drivers/isdn/gigaset/common.c

   1 /*
   2  * Stuff used by all variants of the driver
   3  *
   4  * Copyright (c) 2001 by Stefan Eilers,
   5  *                       Hansjoerg Lipp <hjlipp@web.de>,
   6  *                       Tilman Schmidt <tilman@imap.cc>.
   7  *
   8  * =====================================================================
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License as
  11  *      published by the Free Software Foundation; either version 2 of
  12  *      the License, or (at your option) any later version.
  13  * =====================================================================
  14  */
  15
  16 #include "gigaset.h"
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19
  20 /* Version Information */
  21 #define DRIVER_AUTHOR "Hansjoerg Lipp <hjlipp@web.de>, Tilman Schmidt <tilman@imap.cc>, Stefan Eilers"
  22 #define DRIVER_DESC "Driver for Gigaset 307x"
  23
  24 #ifdef CONFIG_GIGASET_DEBUG
  25 #define DRIVER_DESC_DEBUG " (debug build)"
  26 #else
  27 #define DRIVER_DESC_DEBUG ""
  28 #endif
  29
  30 /* Module parameters */
  31 int gigaset_debuglevel;
  32 EXPORT_SYMBOL_GPL(gigaset_debuglevel);
  33 module_param_named(debug, gigaset_debuglevel, int, S_IRUGO|S_IWUSR);
  34 MODULE_PARM_DESC(debug, "debug level");
  35
  36 /* driver state flags */
  37 #define VALID_MINOR     0x01
  38 #define VALID_ID        0x02
  39
  40 /**
  41  * gigaset_dbg_buffer() - dump data in ASCII and hex for debugging
  42  * @level:      debugging level.
  43  * @msg:        message prefix.
  44  * @len:        number of bytes to dump.
  45  * @buf:        data to dump.
  46  *
  47  * If the current debugging level includes one of the bits set in @level,
  48  * @len bytes starting at @buf are logged to dmesg at KERN_DEBUG prio,
  49  * prefixed by the text @msg.
  50  */
  51 void gigaset_dbg_buffer(enum debuglevel level, const unsigned char *msg,
  52                         size_t len, const unsigned char *buf)
  53 {
  54         unsigned char outbuf[80];
  55         unsigned char c;
  56         size_t space = sizeof outbuf - 1;
  57         unsigned char *out = outbuf;
  58         size_t numin = len;
  59
  60         while (numin--) {
  61                 c = *buf++;
  62                 if (c == '~' || c == '^' || c == '\\') {
  63                         if (!space--)
  64                                 break;
  65                         *out++ = '\\';
  66                 }
  67                 if (c & 0x80) {
  68                         if (!space--)
  69                                 break;
  70                         *out++ = '~';
  71                         c ^= 0x80;
  72                 }
  73                 if (c < 0x20 || c == 0x7f) {
  74                         if (!space--)
  75                                 break;
  76                         *out++ = '^';
  77                         c ^= 0x40;
  78                 }
  79                 if (!space--)
  80                         break;
  81                 *out++ = c;
  82         }
  83         *out = 0;
  84
  85         gig_dbg(level, "%s (%u bytes): %s", msg, (unsigned) len, outbuf);
  86 }
  87 EXPORT_SYMBOL_GPL(gigaset_dbg_buffer);
  88
  89 static int setflags(struct cardstate *cs, unsigned flags, unsigned delay)
  90 {
  91         int r;
  92
  93         r = cs->ops->set_modem_ctrl(cs, cs->control_state, flags);
  94         cs->control_state = flags;
  95         if (r < 0)
  96                 return r;
  97
  98         if (delay) {
  99                 set_current_state(TASK_INTERRUPTIBLE);
 100                 schedule_timeout(delay * HZ / 1000);
 101         }
 102
 103         return 0;
 104 }
 105
 106 int gigaset_enterconfigmode(struct cardstate *cs)
 107 {
 108         int i, r;
 109
 110         cs->control_state = TIOCM_RTS;
 111
 112         r = setflags(cs, TIOCM_DTR, 200);
 113         if (r < 0)
 114                 goto error;
 115         r = setflags(cs, 0, 200);
 116         if (r < 0)
 117                 goto error;
 118         for (i = 0; i < 5; ++i) {
 119                 r = setflags(cs, TIOCM_RTS, 100);
 120                 if (r < 0)
 121                         goto error;
 122                 r = setflags(cs, 0, 100);
 123                 if (r < 0)
 124                         goto error;
 125         }
 126         r = setflags(cs, TIOCM_RTS|TIOCM_DTR, 800);
 127         if (r < 0)
 128                 goto error;
 129
 130         return 0;
 131
 132 error:
 133         dev_err(cs->dev, "error %d on setuartbits\n", -r);
 134         cs->control_state = TIOCM_RTS|TIOCM_DTR;
 135         cs->ops->set_modem_ctrl(cs, 0, TIOCM_RTS|TIOCM_DTR);
 136
 137         return -1;
 138 }
 139
 140 static int test_timeout(struct at_state_t *at_state)
 141 {
 142         if (!at_state->timer_expires)
 143                 return 0;
 144
 145         if (--at_state->timer_expires) {
 146                 gig_dbg(DEBUG_MCMD, "decreased timer of %p to %lu",
 147                         at_state, at_state->timer_expires);
 148                 return 0;
 149         }
 150
 151         gigaset_add_event(at_state->cs, at_state, EV_TIMEOUT, NULL,
 152                           at_state->timer_index, NULL);
 153         return 1;
 154 }
 155
 156 static void timer_tick(unsigned long data)
 157 {
 158         struct cardstate *cs = (struct cardstate *) data;
 159         unsigned long flags;
 160         unsigned channel;
 161         struct at_state_t *at_state;
 162         int timeout = 0;
 163
 164         spin_lock_irqsave(&cs->lock, flags);
 165
 166         for (channel = 0; channel < cs->channels; ++channel)
 167                 if (test_timeout(&cs->bcs[channel].at_state))
 168                         timeout = 1;
 169
 170         if (test_timeout(&cs->at_state))
 171                 timeout = 1;
 172
 173         list_for_each_entry(at_state, &cs->temp_at_states, list)
 174                 if (test_timeout(at_state))
 175                         timeout = 1;
 176
 177         if (cs->running) {
 178                 mod_timer(&cs->timer, jiffies + msecs_to_jiffies(GIG_TICK));
 179                 if (timeout) {
 180                         gig_dbg(DEBUG_EVENT, "scheduling timeout");
 181                         tasklet_schedule(&cs->event_tasklet);
 182                 }
 183         }
 184
 185         spin_unlock_irqrestore(&cs->lock, flags);
 186 }
 187
 188 int gigaset_get_channel(struct bc_state *bcs)
 189 {
 190         unsigned long flags;
 191
 192         spin_lock_irqsave(&bcs->cs->lock, flags);
 193         if (bcs->use_count || !try_module_get(bcs->cs->driver->owner)) {
 194                 gig_dbg(DEBUG_CHANNEL, "could not allocate channel %d",
 195                         bcs->channel);
 196                 spin_unlock_irqrestore(&bcs->cs->lock, flags);
 197                 return 0;
 198         }
 199         ++bcs->use_count;
 200         bcs->busy = 1;
 201         gig_dbg(DEBUG_CHANNEL, "allocated channel %d", bcs->channel);
 202         spin_unlock_irqrestore(&bcs->cs->lock, flags);
 203         return 1;
 204 }
 205
 206 struct bc_state *gigaset_get_free_channel(struct cardstate *cs)
 207 {
 208         unsigned long flags;
 209         int i;
 210
 211         spin_lock_irqsave(&cs->lock, flags);
 212         if (!try_module_get(cs->driver->owner)) {
 213                 gig_dbg(DEBUG_CHANNEL,
 214                         "could not get module for allocating channel");
 215                 spin_unlock_irqrestore(&cs->lock, flags);
 216                 return NULL;
 217         }
 218         for (i = 0; i < cs->channels; ++i)
 219                 if (!cs->bcs[i].use_count) {
 220                         ++cs->bcs[i].use_count;
 221                         cs->bcs[i].busy = 1;
 222                         spin_unlock_irqrestore(&cs->lock, flags);
 223                         gig_dbg(DEBUG_CHANNEL, "allocated channel %d", i);
 224                         return cs->bcs + i;
 225                 }
 226         module_put(cs->driver->owner);
 227         spin_unlock_irqrestore(&cs->lock, flags);
 228         gig_dbg(DEBUG_CHANNEL, "no free channel");
 229         return NULL;
 230 }
 231
 232 void gigaset_free_channel(struct bc_state *bcs)
 233 {
 234         unsigned long flags;
 235
 236         spin_lock_irqsave(&bcs->cs->lock, flags);
 237         if (!bcs->busy) {
 238                 gig_dbg(DEBUG_CHANNEL, "could not free channel %d",
 239                         bcs->channel);
 240                 spin_unlock_irqrestore(&bcs->cs->lock, flags);
 241                 return;
 242         }
 243         --bcs->use_count;
 244         bcs->busy = 0;
 245         module_put(bcs->cs->driver->owner);
 246         gig_dbg(DEBUG_CHANNEL, "freed channel %d", bcs->channel);
 247         spin_unlock_irqrestore(&bcs->cs->lock, flags);
 248 }
 249
 250 int gigaset_get_channels(struct cardstate *cs)
 251 {
 252         unsigned long flags;
 253         int i;
 254
 255         spin_lock_irqsave(&cs->lock, flags);
 256         for (i = 0; i < cs->channels; ++i)
 257                 if (cs->bcs[i].use_count) {
 258                         spin_unlock_irqrestore(&cs->lock, flags);
 259                         gig_dbg(DEBUG_CHANNEL,
 260                                 "could not allocate all channels");
 261                         return 0;
 262                 }
 263         for (i = 0; i < cs->channels; ++i)
 264                 ++cs->bcs[i].use_count;
 265         spin_unlock_irqrestore(&cs->lock, flags);
 266
 267         gig_dbg(DEBUG_CHANNEL, "allocated all channels");
 268
 269         return 1;
 270 }
 271
 272 void gigaset_free_channels(struct cardstate *cs)
 273 {
 274         unsigned long flags;
 275         int i;
 276
 277         gig_dbg(DEBUG_CHANNEL, "unblocking all channels");
 278         spin_lock_irqsave(&cs->lock, flags);
 279         for (i = 0; i < cs->channels; ++i)
 280                 --cs->bcs[i].use_count;
 281         spin_unlock_irqrestore(&cs->lock, flags);
 282 }
 283
 284 void gigaset_block_channels(struct cardstate *cs)
 285 {
 286         unsigned long flags;
 287         int i;
 288
 289         gig_dbg(DEBUG_CHANNEL, "blocking all channels");
 290         spin_lock_irqsave(&cs->lock, flags);
 291         for (i = 0; i < cs->channels; ++i)
 292                 ++cs->bcs[i].use_count;
 293         spin_unlock_irqrestore(&cs->lock, flags);
 294 }
 295
 296 static void clear_events(struct cardstate *cs)
 297 {
 298         struct event_t *ev;
 299         unsigned head, tail;
 300         unsigned long flags;
 301
 302         spin_lock_irqsave(&cs->ev_lock, flags);
 303
 304         head = cs->ev_head;
 305         tail = cs->ev_tail;
 306
 307         while (tail != head) {
 308                 ev = cs->events + head;
 309                 kfree(ev->ptr);
 310                 head = (head + 1) % MAX_EVENTS;
 311         }
 312
 313         cs->ev_head = tail;
 314
 315         spin_unlock_irqrestore(&cs->ev_lock, flags);
 316 }
 317
 318 /**
 319  * gigaset_add_event() - add event to device event queue
 320  * @cs:         device descriptor structure.
 321  * @at_state:   connection state structure.
 322  * @type:       event type.
 323  * @ptr:        pointer parameter for event.
 324  * @parameter:  integer parameter for event.
 325  * @arg:        pointer parameter for event.
 326  *
 327  * Allocate an event queue entry from the device's event queue, and set it up
 328  * with the parameters given.
 329  *
 330  * Return value: added event
 331  */
 332 struct event_t *gigaset_add_event(struct cardstate *cs,
 333                                   struct at_state_t *at_state, int type,
 334                                   void *ptr, int parameter, void *arg)
 335 {
 336         unsigned long flags;
 337         unsigned next, tail;
 338         struct event_t *event = NULL;
 339
 340         gig_dbg(DEBUG_EVENT, "queueing event %d", type);
 341
 342         spin_lock_irqsave(&cs->ev_lock, flags);
 343
 344         tail = cs->ev_tail;
 345         next = (tail + 1) % MAX_EVENTS;
 346         if (unlikely(next == cs->ev_head))
 347                 dev_err(cs->dev, "event queue full\n");
 348         else {
 349                 event = cs->events + tail;
 350                 event->type = type;
 351                 event->at_state = at_state;
 352                 event->cid = -1;
 353                 event->ptr = ptr;
 354                 event->arg = arg;
 355                 event->parameter = parameter;
 356                 cs->ev_tail = next;
 357         }
 358
 359         spin_unlock_irqrestore(&cs->ev_lock, flags);
 360
 361         return event;
 362 }
 363 EXPORT_SYMBOL_GPL(gigaset_add_event);
 364
 365 static void free_strings(struct at_state_t *at_state)
 366 {
 367         int i;
 368
 369         for (i = 0; i < STR_NUM; ++i) {
 370                 kfree(at_state->str_var[i]);
 371                 at_state->str_var[i] = NULL;
 372         }
 373 }
 374
 375 static void clear_at_state(struct at_state_t *at_state)
 376 {
 377         free_strings(at_state);
 378 }
 379
 380 static void dealloc_at_states(struct cardstate *cs)
 381 {
 382         struct at_state_t *cur, *next;
 383
 384         list_for_each_entry_safe(cur, next, &cs->temp_at_states, list) {
 385                 list_del(&cur->list);
 386                 free_strings(cur);
 387                 kfree(cur);
 388         }
 389 }
 390
 391 static void gigaset_freebcs(struct bc_state *bcs)
 392 {
 393         int i;
 394
 395         gig_dbg(DEBUG_INIT, "freeing bcs[%d]->hw", bcs->channel);
 396         if (!bcs->cs->ops->freebcshw(bcs))
 397                 gig_dbg(DEBUG_INIT, "failed");
 398
 399         gig_dbg(DEBUG_INIT, "clearing bcs[%d]->at_state", bcs->channel);
 400         clear_at_state(&bcs->at_state);
 401         gig_dbg(DEBUG_INIT, "freeing bcs[%d]->skb", bcs->channel);
 402         dev_kfree_skb(bcs->rx_skb);
 403         bcs->rx_skb = NULL;
 404
 405         for (i = 0; i < AT_NUM; ++i) {
 406                 kfree(bcs->commands[i]);
 407                 bcs->commands[i] = NULL;
 408         }
 409 }
 410
 411 static struct cardstate *alloc_cs(struct gigaset_driver *drv)
 412 {
 413         unsigned long flags;
 414         unsigned i;
 415         struct cardstate *cs;
 416         struct cardstate *ret = NULL;
 417
 418         spin_lock_irqsave(&drv->lock, flags);
 419         if (drv->blocked)
 420                 goto exit;
 421         for (i = 0; i < drv->minors; ++i) {
 422                 cs = drv->cs + i;
 423                 if (!(cs->flags & VALID_MINOR)) {
 424                         cs->flags = VALID_MINOR;
 425                         ret = cs;
 426                         break;
 427                 }
 428         }
 429 exit:
 430         spin_unlock_irqrestore(&drv->lock, flags);
 431         return ret;
 432 }
 433
 434 static void free_cs(struct cardstate *cs)
 435 {
 436         cs->flags = 0;
 437 }
 438
 439 static void make_valid(struct cardstate *cs, unsigned mask)
 440 {
 441         unsigned long flags;
 442         struct gigaset_driver *drv = cs->driver;
 443         spin_lock_irqsave(&drv->lock, flags);
 444         cs->flags |= mask;
 445         spin_unlock_irqrestore(&drv->lock, flags);
 446 }
 447
 448 static void make_invalid(struct cardstate *cs, unsigned mask)
 449 {
 450         unsigned long flags;
 451         struct gigaset_driver *drv = cs->driver;
 452         spin_lock_irqsave(&drv->lock, flags);
 453         cs->flags &= ~mask;
 454         spin_unlock_irqrestore(&drv->lock, flags);
 455 }
 456
 457 /**
 458  * gigaset_freecs() - free all associated ressources of a device
 459  * @cs:         device descriptor structure.
 460  *
 461  * Stops all tasklets and timers, unregisters the device from all
 462  * subsystems it was registered to, deallocates the device structure
 463  * @cs and all structures referenced from it.
 464  * Operations on the device should be stopped before calling this.
 465  */
 466 void gigaset_freecs(struct cardstate *cs)
 467 {
 468         int i;
 469         unsigned long flags;
 470
 471         if (!cs)
 472                 return;
 473
 474         mutex_lock(&cs->mutex);
 475
 476         if (!cs->bcs)
 477                 goto f_cs;
 478         if (!cs->inbuf)
 479                 goto f_bcs;
 480
 481         spin_lock_irqsave(&cs->lock, flags);
 482         cs->running = 0;
 483         spin_unlock_irqrestore(&cs->lock, flags); /* event handler and timer are
 484                                                      not rescheduled below */
 485
 486         tasklet_kill(&cs->event_tasklet);
 487         del_timer_sync(&cs->timer);
 488
 489         switch (cs->cs_init) {
 490         default:
 491                 /* clear B channel structures */
 492                 for (i = 0; i < cs->channels; ++i) {
 493                         gig_dbg(DEBUG_INIT, "clearing bcs[%d]", i);
 494                         gigaset_freebcs(cs->bcs + i);
 495                 }
 496
 497                 /* clear device sysfs */
 498                 gigaset_free_dev_sysfs(cs);
 499
 500                 gigaset_if_free(cs);
 501
 502                 gig_dbg(DEBUG_INIT, "clearing hw");
 503                 cs->ops->freecshw(cs);
 504
 505                 /* fall through */
 506         case 2: /* error in initcshw */
 507                 /* Deregister from LL */
 508                 make_invalid(cs, VALID_ID);
 509                 gigaset_isdn_unregdev(cs);
 510
 511                 /* fall through */
 512         case 1: /* error when registering to LL */
 513                 gig_dbg(DEBUG_INIT, "clearing at_state");
 514                 clear_at_state(&cs->at_state);
 515                 dealloc_at_states(cs);
 516
 517                 /* fall through */
 518         case 0: /* error in basic setup */
 519                 clear_events(cs);
 520                 gig_dbg(DEBUG_INIT, "freeing inbuf");
 521                 kfree(cs->inbuf);
 522         }
 523 f_bcs:  gig_dbg(DEBUG_INIT, "freeing bcs[]");
 524         kfree(cs->bcs);
 525 f_cs:   gig_dbg(DEBUG_INIT, "freeing cs");
 526         mutex_unlock(&cs->mutex);
 527         free_cs(cs);
 528 }
 529 EXPORT_SYMBOL_GPL(gigaset_freecs);
 530
 531 void gigaset_at_init(struct at_state_t *at_state, struct bc_state *bcs,
 532                      struct cardstate *cs, int cid)
 533 {
 534         int i;
 535
 536         INIT_LIST_HEAD(&at_state->list);
 537         at_state->waiting = 0;
 538         at_state->getstring = 0;
 539         at_state->pending_commands = 0;
 540         at_state->timer_expires = 0;
 541         at_state->timer_active = 0;
 542         at_state->timer_index = 0;
 543         at_state->seq_index = 0;
 544         at_state->ConState = 0;
 545         for (i = 0; i < STR_NUM; ++i)
 546                 at_state->str_var[i] = NULL;
 547         at_state->int_var[VAR_ZDLE] = 0;
 548         at_state->int_var[VAR_ZCTP] = -1;
 549         at_state->int_var[VAR_ZSAU] = ZSAU_NULL;
 550         at_state->cs = cs;
 551         at_state->bcs = bcs;
 552         at_state->cid = cid;
 553         if (!cid)
 554                 at_state->replystruct = cs->tabnocid;
 555         else
 556                 at_state->replystruct = cs->tabcid;
 557 }
 558
 559
 560 static void gigaset_inbuf_init(struct inbuf_t *inbuf, struct cardstate *cs)
 561 /* inbuf->read must be allocated before! */
 562 {
 563         inbuf->head = 0;
 564         inbuf->tail = 0;
 565         inbuf->cs = cs;
 566         inbuf->inputstate = INS_command;
 567 }
 568
 569 /**
 570  * gigaset_fill_inbuf() - append received data to input buffer
 571  * @inbuf:      buffer structure.
 572  * @src:        received data.
 573  * @numbytes:   number of bytes received.
 574  */
 575 int gigaset_fill_inbuf(struct inbuf_t *inbuf, const unsigned char *src,
 576                        unsigned numbytes)
 577 {
 578         unsigned n, head, tail, bytesleft;
 579
 580         gig_dbg(DEBUG_INTR, "received %u bytes", numbytes);
 581
 582         if (!numbytes)
 583                 return 0;
 584
 585         bytesleft = numbytes;
 586         tail = inbuf->tail;
 587         head = inbuf->head;
 588         gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
 589
 590         while (bytesleft) {
 591                 if (head > tail)
 592                         n = head - 1 - tail;
 593                 else if (head == 0)
 594                         n = (RBUFSIZE-1) - tail;
 595                 else
 596                         n = RBUFSIZE - tail;
 597                 if (!n) {
 598                         dev_err(inbuf->cs->dev,
 599                                 "buffer overflow (%u bytes lost)\n",
 600                                 bytesleft);
 601                         break;
 602                 }
 603                 if (n > bytesleft)
 604                         n = bytesleft;
 605                 memcpy(inbuf->data + tail, src, n);
 606                 bytesleft -= n;
 607                 tail = (tail + n) % RBUFSIZE;
 608                 src += n;
 609         }
 610         gig_dbg(DEBUG_INTR, "setting tail to %u", tail);
 611         inbuf->tail = tail;
 612         return numbytes != bytesleft;
 613 }
 614 EXPORT_SYMBOL_GPL(gigaset_fill_inbuf);
 615
 616 /* Initialize the b-channel structure */
 617 static struct bc_state *gigaset_initbcs(struct bc_state *bcs,
 618                                         struct cardstate *cs, int channel)
 619 {
 620         int i;
 621
 622         bcs->tx_skb = NULL;
 623
 624         skb_queue_head_init(&bcs->squeue);
 625
 626         bcs->corrupted = 0;
 627         bcs->trans_down = 0;
 628         bcs->trans_up = 0;
 629
 630         gig_dbg(DEBUG_INIT, "setting up bcs[%d]->at_state", channel);
 631         gigaset_at_init(&bcs->at_state, bcs, cs, -1);
 632
 633 #ifdef CONFIG_GIGASET_DEBUG
 634         bcs->emptycount = 0;
 635 #endif
 636
 637         bcs->rx_bufsize = 0;
 638         bcs->rx_skb = NULL;
 639         bcs->rx_fcs = PPP_INITFCS;
 640         bcs->inputstate = 0;
 641         bcs->channel = channel;
 642         bcs->cs = cs;
 643
 644         bcs->chstate = 0;
 645         bcs->use_count = 1;
 646         bcs->busy = 0;
 647         bcs->ignore = cs->ignoreframes;
 648
 649         for (i = 0; i < AT_NUM; ++i)
 650                 bcs->commands[i] = NULL;
 651
 652         spin_lock_init(&bcs->aplock);
 653         bcs->ap = NULL;
 654         bcs->apconnstate = 0;
 655
 656         gig_dbg(DEBUG_INIT, "  setting up bcs[%d]->hw", channel);
 657         if (cs->ops->initbcshw(bcs))
 658                 return bcs;
 659
 660         gig_dbg(DEBUG_INIT, "  failed");
 661         return NULL;
 662 }
 663
 664 /**
 665  * gigaset_initcs() - initialize device structure
 666  * @drv:        hardware driver the device belongs to
 667  * @channels:   number of B channels supported by device
 668  * @onechannel: !=0 if B channel data and AT commands share one
 669  *                  communication channel (M10x),
 670  *              ==0 if B channels have separate communication channels (base)
 671  * @ignoreframes:       number of frames to ignore after setting up B channel
 672  * @cidmode:    !=0: start in CallID mode
 673  * @modulename: name of driver module for LL registration
 674  *
 675  * Allocate and initialize cardstate structure for Gigaset driver
 676  * Calls hardware dependent gigaset_initcshw() function
 677  * Calls B channel initialization function gigaset_initbcs() for each B channel
 678  *
 679  * Return value:
 680  *      pointer to cardstate structure
 681  */
 682 struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 683                                  int onechannel, int ignoreframes,
 684                                  int cidmode, const char *modulename)
 685 {
 686         struct cardstate *cs;
 687         unsigned long flags;
 688         int i;
 689
 690         gig_dbg(DEBUG_INIT, "allocating cs");
 691         cs = alloc_cs(drv);
 692         if (!cs) {
 693                 pr_err("maximum number of devices exceeded\n");
 694                 return NULL;
 695         }
 696
 697         gig_dbg(DEBUG_INIT, "allocating bcs[0..%d]", channels - 1);
 698         cs->bcs = kmalloc(channels * sizeof(struct bc_state), GFP_KERNEL);
 699         if (!cs->bcs) {
 700                 pr_err("out of memory\n");
 701                 goto error;
 702         }
 703         gig_dbg(DEBUG_INIT, "allocating inbuf");
 704         cs->inbuf = kmalloc(sizeof(struct inbuf_t), GFP_KERNEL);
 705         if (!cs->inbuf) {
 706                 pr_err("out of memory\n");
 707                 goto error;
 708         }
 709
 710         cs->cs_init = 0;
 711         cs->channels = channels;
 712         cs->onechannel = onechannel;
 713         cs->ignoreframes = ignoreframes;
 714         INIT_LIST_HEAD(&cs->temp_at_states);
 715         cs->running = 0;
 716         init_timer(&cs->timer); /* clear next & prev */
 717         spin_lock_init(&cs->ev_lock);
 718         cs->ev_tail = 0;
 719         cs->ev_head = 0;
 720
 721         tasklet_init(&cs->event_tasklet, gigaset_handle_event,
 722                      (unsigned long) cs);
 723         cs->commands_pending = 0;
 724         cs->cur_at_seq = 0;
 725         cs->gotfwver = -1;
 726         cs->open_count = 0;
 727         cs->dev = NULL;
 728         cs->tty = NULL;
 729         cs->tty_dev = NULL;
 730         cs->cidmode = cidmode != 0;
 731         cs->tabnocid = gigaset_tab_nocid;
 732         cs->tabcid = gigaset_tab_cid;
 733
 734         init_waitqueue_head(&cs->waitqueue);
 735         cs->waiting = 0;
 736
 737         cs->mode = M_UNKNOWN;
 738         cs->mstate = MS_UNINITIALIZED;
 739
 740         ++cs->cs_init;
 741
 742         gig_dbg(DEBUG_INIT, "setting up at_state");
 743         spin_lock_init(&cs->lock);
 744         gigaset_at_init(&cs->at_state, NULL, cs, 0);
 745         cs->dle = 0;
 746         cs->cbytes = 0;
 747
 748         gig_dbg(DEBUG_INIT, "setting up inbuf");
 749         gigaset_inbuf_init(cs->inbuf, cs);
 750
 751         cs->connected = 0;
 752         cs->isdn_up = 0;
 753
 754         gig_dbg(DEBUG_INIT, "setting up cmdbuf");
 755         cs->cmdbuf = cs->lastcmdbuf = NULL;
 756         spin_lock_init(&cs->cmdlock);
 757         cs->curlen = 0;
 758         cs->cmdbytes = 0;
 759
 760         gig_dbg(DEBUG_INIT, "setting up iif");
 761         if (!gigaset_isdn_regdev(cs, modulename)) {
 762                 pr_err("error registering ISDN device\n");
 763                 goto error;
 764         }
 765
 766         make_valid(cs, VALID_ID);
 767         ++cs->cs_init;
 768         gig_dbg(DEBUG_INIT, "setting up hw");
 769         if (!cs->ops->initcshw(cs))
 770                 goto error;
 771
 772         ++cs->cs_init;
 773
 774         /* set up character device */
 775         gigaset_if_init(cs);
 776
 777         /* set up device sysfs */
 778         gigaset_init_dev_sysfs(cs);
 779
 780         /* set up channel data structures */
 781         for (i = 0; i < channels; ++i) {
 782                 gig_dbg(DEBUG_INIT, "setting up bcs[%d]", i);
 783                 if (!gigaset_initbcs(cs->bcs + i, cs, i)) {
 784                         pr_err("could not allocate channel %d data\n", i);
 785                         goto error;
 786                 }
 787         }
 788
 789         spin_lock_irqsave(&cs->lock, flags);
 790         cs->running = 1;
 791         spin_unlock_irqrestore(&cs->lock, flags);
 792         setup_timer(&cs->timer, timer_tick, (unsigned long) cs);
 793         cs->timer.expires = jiffies + msecs_to_jiffies(GIG_TICK);
 794         /* FIXME: can jiffies increase too much until the timer is added?
 795          * Same problem(?) with mod_timer() in timer_tick(). */
 796         add_timer(&cs->timer);
 797
 798         gig_dbg(DEBUG_INIT, "cs initialized");
 799         return cs;
 800
 801 error:
 802         gig_dbg(DEBUG_INIT, "failed");
 803         gigaset_freecs(cs);
 804         return NULL;
 805 }
 806 EXPORT_SYMBOL_GPL(gigaset_initcs);
 807
 808 /* ReInitialize the b-channel structure on hangup */
 809 void gigaset_bcs_reinit(struct bc_state *bcs)
 810 {
 811         struct sk_buff *skb;
 812         struct cardstate *cs = bcs->cs;
 813         unsigned long flags;
 814
 815         while ((skb = skb_dequeue(&bcs->squeue)) != NULL)
 816                 dev_kfree_skb(skb);
 817
 818         spin_lock_irqsave(&cs->lock, flags);
 819         clear_at_state(&bcs->at_state);
 820         bcs->at_state.ConState = 0;
 821         bcs->at_state.timer_active = 0;
 822         bcs->at_state.timer_expires = 0;
 823         bcs->at_state.cid = -1;                 /* No CID defined */
 824         spin_unlock_irqrestore(&cs->lock, flags);
 825
 826         bcs->inputstate = 0;
 827
 828 #ifdef CONFIG_GIGASET_DEBUG
 829         bcs->emptycount = 0;
 830 #endif
 831
 832         bcs->rx_fcs = PPP_INITFCS;
 833         bcs->chstate = 0;
 834
 835         bcs->ignore = cs->ignoreframes;
 836         dev_kfree_skb(bcs->rx_skb);
 837         bcs->rx_skb = NULL;
 838
 839         cs->ops->reinitbcshw(bcs);
 840 }
 841
 842 static void cleanup_cs(struct cardstate *cs)
 843 {
 844         struct cmdbuf_t *cb, *tcb;
 845         int i;
 846         unsigned long flags;
 847
 848         spin_lock_irqsave(&cs->lock, flags);
 849
 850         cs->mode = M_UNKNOWN;
 851         cs->mstate = MS_UNINITIALIZED;
 852
 853         clear_at_state(&cs->at_state);
 854         dealloc_at_states(cs);
 855         free_strings(&cs->at_state);
 856         gigaset_at_init(&cs->at_state, NULL, cs, 0);
 857
 858         cs->inbuf->inputstate = INS_command;
 859         cs->inbuf->head = 0;
 860         cs->inbuf->tail = 0;
 861
 862         cb = cs->cmdbuf;
 863         while (cb) {
 864                 tcb = cb;
 865                 cb = cb->next;
 866                 kfree(tcb);
 867         }
 868         cs->cmdbuf = cs->lastcmdbuf = NULL;
 869         cs->curlen = 0;
 870         cs->cmdbytes = 0;
 871         cs->gotfwver = -1;
 872         cs->dle = 0;
 873         cs->cur_at_seq = 0;
 874         cs->commands_pending = 0;
 875         cs->cbytes = 0;
 876
 877         spin_unlock_irqrestore(&cs->lock, flags);
 878
 879         for (i = 0; i < cs->channels; ++i) {
 880                 gigaset_freebcs(cs->bcs + i);
 881                 if (!gigaset_initbcs(cs->bcs + i, cs, i))
 882                         pr_err("could not allocate channel %d data\n", i);
 883         }
 884
 885         if (cs->waiting) {
 886                 cs->cmd_result = -ENODEV;
 887                 cs->waiting = 0;
 888                 wake_up_interruptible(&cs->waitqueue);
 889         }
 890 }
 891
 892
 893 /**
 894  * gigaset_start() - start device operations
 895  * @cs:         device descriptor structure.
 896  *
 897  * Prepares the device for use by setting up communication parameters,
 898  * scheduling an EV_START event to initiate device initialization, and
 899  * waiting for completion of the initialization.
 900  *
 901  * Return value:
 902  *      1 - success, 0 - error
 903  */
 904 int gigaset_start(struct cardstate *cs)
 905 {
 906         unsigned long flags;
 907
 908         if (mutex_lock_interruptible(&cs->mutex))
 909                 return 0;
 910
 911         spin_lock_irqsave(&cs->lock, flags);
 912         cs->connected = 1;
 913         spin_unlock_irqrestore(&cs->lock, flags);
 914
 915         if (cs->mstate != MS_LOCKED) {
 916                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
 917                 cs->ops->baud_rate(cs, B115200);
 918                 cs->ops->set_line_ctrl(cs, CS8);
 919                 cs->control_state = TIOCM_DTR|TIOCM_RTS;
 920         }
 921
 922         cs->waiting = 1;
 923
 924         if (!gigaset_add_event(cs, &cs->at_state, EV_START, NULL, 0, NULL)) {
 925                 cs->waiting = 0;
 926                 goto error;
 927         }
 928         gigaset_schedule_event(cs);
 929
 930         wait_event(cs->waitqueue, !cs->waiting);
 931
 932         mutex_unlock(&cs->mutex);
 933         return 1;
 934
 935 error:
 936         mutex_unlock(&cs->mutex);
 937         return 0;
 938 }
 939 EXPORT_SYMBOL_GPL(gigaset_start);
 940
 941 /**
 942  * gigaset_shutdown() - shut down device operations
 943  * @cs:         device descriptor structure.
 944  *
 945  * Deactivates the device by scheduling an EV_SHUTDOWN event and
 946  * waiting for completion of the shutdown.
 947  *
 948  * Return value:
 949  *      0 - success, -1 - error (no device associated)
 950  */
 951 int gigaset_shutdown(struct cardstate *cs)
 952 {
 953         mutex_lock(&cs->mutex);
 954
 955         if (!(cs->flags & VALID_MINOR)) {
 956                 mutex_unlock(&cs->mutex);
 957                 return -1;
 958         }
 959
 960         cs->waiting = 1;
 961
 962         if (!gigaset_add_event(cs, &cs->at_state, EV_SHUTDOWN, NULL, 0, NULL))
 963                 goto exit;
 964         gigaset_schedule_event(cs);
 965
 966         wait_event(cs->waitqueue, !cs->waiting);
 967
 968         cleanup_cs(cs);
 969
 970 exit:
 971         mutex_unlock(&cs->mutex);
 972         return 0;
 973 }
 974 EXPORT_SYMBOL_GPL(gigaset_shutdown);
 975
 976 /**
 977  * gigaset_stop() - stop device operations
 978  * @cs:         device descriptor structure.
 979  *
 980  * Stops operations on the device by scheduling an EV_STOP event and
 981  * waiting for completion of the shutdown.
 982  */
 983 void gigaset_stop(struct cardstate *cs)
 984 {
 985         mutex_lock(&cs->mutex);
 986
 987         cs->waiting = 1;
 988
 989         if (!gigaset_add_event(cs, &cs->at_state, EV_STOP, NULL, 0, NULL))
 990                 goto exit;
 991         gigaset_schedule_event(cs);
 992
 993         wait_event(cs->waitqueue, !cs->waiting);
 994
 995         cleanup_cs(cs);
 996
 997 exit:
 998         mutex_unlock(&cs->mutex);
 999 }
1000 EXPORT_SYMBOL_GPL(gigaset_stop);
1001
1002 static LIST_HEAD(drivers);
1003 static DEFINE_SPINLOCK(driver_lock);
1004
1005 struct cardstate *gigaset_get_cs_by_id(int id)
1006 {
1007         unsigned long flags;
1008         struct cardstate *ret = NULL;
1009         struct cardstate *cs;
1010         struct gigaset_driver *drv;
1011         unsigned i;
1012
1013         spin_lock_irqsave(&driver_lock, flags);
1014         list_for_each_entry(drv, &drivers, list) {
1015                 spin_lock(&drv->lock);
1016                 for (i = 0; i < drv->minors; ++i) {
1017                         cs = drv->cs + i;
1018                         if ((cs->flags & VALID_ID) && cs->myid == id) {
1019                                 ret = cs;
1020                                 break;
1021                         }
1022                 }
1023                 spin_unlock(&drv->lock);
1024                 if (ret)
1025                         break;
1026         }
1027         spin_unlock_irqrestore(&driver_lock, flags);
1028         return ret;
1029 }
1030
1031 void gigaset_debugdrivers(void)
1032 {
1033         unsigned long flags;
1034         static struct cardstate *cs;
1035         struct gigaset_driver *drv;
1036         unsigned i;
1037
1038         spin_lock_irqsave(&driver_lock, flags);
1039         list_for_each_entry(drv, &drivers, list) {
1040                 gig_dbg(DEBUG_DRIVER, "driver %p", drv);
1041                 spin_lock(&drv->lock);
1042                 for (i = 0; i < drv->minors; ++i) {
1043                         gig_dbg(DEBUG_DRIVER, "  index %u", i);
1044                         cs = drv->cs + i;
1045                         gig_dbg(DEBUG_DRIVER, "    cardstate %p", cs);
1046                         gig_dbg(DEBUG_DRIVER, "    flags 0x%02x", cs->flags);
1047                         gig_dbg(DEBUG_DRIVER, "    minor_index %u",
1048                                 cs->minor_index);
1049                         gig_dbg(DEBUG_DRIVER, "    driver %p", cs->driver);
1050                         gig_dbg(DEBUG_DRIVER, "    i4l id %d", cs->myid);
1051                 }
1052                 spin_unlock(&drv->lock);
1053         }
1054         spin_unlock_irqrestore(&driver_lock, flags);
1055 }
1056
1057 static struct cardstate *gigaset_get_cs_by_minor(unsigned minor)
1058 {
1059         unsigned long flags;
1060         struct cardstate *ret = NULL;
1061         struct gigaset_driver *drv;
1062         unsigned index;
1063
1064         spin_lock_irqsave(&driver_lock, flags);
1065         list_for_each_entry(drv, &drivers, list) {
1066                 if (minor < drv->minor || minor >= drv->minor + drv->minors)
1067                         continue;
1068                 index = minor - drv->minor;
1069                 spin_lock(&drv->lock);
1070                 if (drv->cs[index].flags & VALID_MINOR)
1071                         ret = drv->cs + index;
1072                 spin_unlock(&drv->lock);
1073                 if (ret)
1074                         break;
1075         }
1076         spin_unlock_irqrestore(&driver_lock, flags);
1077         return ret;
1078 }
1079
1080 struct cardstate *gigaset_get_cs_by_tty(struct tty_struct *tty)
1081 {
1082         if (tty->index < 0 || tty->index >= tty->driver->num)
1083                 return NULL;
1084         return gigaset_get_cs_by_minor(tty->index + tty->driver->minor_start);
1085 }
1086
1087 /**
1088  * gigaset_freedriver() - free all associated ressources of a driver
1089  * @drv:        driver descriptor structure.
1090  *
1091  * Unregisters the driver from the system and deallocates the driver
1092  * structure @drv and all structures referenced from it.
1093  * All devices should be shut down before calling this.
1094  */
1095 void gigaset_freedriver(struct gigaset_driver *drv)
1096 {
1097         unsigned long flags;
1098
1099         spin_lock_irqsave(&driver_lock, flags);
1100         list_del(&drv->list);
1101         spin_unlock_irqrestore(&driver_lock, flags);
1102
1103         gigaset_if_freedriver(drv);
1104
1105         kfree(drv->cs);
1106         kfree(drv);
1107 }
1108 EXPORT_SYMBOL_GPL(gigaset_freedriver);
1109
1110 /**
1111  * gigaset_initdriver() - initialize driver structure
1112  * @minor:      First minor number
1113  * @minors:     Number of minors this driver can handle
1114  * @procname:   Name of the driver
1115  * @devname:    Name of the device files (prefix without minor number)
1116  *
1117  * Allocate and initialize gigaset_driver structure. Initialize interface.
1118  *
1119  * Return value:
1120  *      Pointer to the gigaset_driver structure on success, NULL on failure.
1121  */
1122 struct gigaset_driver *gigaset_initdriver(unsigned minor, unsigned minors,
1123                                           const char *procname,
1124                                           const char *devname,
1125                                           const struct gigaset_ops *ops,
1126                                           struct module *owner)
1127 {
1128         struct gigaset_driver *drv;
1129         unsigned long flags;
1130         unsigned i;
1131
1132         drv = kmalloc(sizeof *drv, GFP_KERNEL);
1133         if (!drv)
1134                 return NULL;
1135
1136         drv->have_tty = 0;
1137         drv->minor = minor;
1138         drv->minors = minors;
1139         spin_lock_init(&drv->lock);
1140         drv->blocked = 0;
1141         drv->ops = ops;
1142         drv->owner = owner;
1143         INIT_LIST_HEAD(&drv->list);
1144
1145         drv->cs = kmalloc(minors * sizeof *drv->cs, GFP_KERNEL);
1146         if (!drv->cs)
1147                 goto error;
1148
1149         for (i = 0; i < minors; ++i) {
1150                 drv->cs[i].flags = 0;
1151                 drv->cs[i].driver = drv;
1152                 drv->cs[i].ops = drv->ops;
1153                 drv->cs[i].minor_index = i;
1154                 mutex_init(&drv->cs[i].mutex);
1155         }
1156
1157         gigaset_if_initdriver(drv, procname, devname);
1158
1159         spin_lock_irqsave(&driver_lock, flags);
1160         list_add(&drv->list, &drivers);
1161         spin_unlock_irqrestore(&driver_lock, flags);
1162
1163         return drv;
1164
1165 error:
1166         kfree(drv->cs);
1167         kfree(drv);
1168         return NULL;
1169 }
1170 EXPORT_SYMBOL_GPL(gigaset_initdriver);
1171
1172 /**
1173  * gigaset_blockdriver() - block driver
1174  * @drv:        driver descriptor structure.
1175  *
1176  * Prevents the driver from attaching new devices, in preparation for
1177  * deregistration.
1178  */
1179 void gigaset_blockdriver(struct gigaset_driver *drv)
1180 {
1181         drv->blocked = 1;
1182 }
1183 EXPORT_SYMBOL_GPL(gigaset_blockdriver);
1184
1185 static int __init gigaset_init_module(void)
1186 {
1187         /* in accordance with the principle of least astonishment,
1188          * setting the 'debug' parameter to 1 activates a sensible
1189          * set of default debug levels
1190          */
1191         if (gigaset_debuglevel == 1)
1192                 gigaset_debuglevel = DEBUG_DEFAULT;
1193
1194         pr_info(DRIVER_DESC DRIVER_DESC_DEBUG "\n");
1195         gigaset_isdn_regdrv();
1196         return 0;
1197 }
1198
1199 static void __exit gigaset_exit_module(void)
1200 {
1201         gigaset_isdn_unregdrv();
1202 }
1203
1204 module_init(gigaset_init_module);
1205 module_exit(gigaset_exit_module);
1206
1207 MODULE_AUTHOR(DRIVER_AUTHOR);
1208 MODULE_DESCRIPTION(DRIVER_DESC);
1209
1210 MODULE_LICENSE("GPL");