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
  32 #include <sound/core.h>
  33 #include <sound/control.h>
  34 #include <sound/info.h>
  35
  36 struct snd_shutdown_f_ops {
  37         struct file_operations f_ops;
  38         struct snd_shutdown_f_ops *next;
  39 };
  40
  41 static unsigned int snd_cards_lock;     /* locked for registering/using */
  42 struct snd_card *snd_cards[SNDRV_CARDS];
  43 EXPORT_SYMBOL(snd_cards);
  44
  45 static DEFINE_MUTEX(snd_card_mutex);
  46
  47 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  48 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  49 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
  50 #endif
  51
  52 #ifdef CONFIG_PROC_FS
  53 static void snd_card_id_read(struct snd_info_entry *entry,
  54                              struct snd_info_buffer *buffer)
  55 {
  56         snd_iprintf(buffer, "%s\n", entry->card->id);
  57 }
  58
  59 static inline int init_info_for_card(struct snd_card *card)
  60 {
  61         int err;
  62         struct snd_info_entry *entry;
  63
  64         if ((err = snd_info_card_register(card)) < 0) {
  65                 snd_printd("unable to create card info\n");
  66                 return err;
  67         }
  68         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
  69                 snd_printd("unable to create card entry\n");
  70                 return err;
  71         }
  72         entry->c.text.read = snd_card_id_read;
  73         if (snd_info_register(entry) < 0) {
  74                 snd_info_free_entry(entry);
  75                 entry = NULL;
  76         }
  77         card->proc_id = entry;
  78         return 0;
  79 }
  80 #else /* !CONFIG_PROC_FS */
  81 #define init_info_for_card(card)
  82 #endif
  83
  84 /**
  85  *  snd_card_new - create and initialize a soundcard structure
  86  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
  87  *  @xid: card identification (ASCII string)
  88  *  @module: top level module for locking
  89  *  @extra_size: allocate this extra size after the main soundcard structure
  90  *
  91  *  Creates and initializes a soundcard structure.
  92  *
  93  *  Returns kmallocated snd_card structure. Creates the ALSA control interface
  94  *  (which is blocked until snd_card_register function is called).
  95  */
  96 struct snd_card *snd_card_new(int idx, const char *xid,
  97                          struct module *module, int extra_size)
  98 {
  99         struct snd_card *card;
 100         int err;
 101
 102         if (extra_size < 0)
 103                 extra_size = 0;
 104         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
 105         if (card == NULL)
 106                 return NULL;
 107         if (xid) {
 108                 if (!snd_info_check_reserved_words(xid))
 109                         goto __error;
 110                 strlcpy(card->id, xid, sizeof(card->id));
 111         }
 112         err = 0;
 113         mutex_lock(&snd_card_mutex);
 114         if (idx < 0) {
 115                 int idx2;
 116                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 117                         if (~snd_cards_lock & idx & 1<<idx2) {
 118                                 idx = idx2;
 119                                 if (idx >= snd_ecards_limit)
 120                                         snd_ecards_limit = idx + 1;
 121                                 break;
 122                         }
 123         } else if (idx < snd_ecards_limit) {
 124                 if (snd_cards_lock & (1 << idx))
 125                         err = -ENODEV;  /* invalid */
 126         } else if (idx < SNDRV_CARDS)
 127                 snd_ecards_limit = idx + 1; /* increase the limit */
 128         else
 129                 err = -ENODEV;
 130         if (idx < 0 || err < 0) {
 131                 mutex_unlock(&snd_card_mutex);
 132                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
 133                 goto __error;
 134         }
 135         snd_cards_lock |= 1 << idx;             /* lock it */
 136         mutex_unlock(&snd_card_mutex);
 137         card->number = idx;
 138         card->module = module;
 139         INIT_LIST_HEAD(&card->devices);
 140         init_rwsem(&card->controls_rwsem);
 141         rwlock_init(&card->ctl_files_rwlock);
 142         INIT_LIST_HEAD(&card->controls);
 143         INIT_LIST_HEAD(&card->ctl_files);
 144         spin_lock_init(&card->files_lock);
 145         init_waitqueue_head(&card->shutdown_sleep);
 146 #ifdef CONFIG_PM
 147         mutex_init(&card->power_lock);
 148         init_waitqueue_head(&card->power_sleep);
 149 #endif
 150         /* the control interface cannot be accessed from the user space until */
 151         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 152         if ((err = snd_ctl_create(card)) < 0) {
 153                 snd_printd("unable to register control minors\n");
 154                 goto __error;
 155         }
 156         if ((err = snd_info_card_create(card)) < 0) {
 157                 snd_printd("unable to create card info\n");
 158                 goto __error_ctl;
 159         }
 160         if (extra_size > 0)
 161                 card->private_data = (char *)card + sizeof(struct snd_card);
 162         return card;
 163
 164       __error_ctl:
 165         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 166       __error:
 167         kfree(card);
 168         return NULL;
 169 }
 170
 171 EXPORT_SYMBOL(snd_card_new);
 172
 173 /* return non-zero if a card is already locked */
 174 int snd_card_locked(int card)
 175 {
 176         int locked;
 177
 178         mutex_lock(&snd_card_mutex);
 179         locked = snd_cards_lock & (1 << card);
 180         mutex_unlock(&snd_card_mutex);
 181         return locked;
 182 }
 183
 184 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 185 {
 186         return -ENODEV;
 187 }
 188
 189 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 190                                    size_t count, loff_t *offset)
 191 {
 192         return -ENODEV;
 193 }
 194
 195 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 196                                     size_t count, loff_t *offset)
 197 {
 198         return -ENODEV;
 199 }
 200
 201 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 202 {
 203         return POLLERR | POLLNVAL;
 204 }
 205
 206 static long snd_disconnect_ioctl(struct file *file,
 207                                  unsigned int cmd, unsigned long arg)
 208 {
 209         return -ENODEV;
 210 }
 211
 212 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 213 {
 214         return -ENODEV;
 215 }
 216
 217 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 218 {
 219         return -ENODEV;
 220 }
 221
 222 /**
 223  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 224  *  @card: soundcard structure
 225  *
 226  *  Disconnects all APIs from the file-operations (user space).
 227  *
 228  *  Returns zero, otherwise a negative error code.
 229  *
 230  *  Note: The current implementation replaces all active file->f_op with special
 231  *        dummy file operations (they do nothing except release).
 232  */
 233 int snd_card_disconnect(struct snd_card *card)
 234 {
 235         struct snd_monitor_file *mfile;
 236         struct file *file;
 237         struct snd_shutdown_f_ops *s_f_ops;
 238         struct file_operations *f_ops;
 239         const struct file_operations *old_f_ops;
 240         int err;
 241
 242         spin_lock(&card->files_lock);
 243         if (card->shutdown) {
 244                 spin_unlock(&card->files_lock);
 245                 return 0;
 246         }
 247         card->shutdown = 1;
 248         spin_unlock(&card->files_lock);
 249
 250         /* phase 1: disable fops (user space) operations for ALSA API */
 251         mutex_lock(&snd_card_mutex);
 252         snd_cards[card->number] = NULL;
 253         mutex_unlock(&snd_card_mutex);
 254
 255         /* phase 2: replace file->f_op with special dummy operations */
 256
 257         spin_lock(&card->files_lock);
 258         mfile = card->files;
 259         while (mfile) {
 260                 file = mfile->file;
 261
 262                 /* it's critical part, use endless loop */
 263                 /* we have no room to fail */
 264                 s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
 265                 if (s_f_ops == NULL)
 266                         panic("Atomic allocation failed for snd_shutdown_f_ops!");
 267
 268                 f_ops = &s_f_ops->f_ops;
 269
 270                 memset(f_ops, 0, sizeof(*f_ops));
 271                 f_ops->owner = file->f_op->owner;
 272                 f_ops->release = file->f_op->release;
 273                 f_ops->llseek = snd_disconnect_llseek;
 274                 f_ops->read = snd_disconnect_read;
 275                 f_ops->write = snd_disconnect_write;
 276                 f_ops->poll = snd_disconnect_poll;
 277                 f_ops->unlocked_ioctl = snd_disconnect_ioctl;
 278 #ifdef CONFIG_COMPAT
 279                 f_ops->compat_ioctl = snd_disconnect_ioctl;
 280 #endif
 281                 f_ops->mmap = snd_disconnect_mmap;
 282                 f_ops->fasync = snd_disconnect_fasync;
 283
 284                 s_f_ops->next = card->s_f_ops;
 285                 card->s_f_ops = s_f_ops;
 286
 287                 f_ops = fops_get(f_ops);
 288
 289                 old_f_ops = file->f_op;
 290                 file->f_op = f_ops;     /* must be atomic */
 291                 fops_put(old_f_ops);
 292
 293                 mfile = mfile->next;
 294         }
 295         spin_unlock(&card->files_lock);
 296
 297         /* phase 3: notify all connected devices about disconnection */
 298         /* at this point, they cannot respond to any calls except release() */
 299
 300 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 301         if (snd_mixer_oss_notify_callback)
 302                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 303 #endif
 304
 305         /* notify all devices that we are disconnected */
 306         err = snd_device_disconnect_all(card);
 307         if (err < 0)
 308                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 309
 310         snd_info_card_disconnect(card);
 311         return 0;
 312 }
 313
 314 EXPORT_SYMBOL(snd_card_disconnect);
 315
 316 /**
 317  *  snd_card_free - frees given soundcard structure
 318  *  @card: soundcard structure
 319  *
 320  *  This function releases the soundcard structure and the all assigned
 321  *  devices automatically.  That is, you don't have to release the devices
 322  *  by yourself.
 323  *
 324  *  Returns zero. Frees all associated devices and frees the control
 325  *  interface associated to given soundcard.
 326  */
 327 static int snd_card_do_free(struct snd_card *card)
 328 {
 329         struct snd_shutdown_f_ops *s_f_ops;
 330
 331 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 332         if (snd_mixer_oss_notify_callback)
 333                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 334 #endif
 335         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 336                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 337                 /* Fatal, but this situation should never occur */
 338         }
 339         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 340                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 341                 /* Fatal, but this situation should never occur */
 342         }
 343         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 344                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 345                 /* Fatal, but this situation should never occur */
 346         }
 347         if (card->private_free)
 348                 card->private_free(card);
 349         snd_info_free_entry(card->proc_id);
 350         if (snd_info_card_free(card) < 0) {
 351                 snd_printk(KERN_WARNING "unable to free card info\n");
 352                 /* Not fatal error */
 353         }
 354         while (card->s_f_ops) {
 355                 s_f_ops = card->s_f_ops;
 356                 card->s_f_ops = s_f_ops->next;
 357                 kfree(s_f_ops);
 358         }
 359         kfree(card);
 360         return 0;
 361 }
 362
 363 static int snd_card_free_prepare(struct snd_card *card)
 364 {
 365         if (card == NULL)
 366                 return -EINVAL;
 367         (void) snd_card_disconnect(card);
 368         mutex_lock(&snd_card_mutex);
 369         snd_cards[card->number] = NULL;
 370         snd_cards_lock &= ~(1 << card->number);
 371         mutex_unlock(&snd_card_mutex);
 372 #ifdef CONFIG_PM
 373         wake_up(&card->power_sleep);
 374 #endif
 375         return 0;
 376 }
 377
 378 int snd_card_free_when_closed(struct snd_card *card)
 379 {
 380         int free_now = 0;
 381         int ret = snd_card_free_prepare(card);
 382         if (ret)
 383                 return ret;
 384
 385         spin_lock(&card->files_lock);
 386         if (card->files == NULL)
 387                 free_now = 1;
 388         else
 389                 card->free_on_last_close = 1;
 390         spin_unlock(&card->files_lock);
 391
 392         if (free_now)
 393                 snd_card_do_free(card);
 394         return 0;
 395 }
 396
 397 EXPORT_SYMBOL(snd_card_free_when_closed);
 398
 399 int snd_card_free(struct snd_card *card)
 400 {
 401         int ret = snd_card_free_prepare(card);
 402         if (ret)
 403                 return ret;
 404
 405         /* wait, until all devices are ready for the free operation */
 406         wait_event(card->shutdown_sleep, card->files == NULL);
 407         snd_card_do_free(card);
 408         return 0;
 409 }
 410
 411 EXPORT_SYMBOL(snd_card_free);
 412
 413 static void choose_default_id(struct snd_card *card)
 414 {
 415         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 416         char *id, *spos;
 417
 418         id = spos = card->shortname;
 419         while (*id != '\0') {
 420                 if (*id == ' ')
 421                         spos = id + 1;
 422                 id++;
 423         }
 424         id = card->id;
 425         while (*spos != '\0' && !isalnum(*spos))
 426                 spos++;
 427         if (isdigit(*spos))
 428                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 429         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 430                 if (isalnum(*spos))
 431                         *id++ = *spos;
 432                 spos++;
 433         }
 434         *id = '\0';
 435
 436         id = card->id;
 437
 438         if (*id == '\0')
 439                 strcpy(id, "default");
 440
 441         while (1) {
 442                 if (loops-- == 0) {
 443                         snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
 444                         strcpy(card->id, card->proc_root->name);
 445                         return;
 446                 }
 447                 if (!snd_info_check_reserved_words(id))
 448                         goto __change;
 449                 for (i = 0; i < snd_ecards_limit; i++) {
 450                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 451                                 goto __change;
 452                 }
 453                 break;
 454
 455               __change:
 456                 len = strlen(id);
 457                 if (idx_flag) {
 458                         if (id[len-1] != '9')
 459                                 id[len-1]++;
 460                         else
 461                                 id[len-1] = 'A';
 462                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 463                         strcat(id, "_1");
 464                         idx_flag++;
 465                 } else {
 466                         spos = id + len - 2;
 467                         if ((size_t)len <= sizeof(card->id) - 2)
 468                                 spos++;
 469                         *spos++ = '_';
 470                         *spos++ = '1';
 471                         *spos++ = '\0';
 472                         idx_flag++;
 473                 }
 474         }
 475 }
 476
 477 /**
 478  *  snd_card_register - register the soundcard
 479  *  @card: soundcard structure
 480  *
 481  *  This function registers all the devices assigned to the soundcard.
 482  *  Until calling this, the ALSA control interface is blocked from the
 483  *  external accesses.  Thus, you should call this function at the end
 484  *  of the initialization of the card.
 485  *
 486  *  Returns zero otherwise a negative error code if the registrain failed.
 487  */
 488 int snd_card_register(struct snd_card *card)
 489 {
 490         int err;
 491
 492         snd_assert(card != NULL, return -EINVAL);
 493         if ((err = snd_device_register_all(card)) < 0)
 494                 return err;
 495         mutex_lock(&snd_card_mutex);
 496         if (snd_cards[card->number]) {
 497                 /* already registered */
 498                 mutex_unlock(&snd_card_mutex);
 499                 return 0;
 500         }
 501         if (card->id[0] == '\0')
 502                 choose_default_id(card);
 503         snd_cards[card->number] = card;
 504         mutex_unlock(&snd_card_mutex);
 505         init_info_for_card(card);
 506 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 507         if (snd_mixer_oss_notify_callback)
 508                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 509 #endif
 510         return 0;
 511 }
 512
 513 EXPORT_SYMBOL(snd_card_register);
 514
 515 #ifdef CONFIG_PROC_FS
 516 static struct snd_info_entry *snd_card_info_entry;
 517
 518 static void snd_card_info_read(struct snd_info_entry *entry,
 519                                struct snd_info_buffer *buffer)
 520 {
 521         int idx, count;
 522         struct snd_card *card;
 523
 524         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 525                 mutex_lock(&snd_card_mutex);
 526                 if ((card = snd_cards[idx]) != NULL) {
 527                         count++;
 528                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 529                                         idx,
 530                                         card->id,
 531                                         card->driver,
 532                                         card->shortname);
 533                         snd_iprintf(buffer, "                      %s\n",
 534                                         card->longname);
 535                 }
 536                 mutex_unlock(&snd_card_mutex);
 537         }
 538         if (!count)
 539                 snd_iprintf(buffer, "--- no soundcards ---\n");
 540 }
 541
 542 #ifdef CONFIG_SND_OSSEMUL
 543
 544 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 545 {
 546         int idx, count;
 547         struct snd_card *card;
 548
 549         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 550                 mutex_lock(&snd_card_mutex);
 551                 if ((card = snd_cards[idx]) != NULL) {
 552                         count++;
 553                         snd_iprintf(buffer, "%s\n", card->longname);
 554                 }
 555                 mutex_unlock(&snd_card_mutex);
 556         }
 557         if (!count) {
 558                 snd_iprintf(buffer, "--- no soundcards ---\n");
 559         }
 560 }
 561
 562 #endif
 563
 564 #ifdef MODULE
 565 static struct snd_info_entry *snd_card_module_info_entry;
 566 static void snd_card_module_info_read(struct snd_info_entry *entry,
 567                                       struct snd_info_buffer *buffer)
 568 {
 569         int idx;
 570         struct snd_card *card;
 571
 572         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 573                 mutex_lock(&snd_card_mutex);
 574                 if ((card = snd_cards[idx]) != NULL)
 575                         snd_iprintf(buffer, "%2i %s\n",
 576                                     idx, card->module->name);
 577                 mutex_unlock(&snd_card_mutex);
 578         }
 579 }
 580 #endif
 581
 582 int __init snd_card_info_init(void)
 583 {
 584         struct snd_info_entry *entry;
 585
 586         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 587         if (! entry)
 588                 return -ENOMEM;
 589         entry->c.text.read = snd_card_info_read;
 590         if (snd_info_register(entry) < 0) {
 591                 snd_info_free_entry(entry);
 592                 return -ENOMEM;
 593         }
 594         snd_card_info_entry = entry;
 595
 596 #ifdef MODULE
 597         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 598         if (entry) {
 599                 entry->c.text.read = snd_card_module_info_read;
 600                 if (snd_info_register(entry) < 0)
 601                         snd_info_free_entry(entry);
 602                 else
 603                         snd_card_module_info_entry = entry;
 604         }
 605 #endif
 606
 607         return 0;
 608 }
 609
 610 int __exit snd_card_info_done(void)
 611 {
 612         snd_info_free_entry(snd_card_info_entry);
 613 #ifdef MODULE
 614         snd_info_free_entry(snd_card_module_info_entry);
 615 #endif
 616         return 0;
 617 }
 618
 619 #endif /* CONFIG_PROC_FS */
 620
 621 /**
 622  *  snd_component_add - add a component string
 623  *  @card: soundcard structure
 624  *  @component: the component id string
 625  *
 626  *  This function adds the component id string to the supported list.
 627  *  The component can be referred from the alsa-lib.
 628  *
 629  *  Returns zero otherwise a negative error code.
 630  */
 631
 632 int snd_component_add(struct snd_card *card, const char *component)
 633 {
 634         char *ptr;
 635         int len = strlen(component);
 636
 637         ptr = strstr(card->components, component);
 638         if (ptr != NULL) {
 639                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 640                         return 1;
 641         }
 642         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 643                 snd_BUG();
 644                 return -ENOMEM;
 645         }
 646         if (card->components[0] != '\0')
 647                 strcat(card->components, " ");
 648         strcat(card->components, component);
 649         return 0;
 650 }
 651
 652 EXPORT_SYMBOL(snd_component_add);
 653
 654 /**
 655  *  snd_card_file_add - add the file to the file list of the card
 656  *  @card: soundcard structure
 657  *  @file: file pointer
 658  *
 659  *  This function adds the file to the file linked-list of the card.
 660  *  This linked-list is used to keep tracking the connection state,
 661  *  and to avoid the release of busy resources by hotplug.
 662  *
 663  *  Returns zero or a negative error code.
 664  */
 665 int snd_card_file_add(struct snd_card *card, struct file *file)
 666 {
 667         struct snd_monitor_file *mfile;
 668
 669         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 670         if (mfile == NULL)
 671                 return -ENOMEM;
 672         mfile->file = file;
 673         mfile->next = NULL;
 674         spin_lock(&card->files_lock);
 675         if (card->shutdown) {
 676                 spin_unlock(&card->files_lock);
 677                 kfree(mfile);
 678                 return -ENODEV;
 679         }
 680         mfile->next = card->files;
 681         card->files = mfile;
 682         spin_unlock(&card->files_lock);
 683         return 0;
 684 }
 685
 686 EXPORT_SYMBOL(snd_card_file_add);
 687
 688 /**
 689  *  snd_card_file_remove - remove the file from the file list
 690  *  @card: soundcard structure
 691  *  @file: file pointer
 692  *
 693  *  This function removes the file formerly added to the card via
 694  *  snd_card_file_add() function.
 695  *  If all files are removed and snd_card_free_when_closed() was
 696  *  called beforehand, it processes the pending release of
 697  *  resources.
 698  *
 699  *  Returns zero or a negative error code.
 700  */
 701 int snd_card_file_remove(struct snd_card *card, struct file *file)
 702 {
 703         struct snd_monitor_file *mfile, *pfile = NULL;
 704         int last_close = 0;
 705
 706         spin_lock(&card->files_lock);
 707         mfile = card->files;
 708         while (mfile) {
 709                 if (mfile->file == file) {
 710                         if (pfile)
 711                                 pfile->next = mfile->next;
 712                         else
 713                                 card->files = mfile->next;
 714                         break;
 715                 }
 716                 pfile = mfile;
 717                 mfile = mfile->next;
 718         }
 719         if (card->files == NULL)
 720                 last_close = 1;
 721         spin_unlock(&card->files_lock);
 722         if (last_close) {
 723                 wake_up(&card->shutdown_sleep);
 724                 if (card->free_on_last_close)
 725                         snd_card_do_free(card);
 726         }
 727         if (!mfile) {
 728                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 729                 return -ENOENT;
 730         }
 731         kfree(mfile);
 732         return 0;
 733 }
 734
 735 EXPORT_SYMBOL(snd_card_file_remove);
 736
 737 #ifdef CONFIG_PM
 738 /**
 739  *  snd_power_wait - wait until the power-state is changed.
 740  *  @card: soundcard structure
 741  *  @power_state: expected power state
 742  *
 743  *  Waits until the power-state is changed.
 744  *
 745  *  Note: the power lock must be active before call.
 746  */
 747 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 748 {
 749         wait_queue_t wait;
 750         int result = 0;
 751
 752         /* fastpath */
 753         if (snd_power_get_state(card) == power_state)
 754                 return 0;
 755         init_waitqueue_entry(&wait, current);
 756         add_wait_queue(&card->power_sleep, &wait);
 757         while (1) {
 758                 if (card->shutdown) {
 759                         result = -ENODEV;
 760                         break;
 761                 }
 762                 if (snd_power_get_state(card) == power_state)
 763                         break;
 764                 set_current_state(TASK_UNINTERRUPTIBLE);
 765                 snd_power_unlock(card);
 766                 schedule_timeout(30 * HZ);
 767                 snd_power_lock(card);
 768         }
 769         remove_wait_queue(&card->power_sleep, &wait);
 770         return result;
 771 }
 772
 773 EXPORT_SYMBOL(snd_power_wait);
 774 #endif /* CONFIG_PM */