sound/core/init.c

   1 /*
   2  *  Initialization routines
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/sched.h>
  25 #include <linux/file.h>
  26 #include <linux/slab.h>
  27 #include <linux/time.h>
  28 #include <linux/ctype.h>
  29 #include <linux/pci.h>
  30 #include <linux/pm.h>
  31 #include <sound/core.h>
  32 #include <sound/control.h>
  33 #include <sound/info.h>
  34
  35 struct snd_shutdown_f_ops {
  36         struct file_operations f_ops;
  37         struct snd_shutdown_f_ops *next;
  38 };
  39
  40 int snd_cards_count = 0;
  41 unsigned int snd_cards_lock = 0;        /* locked for registering/using */
  42 snd_card_t *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
  43 rwlock_t snd_card_rwlock = RW_LOCK_UNLOCKED;
  44
  45 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  46 int (*snd_mixer_oss_notify_callback)(snd_card_t *card, int free_flag);
  47 #endif
  48
  49 static void snd_card_id_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
  50 {
  51         snd_iprintf(buffer, "%s\n", entry->card->id);
  52 }
  53
  54 static void snd_card_free_thread(void * __card);
  55
  56 /**
  57  *  snd_card_new - create and initialize a soundcard structure
  58  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
  59  *  @xid: card identification (ASCII string)
  60  *  @module: top level module for locking
  61  *  @extra_size: allocate this extra size after the main soundcard structure
  62  *
  63  *  Creates and initializes a soundcard structure.
  64  *
  65  *  Returns kmallocated snd_card_t structure. Creates the ALSA control interface
  66  *  (which is blocked until snd_card_register function is called).
  67  */
  68 snd_card_t *snd_card_new(int idx, const char *xid,
  69                          struct module *module, int extra_size)
  70 {
  71         snd_card_t *card;
  72         int err;
  73
  74         if (extra_size < 0)
  75                 extra_size = 0;
  76         card = (snd_card_t *) snd_kcalloc(sizeof(snd_card_t) + extra_size, GFP_KERNEL);
  77         if (card == NULL)
  78                 return NULL;
  79         if (xid) {
  80                 if (!snd_info_check_reserved_words(xid))
  81                         goto __error;
  82                 strlcpy(card->id, xid, sizeof(card->id));
  83         }
  84         err = 0;
  85         write_lock(&snd_card_rwlock);
  86         if (idx < 0) {
  87                 int idx2;
  88                 for (idx2 = 0; idx2 < snd_ecards_limit; idx2++)
  89                         if (!(snd_cards_lock & (1 << idx2))) {
  90                                 idx = idx2;
  91                                 break;
  92                         }
  93                 if (idx < 0 && snd_ecards_limit < SNDRV_CARDS)
  94                         /* for dynamically additional devices like hotplug:
  95                          * increment the limit if still free slot exists.
  96                          */
  97                         idx = snd_ecards_limit++;
  98         } else if (idx < snd_ecards_limit) {
  99                 if (snd_cards_lock & (1 << idx))
 100                         err = -ENODEV;  /* invalid */
 101         } else if (idx < SNDRV_CARDS)
 102                 snd_ecards_limit = idx + 1; /* increase the limit */
 103         else
 104                 err = -ENODEV;
 105         if (idx < 0 || err < 0) {
 106                 write_unlock(&snd_card_rwlock);
 107                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
 108                 goto __error;
 109         }
 110         snd_cards_lock |= 1 << idx;             /* lock it */
 111         write_unlock(&snd_card_rwlock);
 112         card->number = idx;
 113         card->module = module;
 114         INIT_LIST_HEAD(&card->devices);
 115         init_rwsem(&card->controls_rwsem);
 116         rwlock_init(&card->ctl_files_rwlock);
 117         INIT_LIST_HEAD(&card->controls);
 118         INIT_LIST_HEAD(&card->ctl_files);
 119         spin_lock_init(&card->files_lock);
 120         init_waitqueue_head(&card->shutdown_sleep);
 121         INIT_WORK(&card->free_workq, snd_card_free_thread, card);
 122 #ifdef CONFIG_PM
 123         init_MUTEX(&card->power_lock);
 124         init_waitqueue_head(&card->power_sleep);
 125 #endif
 126         /* the control interface cannot be accessed from the user space until */
 127         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 128         if ((err = snd_ctl_register(card)) < 0) {
 129                 snd_printd("unable to register control minors\n");
 130                 goto __error;
 131         }
 132         if ((err = snd_info_card_create(card)) < 0) {
 133                 snd_printd("unable to create card info\n");
 134                 goto __error_ctl;
 135         }
 136         if (extra_size > 0)
 137                 card->private_data = (char *)card + sizeof(snd_card_t);
 138         return card;
 139
 140       __error_ctl:
 141         snd_ctl_unregister(card);
 142       __error:
 143         kfree(card);
 144         return NULL;
 145 }
 146
 147 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 148 {
 149         return POLLERR | POLLNVAL;
 150 }
 151
 152 /**
 153  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 154  *  @card: soundcard structure
 155  *
 156  *  Disconnects all APIs from the file-operations (user space).
 157  *
 158  *  Returns zero, otherwise a negative error code.
 159  *
 160  *  Note: The current implementation replaces all active file->f_op with special
 161  *        dummy file operations (they do nothing except release).
 162  */
 163 int snd_card_disconnect(snd_card_t * card)
 164 {
 165         struct snd_monitor_file *mfile;
 166         struct file *file;
 167         struct snd_shutdown_f_ops *s_f_ops;
 168         struct file_operations *f_ops, *old_f_ops;
 169         int err;
 170
 171         spin_lock(&card->files_lock);
 172         if (card->shutdown) {
 173                 spin_unlock(&card->files_lock);
 174                 return 0;
 175         }
 176         card->shutdown = 1;
 177         spin_unlock(&card->files_lock);
 178
 179         /* phase 1: disable fops (user space) operations for ALSA API */
 180         write_lock(&snd_card_rwlock);
 181         snd_cards[card->number] = NULL;
 182         write_unlock(&snd_card_rwlock);
 183
 184         /* phase 2: replace file->f_op with special dummy operations */
 185
 186         spin_lock(&card->files_lock);
 187         mfile = card->files;
 188         while (mfile) {
 189                 file = mfile->file;
 190
 191                 /* it's critical part, use endless loop */
 192                 /* we have no room to fail */
 193                 s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
 194                 if (s_f_ops == NULL)
 195                         panic("Atomic allocation failed for snd_shutdown_f_ops!");
 196
 197                 f_ops = &s_f_ops->f_ops;
 198
 199                 memset(f_ops, 0, sizeof(*f_ops));
 200                 f_ops->owner = file->f_op->owner;
 201                 f_ops->release = file->f_op->release;
 202                 f_ops->poll = snd_disconnect_poll;
 203
 204                 s_f_ops->next = card->s_f_ops;
 205                 card->s_f_ops = s_f_ops;
 206
 207                 f_ops = fops_get(f_ops);
 208
 209                 old_f_ops = file->f_op;
 210                 file->f_op = f_ops;     /* must be atomic */
 211                 fops_put(old_f_ops);
 212
 213                 mfile = mfile->next;
 214         }
 215         spin_unlock(&card->files_lock);
 216
 217         /* phase 3: notify all connected devices about disconnection */
 218         /* at this point, they cannot respond to any calls except release() */
 219
 220         snd_ctl_disconnect(card);
 221
 222 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 223         if (snd_mixer_oss_notify_callback)
 224                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 225 #endif
 226
 227         /* notify all devices that we are disconnected */
 228         err = snd_device_disconnect_all(card);
 229         if (err < 0)
 230                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 231
 232         return 0;
 233 }
 234
 235 /**
 236  *  snd_card_free - frees given soundcard structure
 237  *  @card: soundcard structure
 238  *
 239  *  This function releases the soundcard structure and the all assigned
 240  *  devices automatically.  That is, you don't have to release the devices
 241  *  by yourself.
 242  *
 243  *  Returns zero. Frees all associated devices and frees the control
 244  *  interface associated to given soundcard.
 245  */
 246 int snd_card_free(snd_card_t * card)
 247 {
 248         struct snd_shutdown_f_ops *s_f_ops;
 249
 250         if (card == NULL)
 251                 return -EINVAL;
 252         write_lock(&snd_card_rwlock);
 253         snd_cards[card->number] = NULL;
 254         snd_cards_count--;
 255         write_unlock(&snd_card_rwlock);
 256
 257 #ifdef CONFIG_PM
 258         wake_up(&card->power_sleep);
 259 #ifdef CONFIG_ISA
 260         if (card->pm_dev) {
 261                 pm_unregister(card->pm_dev);
 262                 card->pm_dev = NULL;
 263         }
 264 #endif
 265 #endif
 266
 267         /* wait, until all devices are ready for the free operation */
 268         wait_event(card->shutdown_sleep, card->files == NULL);
 269
 270 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 271         if (snd_mixer_oss_notify_callback)
 272                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 273 #endif
 274         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 275                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 276                 /* Fatal, but this situation should never occur */
 277         }
 278         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 279                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 280                 /* Fatal, but this situation should never occur */
 281         }
 282         if (snd_ctl_unregister(card) < 0) {
 283                 snd_printk(KERN_ERR "unable to unregister control minors\n");
 284                 /* Not fatal error */
 285         }
 286         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 287                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 288                 /* Fatal, but this situation should never occur */
 289         }
 290         if (card->private_free)
 291                 card->private_free(card);
 292         if (card->proc_id)
 293                 snd_info_unregister(card->proc_id);
 294         if (snd_info_card_free(card) < 0) {
 295                 snd_printk(KERN_WARNING "unable to free card info\n");
 296                 /* Not fatal error */
 297         }
 298         while (card->s_f_ops) {
 299                 s_f_ops = card->s_f_ops;
 300                 card->s_f_ops = s_f_ops->next;
 301                 kfree(s_f_ops);
 302         }
 303         write_lock(&snd_card_rwlock);
 304         snd_cards_lock &= ~(1 << card->number);
 305         write_unlock(&snd_card_rwlock);
 306         kfree(card);
 307         return 0;
 308 }
 309
 310 static void snd_card_free_thread(void * __card)
 311 {
 312         snd_card_t *card = __card;
 313         struct module * module = card->module;
 314
 315         if (!try_module_get(module)) {
 316                 snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
 317                 module = NULL;
 318         }
 319
 320         snd_card_free(card);
 321
 322         module_put(module);
 323 }
 324
 325 /**
 326  *  snd_card_free_in_thread - call snd_card_free() in thread
 327  *  @card: soundcard structure
 328  *
 329  *  This function schedules the call of snd_card_free() function in a
 330  *  work queue.  When all devices are released (non-busy), the work
 331  *  is woken up and calls snd_card_free().
 332  *
 333  *  When a card can be disconnected at any time by hotplug service,
 334  *  this function should be used in disconnect (or detach) callback
 335  *  instead of calling snd_card_free() directly.
 336  *
 337  *  Returns - zero otherwise a negative error code if the start of thread failed.
 338  */
 339 int snd_card_free_in_thread(snd_card_t * card)
 340 {
 341         if (card->files == NULL) {
 342                 snd_card_free(card);
 343                 return 0;
 344         }
 345
 346         if (schedule_work(&card->free_workq))
 347                 return 0;
 348
 349         snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
 350         /* try to free the structure immediately */
 351         snd_card_free(card);
 352         return -EFAULT;
 353 }
 354
 355 static void choose_default_id(snd_card_t * card)
 356 {
 357         int i, len, idx_flag = 0, loops = 8;
 358         char *id, *spos;
 359
 360         id = spos = card->shortname;
 361         while (*id != '\0') {
 362                 if (*id == ' ')
 363                         spos = id + 1;
 364                 id++;
 365         }
 366         id = card->id;
 367         while (*spos != '\0' && !isalnum(*spos))
 368                 spos++;
 369         if (isdigit(*spos))
 370                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 371         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 372                 if (isalnum(*spos))
 373                         *id++ = *spos;
 374                 spos++;
 375         }
 376         *id = '\0';
 377
 378         id = card->id;
 379
 380         if (*id == '\0')
 381                 strcpy(id, "default");
 382
 383         while (1) {
 384                 if (loops-- == 0) {
 385                         snd_printk(KERN_ERR "unable to choose default card id (%s)", id);
 386                         strcpy(card->id, card->proc_root->name);
 387                         return;
 388                 }
 389                 if (!snd_info_check_reserved_words(id))
 390                         goto __change;
 391                 for (i = 0; i < snd_ecards_limit; i++) {
 392                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 393                                 goto __change;
 394                 }
 395                 break;
 396
 397               __change:
 398                 len = strlen(id);
 399                 if (idx_flag)
 400                         id[len-1]++;
 401                 else if ((size_t)len <= sizeof(card->id) - 3) {
 402                         strcat(id, "_1");
 403                         idx_flag++;
 404                 } else {
 405                         spos = id + len - 2;
 406                         if ((size_t)len <= sizeof(card->id) - 2)
 407                                 spos++;
 408                         *spos++ = '_';
 409                         *spos++ = '1';
 410                         *spos++ = '\0';
 411                         idx_flag++;
 412                 }
 413         }
 414 }
 415
 416 /**
 417  *  snd_card_register - register the soundcard
 418  *  @card: soundcard structure
 419  *
 420  *  This function registers all the devices assigned to the soundcard.
 421  *  Until calling this, the ALSA control interface is blocked from the
 422  *  external accesses.  Thus, you should call this function at the end
 423  *  of the initialization of the card.
 424  *
 425  *  Returns zero otherwise a negative error code if the registrain failed.
 426  */
 427 int snd_card_register(snd_card_t * card)
 428 {
 429         int err;
 430         snd_info_entry_t *entry;
 431
 432         snd_runtime_check(card != NULL, return -EINVAL);
 433         if ((err = snd_device_register_all(card)) < 0)
 434                 return err;
 435         write_lock(&snd_card_rwlock);
 436         if (snd_cards[card->number]) {
 437                 /* already registered */
 438                 write_unlock(&snd_card_rwlock);
 439                 return 0;
 440         }
 441         if (card->id[0] == '\0')
 442                 choose_default_id(card);
 443         snd_cards[card->number] = card;
 444         snd_cards_count++;
 445         write_unlock(&snd_card_rwlock);
 446         if ((err = snd_info_card_register(card)) < 0) {
 447                 snd_printd("unable to create card info\n");
 448                 goto __skip_info;
 449         }
 450         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 451                 snd_printd("unable to create card entry\n");
 452                 goto __skip_info;
 453         }
 454         entry->c.text.read_size = PAGE_SIZE;
 455         entry->c.text.read = snd_card_id_read;
 456         if (snd_info_register(entry) < 0) {
 457                 snd_info_free_entry(entry);
 458                 entry = NULL;
 459         }
 460         card->proc_id = entry;
 461       __skip_info:
 462 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 463         if (snd_mixer_oss_notify_callback)
 464                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 465 #endif
 466         return 0;
 467 }
 468
 469 static snd_info_entry_t *snd_card_info_entry = NULL;
 470
 471 static void snd_card_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 472 {
 473         int idx, count;
 474         snd_card_t *card;
 475
 476         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 477                 read_lock(&snd_card_rwlock);
 478                 if ((card = snd_cards[idx]) != NULL) {
 479                         count++;
 480                         snd_iprintf(buffer, "%i [%-15s]: %s - %s\n",
 481                                         idx,
 482                                         card->id,
 483                                         card->driver,
 484                                         card->shortname);
 485                         snd_iprintf(buffer, "                     %s\n",
 486                                         card->longname);
 487                 }
 488                 read_unlock(&snd_card_rwlock);
 489         }
 490         if (!count)
 491                 snd_iprintf(buffer, "--- no soundcards ---\n");
 492 }
 493
 494 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
 495
 496 void snd_card_info_read_oss(snd_info_buffer_t * buffer)
 497 {
 498         int idx, count;
 499         snd_card_t *card;
 500
 501         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 502                 read_lock(&snd_card_rwlock);
 503                 if ((card = snd_cards[idx]) != NULL) {
 504                         count++;
 505                         snd_iprintf(buffer, "%s\n", card->longname);
 506                 }
 507                 read_unlock(&snd_card_rwlock);
 508         }
 509         if (!count) {
 510                 snd_iprintf(buffer, "--- no soundcards ---\n");
 511         }
 512 }
 513
 514 #endif
 515
 516 #ifdef MODULE
 517 static snd_info_entry_t *snd_card_module_info_entry;
 518 static void snd_card_module_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 519 {
 520         int idx;
 521         snd_card_t *card;
 522
 523         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 524                 read_lock(&snd_card_rwlock);
 525                 if ((card = snd_cards[idx]) != NULL)
 526                         snd_iprintf(buffer, "%i %s\n", idx, card->module->name);
 527                 read_unlock(&snd_card_rwlock);
 528         }
 529 }
 530 #endif
 531
 532 int __init snd_card_info_init(void)
 533 {
 534         snd_info_entry_t *entry;
 535
 536         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 537         snd_runtime_check(entry != NULL, return -ENOMEM);
 538         entry->c.text.read_size = PAGE_SIZE;
 539         entry->c.text.read = snd_card_info_read;
 540         if (snd_info_register(entry) < 0) {
 541                 snd_info_free_entry(entry);
 542                 return -ENOMEM;
 543         }
 544         snd_card_info_entry = entry;
 545
 546 #ifdef MODULE
 547         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 548         if (entry) {
 549                 entry->c.text.read_size = PAGE_SIZE;
 550                 entry->c.text.read = snd_card_module_info_read;
 551                 if (snd_info_register(entry) < 0)
 552                         snd_info_free_entry(entry);
 553                 else
 554                         snd_card_module_info_entry = entry;
 555         }
 556 #endif
 557
 558         return 0;
 559 }
 560
 561 int __exit snd_card_info_done(void)
 562 {
 563         if (snd_card_info_entry)
 564                 snd_info_unregister(snd_card_info_entry);
 565 #ifdef MODULE
 566         if (snd_card_module_info_entry)
 567                 snd_info_unregister(snd_card_module_info_entry);
 568 #endif
 569         return 0;
 570 }
 571
 572 /**
 573  *  snd_component_add - add a component string
 574  *  @card: soundcard structure
 575  *  @component: the component id string
 576  *
 577  *  This function adds the component id string to the supported list.
 578  *  The component can be referred from the alsa-lib.
 579  *
 580  *  Returns zero otherwise a negative error code.
 581  */
 582
 583 int snd_component_add(snd_card_t *card, const char *component)
 584 {
 585         char *ptr;
 586         int len = strlen(component);
 587
 588         ptr = strstr(card->components, component);
 589         if (ptr != NULL) {
 590                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 591                         return 1;
 592         }
 593         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 594                 snd_BUG();
 595                 return -ENOMEM;
 596         }
 597         if (card->components[0] != '\0')
 598                 strcat(card->components, " ");
 599         strcat(card->components, component);
 600         return 0;
 601 }
 602
 603 /**
 604  *  snd_card_file_add - add the file to the file list of the card
 605  *  @card: soundcard structure
 606  *  @file: file pointer
 607  *
 608  *  This function adds the file to the file linked-list of the card.
 609  *  This linked-list is used to keep tracking the connection state,
 610  *  and to avoid the release of busy resources by hotplug.
 611  *
 612  *  Returns zero or a negative error code.
 613  */
 614 int snd_card_file_add(snd_card_t *card, struct file *file)
 615 {
 616         struct snd_monitor_file *mfile;
 617
 618         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 619         if (mfile == NULL)
 620                 return -ENOMEM;
 621         mfile->file = file;
 622         mfile->next = NULL;
 623         spin_lock(&card->files_lock);
 624         if (card->shutdown) {
 625                 spin_unlock(&card->files_lock);
 626                 kfree(mfile);
 627                 return -ENODEV;
 628         }
 629         mfile->next = card->files;
 630         card->files = mfile;
 631         spin_unlock(&card->files_lock);
 632         return 0;
 633 }
 634
 635 /**
 636  *  snd_card_file_remove - remove the file from the file list
 637  *  @card: soundcard structure
 638  *  @file: file pointer
 639  *
 640  *  This function removes the file formerly added to the card via
 641  *  snd_card_file_add() function.
 642  *  If all files are removed and the release of the card is
 643  *  scheduled, it will wake up the the thread to call snd_card_free()
 644  *  (see snd_card_free_in_thread() function).
 645  *
 646  *  Returns zero or a negative error code.
 647  */
 648 int snd_card_file_remove(snd_card_t *card, struct file *file)
 649 {
 650         struct snd_monitor_file *mfile, *pfile = NULL;
 651
 652         spin_lock(&card->files_lock);
 653         mfile = card->files;
 654         while (mfile) {
 655                 if (mfile->file == file) {
 656                         if (pfile)
 657                                 pfile->next = mfile->next;
 658                         else
 659                                 card->files = mfile->next;
 660                         break;
 661                 }
 662                 pfile = mfile;
 663                 mfile = mfile->next;
 664         }
 665         spin_unlock(&card->files_lock);
 666         if (card->files == NULL)
 667                 wake_up(&card->shutdown_sleep);
 668         if (mfile) {
 669                 kfree(mfile);
 670         } else {
 671                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 672                 return -ENOENT;
 673         }
 674         return 0;
 675 }
 676
 677 #ifdef CONFIG_PM
 678 /**
 679  *  snd_power_wait - wait until the power-state is changed.
 680  *  @card: soundcard structure
 681  *  @power_state: expected power state
 682  *  @file: file structure for the O_NONBLOCK check (optional)
 683  *
 684  *  Waits until the power-state is changed.
 685  *
 686  *  Note: the power lock must be active before call.
 687  */
 688 int snd_power_wait(snd_card_t *card, unsigned int power_state, struct file *file)
 689 {
 690         wait_queue_t wait;
 691         int result = 0;
 692
 693         /* fastpath */
 694         if (snd_power_get_state(card) == power_state)
 695                 return 0;
 696         init_waitqueue_entry(&wait, current);
 697         add_wait_queue(&card->power_sleep, &wait);
 698         while (1) {
 699                 if (card->shutdown) {
 700                         result = -ENODEV;
 701                         break;
 702                 }
 703                 if (snd_power_get_state(card) == power_state)
 704                         break;
 705 #if 0 /* block all devices */
 706                 if (file && (file->f_flags & O_NONBLOCK)) {
 707                         result = -EAGAIN;
 708                         break;
 709                 }
 710 #endif
 711                 set_current_state(TASK_UNINTERRUPTIBLE);
 712                 snd_power_unlock(card);
 713                 schedule_timeout(30 * HZ);
 714                 snd_power_lock(card);
 715         }
 716         remove_wait_queue(&card->power_sleep, &wait);
 717         return result;
 718 }
 719
 720 /**
 721  * snd_card_set_pm_callback - set the PCI power-management callbacks
 722  * @card: soundcard structure
 723  * @suspend: suspend callback function
 724  * @resume: resume callback function
 725  * @private_data: private data to pass to the callback functions
 726  *
 727  * Sets the power-management callback functions of the card.
 728  * These callbacks are called from ALSA's common PCI suspend/resume
 729  * handler and from the control API.
 730  */
 731 int snd_card_set_pm_callback(snd_card_t *card,
 732                              int (*suspend)(snd_card_t *, unsigned int),
 733                              int (*resume)(snd_card_t *, unsigned int),
 734                              void *private_data)
 735 {
 736         card->pm_suspend = suspend;
 737         card->pm_resume = resume;
 738         card->pm_private_data = private_data;
 739         return 0;
 740 }
 741
 742 static int snd_generic_pm_callback(struct pm_dev *dev, pm_request_t rqst, void *data)
 743 {
 744         snd_card_t *card = dev->data;
 745
 746         switch (rqst) {
 747         case PM_SUSPEND:
 748                 /* FIXME: the correct state value? */
 749                 card->pm_suspend(card, 0);
 750                 break;
 751         case PM_RESUME:
 752                 /* FIXME: the correct state value? */
 753                 card->pm_resume(card, 0);
 754                 break;
 755         }
 756         return 0;
 757 }
 758
 759 /**
 760  * snd_card_set_dev_pm_callback - set the generic power-management callbacks
 761  * @card: soundcard structure
 762  * @type: PM device type (PM_XXX)
 763  * @suspend: suspend callback function
 764  * @resume: resume callback function
 765  * @private_data: private data to pass to the callback functions
 766  *
 767  * Registers the power-management and sets the lowlevel callbacks for
 768  * the given card with the given PM type.  These callbacks are called
 769  * from the ALSA's common PM handler and from the control API.
 770  */
 771 int snd_card_set_dev_pm_callback(snd_card_t *card, int type,
 772                                  int (*suspend)(snd_card_t *, unsigned int),
 773                                  int (*resume)(snd_card_t *, unsigned int),
 774                                  void *private_data)
 775 {
 776         card->pm_dev = pm_register(type, 0, snd_generic_pm_callback);
 777         if (! card->pm_dev)
 778                 return -ENOMEM;
 779         card->pm_dev->data = card;
 780         snd_card_set_pm_callback(card, suspend, resume, private_data);
 781         return 0;
 782 }
 783
 784 #ifdef CONFIG_PCI
 785 int snd_card_pci_suspend(struct pci_dev *dev, u32 state)
 786 {
 787         snd_card_t *card = pci_get_drvdata(dev);
 788         if (! card || ! card->pm_suspend)
 789                 return 0;
 790         if (card->power_state == SNDRV_CTL_POWER_D3hot)
 791                 return 0;
 792         /* FIXME: correct state value? */
 793         return card->pm_suspend(card, 0);
 794 }
 795
 796 int snd_card_pci_resume(struct pci_dev *dev)
 797 {
 798         snd_card_t *card = pci_get_drvdata(dev);
 799         if (! card || ! card->pm_resume)
 800                 return 0;
 801         if (card->power_state == SNDRV_CTL_POWER_D0)
 802                 return 0;
 803         /* FIXME: correct state value? */
 804         return card->pm_resume(card, 0);
 805 }
 806 #endif
 807
 808 #endif /* CONFIG_PM */