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