completely.
 432          * Premature optimization is the root of all evil.
 433          */
 434
 435         /* reassert DTR and (maybe) RTS on transition from B0 */
 436         if ((old_cflag & CBAUD) == B0) {
 437                 new_state = control_state | TIOCM_DTR;
 438                 /* don't set RTS if using hardware flow control */
 439                 if (!(old_cflag & CRTSCTS))
 440                         new_state |= TIOCM_RTS;
 441                 gig_dbg(DEBUG_IF, "%u: from B0 - set DTR%s",
 442                         cs->minor_index,
 443                         (new_state & TIOCM_RTS) ? " only" : "/RTS");
 444                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 445                 control_state = new_state;
 446         }
 447
 448         cs->ops->baud_rate(cs, cflag & CBAUD);
 449
 450         if ((cflag & CBAUD) == B0) {
 451                 /* Drop RTS and DTR */
 452                 gig_dbg(DEBUG_IF, "%u: to B0 - drop DTR/RTS", cs->minor_index);
 453                 new_state = control_state & ~(TIOCM_DTR | TIOCM_RTS);
 454                 cs->ops->set_modem_ctrl(cs, control_state, new_state);
 455                 control_state = new_state;
 456         }
 457
 458         /*
 459          * Update line control register (LCR)
 460          */
 461
 462         cs->ops->set_line_ctrl(cs, cflag);
 463
 464         /* save off the modified port settings */
 465         cs->control_state = control_state;
 466
 467 out:
 468         mutex_unlock(&cs->mutex);
 469 }
 470
 471 static const struct tty_operations if_ops = {
 472         .open =                 if_open,
 473         .close =                if_close,
 474         .ioctl =                if_ioctl,
 475         .write =                if_write,
 476         .write_room =           if_write_room,
 477         .chars_in_buffer =      if_chars_in_buffer,
 478         .set_termios =          if_set_termios,
 479         .throttle =             if_throttle,
 480         .unthrottle =           if_unthrottle,
 481         .tiocmget =             if_tiocmget,
 482         .tiocmset =             if_tiocmset,
 483 };
 484
 485
 486 /* wakeup tasklet for the write operation */
 487 static void if_wake(unsigned long data)
 488 {
 489         struct cardstate *cs = (struct cardstate *)data;
 490         struct tty_struct *tty = tty_port_tty_get(&cs->port);
 491
 492         if (tty) {
 493                 tty_wakeup(tty);
 494                 tty_kref_put(tty);
 495         }
 496 }
 497
 498 /*** interface to common ***/
 499
 500 void gigaset_if_init(struct cardstate *cs)
 501 {
 502         struct gigaset_driver *drv;
 503
 504         drv = cs->driver;
 505         if (!drv->have_tty)
 506                 return;
 507
 508         tasklet_init(&cs->if_wake_tasklet, if_wake, (unsigned long) cs);
 509
 510         mutex_lock(&cs->mutex);
 511         cs->tty_dev = tty_port_register_device(&cs->port, drv->tty,
 512                         cs->minor_index, NULL);
 513
 514         if (!IS_ERR(cs->tty_dev))
 515                 dev_set_drvdata(cs->tty_dev, cs);
 516         else {
 517                 pr_warning("could not register device to the tty subsystem\n");
 518                 cs->tty_dev = NULL;
 519         }
 520         mutex_unlock(&cs->mutex);
 521 }
 522
 523 void gigaset_if_free(struct cardstate *cs)
 524 {
 525         struct gigaset_driver *drv;
 526
 527         drv = cs->driver;
 528         if (!drv->have_tty)
 529                 return;
 530
 531         tasklet_disable(&cs->if_wake_tasklet);
 532         tasklet_kill(&cs->if_wake_tasklet);
 533         cs->tty_dev = NULL;
 534         tty_unregister_device(drv->tty, cs->minor_index);
 535 }
 536
 537 /**
 538  * gigaset_if_receive() - pass a received block of data to the tty device
 539  * @cs:         device descriptor structure.
 540  * @buffer:     received data.
 541  * @len:        number of bytes received.
 542  *
 543  * Called by asyncdata/isocdata if a block of data received from the
 544  * device must be sent to userspace through the ttyG* device.
 545  */
 546 void gigaset_if_receive(struct cardstate *cs,
 547                         unsigned char *buffer, size_t len)
 548 {
 549         tty_insert_flip_string(&cs->port, buffer, len);
 550         tty_flip_buffer_push(&cs->port);
 551 }
 552 EXPORT_SYMBOL_GPL(gigaset_if_receive);
 553
 554 /* gigaset_if_initdriver
 555  * Initialize tty interface.
 556  * parameters:
 557  *      drv             Driver
 558  *      procname        Name of the driver (e.g. for /proc/tty/drivers)
 559  *      devname         Name of the device files (prefix without minor number)
 560  */
 561 void gigaset_if_initdriver(struct gigaset_driver *drv, const char *procname,
 562                            const char *devname)
 563 {
 564         int ret;
 565         struct tty_driver *tty;
 566
 567         drv->have_tty = 0;
 568
 569         drv->tty = tty = alloc_tty_driver(drv->minors);
 570         if (tty == NULL)
 571                 goto enomem;
 572
 573         tty->type =             TTY_DRIVER_TYPE_SERIAL;
 574         tty->subtype =          SERIAL_TYPE_NORMAL;
 575         tty->flags =            TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 576
 577         tty->driver_name =      procname;
 578         tty->name =             devname;
 579         tty->minor_start =      drv->minor;
 580
 581         tty->init_termios          = tty_std_termios;
 582         tty->init_termios.c_cflag  = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 583         tty_set_operations(tty, &if_ops);
 584
 585         ret = tty_register_driver(tty);
 586         if (ret < 0) {
 587                 pr_err("error %d registering tty driver\n", ret);
 588                 goto error;
 589         }
 590         gig_dbg(DEBUG_IF, "tty driver initialized");
 591         drv->have_tty = 1;
 592         return;
 593
 594 enomem:
 595         pr_err("out of memory\n");
 596 error:
 597         if (drv->tty)
 598                 put_tty_driver(drv->tty);
 599 }
 600
 601 void gigaset_if_freedriver(struct gigaset_driver *drv)
 602 {
 603         if (!drv->have_tty)
 604                 return;
 605
 606         drv->have_tty = 0;
 607         tty_unregister_driver(drv->tty);
 608         put_tty_driver(drv->tty);
 609 }