git.oblomov.eu Git - linux-2.6/blob - sound/core/init.c

   1 /*
   2  *  Initialization routines
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/init.h>
  23 #include <linux/sched.h>
  24 #include <linux/file.h>
  25 #include <linux/slab.h>
  26 #include <linux/time.h>
  27 #include <linux/ctype.h>
  28 #include <linux/pm.h>
  29
  30 #include <sound/core.h>
  31 #include <sound/control.h>
  32 #include <sound/info.h>
  33
  34 static DEFINE_SPINLOCK(shutdown_lock);
  35 static LIST_HEAD(shutdown_files);
  36
  37 static const struct file_operations snd_shutdown_f_ops;
  38
  39 static unsigned int snd_cards_lock;     /* locked for registering/using */
  40 struct snd_card *snd_cards[SNDRV_CARDS];
  41 EXPORT_SYMBOL(snd_cards);
  42
  43 static DEFINE_MUTEX(snd_card_mutex);
  44
  45 static char *slots[SNDRV_CARDS];
  46 module_param_array(slots, charp, NULL, 0444);
  47 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
  48
  49 /* return non-zero if the given index is reserved for the given
  50  * module via slots option
  51  */
  52 static int module_slot_match(struct module *module, int idx)
  53 {
  54         int match = 1;
  55 #ifdef MODULE
  56         const char *s1, *s2;
  57
  58         if (!module || !module->name || !slots[idx])
  59                 return 0;
  60
  61         s1 = module->name;
  62         s2 = slots[idx];
  63         if (*s2 == '!') {
  64                 match = 0; /* negative match */
  65                 s2++;
  66         }
  67         /* compare module name strings
  68          * hyphens are handled as equivalent with underscore
  69          */
  70         for (;;) {
  71                 char c1 = *s1++;
  72                 char c2 = *s2++;
  73                 if (c1 == '-')
  74                         c1 = '_';
  75                 if (c2 == '-')
  76                         c2 = '_';
  77                 if (c1 != c2)
  78                         return !match;
  79                 if (!c1)
  80                         break;
  81         }
  82 #endif /* MODULE */
  83         return match;
  84 }
  85
  86 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  87 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  88 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
  89 #endif
  90
  91 #ifdef CONFIG_PROC_FS
  92 static void snd_card_id_read(struct snd_info_entry *entry,
  93                              struct snd_info_buffer *buffer)
  94 {
  95         snd_iprintf(buffer, "%s\n", entry->card->id);
  96 }
  97
  98 static inline int init_info_for_card(struct snd_card *card)
  99 {
 100         int err;
 101         struct snd_info_entry *entry;
 102
 103         if ((err = snd_info_card_register(card)) < 0) {
 104                 snd_printd("unable to create card info\n");
 105                 return err;
 106         }
 107         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 108                 snd_printd("unable to create card entry\n");
 109                 return err;
 110         }
 111         entry->c.text.read = snd_card_id_read;
 112         if (snd_info_register(entry) < 0) {
 113                 snd_info_free_entry(entry);
 114                 entry = NULL;
 115         }
 116         card->proc_id = entry;
 117         return 0;
 118 }
 119 #else /* !CONFIG_PROC_FS */
 120 #define init_info_for_card(card)
 121 #endif
 122
 123 /**
 124  *  snd_card_create - create and initialize a soundcard structure
 125  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
 126  *  @xid: card identification (ASCII string)
 127  *  @module: top level module for locking
 128  *  @extra_size: allocate this extra size after the main soundcard structure
 129  *  @card_ret: the pointer to store the created card instance
 130  *
 131  *  Creates and initializes a soundcard structure.
 132  *
 133  *  The function allocates snd_card instance via kzalloc with the given
 134  *  space for the driver to use freely.  The allocated struct is stored
 135  *  in the given card_ret pointer.
 136  *
 137  *  Returns zero if successful or a negative error code.
 138  */
 139 int snd_card_create(int idx, const char *xid,
 140                     struct module *module, int extra_size,
 141                     struct snd_card **card_ret)
 142 {
 143         struct snd_card *card;
 144         int err, idx2;
 145
 146         if (snd_BUG_ON(!card_ret))
 147                 return -EINVAL;
 148         *card_ret = NULL;
 149
 150         if (extra_size < 0)
 151                 extra_size = 0;
 152         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
 153         if (!card)
 154                 return -ENOMEM;
 155         if (xid) {
 156                 if (!snd_info_check_reserved_words(xid)) {
 157                         snd_printk(KERN_ERR
 158                                    "given id string '%s' is reserved.\n", xid);
 159                         err = -EBUSY;
 160                         goto __error;
 161                 }
 162                 strlcpy(card->id, xid, sizeof(card->id));
 163         }
 164         err = 0;
 165         mutex_lock(&snd_card_mutex);
 166         if (idx < 0) {
 167                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 168                         /* idx == -1 == 0xffff means: take any free slot */
 169                         if (~snd_cards_lock & idx & 1<<idx2) {
 170                                 if (module_slot_match(module, idx2)) {
 171                                         idx = idx2;
 172                                         break;
 173                                 }
 174                         }
 175         }
 176         if (idx < 0) {
 177                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 178                         /* idx == -1 == 0xffff means: take any free slot */
 179                         if (~snd_cards_lock & idx & 1<<idx2) {
 180                                 if (!slots[idx2] || !*slots[idx2]) {
 181                                         idx = idx2;
 182                                         break;
 183                                 }
 184                         }
 185         }
 186         if (idx < 0)
 187                 err = -ENODEV;
 188         else if (idx < snd_ecards_limit) {
 189                 if (snd_cards_lock & (1 << idx))
 190                         err = -EBUSY;   /* invalid */
 191         } else if (idx >= SNDRV_CARDS)
 192                 err = -ENODEV;
 193         if (err < 0) {
 194                 mutex_unlock(&snd_card_mutex);
 195                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
 196                          idx, snd_ecards_limit - 1, err);
 197                 goto __error;
 198         }
 199         snd_cards_lock |= 1 << idx;             /* lock it */
 200         if (idx >= snd_ecards_limit)
 201                 snd_ecards_limit = idx + 1; /* increase the limit */
 202         mutex_unlock(&snd_card_mutex);
 203         card->number = idx;
 204         card->module = module;
 205         INIT_LIST_HEAD(&card->devices);
 206         init_rwsem(&card->controls_rwsem);
 207         rwlock_init(&card->ctl_files_rwlock);
 208         INIT_LIST_HEAD(&card->controls);
 209         INIT_LIST_HEAD(&card->ctl_files);
 210         spin_lock_init(&card->files_lock);
 211         init_waitqueue_head(&card->shutdown_sleep);
 212 #ifdef CONFIG_PM
 213         mutex_init(&card->power_lock);
 214         init_waitqueue_head(&card->power_sleep);
 215 #endif
 216         /* the control interface cannot be accessed from the user space until */
 217         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 218         err = snd_ctl_create(card);
 219         if (err < 0) {
 220                 snd_printk(KERN_ERR "unable to register control minors\n");
 221                 goto __error;
 222         }
 223         err = snd_info_card_create(card);
 224         if (err < 0) {
 225                 snd_printk(KERN_ERR "unable to create card info\n");
 226                 goto __error_ctl;
 227         }
 228         if (extra_size > 0)
 229                 card->private_data = (char *)card + sizeof(struct snd_card);
 230         *card_ret = card;
 231         return 0;
 232
 233       __error_ctl:
 234         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 235       __error:
 236         kfree(card);
 237         return err;
 238 }
 239 EXPORT_SYMBOL(snd_card_create);
 240
 241 /* return non-zero if a card is already locked */
 242 int snd_card_locked(int card)
 243 {
 244         int locked;
 245
 246         mutex_lock(&snd_card_mutex);
 247         locked = snd_cards_lock & (1 << card);
 248         mutex_unlock(&snd_card_mutex);
 249         return locked;
 250 }
 251
 252 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 253 {
 254         return -ENODEV;
 255 }
 256
 257 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 258                                    size_t count, loff_t *offset)
 259 {
 260         return -ENODEV;
 261 }
 262
 263 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 264                                     size_t count, loff_t *offset)
 265 {
 266         return -ENODEV;
 267 }
 268
 269 static int snd_disconnect_release(struct inode *inode, struct file *file)
 270 {
 271         struct snd_monitor_file *df = NULL, *_df;
 272
 273         spin_lock(&shutdown_lock);
 274         list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 275                 if (_df->file == file) {
 276                         df = _df;
 277                         break;
 278                 }
 279         }
 280         spin_unlock(&shutdown_lock);
 281
 282         if (likely(df)) {
 283                 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
 284                         df->disconnected_f_op->fasync(-1, file, 0);
 285                 return df->disconnected_f_op->release(inode, file);
 286         }
 287
 288         panic("%s(%p, %p) failed!", __func__, inode, file);
 289 }
 290
 291 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 292 {
 293         return POLLERR | POLLNVAL;
 294 }
 295
 296 static long snd_disconnect_ioctl(struct file *file,
 297                                  unsigned int cmd, unsigned long arg)
 298 {
 299         return -ENODEV;
 300 }
 301
 302 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 303 {
 304         return -ENODEV;
 305 }
 306
 307 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 308 {
 309         return -ENODEV;
 310 }
 311
 312 static const struct file_operations snd_shutdown_f_ops =
 313 {
 314         .owner =        THIS_MODULE,
 315         .llseek =       snd_disconnect_llseek,
 316         .read =         snd_disconnect_read,
 317         .write =        snd_disconnect_write,
 318         .release =      snd_disconnect_release,
 319         .poll =         snd_disconnect_poll,
 320         .unlocked_ioctl = snd_disconnect_ioctl,
 321 #ifdef CONFIG_COMPAT
 322         .compat_ioctl = snd_disconnect_ioctl,
 323 #endif
 324         .mmap =         snd_disconnect_mmap,
 325         .fasync =       snd_disconnect_fasync
 326 };
 327
 328 /**
 329  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 330  *  @card: soundcard structure
 331  *
 332  *  Disconnects all APIs from the file-operations (user space).
 333  *
 334  *  Returns zero, otherwise a negative error code.
 335  *
 336  *  Note: The current implementation replaces all active file->f_op with special
 337  *        dummy file operations (they do nothing except release).
 338  */
 339 int snd_card_disconnect(struct snd_card *card)
 340 {
 341         struct snd_monitor_file *mfile;
 342         struct file *file;
 343         int err;
 344
 345         if (!card)
 346                 return -EINVAL;
 347
 348         spin_lock(&card->files_lock);
 349         if (card->shutdown) {
 350                 spin_unlock(&card->files_lock);
 351                 return 0;
 352         }
 353         card->shutdown = 1;
 354         spin_unlock(&card->files_lock);
 355
 356         /* phase 1: disable fops (user space) operations for ALSA API */
 357         mutex_lock(&snd_card_mutex);
 358         snd_cards[card->number] = NULL;
 359         snd_cards_lock &= ~(1 << card->number);
 360         mutex_unlock(&snd_card_mutex);
 361
 362         /* phase 2: replace file->f_op with special dummy operations */
 363
 364         spin_lock(&card->files_lock);
 365         mfile = card->files;
 366         while (mfile) {
 367                 file = mfile->file;
 368
 369                 /* it's critical part, use endless loop */
 370                 /* we have no room to fail */
 371                 mfile->disconnected_f_op = mfile->file->f_op;
 372
 373                 spin_lock(&shutdown_lock);
 374                 list_add(&mfile->shutdown_list, &shutdown_files);
 375                 spin_unlock(&shutdown_lock);
 376
 377                 mfile->file->f_op = &snd_shutdown_f_ops;
 378                 fops_get(mfile->file->f_op);
 379
 380                 mfile = mfile->next;
 381         }
 382         spin_unlock(&card->files_lock);
 383
 384         /* phase 3: notify all connected devices about disconnection */
 385         /* at this point, they cannot respond to any calls except release() */
 386
 387 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 388         if (snd_mixer_oss_notify_callback)
 389                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 390 #endif
 391
 392         /* notify all devices that we are disconnected */
 393         err = snd_device_disconnect_all(card);
 394         if (err < 0)
 395                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 396
 397         snd_info_card_disconnect(card);
 398 #ifndef CONFIG_SYSFS_DEPRECATED
 399         if (card->card_dev) {
 400                 device_unregister(card->card_dev);
 401                 card->card_dev = NULL;
 402         }
 403 #endif
 404 #ifdef CONFIG_PM
 405         wake_up(&card->power_sleep);
 406 #endif
 407         return 0;
 408 }
 409
 410 EXPORT_SYMBOL(snd_card_disconnect);
 411
 412 /**
 413  *  snd_card_free - frees given soundcard structure
 414  *  @card: soundcard structure
 415  *
 416  *  This function releases the soundcard structure and the all assigned
 417  *  devices automatically.  That is, you don't have to release the devices
 418  *  by yourself.
 419  *
 420  *  Returns zero. Frees all associated devices and frees the control
 421  *  interface associated to given soundcard.
 422  */
 423 static int snd_card_do_free(struct snd_card *card)
 424 {
 425 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 426         if (snd_mixer_oss_notify_callback)
 427                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 428 #endif
 429         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 430                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 431                 /* Fatal, but this situation should never occur */
 432         }
 433         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 434                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 435                 /* Fatal, but this situation should never occur */
 436         }
 437         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 438                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 439                 /* Fatal, but this situation should never occur */
 440         }
 441         if (card->private_free)
 442                 card->private_free(card);
 443         snd_info_free_entry(card->proc_id);
 444         if (snd_info_card_free(card) < 0) {
 445                 snd_printk(KERN_WARNING "unable to free card info\n");
 446                 /* Not fatal error */
 447         }
 448         kfree(card);
 449         return 0;
 450 }
 451
 452 int snd_card_free_when_closed(struct snd_card *card)
 453 {
 454         int free_now = 0;
 455         int ret = snd_card_disconnect(card);
 456         if (ret)
 457                 return ret;
 458
 459         spin_lock(&card->files_lock);
 460         if (card->files == NULL)
 461                 free_now = 1;
 462         else
 463                 card->free_on_last_close = 1;
 464         spin_unlock(&card->files_lock);
 465
 466         if (free_now)
 467                 snd_card_do_free(card);
 468         return 0;
 469 }
 470
 471 EXPORT_SYMBOL(snd_card_free_when_closed);
 472
 473 int snd_card_free(struct snd_card *card)
 474 {
 475         int ret = snd_card_disconnect(card);
 476         if (ret)
 477                 return ret;
 478
 479         /* wait, until all devices are ready for the free operation */
 480         wait_event(card->shutdown_sleep, card->files == NULL);
 481         snd_card_do_free(card);
 482         return 0;
 483 }
 484
 485 EXPORT_SYMBOL(snd_card_free);
 486
 487 static void choose_default_id(struct snd_card *card)
 488 {
 489         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 490         char *id, *spos;
 491
 492         id = spos = card->shortname;
 493         while (*id != '\0') {
 494                 if (*id == ' ')
 495                         spos = id + 1;
 496                 id++;
 497         }
 498         id = card->id;
 499         while (*spos != '\0' && !isalnum(*spos))
 500                 spos++;
 501         if (isdigit(*spos))
 502                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 503         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 504                 if (isalnum(*spos))
 505                         *id++ = *spos;
 506                 spos++;
 507         }
 508         *id = '\0';
 509
 510         id = card->id;
 511
 512         if (*id == '\0')
 513                 strcpy(id, "default");
 514
 515         while (1) {
 516                 if (loops-- == 0) {
 517                         snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
 518                         strcpy(card->id, card->proc_root->name);
 519                         return;
 520                 }
 521                 if (!snd_info_check_reserved_words(id))
 522                         goto __change;
 523                 for (i = 0; i < snd_ecards_limit; i++) {
 524                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 525                                 goto __change;
 526                 }
 527                 break;
 528
 529               __change:
 530                 len = strlen(id);
 531                 if (idx_flag) {
 532                         if (id[len-1] != '9')
 533                                 id[len-1]++;
 534                         else
 535                                 id[len-1] = 'A';
 536                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 537                         strcat(id, "_1");
 538                         idx_flag++;
 539                 } else {
 540                         spos = id + len - 2;
 541                         if ((size_t)len <= sizeof(card->id) - 2)
 542                                 spos++;
 543                         *spos++ = '_';
 544                         *spos++ = '1';
 545                         *spos++ = '\0';
 546                         idx_flag++;
 547                 }
 548         }
 549 }
 550
 551 #ifndef CONFIG_SYSFS_DEPRECATED
 552 static ssize_t
 553 card_id_show_attr(struct device *dev,
 554                   struct device_attribute *attr, char *buf)
 555 {
 556         struct snd_card *card = dev_get_drvdata(dev);
 557         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 558 }
 559
 560 static ssize_t
 561 card_id_store_attr(struct device *dev, struct device_attribute *attr,
 562                    const char *buf, size_t count)
 563 {
 564         struct snd_card *card = dev_get_drvdata(dev);
 565         char buf1[sizeof(card->id)];
 566         size_t copy = count > sizeof(card->id) - 1 ?
 567                                         sizeof(card->id) - 1 : count;
 568         size_t idx;
 569         int c;
 570
 571         for (idx = 0; idx < copy; idx++) {
 572                 c = buf[idx];
 573                 if (!isalnum(c) && c != '_' && c != '-')
 574                         return -EINVAL;
 575         }
 576         memcpy(buf1, buf, copy);
 577         buf1[copy] = '\0';
 578         mutex_lock(&snd_card_mutex);
 579         if (!snd_info_check_reserved_words(buf1)) {
 580              __exist:
 581                 mutex_unlock(&snd_card_mutex);
 582                 return -EEXIST;
 583         }
 584         for (idx = 0; idx < snd_ecards_limit; idx++) {
 585                 if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1))
 586                         goto __exist;
 587         }
 588         strcpy(card->id, buf1);
 589         snd_info_card_id_change(card);
 590         mutex_unlock(&snd_card_mutex);
 591
 592         return count;
 593 }
 594
 595 static struct device_attribute card_id_attrs =
 596         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 597
 598 static ssize_t
 599 card_number_show_attr(struct device *dev,
 600                      struct device_attribute *attr, char *buf)
 601 {
 602         struct snd_card *card = dev_get_drvdata(dev);
 603         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 604 }
 605
 606 static struct device_attribute card_number_attrs =
 607         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 608 #endif /* CONFIG_SYSFS_DEPRECATED */
 609
 610 /**
 611  *  snd_card_register - register the soundcard
 612  *  @card: soundcard structure
 613  *
 614  *  This function registers all the devices assigned to the soundcard.
 615  *  Until calling this, the ALSA control interface is blocked from the
 616  *  external accesses.  Thus, you should call this function at the end
 617  *  of the initialization of the card.
 618  *
 619  *  Returns zero otherwise a negative error code if the registrain failed.
 620  */
 621 int snd_card_register(struct snd_card *card)
 622 {
 623         int err;
 624
 625         if (snd_BUG_ON(!card))
 626                 return -EINVAL;
 627 #ifndef CONFIG_SYSFS_DEPRECATED
 628         if (!card->card_dev) {
 629                 card->card_dev = device_create(sound_class, card->dev,
 630                                                MKDEV(0, 0), card,
 631                                                "card%i", card->number);
 632                 if (IS_ERR(card->card_dev))
 633                         card->card_dev = NULL;
 634         }
 635 #endif
 636         if ((err = snd_device_register_all(card)) < 0)
 637                 return err;
 638         mutex_lock(&snd_card_mutex);
 639         if (snd_cards[card->number]) {
 640                 /* already registered */
 641                 mutex_unlock(&snd_card_mutex);
 642                 return 0;
 643         }
 644         if (card->id[0] == '\0')
 645                 choose_default_id(card);
 646         snd_cards[card->number] = card;
 647         mutex_unlock(&snd_card_mutex);
 648         init_info_for_card(card);
 649 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 650         if (snd_mixer_oss_notify_callback)
 651                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 652 #endif
 653 #ifndef CONFIG_SYSFS_DEPRECATED
 654         if (card->card_dev) {
 655                 err = device_create_file(card->card_dev, &card_id_attrs);
 656                 if (err < 0)
 657                         return err;
 658                 err = device_create_file(card->card_dev, &card_number_attrs);
 659                 if (err < 0)
 660                         return err;
 661         }
 662 #endif
 663         return 0;
 664 }
 665
 666 EXPORT_SYMBOL(snd_card_register);
 667
 668 #ifdef CONFIG_PROC_FS
 669 static struct snd_info_entry *snd_card_info_entry;
 670
 671 static void snd_card_info_read(struct snd_info_entry *entry,
 672                                struct snd_info_buffer *buffer)
 673 {
 674         int idx, count;
 675         struct snd_card *card;
 676
 677         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 678                 mutex_lock(&snd_card_mutex);
 679                 if ((card = snd_cards[idx]) != NULL) {
 680                         count++;
 681                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 682                                         idx,
 683                                         card->id,
 684                                         card->driver,
 685                                         card->shortname);
 686                         snd_iprintf(buffer, "                      %s\n",
 687                                         card->longname);
 688                 }
 689                 mutex_unlock(&snd_card_mutex);
 690         }
 691         if (!count)
 692                 snd_iprintf(buffer, "--- no soundcards ---\n");
 693 }
 694
 695 #ifdef CONFIG_SND_OSSEMUL
 696
 697 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 698 {
 699         int idx, count;
 700         struct snd_card *card;
 701
 702         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 703                 mutex_lock(&snd_card_mutex);
 704                 if ((card = snd_cards[idx]) != NULL) {
 705                         count++;
 706                         snd_iprintf(buffer, "%s\n", card->longname);
 707                 }
 708                 mutex_unlock(&snd_card_mutex);
 709         }
 710         if (!count) {
 711                 snd_iprintf(buffer, "--- no soundcards ---\n");
 712         }
 713 }
 714
 715 #endif
 716
 717 #ifdef MODULE
 718 static struct snd_info_entry *snd_card_module_info_entry;
 719 static void snd_card_module_info_read(struct snd_info_entry *entry,
 720                                       struct snd_info_buffer *buffer)
 721 {
 722         int idx;
 723         struct snd_card *card;
 724
 725         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 726                 mutex_lock(&snd_card_mutex);
 727                 if ((card = snd_cards[idx]) != NULL)
 728                         snd_iprintf(buffer, "%2i %s\n",
 729                                     idx, card->module->name);
 730                 mutex_unlock(&snd_card_mutex);
 731         }
 732 }
 733 #endif
 734
 735 int __init snd_card_info_init(void)
 736 {
 737         struct snd_info_entry *entry;
 738
 739         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 740         if (! entry)
 741                 return -ENOMEM;
 742         entry->c.text.read = snd_card_info_read;
 743         if (snd_info_register(entry) < 0) {
 744                 snd_info_free_entry(entry);
 745                 return -ENOMEM;
 746         }
 747         snd_card_info_entry = entry;
 748
 749 #ifdef MODULE
 750         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 751         if (entry) {
 752                 entry->c.text.read = snd_card_module_info_read;
 753                 if (snd_info_register(entry) < 0)
 754                         snd_info_free_entry(entry);
 755                 else
 756                         snd_card_module_info_entry = entry;
 757         }
 758 #endif
 759
 760         return 0;
 761 }
 762
 763 int __exit snd_card_info_done(void)
 764 {
 765         snd_info_free_entry(snd_card_info_entry);
 766 #ifdef MODULE
 767         snd_info_free_entry(snd_card_module_info_entry);
 768 #endif
 769         return 0;
 770 }
 771
 772 #endif /* CONFIG_PROC_FS */
 773
 774 /**
 775  *  snd_component_add - add a component string
 776  *  @card: soundcard structure
 777  *  @component: the component id string
 778  *
 779  *  This function adds the component id string to the supported list.
 780  *  The component can be referred from the alsa-lib.
 781  *
 782  *  Returns zero otherwise a negative error code.
 783  */
 784
 785 int snd_component_add(struct snd_card *card, const char *component)
 786 {
 787         char *ptr;
 788         int len = strlen(component);
 789
 790         ptr = strstr(card->components, component);
 791         if (ptr != NULL) {
 792                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 793                         return 1;
 794         }
 795         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 796                 snd_BUG();
 797                 return -ENOMEM;
 798         }
 799         if (card->components[0] != '\0')
 800                 strcat(card->components, " ");
 801         strcat(card->components, component);
 802         return 0;
 803 }
 804
 805 EXPORT_SYMBOL(snd_component_add);
 806
 807 /**
 808  *  snd_card_file_add - add the file to the file list of the card
 809  *  @card: soundcard structure
 810  *  @file: file pointer
 811  *
 812  *  This function adds the file to the file linked-list of the card.
 813  *  This linked-list is used to keep tracking the connection state,
 814  *  and to avoid the release of busy resources by hotplug.
 815  *
 816  *  Returns zero or a negative error code.
 817  */
 818 int snd_card_file_add(struct snd_card *card, struct file *file)
 819 {
 820         struct snd_monitor_file *mfile;
 821
 822         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 823         if (mfile == NULL)
 824                 return -ENOMEM;
 825         mfile->file = file;
 826         mfile->disconnected_f_op = NULL;
 827         mfile->next = NULL;
 828         spin_lock(&card->files_lock);
 829         if (card->shutdown) {
 830                 spin_unlock(&card->files_lock);
 831                 kfree(mfile);
 832                 return -ENODEV;
 833         }
 834         mfile->next = card->files;
 835         card->files = mfile;
 836         spin_unlock(&card->files_lock);
 837         return 0;
 838 }
 839
 840 EXPORT_SYMBOL(snd_card_file_add);
 841
 842 /**
 843  *  snd_card_file_remove - remove the file from the file list
 844  *  @card: soundcard structure
 845  *  @file: file pointer
 846  *
 847  *  This function removes the file formerly added to the card via
 848  *  snd_card_file_add() function.
 849  *  If all files are removed and snd_card_free_when_closed() was
 850  *  called beforehand, it processes the pending release of
 851  *  resources.
 852  *
 853  *  Returns zero or a negative error code.
 854  */
 855 int snd_card_file_remove(struct snd_card *card, struct file *file)
 856 {
 857         struct snd_monitor_file *mfile, *pfile = NULL;
 858         int last_close = 0;
 859
 860         spin_lock(&card->files_lock);
 861         mfile = card->files;
 862         while (mfile) {
 863                 if (mfile->file == file) {
 864                         if (pfile)
 865                                 pfile->next = mfile->next;
 866                         else
 867                                 card->files = mfile->next;
 868                         break;
 869                 }
 870                 pfile = mfile;
 871                 mfile = mfile->next;
 872         }
 873         if (mfile && mfile->disconnected_f_op) {
 874                 fops_put(mfile->disconnected_f_op);
 875                 spin_lock(&shutdown_lock);
 876                 list_del(&mfile->shutdown_list);
 877                 spin_unlock(&shutdown_lock);
 878         }
 879         if (card->files == NULL)
 880                 last_close = 1;
 881         spin_unlock(&card->files_lock);
 882         if (last_close) {
 883                 wake_up(&card->shutdown_sleep);
 884                 if (card->free_on_last_close)
 885                         snd_card_do_free(card);
 886         }
 887         if (!mfile) {
 888                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 889                 return -ENOENT;
 890         }
 891         kfree(mfile);
 892         return 0;
 893 }
 894
 895 EXPORT_SYMBOL(snd_card_file_remove);
 896
 897 #ifdef CONFIG_PM
 898 /**
 899  *  snd_power_wait - wait until the power-state is changed.
 900  *  @card: soundcard structure
 901  *  @power_state: expected power state
 902  *
 903  *  Waits until the power-state is changed.
 904  *
 905  *  Note: the power lock must be active before call.
 906  */
 907 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 908 {
 909         wait_queue_t wait;
 910         int result = 0;
 911
 912         /* fastpath */
 913         if (snd_power_get_state(card) == power_state)
 914                 return 0;
 915         init_waitqueue_entry(&wait, current);
 916         add_wait_queue(&card->power_sleep, &wait);
 917         while (1) {
 918                 if (card->shutdown) {
 919                         result = -ENODEV;
 920                         break;
 921                 }
 922                 if (snd_power_get_state(card) == power_state)
 923                         break;
 924                 set_current_state(TASK_UNINTERRUPTIBLE);
 925                 snd_power_unlock(card);
 926                 schedule_timeout(30 * HZ);
 927                 snd_power_lock(card);
 928         }
 929         remove_wait_queue(&card->power_sleep, &wait);
 930         return result;
 931 }
 932
 933 EXPORT_SYMBOL(snd_power_wait);
 934 #endif /* CONFIG_PM */