drivers/tty/ipwireless/tty.c

   1 /*
   2  * IPWireless 3G PCMCIA Network Driver
   3  *
   4  * Original code
   5  *   by Stephen Blackheath <stephen@blacksapphire.com>,
   6  *      Ben Martel <benm@symmetric.co.nz>
   7  *
   8  * Copyrighted as follows:
   9  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
  10  *
  11  * Various driver changes and rewrites, port to new kernels
  12  *   Copyright (C) 2006-2007 Jiri Kosina
  13  *
  14  * Misc code cleanups and updates
  15  *   Copyright (C) 2007 David Sterba
  16  */
  17
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/ppp_defs.h>
  23 #include <linux/if.h>
  24 #include <linux/ppp-ioctl.h>
  25 #include <linux/sched.h>
  26 #include <linux/serial.h>
  27 #include <linux/slab.h>
  28 #include <linux/tty.h>
  29 #include <linux/tty_driver.h>
  30 #include <linux/tty_flip.h>
  31 #include <linux/uaccess.h>
  32
  33 #include "tty.h"
  34 #include "network.h"
  35 #include "hardware.h"
  36 #include "main.h"
  37
  38 #define IPWIRELESS_PCMCIA_START         (0)
  39 #define IPWIRELESS_PCMCIA_MINORS        (24)
  40 #define IPWIRELESS_PCMCIA_MINOR_RANGE   (8)
  41
  42 #define TTYTYPE_MODEM    (0)
  43 #define TTYTYPE_MONITOR  (1)
  44 #define TTYTYPE_RAS_RAW  (2)
  45
  46 struct ipw_tty {
  47         struct tty_port port;
  48         int index;
  49         struct ipw_hardware *hardware;
  50         unsigned int channel_idx;
  51         unsigned int secondary_channel_idx;
  52         int tty_type;
  53         struct ipw_network *network;
  54         unsigned int control_lines;
  55         struct mutex ipw_tty_mutex;
  56         int tx_bytes_queued;
  57         int closing;
  58 };
  59
  60 static struct ipw_tty *ttys[IPWIRELESS_PCMCIA_MINORS];
  61
  62 static struct tty_driver *ipw_tty_driver;
  63
  64 static char *tty_type_name(int tty_type)
  65 {
  66         static char *channel_names[] = {
  67                 "modem",
  68                 "monitor",
  69                 "RAS-raw"
  70         };
  71
  72         return channel_names[tty_type];
  73 }
  74
  75 static struct ipw_tty *get_tty(int index)
  76 {
  77         /*
  78          * The 'ras_raw' channel is only available when 'loopback' mode
  79          * is enabled.
  80          * Number of minor starts with 16 (_RANGE * _RAS_RAW).
  81          */
  82         if (!ipwireless_loopback && index >=
  83                          IPWIRELESS_PCMCIA_MINOR_RANGE * TTYTYPE_RAS_RAW)
  84                 return NULL;
  85
  86         return ttys[index];
  87 }
  88
  89 static int ipw_open(struct tty_struct *linux_tty, struct file *filp)
  90 {
  91         struct ipw_tty *tty = get_tty(linux_tty->index);
  92
  93         if (!tty)
  94                 return -ENODEV;
  95
  96         mutex_lock(&tty->ipw_tty_mutex);
  97
  98         if (tty->closing) {
  99                 mutex_unlock(&tty->ipw_tty_mutex);
 100                 return -ENODEV;
 101         }
 102         if (tty->port.count == 0)
 103                 tty->tx_bytes_queued = 0;
 104
 105         tty->port.count++;
 106
 107         tty->port.tty = linux_tty;
 108         linux_tty->driver_data = tty;
 109         tty->port.low_latency = 1;
 110
 111         if (tty->tty_type == TTYTYPE_MODEM)
 112                 ipwireless_ppp_open(tty->network);
 113
 114         mutex_unlock(&tty->ipw_tty_mutex);
 115
 116         return 0;
 117 }
 118
 119 static void do_ipw_close(struct ipw_tty *tty)
 120 {
 121         tty->port.count--;
 122
 123         if (tty->port.count == 0) {
 124                 struct tty_struct *linux_tty = tty->port.tty;
 125
 126                 if (linux_tty != NULL) {
 127                         tty->port.tty = NULL;
 128                         linux_tty->driver_data = NULL;
 129
 130                         if (tty->tty_type == TTYTYPE_MODEM)
 131                                 ipwireless_ppp_close(tty->network);
 132                 }
 133         }
 134 }
 135
 136 static void ipw_hangup(struct tty_struct *linux_tty)
 137 {
 138         struct ipw_tty *tty = linux_tty->driver_data;
 139
 140         if (!tty)
 141                 return;
 142
 143         mutex_lock(&tty->ipw_tty_mutex);
 144         if (tty->port.count == 0) {
 145                 mutex_unlock(&tty->ipw_tty_mutex);
 146                 return;
 147         }
 148
 149         do_ipw_close(tty);
 150
 151         mutex_unlock(&tty->ipw_tty_mutex);
 152 }
 153
 154 static void ipw_close(struct tty_struct *linux_tty, struct file *filp)
 155 {
 156         ipw_hangup(linux_tty);
 157 }
 158
 159 /* Take data received from hardware, and send it out the tty */
 160 void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
 161                         unsigned int length)
 162 {
 163         int work = 0;
 164
 165         mutex_lock(&tty->ipw_tty_mutex);
 166
 167         if (!tty->port.count) {
 168                 mutex_unlock(&tty->ipw_tty_mutex);
 169                 return;
 170         }
 171         mutex_unlock(&tty->ipw_tty_mutex);
 172
 173         work = tty_insert_flip_string(&tty->port, data, length);
 174
 175         if (work != length)
 176                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
 177                                 ": %d chars not inserted to flip buffer!\n",
 178                                 length - work);
 179
 180         if (work)
 181                 tty_flip_buffer_push(&tty->port);
 182 }
 183
 184 static void ipw_write_packet_sent_callback(void *callback_data,
 185                                            unsigned int packet_length)
 186 {
 187         struct ipw_tty *tty = callback_data;
 188
 189         /*
 190          * Packet has been sent, so we subtract the number of bytes from our
 191          * tally of outstanding TX bytes.
 192          */
 193         tty->tx_bytes_queued -= packet_length;
 194 }
 195
 196 static int ipw_write(struct tty_struct *linux_tty,
 197                      const unsigned char *buf, int count)
 198 {
 199         struct ipw_tty *tty = linux_tty->driver_data;
 200         int room, ret;
 201
 202         if (!tty)
 203                 return -ENODEV;
 204
 205         mutex_lock(&tty->ipw_tty_mutex);
 206         if (!tty->port.count) {
 207                 mutex_unlock(&tty->ipw_tty_mutex);
 208                 return -EINVAL;
 209         }
 210
 211         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
 212         if (room < 0)
 213                 room = 0;
 214         /* Don't allow caller to write any more than we have room for */
 215         if (count > room)
 216                 count = room;
 217
 218         if (count == 0) {
 219                 mutex_unlock(&tty->ipw_tty_mutex);
 220                 return 0;
 221         }
 222
 223         ret = ipwireless_send_packet(tty->hardware, IPW_CHANNEL_RAS,
 224                                buf, count,
 225                                ipw_write_packet_sent_callback, tty);
 226         if (ret == -1) {
 227                 mutex_unlock(&tty->ipw_tty_mutex);
 228                 return 0;
 229         }
 230
 231         tty->tx_bytes_queued += count;
 232         mutex_unlock(&tty->ipw_tty_mutex);
 233
 234         return count;
 235 }
 236
 237 static int ipw_write_room(struct tty_struct *linux_tty)
 238 {
 239         struct ipw_tty *tty = linux_tty->driver_data;
 240         int room;
 241
 242         /* FIXME: Exactly how is the tty object locked here .. */
 243         if (!tty)
 244                 return -ENODEV;
 245
 246         if (!tty->port.count)
 247                 return -EINVAL;
 248
 249         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
 250         if (room < 0)
 251                 room = 0;
 252
 253         return room;
 254 }
 255
 256 static int ipwireless_get_serial_info(struct ipw_tty *tty,
 257                                       struct serial_struct __user *retinfo)
 258 {
 259         struct serial_struct tmp;
 260
 261         if (!retinfo)
 262                 return (-EFAULT);
 263
 264         memset(&tmp, 0, sizeof(tmp));
 265         tmp.type = PORT_UNKNOWN;
 266         tmp.line = tty->index;
 267         tmp.port = 0;
 268         tmp.irq = 0;
 269         tmp.flags = 0;
 270         tmp.baud_base = 115200;
 271         tmp.close_delay = 0;
 272         tmp.closing_wait = 0;
 273         tmp.custom_divisor = 0;
 274         tmp.hub6 = 0;
 275         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 276                 return -EFAULT;
 277
 278         return 0;
 279 }
 280
 281 static int ipw_chars_in_buffer(struct tty_struct *linux_tty)
 282 {
 283         struct ipw_tty *tty = linux_tty->driver_data;
 284
 285         if (!tty)
 286                 return 0;
 287
 288         if (!tty->port.count)
 289                 return 0;
 290
 291         return tty->tx_bytes_queued;
 292 }
 293
 294 static int get_control_lines(struct ipw_tty *tty)
 295 {
 296         unsigned int my = tty->control_lines;
 297         unsigned int out = 0;
 298
 299         if (my & IPW_CONTROL_LINE_RTS)
 300                 out |= TIOCM_RTS;
 301         if (my & IPW_CONTROL_LINE_DTR)
 302                 out |= TIOCM_DTR;
 303         if (my & IPW_CONTROL_LINE_CTS)
 304                 out |= TIOCM_CTS;
 305         if (my & IPW_CONTROL_LINE_DSR)
 306                 out |= TIOCM_DSR;
 307         if (my & IPW_CONTROL_LINE_DCD)
 308                 out |= TIOCM_CD;
 309
 310         return out;
 311 }
 312
 313 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
 314                              unsigned int clear)
 315 {
 316         int ret;
 317
 318         if (set & TIOCM_RTS) {
 319                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
 320                 if (ret)
 321                         return ret;
 322                 if (tty->secondary_channel_idx != -1) {
 323                         ret = ipwireless_set_RTS(tty->hardware,
 324                                           tty->secondary_channel_idx, 1);
 325                         if (ret)
 326                                 return ret;
 327                 }
 328         }
 329         if (set & TIOCM_DTR) {
 330                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
 331                 if (ret)
 332                         return ret;
 333                 if (tty->secondary_channel_idx != -1) {
 334                         ret = ipwireless_set_DTR(tty->hardware,
 335                                           tty->secondary_channel_idx, 1);
 336                         if (ret)
 337                                 return ret;
 338                 }
 339         }
 340         if (clear & TIOCM_RTS) {
 341                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
 342                 if (tty->secondary_channel_idx != -1) {
 343                         ret = ipwireless_set_RTS(tty->hardware,
 344                                           tty->secondary_channel_idx, 0);
 345                         if (ret)
 346                                 return ret;
 347                 }
 348         }
 349         if (clear & TIOCM_DTR) {
 350                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
 351                 if (tty->secondary_channel_idx != -1) {
 352                         ret = ipwireless_set_DTR(tty->hardware,
 353                                           tty->secondary_channel_idx, 0);
 354                         if (ret)
 355                                 return ret;
 356                 }
 357         }
 358         return 0;
 359 }
 360
 361 static int ipw_tiocmget(struct tty_struct *linux_tty)
 362 {
 363         struct ipw_tty *tty = linux_tty->driver_data;
 364         /* FIXME: Exactly how is the tty object locked here .. */
 365
 366         if (!tty)
 367                 return -ENODEV;
 368
 369         if (!tty->port.count)
 370                 return -EINVAL;
 371
 372         return get_control_lines(tty);
 373 }
 374
 375 static int
 376 ipw_tiocmset(struct tty_struct *linux_tty,
 377              unsigned int set, unsigned int clear)
 378 {
 379         struct ipw_tty *tty = linux_tty->driver_data;
 380         /* FIXME: Exactly how is the tty object locked here .. */
 381
 382         if (!tty)
 383                 return -ENODEV;
 384
 385         if (!tty->port.count)
 386                 return -EINVAL;
 387
 388         return set_control_lines(tty, set, clear);
 389 }
 390
 391 static int ipw_ioctl(struct tty_struct *linux_tty,
 392                      unsigned int cmd, unsigned long arg)
 393 {
 394         struct ipw_tty *tty = linux_tty->driver_data;
 395
 396         if (!tty)
 397                 return -ENODEV;
 398
 399         if (!tty->port.count)
 400                 return -EINVAL;
 401
 402         /* FIXME: Exactly how is the tty object locked here .. */
 403
 404         switch (cmd) {
 405         case TIOCGSERIAL:
 406                 return ipwireless_get_serial_info(tty, (void __user *) arg);
 407
 408         case TIOCSSERIAL:
 409                 return 0;       /* Keeps the PCMCIA scripts happy. */
 410         }
 411
 412         if (tty->tty_type == TTYTYPE_MODEM) {
 413                 switch (cmd) {
 414                 case PPPIOCGCHAN:
 415                         {
 416                                 int chan = ipwireless_ppp_channel_index(
 417                                                         tty->network);
 418
 419                                 if (chan < 0)
 420                                         return -ENODEV;
 421                                 if (put_user(chan, (int __user *) arg))
 422                                         return -EFAULT;
 423                         }
 424                         return 0;
 425
 426                 case PPPIOCGUNIT:
 427                         {
 428                                 int unit = ipwireless_ppp_unit_number(
 429                                                 tty->network);
 430
 431                                 if (unit < 0)
 432                                         return -ENODEV;
 433                                 if (put_user(unit, (int __user *) arg))
 434                                         return -EFAULT;
 435                         }
 436                         return 0;
 437
 438                 case FIONREAD:
 439                         {
 440                                 int val = 0;
 441
 442                                 if (put_user(val, (int __user *) arg))
 443                                         return -EFAULT;
 444                         }
 445                         return 0;
 446                 case TCFLSH:
 447                         return tty_perform_flush(linux_tty, arg);
 448                 }
 449         }
 450         return -ENOIOCTLCMD;
 451 }
 452
 453 static int add_tty(int j,
 454                     struct ipw_hardware *hardware,
 455                     struct ipw_network *network, int channel_idx,
 456                     int secondary_channel_idx, int tty_type)
 457 {
 458         ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
 459         if (!ttys[j])
 460                 return -ENOMEM;
 461         ttys[j]->index = j;
 462         ttys[j]->hardware = hardware;
 463         ttys[j]->channel_idx = channel_idx;
 464         ttys[j]->secondary_channel_idx = secondary_channel_idx;
 465         ttys[j]->network = network;
 466         ttys[j]->tty_type = tty_type;
 467         mutex_init(&ttys[j]->ipw_tty_mutex);
 468         tty_port_init(&ttys[j]->port);
 469
 470         tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
 471         ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
 472
 473         if (secondary_channel_idx != -1)
 474                 ipwireless_associate_network_tty(network,
 475                                                  secondary_channel_idx,
 476                                                  ttys[j]);
 477         /* check if we provide raw device (if loopback is enabled) */
 478         if (get_tty(j))
 479                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 480                        ": registering %s device ttyIPWp%d\n",
 481                        tty_type_name(tty_type), j);
 482
 483         return 0;
 484 }
 485
 486 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
 487                                       struct ipw_network *network)
 488 {
 489         int i, j;
 490
 491         for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
 492                 int allfree = 1;
 493
 494                 for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
 495                                 j += IPWIRELESS_PCMCIA_MINOR_RANGE)
 496                         if (ttys[j] != NULL) {
 497                                 allfree = 0;
 498                                 break;
 499                         }
 500
 501                 if (allfree) {
 502                         j = i;
 503
 504                         if (add_tty(j, hardware, network,
 505                                         IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
 506                                         TTYTYPE_MODEM))
 507                                 return NULL;
 508
 509                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 510                         if (add_tty(j, hardware, network,
 511                                         IPW_CHANNEL_DIALLER, -1,
 512                                         TTYTYPE_MONITOR))
 513                                 return NULL;
 514
 515                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 516                         if (add_tty(j, hardware, network,
 517                                         IPW_CHANNEL_RAS, -1,
 518                                         TTYTYPE_RAS_RAW))
 519                                 return NULL;
 520
 521                         return ttys[i];
 522                 }
 523         }
 524         return NULL;
 525 }
 526
 527 /*
 528  * Must be called before ipwireless_network_free().
 529  */
 530 void ipwireless_tty_free(struct ipw_tty *tty)
 531 {
 532         int j;
 533         struct ipw_network *network = ttys[tty->index]->network;
 534
 535         for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
 536                         j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
 537                 struct ipw_tty *ttyj = ttys[j];
 538
 539                 if (ttyj) {
 540                         mutex_lock(&ttyj->ipw_tty_mutex);
 541                         if (get_tty(j))
 542                                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 543                                        ": deregistering %s device ttyIPWp%d\n",
 544                                        tty_type_name(ttyj->tty_type), j);
 545                         ttyj->closing = 1;
 546                         if (ttyj->port.tty != NULL) {
 547                                 mutex_unlock(&ttyj->ipw_tty_mutex);
 548                                 tty_vhangup(ttyj->port.tty);
 549                                 /* FIXME: Exactly how is the tty object locked here
 550                                    against a parallel ioctl etc */
 551                                 /* FIXME2: hangup does not mean all processes
 552                                  * are gone */
 553                                 mutex_lock(&ttyj->ipw_tty_mutex);
 554                         }
 555                         while (ttyj->port.count)
 556                                 do_ipw_close(ttyj);
 557                         ipwireless_disassociate_network_ttys(network,
 558                                                              ttyj->channel_idx);
 559                         tty_unregister_device(ipw_tty_driver, j);
 560                         tty_port_destroy(&ttyj->port);
 561                         ttys[j] = NULL;
 562                         mutex_unlock(&ttyj->ipw_tty_mutex);
 563                         kfree(ttyj);
 564                 }
 565         }
 566 }
 567
 568 static const struct tty_operations tty_ops = {
 569         .open = ipw_open,
 570         .close = ipw_close,
 571         .hangup = ipw_hangup,
 572         .write = ipw_write,
 573         .write_room = ipw_write_room,
 574         .ioctl = ipw_ioctl,
 575         .chars_in_buffer = ipw_chars_in_buffer,
 576         .tiocmget = ipw_tiocmget,
 577         .tiocmset = ipw_tiocmset,
 578 };
 579
 580 int ipwireless_tty_init(void)
 581 {
 582         int result;
 583
 584         ipw_tty_driver = alloc_tty_driver(IPWIRELESS_PCMCIA_MINORS);
 585         if (!ipw_tty_driver)
 586                 return -ENOMEM;
 587
 588         ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
 589         ipw_tty_driver->name = "ttyIPWp";
 590         ipw_tty_driver->major = 0;
 591         ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
 592         ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 593         ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
 594         ipw_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 595         ipw_tty_driver->init_termios = tty_std_termios;
 596         ipw_tty_driver->init_termios.c_cflag =
 597             B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 598         ipw_tty_driver->init_termios.c_ispeed = 9600;
 599         ipw_tty_driver->init_termios.c_ospeed = 9600;
 600         tty_set_operations(ipw_tty_driver, &tty_ops);
 601         result = tty_register_driver(ipw_tty_driver);
 602         if (result) {
 603                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 604                        ": failed to register tty driver\n");
 605                 put_tty_driver(ipw_tty_driver);
 606                 return result;
 607         }
 608
 609         return 0;
 610 }
 611
 612 void ipwireless_tty_release(void)
 613 {
 614         int ret;
 615
 616         ret = tty_unregister_driver(ipw_tty_driver);
 617         put_tty_driver(ipw_tty_driver);
 618         if (ret != 0)
 619                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 620                         ": tty_unregister_driver failed with code %d\n", ret);
 621 }
 622
 623 int ipwireless_tty_is_modem(struct ipw_tty *tty)
 624 {
 625         return tty->tty_type == TTYTYPE_MODEM;
 626 }
 627
 628 void
 629 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
 630                                           unsigned int channel_idx,
 631                                           unsigned int control_lines,
 632                                           unsigned int changed_mask)
 633 {
 634         unsigned int old_control_lines = tty->control_lines;
 635
 636         tty->control_lines = (tty->control_lines & ~changed_mask)
 637                 | (control_lines & changed_mask);
 638
 639         /*
 640          * If DCD is de-asserted, we close the tty so pppd can tell that we
 641          * have gone offline.
 642          */
 643         if ((old_control_lines & IPW_CONTROL_LINE_DCD)
 644                         && !(tty->control_lines & IPW_CONTROL_LINE_DCD)
 645                         && tty->port.tty) {
 646                 tty_hangup(tty->port.tty);
 647         }
 648 }
 649