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 <[email protected]>,
   7  *      Ben Martel <[email protected]>
   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 };
  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
 104         if (tty->tty_type == TTYTYPE_MODEM)
 105                 ipwireless_ppp_open(tty->network);
 106
 107         mutex_unlock(&tty->ipw_tty_mutex);
 108
 109         return 0;
 110 }
 111
 112 static void do_ipw_close(struct ipw_tty *tty)
 113 {
 114         tty->port.count--;
 115
 116         if (tty->port.count == 0) {
 117                 struct tty_struct *linux_tty = tty->port.tty;
 118
 119                 if (linux_tty != NULL) {
 120                         tty->port.tty = NULL;
 121                         linux_tty->driver_data = NULL;
 122
 123                         if (tty->tty_type == TTYTYPE_MODEM)
 124                                 ipwireless_ppp_close(tty->network);
 125                 }
 126         }
 127 }
 128
 129 static void ipw_hangup(struct tty_struct *linux_tty)
 130 {
 131         struct ipw_tty *tty = linux_tty->driver_data;
 132
 133         if (!tty)
 134                 return;
 135
 136         mutex_lock(&tty->ipw_tty_mutex);
 137         if (tty->port.count == 0) {
 138                 mutex_unlock(&tty->ipw_tty_mutex);
 139                 return;
 140         }
 141
 142         do_ipw_close(tty);
 143
 144         mutex_unlock(&tty->ipw_tty_mutex);
 145 }
 146
 147 static void ipw_close(struct tty_struct *linux_tty, struct file *filp)
 148 {
 149         ipw_hangup(linux_tty);
 150 }
 151
 152 /* Take data received from hardware, and send it out the tty */
 153 void ipwireless_tty_received(struct ipw_tty *tty, unsigned char *data,
 154                         unsigned int length)
 155 {
 156         int work = 0;
 157
 158         mutex_lock(&tty->ipw_tty_mutex);
 159
 160         if (!tty->port.count) {
 161                 mutex_unlock(&tty->ipw_tty_mutex);
 162                 return;
 163         }
 164         mutex_unlock(&tty->ipw_tty_mutex);
 165
 166         work = tty_insert_flip_string(&tty->port, data, length);
 167
 168         if (work != length)
 169                 printk(KERN_DEBUG IPWIRELESS_PCCARD_NAME
 170                                 ": %d chars not inserted to flip buffer!\n",
 171                                 length - work);
 172
 173         if (work)
 174                 tty_flip_buffer_push(&tty->port);
 175 }
 176
 177 static void ipw_write_packet_sent_callback(void *callback_data,
 178                                            unsigned int packet_length)
 179 {
 180         struct ipw_tty *tty = callback_data;
 181
 182         /*
 183          * Packet has been sent, so we subtract the number of bytes from our
 184          * tally of outstanding TX bytes.
 185          */
 186         tty->tx_bytes_queued -= packet_length;
 187 }
 188
 189 static ssize_t ipw_write(struct tty_struct *linux_tty, const u8 *buf,
 190                          size_t count)
 191 {
 192         struct ipw_tty *tty = linux_tty->driver_data;
 193         int room, ret;
 194
 195         if (!tty)
 196                 return -ENODEV;
 197
 198         mutex_lock(&tty->ipw_tty_mutex);
 199         if (!tty->port.count) {
 200                 mutex_unlock(&tty->ipw_tty_mutex);
 201                 return -EINVAL;
 202         }
 203
 204         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
 205         if (room < 0)
 206                 room = 0;
 207         /* Don't allow caller to write any more than we have room for */
 208         if (count > room)
 209                 count = room;
 210
 211         if (count == 0) {
 212                 mutex_unlock(&tty->ipw_tty_mutex);
 213                 return 0;
 214         }
 215
 216         ret = ipwireless_send_packet(tty->hardware, IPW_CHANNEL_RAS,
 217                                buf, count,
 218                                ipw_write_packet_sent_callback, tty);
 219         if (ret < 0) {
 220                 mutex_unlock(&tty->ipw_tty_mutex);
 221                 return 0;
 222         }
 223
 224         tty->tx_bytes_queued += count;
 225         mutex_unlock(&tty->ipw_tty_mutex);
 226
 227         return count;
 228 }
 229
 230 static unsigned int ipw_write_room(struct tty_struct *linux_tty)
 231 {
 232         struct ipw_tty *tty = linux_tty->driver_data;
 233         int room;
 234
 235         /* FIXME: Exactly how is the tty object locked here .. */
 236         if (!tty)
 237                 return 0;
 238
 239         if (!tty->port.count)
 240                 return 0;
 241
 242         room = IPWIRELESS_TX_QUEUE_SIZE - tty->tx_bytes_queued;
 243         if (room < 0)
 244                 room = 0;
 245
 246         return room;
 247 }
 248
 249 static int ipwireless_get_serial_info(struct tty_struct *linux_tty,
 250                                       struct serial_struct *ss)
 251 {
 252         struct ipw_tty *tty = linux_tty->driver_data;
 253
 254         if (!tty)
 255                 return -ENODEV;
 256
 257         if (!tty->port.count)
 258                 return -EINVAL;
 259
 260         ss->type = PORT_UNKNOWN;
 261         ss->line = tty->index;
 262         ss->baud_base = 115200;
 263         return 0;
 264 }
 265
 266 static int ipwireless_set_serial_info(struct tty_struct *linux_tty,
 267                                       struct serial_struct *ss)
 268 {
 269         return 0;       /* Keeps the PCMCIA scripts happy. */
 270 }
 271
 272 static unsigned int ipw_chars_in_buffer(struct tty_struct *linux_tty)
 273 {
 274         struct ipw_tty *tty = linux_tty->driver_data;
 275
 276         if (!tty)
 277                 return 0;
 278
 279         if (!tty->port.count)
 280                 return 0;
 281
 282         return tty->tx_bytes_queued;
 283 }
 284
 285 static int get_control_lines(struct ipw_tty *tty)
 286 {
 287         unsigned int my = tty->control_lines;
 288         unsigned int out = 0;
 289
 290         if (my & IPW_CONTROL_LINE_RTS)
 291                 out |= TIOCM_RTS;
 292         if (my & IPW_CONTROL_LINE_DTR)
 293                 out |= TIOCM_DTR;
 294         if (my & IPW_CONTROL_LINE_CTS)
 295                 out |= TIOCM_CTS;
 296         if (my & IPW_CONTROL_LINE_DSR)
 297                 out |= TIOCM_DSR;
 298         if (my & IPW_CONTROL_LINE_DCD)
 299                 out |= TIOCM_CD;
 300
 301         return out;
 302 }
 303
 304 static int set_control_lines(struct ipw_tty *tty, unsigned int set,
 305                              unsigned int clear)
 306 {
 307         int ret;
 308
 309         if (set & TIOCM_RTS) {
 310                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 1);
 311                 if (ret)
 312                         return ret;
 313                 if (tty->secondary_channel_idx != -1) {
 314                         ret = ipwireless_set_RTS(tty->hardware,
 315                                           tty->secondary_channel_idx, 1);
 316                         if (ret)
 317                                 return ret;
 318                 }
 319         }
 320         if (set & TIOCM_DTR) {
 321                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 1);
 322                 if (ret)
 323                         return ret;
 324                 if (tty->secondary_channel_idx != -1) {
 325                         ret = ipwireless_set_DTR(tty->hardware,
 326                                           tty->secondary_channel_idx, 1);
 327                         if (ret)
 328                                 return ret;
 329                 }
 330         }
 331         if (clear & TIOCM_RTS) {
 332                 ret = ipwireless_set_RTS(tty->hardware, tty->channel_idx, 0);
 333                 if (tty->secondary_channel_idx != -1) {
 334                         ret = ipwireless_set_RTS(tty->hardware,
 335                                           tty->secondary_channel_idx, 0);
 336                         if (ret)
 337                                 return ret;
 338                 }
 339         }
 340         if (clear & TIOCM_DTR) {
 341                 ret = ipwireless_set_DTR(tty->hardware, tty->channel_idx, 0);
 342                 if (tty->secondary_channel_idx != -1) {
 343                         ret = ipwireless_set_DTR(tty->hardware,
 344                                           tty->secondary_channel_idx, 0);
 345                         if (ret)
 346                                 return ret;
 347                 }
 348         }
 349         return 0;
 350 }
 351
 352 static int ipw_tiocmget(struct tty_struct *linux_tty)
 353 {
 354         struct ipw_tty *tty = linux_tty->driver_data;
 355         /* FIXME: Exactly how is the tty object locked here .. */
 356
 357         if (!tty)
 358                 return -ENODEV;
 359
 360         if (!tty->port.count)
 361                 return -EINVAL;
 362
 363         return get_control_lines(tty);
 364 }
 365
 366 static int
 367 ipw_tiocmset(struct tty_struct *linux_tty,
 368              unsigned int set, unsigned int clear)
 369 {
 370         struct ipw_tty *tty = linux_tty->driver_data;
 371         /* FIXME: Exactly how is the tty object locked here .. */
 372
 373         if (!tty)
 374                 return -ENODEV;
 375
 376         if (!tty->port.count)
 377                 return -EINVAL;
 378
 379         return set_control_lines(tty, set, clear);
 380 }
 381
 382 static int ipw_ioctl(struct tty_struct *linux_tty,
 383                      unsigned int cmd, unsigned long arg)
 384 {
 385         struct ipw_tty *tty = linux_tty->driver_data;
 386
 387         if (!tty)
 388                 return -ENODEV;
 389
 390         if (!tty->port.count)
 391                 return -EINVAL;
 392
 393         /* FIXME: Exactly how is the tty object locked here .. */
 394         if (tty->tty_type == TTYTYPE_MODEM) {
 395                 switch (cmd) {
 396                 case PPPIOCGCHAN:
 397                         {
 398                                 int chan = ipwireless_ppp_channel_index(
 399                                                         tty->network);
 400
 401                                 if (chan < 0)
 402                                         return -ENODEV;
 403                                 if (put_user(chan, (int __user *) arg))
 404                                         return -EFAULT;
 405                         }
 406                         return 0;
 407
 408                 case PPPIOCGUNIT:
 409                         {
 410                                 int unit = ipwireless_ppp_unit_number(
 411                                                 tty->network);
 412
 413                                 if (unit < 0)
 414                                         return -ENODEV;
 415                                 if (put_user(unit, (int __user *) arg))
 416                                         return -EFAULT;
 417                         }
 418                         return 0;
 419
 420                 case FIONREAD:
 421                         {
 422                                 int val = 0;
 423
 424                                 if (put_user(val, (int __user *) arg))
 425                                         return -EFAULT;
 426                         }
 427                         return 0;
 428                 case TCFLSH:
 429                         return tty_perform_flush(linux_tty, arg);
 430                 }
 431         }
 432         return -ENOIOCTLCMD;
 433 }
 434
 435 static int add_tty(int j,
 436                     struct ipw_hardware *hardware,
 437                     struct ipw_network *network, int channel_idx,
 438                     int secondary_channel_idx, int tty_type)
 439 {
 440         ttys[j] = kzalloc(sizeof(struct ipw_tty), GFP_KERNEL);
 441         if (!ttys[j])
 442                 return -ENOMEM;
 443         ttys[j]->index = j;
 444         ttys[j]->hardware = hardware;
 445         ttys[j]->channel_idx = channel_idx;
 446         ttys[j]->secondary_channel_idx = secondary_channel_idx;
 447         ttys[j]->network = network;
 448         ttys[j]->tty_type = tty_type;
 449         mutex_init(&ttys[j]->ipw_tty_mutex);
 450         tty_port_init(&ttys[j]->port);
 451
 452         tty_port_register_device(&ttys[j]->port, ipw_tty_driver, j, NULL);
 453         ipwireless_associate_network_tty(network, channel_idx, ttys[j]);
 454
 455         if (secondary_channel_idx != -1)
 456                 ipwireless_associate_network_tty(network,
 457                                                  secondary_channel_idx,
 458                                                  ttys[j]);
 459         /* check if we provide raw device (if loopback is enabled) */
 460         if (get_tty(j))
 461                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 462                        ": registering %s device ttyIPWp%d\n",
 463                        tty_type_name(tty_type), j);
 464
 465         return 0;
 466 }
 467
 468 struct ipw_tty *ipwireless_tty_create(struct ipw_hardware *hardware,
 469                                       struct ipw_network *network)
 470 {
 471         int i, j;
 472
 473         for (i = 0; i < IPWIRELESS_PCMCIA_MINOR_RANGE; i++) {
 474                 int allfree = 1;
 475
 476                 for (j = i; j < IPWIRELESS_PCMCIA_MINORS;
 477                                 j += IPWIRELESS_PCMCIA_MINOR_RANGE)
 478                         if (ttys[j] != NULL) {
 479                                 allfree = 0;
 480                                 break;
 481                         }
 482
 483                 if (allfree) {
 484                         j = i;
 485
 486                         if (add_tty(j, hardware, network,
 487                                         IPW_CHANNEL_DIALLER, IPW_CHANNEL_RAS,
 488                                         TTYTYPE_MODEM))
 489                                 return NULL;
 490
 491                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 492                         if (add_tty(j, hardware, network,
 493                                         IPW_CHANNEL_DIALLER, -1,
 494                                         TTYTYPE_MONITOR))
 495                                 return NULL;
 496
 497                         j += IPWIRELESS_PCMCIA_MINOR_RANGE;
 498                         if (add_tty(j, hardware, network,
 499                                         IPW_CHANNEL_RAS, -1,
 500                                         TTYTYPE_RAS_RAW))
 501                                 return NULL;
 502
 503                         return ttys[i];
 504                 }
 505         }
 506         return NULL;
 507 }
 508
 509 /*
 510  * Must be called before ipwireless_network_free().
 511  */
 512 void ipwireless_tty_free(struct ipw_tty *tty)
 513 {
 514         int j;
 515         struct ipw_network *network = ttys[tty->index]->network;
 516
 517         for (j = tty->index; j < IPWIRELESS_PCMCIA_MINORS;
 518                         j += IPWIRELESS_PCMCIA_MINOR_RANGE) {
 519                 struct ipw_tty *ttyj = ttys[j];
 520
 521                 if (ttyj) {
 522                         mutex_lock(&ttyj->ipw_tty_mutex);
 523                         if (get_tty(j))
 524                                 printk(KERN_INFO IPWIRELESS_PCCARD_NAME
 525                                        ": deregistering %s device ttyIPWp%d\n",
 526                                        tty_type_name(ttyj->tty_type), j);
 527                         if (ttyj->port.tty != NULL) {
 528                                 mutex_unlock(&ttyj->ipw_tty_mutex);
 529                                 tty_vhangup(ttyj->port.tty);
 530                                 /* FIXME: Exactly how is the tty object locked here
 531                                    against a parallel ioctl etc */
 532                                 /* FIXME2: hangup does not mean all processes
 533                                  * are gone */
 534                                 mutex_lock(&ttyj->ipw_tty_mutex);
 535                         }
 536                         while (ttyj->port.count)
 537                                 do_ipw_close(ttyj);
 538                         ipwireless_disassociate_network_ttys(network,
 539                                                              ttyj->channel_idx);
 540                         tty_unregister_device(ipw_tty_driver, j);
 541                         tty_port_destroy(&ttyj->port);
 542                         ttys[j] = NULL;
 543                         mutex_unlock(&ttyj->ipw_tty_mutex);
 544                         kfree(ttyj);
 545                 }
 546         }
 547 }
 548
 549 static const struct tty_operations tty_ops = {
 550         .open = ipw_open,
 551         .close = ipw_close,
 552         .hangup = ipw_hangup,
 553         .write = ipw_write,
 554         .write_room = ipw_write_room,
 555         .ioctl = ipw_ioctl,
 556         .chars_in_buffer = ipw_chars_in_buffer,
 557         .tiocmget = ipw_tiocmget,
 558         .tiocmset = ipw_tiocmset,
 559         .set_serial = ipwireless_set_serial_info,
 560         .get_serial = ipwireless_get_serial_info,
 561 };
 562
 563 int ipwireless_tty_init(void)
 564 {
 565         int result;
 566
 567         ipw_tty_driver = tty_alloc_driver(IPWIRELESS_PCMCIA_MINORS,
 568                         TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
 569         if (IS_ERR(ipw_tty_driver))
 570                 return PTR_ERR(ipw_tty_driver);
 571
 572         ipw_tty_driver->driver_name = IPWIRELESS_PCCARD_NAME;
 573         ipw_tty_driver->name = "ttyIPWp";
 574         ipw_tty_driver->major = 0;
 575         ipw_tty_driver->minor_start = IPWIRELESS_PCMCIA_START;
 576         ipw_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 577         ipw_tty_driver->subtype = SERIAL_TYPE_NORMAL;
 578         ipw_tty_driver->init_termios = tty_std_termios;
 579         ipw_tty_driver->init_termios.c_cflag =
 580             B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 581         ipw_tty_driver->init_termios.c_ispeed = 9600;
 582         ipw_tty_driver->init_termios.c_ospeed = 9600;
 583         tty_set_operations(ipw_tty_driver, &tty_ops);
 584         result = tty_register_driver(ipw_tty_driver);
 585         if (result) {
 586                 printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 587                        ": failed to register tty driver\n");
 588                 tty_driver_kref_put(ipw_tty_driver);
 589                 return result;
 590         }
 591
 592         return 0;
 593 }
 594
 595 void ipwireless_tty_release(void)
 596 {
 597         tty_unregister_driver(ipw_tty_driver);
 598         tty_driver_kref_put(ipw_tty_driver);
 599 }
 600
 601 int ipwireless_tty_is_modem(struct ipw_tty *tty)
 602 {
 603         return tty->tty_type == TTYTYPE_MODEM;
 604 }
 605
 606 void
 607 ipwireless_tty_notify_control_line_change(struct ipw_tty *tty,
 608                                           unsigned int channel_idx,
 609                                           unsigned int control_lines,
 610                                           unsigned int changed_mask)
 611 {
 612         unsigned int old_control_lines = tty->control_lines;
 613
 614         tty->control_lines = (tty->control_lines & ~changed_mask)
 615                 | (control_lines & changed_mask);
 616
 617         /*
 618          * If DCD is de-asserted, we close the tty so pppd can tell that we
 619          * have gone offline.
 620          */
 621         if ((old_control_lines & IPW_CONTROL_LINE_DCD)
 622                         && !(tty->control_lines & IPW_CONTROL_LINE_DCD)
 623                         && tty->port.tty) {
 624                 tty_hangup(tty->port.tty);
 625         }
 626 }
 627