drivers/tty/ipwireless/tty.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * IPWireless 3G PCMCIA Network Driver
   4  *
   5  * Original code
   6  *   by Stephen Blackheath <stephen@blacksapphire.com>,
   7  *      Ben Martel <benm@symmetric.co.nz>
   8  *
   9  * Copyrighted as follows:
  10  *   Copyright (C) 2004 by Symmetric Systems Ltd (NZ)
  11  *
  12  * Various driver changes and rewrites, port to new kernels
  13  *   Copyright (C) 2006-2007 Jiri Kosina
  14  *
  15  * Misc code cleanups and updates
  16  *   Copyright (C) 2007 David Sterba
  17  */
  18
  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         if (tty->port.count == 0)
  98                 tty->tx_bytes_queued = 0;
  99
 100         tty->port.count++;
 101
 102         tty->port.tty = linux_tty;
 103         linux_tty->driver_data = tty;
 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 < 0) {
 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 0;
 239
 240         if (!tty->port.count)
 241                 return 0;
 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 tty_struct *linux_tty,
 251                                       struct serial_struct *ss)
 252 {
 253         struct ipw_tty *tty = linux_tty->driver_data;
 254
 255         if (!tty)
 256                 return -ENODEV;
 257
 258         if (!tty->port.count)
 259                 return -EINVAL;
 260
 261         ss->type = PORT_UNKNOWN;
 262         ss->line = tty->index;
 263         ss->baud_base = 115200;
 264         return 0;
 265 }
 266
 267 static int ipwireless_set_serial_info(struct tty_struct *linux_tty,
 268                                       struct serial_struct *ss)
 269 {
 270         return 0;       /* Keeps the PCMCIA scripts happy. */
 271 }
 272
 273 static int ipw_chars_in_buffer(struct tty_struct *linux_tty)
 274 {
 275         struct ipw_tty *tty = linux_tty->driver_data;
 276
 277         if (!tty)
 278                 return 0;
 279
 280         if (!tty->port.count)
 281                 return 0;
 282
 283         return tty->tx_bytes_queued;
 284 }
 285
 286 static int get_control_lines(struct ipw_tty *tty)
 287 {
 288         unsigned int my = tty->control_lines;
 289         unsigned int out = 0;
 290
 291         if (my & IPW_CONTROL_LINE_RTS)
 292                 out |= TIOCM_RTS;
 293         if (my & IPW_CONTROL_LINE_DTR)
 294                 out |= TIOCM_DTR;
 295         if (my & IPW_CONTROL_LINE_CTS)
 296                 out |= TIOCM_CTS;
 297         if (my & IPW_CONTROL_LINE_DSR)
 298                 out |= TIOCM_DSR;
 299         if (my & IPW_CONTROL_LINE_DCD)
 300                 out |= TIOCM_CD;
 301
 302         return out;
 303 }
 304
 305 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
 306                              unsigned int clear)
 307 {
 308         int ret;
 309
 310         if (set & TIOCM_RTS) {
 311                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
 312                 if (ret)
 313                         return ret;
 314                 if (tty->secondary_channel_idx != -1) {
 315                         ret = ipwireless_set_RTS(tty->hardware,
 316                                           tty->secondary_channel_idx, 1);
 317                         if (ret)
 318                                 return ret;
 319                 }
 320         }
 321         if (set & TIOCM_DTR) {
 322                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
 323                 if (ret)
 324                         return ret;
 325                 if (tty->secondary_channel_idx != -1) {
 326                         ret = ipwireless_set_DTR(tty->hardware,
 327                                           tty->secondary_channel_idx, 1);
 328                         if (ret)
 329                                 return ret;
 330                 }
 331         }
 332         if (clear & TIOCM_RTS) {
 333                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
 334                 if (tty->secondary_channel_idx != -1) {
 335                         ret = ipwireless_set_RTS(tty->hardware,
 336                                           tty->secondary_channel_idx, 0);
 337                         if (ret)
 338                                 return ret;
 339                 }
 340         }
 341         if (clear & TIOCM_DTR) {
 342                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
 343                 if (tty->secondary_channel_idx != -1) {
 344                         ret = ipwireless_set_DTR(tty->hardware,
 345                                           tty->secondary_channel_idx, 0);
 346                         if (ret)
 347                                 return ret;
 348                 }
 349         }
 350         return 0;
 351 }
 352
 353 static int ipw_tiocmget(struct tty_struct *linux_tty)
 354 {
 355         struct ipw_tty *tty = linux_tty->driver_data;
 356         /* FIXME: Exactly how is the tty object locked here .. */
 357
 358         if (!tty)
 359                 return -ENODEV;
 360
 361         if (!tty->port.count)
 362                 return -EINVAL;
 363
 364         return get_control_lines(tty);
 365 }
 366
 367 static int
 368 ipw_tiocmset(struct tty_struct *linux_tty,
 369              unsigned int set, unsigned int clear)
 370 {
 371         struct ipw_tty *tty = linux_tty->driver_data;
 372         /* FIXME: Exactly how is the tty object locked here .. */
 373
 374         if (!tty)
 375                 return -ENODEV;
 376
 377         if (!tty->port.count)
 378                 return -EINVAL;
 379
 380         return set_control_lines(tty, set, clear);
 381 }
 382
 383 static int ipw_ioctl(struct tty_struct *linux_tty,
 384                      unsigned int cmd, unsigned long arg)
 385 {
 386         struct ipw_tty *tty = linux_tty->driver_data;
 387
 388         if (!tty)
 389                 return -ENODEV;
 390
 391         if (!tty->port.count)
 392                 return -EINVAL;
 393
 394         /* FIXME: Exactly how is the tty object locked here .. */
 395         if (tty->tty_type == TTYTYPE_MODEM) {
 396                 switch (cmd) {
 397                 case PPPIOCGCHAN:
 398                         {
 399                                 int chan = ipwireless_ppp_channel_index(
 400                                                         tty->network);
 401
 402                                 if (chan < 0)
 403                                         return -ENODEV;
 404                                 if (put_user(chan, (int __user *) arg))
 405                                         return -EFAULT;
 406                         }
 407                         return 0;
 408
 409                 case PPPIOCGUNIT:
 410                         {
 411                                 int unit = ipwireless_ppp_unit_number(
 412                                                 tty->network);
 413
 414                                 if (unit < 0)
 415                                         return -ENODEV;
 416                                 if (put_user(unit, (int __user *) arg))
 417                                         return -EFAULT;
 418                         }
 419                         return 0;
 420
 421                 case FIONREAD:
 422                         {
 423                                 int val = 0;
 424
 425                                 if (put_user(val, (int __user *) arg))
 426                                         return -EFAULT;
 427                         }
 428                         return 0;
 429                 case TCFLSH:
 430                         return tty_perform_flush(linux_tty, arg);
 431                 }
 432         }
 433         return -ENOIOCTLCMD;
 434 }
 435
 436 static int add_tty(int j,
 437                     struct ipw_hardware *hardware,
 438                     struct ipw_network *network, int channel_idx,
 439                     int secondary_channel_idx, int tty_type)
 440 {
 441         ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
 442         if (!ttys[j])
 443                 return -ENOMEM;
 444         ttys[j]->index = j;
 445         ttys[j]->hardware = hardware;
 446         ttys[j]->channel_idx = channel_idx;
 447         ttys[j]->secondary_channel_idx = secondary_channel_idx;
 448         ttys[j]->network = network;
 449         ttys[j]->tty_type = tty_type;
 450         mutex_init(&ttys[j]->ipw_tty_mutex);
 451         tty_port_init(&ttys[j]->port);
 452
 453         tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
 454         ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
 455
 456         if (secondary_channel_idx != -1)
 457                 ipwireless_associate_network_tty(network,
 458                                                  secondary_channel_idx,
 459                                                  ttys[j]);
 460         /* check if we provide raw device (if loopback is enabled) */
 461         if (get_tty(j))
 462                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 463                        ": registering %s device ttyIPWp%d\n",
 464                        tty_type_name(tty_type), j);
 465
 466         return 0;
 467 }
 468
 469 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
 470                                       struct ipw_network *network)
 471 {
 472         int i, j;
 473
 474         for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
 475                 int allfree = 1;
 476
 477                 for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
 478                                 j += IPWIRELESS_PCMCIA_MINOR_RANGE)
 479                         if (ttys[j] != NULL) {
 480                                 allfree = 0;
 481                                 break;
 482                         }
 483
 484                 if (allfree) {
 485                         j = i;
 486
 487                         if (add_tty(j, hardware, network,
 488                                         IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
 489                                         TTYTYPE_MODEM))
 490                                 return NULL;
 491
 492                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 493                         if (add_tty(j, hardware, network,
 494                                         IPW_CHANNEL_DIALLER, -1,
 495                                         TTYTYPE_MONITOR))
 496                                 return NULL;
 497
 498                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 499                         if (add_tty(j, hardware, network,
 500                                         IPW_CHANNEL_RAS, -1,
 501                                         TTYTYPE_RAS_RAW))
 502                                 return NULL;
 503
 504                         return ttys[i];
 505                 }
 506         }
 507         return NULL;
 508 }
 509
 510 /*
 511  * Must be called before ipwireless_network_free().
 512  */
 513 void ipwireless_tty_free(struct ipw_tty *tty)
 514 {
 515         int j;
 516         struct ipw_network *network = ttys[tty->index]->network;
 517
 518         for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
 519                         j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
 520                 struct ipw_tty *ttyj = ttys[j];
 521
 522                 if (ttyj) {
 523                         mutex_lock(&ttyj->ipw_tty_mutex);
 524                         if (get_tty(j))
 525                                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 526                                        ": deregistering %s device ttyIPWp%d\n",
 527                                        tty_type_name(ttyj->tty_type), j);
 528                         ttyj->closing = 1;
 529                         if (ttyj->port.tty != NULL) {
 530                                 mutex_unlock(&ttyj->ipw_tty_mutex);
 531                                 tty_vhangup(ttyj->port.tty);
 532                                 /* FIXME: Exactly how is the tty object locked here
 533                                    against a parallel ioctl etc */
 534                                 /* FIXME2: hangup does not mean all processes
 535                                  * are gone */
 536                                 mutex_lock(&ttyj->ipw_tty_mutex);
 537                         }
 538                         while (ttyj->port.count)
 539                                 do_ipw_close(ttyj);
 540                         ipwireless_disassociate_network_ttys(network,
 541                                                              ttyj->channel_idx);
 542                         tty_unregister_device(ipw_tty_driver, j);
 543                         tty_port_destroy(&ttyj->port);
 544                         ttys[j] = NULL;
 545                         mutex_unlock(&ttyj->ipw_tty_mutex);
 546                         kfree(ttyj);
 547                 }
 548         }
 549 }
 550
 551 static const struct tty_operations tty_ops = {
 552         .open = ipw_open,
 553         .close = ipw_close,
 554         .hangup = ipw_hangup,
 555         .write = ipw_write,
 556         .write_room = ipw_write_room,
 557         .ioctl = ipw_ioctl,
 558         .chars_in_buffer = ipw_chars_in_buffer,
 559         .tiocmget = ipw_tiocmget,
 560         .tiocmset = ipw_tiocmset,
 561         .set_serial = ipwireless_set_serial_info,
 562         .get_serial = ipwireless_get_serial_info,
 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         tty_unregister_driver(ipw_tty_driver);
 600         put_tty_driver(ipw_tty_driver);
 601 }
 602
 603 int ipwireless_tty_is_modem(struct ipw_tty *tty)
 604 {
 605         return tty->tty_type == TTYTYPE_MODEM;
 606 }
 607
 608 void
 609 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
 610                                           unsigned int channel_idx,
 611                                           unsigned int control_lines,
 612                                           unsigned int changed_mask)
 613 {
 614         unsigned int old_control_lines = tty->control_lines;
 615
 616         tty->control_lines = (tty->control_lines & ~changed_mask)
 617                 | (control_lines & changed_mask);
 618
 619         /*
 620          * If DCD is de-asserted, we close the tty so pppd can tell that we
 621          * have gone offline.
 622          */
 623         if ((old_control_lines & IPW_CONTROL_LINE_DCD)
 624                         && !(tty->control_lines & IPW_CONTROL_LINE_DCD)
 625                         && tty->port.tty) {
 626                 tty_hangup(tty->port.tty);
 627         }
 628 }
 629