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         /*
 181          * This may sleep if ->low_latency is set
 182          */
 183         if (work)
 184                 tty_flip_buffer_push(&tty->port);
 185 }
 186
 187 static void ipw_write_packet_sent_callback(void *callback_data,
 188                                            unsigned int packet_length)
 189 {
 190         struct ipw_tty *tty = callback_data;
 191
 192         /*
 193          * Packet has been sent, so we subtract the number of bytes from our
 194          * tally of outstanding TX bytes.
 195          */
 196         tty->tx_bytes_queued -= packet_length;
 197 }
 198
 199 static int ipw_write(struct tty_struct *linux_tty,
 200                      const unsigned char *buf, int count)
 201 {
 202         struct ipw_tty *tty = linux_tty->driver_data;
 203         int room, ret;
 204
 205         if (!tty)
 206                 return -ENODEV;
 207
 208         mutex_lock(&tty->ipw_tty_mutex);
 209         if (!tty->port.count) {
 210                 mutex_unlock(&tty->ipw_tty_mutex);
 211                 return -EINVAL;
 212         }
 213
 214         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
 215         if (room < 0)
 216                 room = 0;
 217         /* Don't allow caller to write any more than we have room for */
 218         if (count > room)
 219                 count = room;
 220
 221         if (count == 0) {
 222                 mutex_unlock(&tty->ipw_tty_mutex);
 223                 return 0;
 224         }
 225
 226         ret = ipwireless_send_packet(tty->hardware, IPW_CHANNEL_RAS,
 227                                buf, count,
 228                                ipw_write_packet_sent_callback, tty);
 229         if (ret == -1) {
 230                 mutex_unlock(&tty->ipw_tty_mutex);
 231                 return 0;
 232         }
 233
 234         tty->tx_bytes_queued += count;
 235         mutex_unlock(&tty->ipw_tty_mutex);
 236
 237         return count;
 238 }
 239
 240 static int ipw_write_room(struct tty_struct *linux_tty)
 241 {
 242         struct ipw_tty *tty = linux_tty->driver_data;
 243         int room;
 244
 245         /* FIXME: Exactly how is the tty object locked here .. */
 246         if (!tty)
 247                 return -ENODEV;
 248
 249         if (!tty->port.count)
 250                 return -EINVAL;
 251
 252         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
 253         if (room < 0)
 254                 room = 0;
 255
 256         return room;
 257 }
 258
 259 static int ipwireless_get_serial_info(struct ipw_tty *tty,
 260                                       struct serial_struct __user *retinfo)
 261 {
 262         struct serial_struct tmp;
 263
 264         if (!retinfo)
 265                 return (-EFAULT);
 266
 267         memset(&tmp, 0, sizeof(tmp));
 268         tmp.type = PORT_UNKNOWN;
 269         tmp.line = tty->index;
 270         tmp.port = 0;
 271         tmp.irq = 0;
 272         tmp.flags = 0;
 273         tmp.baud_base = 115200;
 274         tmp.close_delay = 0;
 275         tmp.closing_wait = 0;
 276         tmp.custom_divisor = 0;
 277         tmp.hub6 = 0;
 278         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 279                 return -EFAULT;
 280
 281         return 0;
 282 }
 283
 284 static int ipw_chars_in_buffer(struct tty_struct *linux_tty)
 285 {
 286         struct ipw_tty *tty = linux_tty->driver_data;
 287
 288         if (!tty)
 289                 return 0;
 290
 291         if (!tty->port.count)
 292                 return 0;
 293
 294         return tty->tx_bytes_queued;
 295 }
 296
 297 static int get_control_lines(struct ipw_tty *tty)
 298 {
 299         unsigned int my = tty->control_lines;
 300         unsigned int out = 0;
 301
 302         if (my & IPW_CONTROL_LINE_RTS)
 303                 out |= TIOCM_RTS;
 304         if (my & IPW_CONTROL_LINE_DTR)
 305                 out |= TIOCM_DTR;
 306         if (my & IPW_CONTROL_LINE_CTS)
 307                 out |= TIOCM_CTS;
 308         if (my & IPW_CONTROL_LINE_DSR)
 309                 out |= TIOCM_DSR;
 310         if (my & IPW_CONTROL_LINE_DCD)
 311                 out |= TIOCM_CD;
 312
 313         return out;
 314 }
 315
 316 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
 317                              unsigned int clear)
 318 {
 319         int ret;
 320
 321         if (set & TIOCM_RTS) {
 322                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
 323                 if (ret)
 324                         return ret;
 325                 if (tty->secondary_channel_idx != -1) {
 326                         ret = ipwireless_set_RTS(tty->hardware,
 327                                           tty->secondary_channel_idx, 1);
 328                         if (ret)
 329                                 return ret;
 330                 }
 331         }
 332         if (set & TIOCM_DTR) {
 333                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
 334                 if (ret)
 335                         return ret;
 336                 if (tty->secondary_channel_idx != -1) {
 337                         ret = ipwireless_set_DTR(tty->hardware,
 338                                           tty->secondary_channel_idx, 1);
 339                         if (ret)
 340                                 return ret;
 341                 }
 342         }
 343         if (clear & TIOCM_RTS) {
 344                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
 345                 if (tty->secondary_channel_idx != -1) {
 346                         ret = ipwireless_set_RTS(tty->hardware,
 347                                           tty->secondary_channel_idx, 0);
 348                         if (ret)
 349                                 return ret;
 350                 }
 351         }
 352         if (clear & TIOCM_DTR) {
 353                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
 354                 if (tty->secondary_channel_idx != -1) {
 355                         ret = ipwireless_set_DTR(tty->hardware,
 356                                           tty->secondary_channel_idx, 0);
 357                         if (ret)
 358                                 return ret;
 359                 }
 360         }
 361         return 0;
 362 }
 363
 364 static int ipw_tiocmget(struct tty_struct *linux_tty)
 365 {
 366         struct ipw_tty *tty = linux_tty->driver_data;
 367         /* FIXME: Exactly how is the tty object locked here .. */
 368
 369         if (!tty)
 370                 return -ENODEV;
 371
 372         if (!tty->port.count)
 373                 return -EINVAL;
 374
 375         return get_control_lines(tty);
 376 }
 377
 378 static int
 379 ipw_tiocmset(struct tty_struct *linux_tty,
 380              unsigned int set, unsigned int clear)
 381 {
 382         struct ipw_tty *tty = linux_tty->driver_data;
 383         /* FIXME: Exactly how is the tty object locked here .. */
 384
 385         if (!tty)
 386                 return -ENODEV;
 387
 388         if (!tty->port.count)
 389                 return -EINVAL;
 390
 391         return set_control_lines(tty, set, clear);
 392 }
 393
 394 static int ipw_ioctl(struct tty_struct *linux_tty,
 395                      unsigned int cmd, unsigned long arg)
 396 {
 397         struct ipw_tty *tty = linux_tty->driver_data;
 398
 399         if (!tty)
 400                 return -ENODEV;
 401
 402         if (!tty->port.count)
 403                 return -EINVAL;
 404
 405         /* FIXME: Exactly how is the tty object locked here .. */
 406
 407         switch (cmd) {
 408         case TIOCGSERIAL:
 409                 return ipwireless_get_serial_info(tty, (void __user *) arg);
 410
 411         case TIOCSSERIAL:
 412                 return 0;       /* Keeps the PCMCIA scripts happy. */
 413         }
 414
 415         if (tty->tty_type == TTYTYPE_MODEM) {
 416                 switch (cmd) {
 417                 case PPPIOCGCHAN:
 418                         {
 419                                 int chan = ipwireless_ppp_channel_index(
 420                                                         tty->network);
 421
 422                                 if (chan < 0)
 423                                         return -ENODEV;
 424                                 if (put_user(chan, (int __user *) arg))
 425                                         return -EFAULT;
 426                         }
 427                         return 0;
 428
 429                 case PPPIOCGUNIT:
 430                         {
 431                                 int unit = ipwireless_ppp_unit_number(
 432                                                 tty->network);
 433
 434                                 if (unit < 0)
 435                                         return -ENODEV;
 436                                 if (put_user(unit, (int __user *) arg))
 437                                         return -EFAULT;
 438                         }
 439                         return 0;
 440
 441                 case FIONREAD:
 442                         {
 443                                 int val = 0;
 444
 445                                 if (put_user(val, (int __user *) arg))
 446                                         return -EFAULT;
 447                         }
 448                         return 0;
 449                 case TCFLSH:
 450                         return tty_perform_flush(linux_tty, arg);
 451                 }
 452         }
 453         return -ENOIOCTLCMD;
 454 }
 455
 456 static int add_tty(int j,
 457                     struct ipw_hardware *hardware,
 458                     struct ipw_network *network, int channel_idx,
 459                     int secondary_channel_idx, int tty_type)
 460 {
 461         ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
 462         if (!ttys[j])
 463                 return -ENOMEM;
 464         ttys[j]->index = j;
 465         ttys[j]->hardware = hardware;
 466         ttys[j]->channel_idx = channel_idx;
 467         ttys[j]->secondary_channel_idx = secondary_channel_idx;
 468         ttys[j]->network = network;
 469         ttys[j]->tty_type = tty_type;
 470         mutex_init(&ttys[j]->ipw_tty_mutex);
 471         tty_port_init(&ttys[j]->port);
 472
 473         tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
 474         ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
 475
 476         if (secondary_channel_idx != -1)
 477                 ipwireless_associate_network_tty(network,
 478                                                  secondary_channel_idx,
 479                                                  ttys[j]);
 480         /* check if we provide raw device (if loopback is enabled) */
 481         if (get_tty(j))
 482                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 483                        ": registering %s device ttyIPWp%d\n",
 484                        tty_type_name(tty_type), j);
 485
 486         return 0;
 487 }
 488
 489 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
 490                                       struct ipw_network *network)
 491 {
 492         int i, j;
 493
 494         for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
 495                 int allfree = 1;
 496
 497                 for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
 498                                 j += IPWIRELESS_PCMCIA_MINOR_RANGE)
 499                         if (ttys[j] != NULL) {
 500                                 allfree = 0;
 501                                 break;
 502                         }
 503
 504                 if (allfree) {
 505                         j = i;
 506
 507                         if (add_tty(j, hardware, network,
 508                                         IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
 509                                         TTYTYPE_MODEM))
 510                                 return NULL;
 511
 512                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 513                         if (add_tty(j, hardware, network,
 514                                         IPW_CHANNEL_DIALLER, -1,
 515                                         TTYTYPE_MONITOR))
 516                                 return NULL;
 517
 518                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 519                         if (add_tty(j, hardware, network,
 520                                         IPW_CHANNEL_RAS, -1,
 521                                         TTYTYPE_RAS_RAW))
 522                                 return NULL;
 523
 524                         return ttys[i];
 525                 }
 526         }
 527         return NULL;
 528 }
 529
 530 /*
 531  * Must be called before ipwireless_network_free().
 532  */
 533 void ipwireless_tty_free(struct ipw_tty *tty)
 534 {
 535         int j;
 536         struct ipw_network *network = ttys[tty->index]->network;
 537
 538         for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
 539                         j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
 540                 struct ipw_tty *ttyj = ttys[j];
 541
 542                 if (ttyj) {
 543                         mutex_lock(&ttyj->ipw_tty_mutex);
 544                         if (get_tty(j))
 545                                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 546                                        ": deregistering %s device ttyIPWp%d\n",
 547                                        tty_type_name(ttyj->tty_type), j);
 548                         ttyj->closing = 1;
 549                         if (ttyj->port.tty != NULL) {
 550                                 mutex_unlock(&ttyj->ipw_tty_mutex);
 551                                 tty_vhangup(ttyj->port.tty);
 552                                 /* FIXME: Exactly how is the tty object locked here
 553                                    against a parallel ioctl etc */
 554                                 /* FIXME2: hangup does not mean all processes
 555                                  * are gone */
 556                                 mutex_lock(&ttyj->ipw_tty_mutex);
 557                         }
 558                         while (ttyj->port.count)
 559                                 do_ipw_close(ttyj);
 560                         ipwireless_disassociate_network_ttys(network,
 561                                                              ttyj->channel_idx);
 562                         tty_unregister_device(ipw_tty_driver, j);
 563                         tty_port_destroy(&ttyj->port);
 564                         ttys[j] = NULL;
 565                         mutex_unlock(&ttyj->ipw_tty_mutex);
 566                         kfree(ttyj);
 567                 }
 568         }
 569 }
 570
 571 static const struct tty_operations tty_ops = {
 572         .open = ipw_open,
 573         .close = ipw_close,
 574         .hangup = ipw_hangup,
 575         .write = ipw_write,
 576         .write_room = ipw_write_room,
 577         .ioctl = ipw_ioctl,
 578         .chars_in_buffer = ipw_chars_in_buffer,
 579         .tiocmget = ipw_tiocmget,
 580         .tiocmset = ipw_tiocmset,
 581 };
 582
 583 int ipwireless_tty_init(void)
 584 {
 585         int result;
 586
 587         ipw_tty_driver = alloc_tty_driver(IPWIRELESS_PCMCIA_MINORS);
 588         if (!ipw_tty_driver)
 589                 return -ENOMEM;
 590
 591         ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
 592         ipw_tty_driver->name = "ttyIPWp";
 593         ipw_tty_driver->major = 0;
 594         ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
 595         ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 596         ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
 597         ipw_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 598         ipw_tty_driver->init_termios = tty_std_termios;
 599         ipw_tty_driver->init_termios.c_cflag =
 600             B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 601         ipw_tty_driver->init_termios.c_ispeed = 9600;
 602         ipw_tty_driver->init_termios.c_ospeed = 9600;
 603         tty_set_operations(ipw_tty_driver, &tty_ops);
 604         result = tty_register_driver(ipw_tty_driver);
 605         if (result) {
 606                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 607                        ": failed to register tty driver\n");
 608                 put_tty_driver(ipw_tty_driver);
 609                 return result;
 610         }
 611
 612         return 0;
 613 }
 614
 615 void ipwireless_tty_release(void)
 616 {
 617         int ret;
 618
 619         ret = tty_unregister_driver(ipw_tty_driver);
 620         put_tty_driver(ipw_tty_driver);
 621         if (ret != 0)
 622                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 623                         ": tty_unregister_driver failed with code %d\n", ret);
 624 }
 625
 626 int ipwireless_tty_is_modem(struct ipw_tty *tty)
 627 {
 628         return tty->tty_type == TTYTYPE_MODEM;
 629 }
 630
 631 void
 632 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
 633                                           unsigned int channel_idx,
 634                                           unsigned int control_lines,
 635                                           unsigned int changed_mask)
 636 {
 637         unsigned int old_control_lines = tty->control_lines;
 638
 639         tty->control_lines = (tty->control_lines & ~changed_mask)
 640                 | (control_lines & changed_mask);
 641
 642         /*
 643          * If DCD is de-asserted, we close the tty so pppd can tell that we
 644          * have gone offline.
 645          */
 646         if ((old_control_lines & IPW_CONTROL_LINE_DCD)
 647                         && !(tty->control_lines & IPW_CONTROL_LINE_DCD)
 648                         && tty->port.tty) {
 649                 tty_hangup(tty->port.tty);
 650         }
 651 }
 652