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