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