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                 snd_card_set_id(card, xid);
 157         err = 0;
 158         mutex_lock(&snd_card_mutex);
 159         if (idx < 0) {
 160                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 161                         /* idx == -1 == 0xffff means: take any free slot */
 162                         if (~snd_cards_lock & idx & 1<<idx2) {
 163                                 if (module_slot_match(module, idx2)) {
 164                                         idx = idx2;
 165                                         break;
 166                                 }
 167                         }
 168         }
 169         if (idx < 0) {
 170                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 171                         /* idx == -1 == 0xffff means: take any free slot */
 172                         if (~snd_cards_lock & idx & 1<<idx2) {
 173                                 if (!slots[idx2] || !*slots[idx2]) {
 174                                         idx = idx2;
 175                                         break;
 176                                 }
 177                         }
 178         }
 179         if (idx < 0)
 180                 err = -ENODEV;
 181         else if (idx < snd_ecards_limit) {
 182                 if (snd_cards_lock & (1 << idx))
 183                         err = -EBUSY;   /* invalid */
 184         } else if (idx >= SNDRV_CARDS)
 185                 err = -ENODEV;
 186         if (err < 0) {
 187                 mutex_unlock(&snd_card_mutex);
 188                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
 189                          idx, snd_ecards_limit - 1, err);
 190                 goto __error;
 191         }
 192         snd_cards_lock |= 1 << idx;             /* lock it */
 193         if (idx >= snd_ecards_limit)
 194                 snd_ecards_limit = idx + 1; /* increase the limit */
 195         mutex_unlock(&snd_card_mutex);
 196         card->number = idx;
 197         card->module = module;
 198         INIT_LIST_HEAD(&card->devices);
 199         init_rwsem(&card->controls_rwsem);
 200         rwlock_init(&card->ctl_files_rwlock);
 201         INIT_LIST_HEAD(&card->controls);
 202         INIT_LIST_HEAD(&card->ctl_files);
 203         spin_lock_init(&card->files_lock);
 204         INIT_LIST_HEAD(&card->files_list);
 205         init_waitqueue_head(&card->shutdown_sleep);
 206 #ifdef CONFIG_PM
 207         mutex_init(&card->power_lock);
 208         init_waitqueue_head(&card->power_sleep);
 209 #endif
 210         /* the control interface cannot be accessed from the user space until */
 211         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 212         err = snd_ctl_create(card);
 213         if (err < 0) {
 214                 snd_printk(KERN_ERR "unable to register control minors\n");
 215                 goto __error;
 216         }
 217         err = snd_info_card_create(card);
 218         if (err < 0) {
 219                 snd_printk(KERN_ERR "unable to create card info\n");
 220                 goto __error_ctl;
 221         }
 222         if (extra_size > 0)
 223                 card->private_data = (char *)card + sizeof(struct snd_card);
 224         *card_ret = card;
 225         return 0;
 226
 227       __error_ctl:
 228         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 229       __error:
 230         kfree(card);
 231         return err;
 232 }
 233 EXPORT_SYMBOL(snd_card_create);
 234
 235 /* return non-zero if a card is already locked */
 236 int snd_card_locked(int card)
 237 {
 238         int locked;
 239
 240         mutex_lock(&snd_card_mutex);
 241         locked = snd_cards_lock & (1 << card);
 242         mutex_unlock(&snd_card_mutex);
 243         return locked;
 244 }
 245
 246 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 247 {
 248         return -ENODEV;
 249 }
 250
 251 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 252                                    size_t count, loff_t *offset)
 253 {
 254         return -ENODEV;
 255 }
 256
 257 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 258                                     size_t count, loff_t *offset)
 259 {
 260         return -ENODEV;
 261 }
 262
 263 static int snd_disconnect_release(struct inode *inode, struct file *file)
 264 {
 265         struct snd_monitor_file *df = NULL, *_df;
 266
 267         spin_lock(&shutdown_lock);
 268         list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 269                 if (_df->file == file) {
 270                         df = _df;
 271                         list_del_init(&df->shutdown_list);
 272                         break;
 273                 }
 274         }
 275         spin_unlock(&shutdown_lock);
 276
 277         if (likely(df)) {
 278                 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
 279                         df->disconnected_f_op->fasync(-1, file, 0);
 280                 return df->disconnected_f_op->release(inode, file);
 281         }
 282
 283         panic("%s(%p, %p) failed!", __func__, inode, file);
 284 }
 285
 286 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 287 {
 288         return POLLERR | POLLNVAL;
 289 }
 290
 291 static long snd_disconnect_ioctl(struct file *file,
 292                                  unsigned int cmd, unsigned long arg)
 293 {
 294         return -ENODEV;
 295 }
 296
 297 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 298 {
 299         return -ENODEV;
 300 }
 301
 302 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 303 {
 304         return -ENODEV;
 305 }
 306
 307 static const struct file_operations snd_shutdown_f_ops =
 308 {
 309         .owner =        THIS_MODULE,
 310         .llseek =       snd_disconnect_llseek,
 311         .read =         snd_disconnect_read,
 312         .write =        snd_disconnect_write,
 313         .release =      snd_disconnect_release,
 314         .poll =         snd_disconnect_poll,
 315         .unlocked_ioctl = snd_disconnect_ioctl,
 316 #ifdef CONFIG_COMPAT
 317         .compat_ioctl = snd_disconnect_ioctl,
 318 #endif
 319         .mmap =         snd_disconnect_mmap,
 320         .fasync =       snd_disconnect_fasync
 321 };
 322
 323 /**
 324  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 325  *  @card: soundcard structure
 326  *
 327  *  Disconnects all APIs from the file-operations (user space).
 328  *
 329  *  Returns zero, otherwise a negative error code.
 330  *
 331  *  Note: The current implementation replaces all active file->f_op with special
 332  *        dummy file operations (they do nothing except release).
 333  */
 334 int snd_card_disconnect(struct snd_card *card)
 335 {
 336         struct snd_monitor_file *mfile;
 337         struct file *file;
 338         int err;
 339
 340         if (!card)
 341                 return -EINVAL;
 342
 343         spin_lock(&card->files_lock);
 344         if (card->shutdown) {
 345                 spin_unlock(&card->files_lock);
 346                 return 0;
 347         }
 348         card->shutdown = 1;
 349         spin_unlock(&card->files_lock);
 350
 351         /* phase 1: disable fops (user space) operations for ALSA API */
 352         mutex_lock(&snd_card_mutex);
 353         snd_cards[card->number] = NULL;
 354         snd_cards_lock &= ~(1 << card->number);
 355         mutex_unlock(&snd_card_mutex);
 356
 357         /* phase 2: replace file->f_op with special dummy operations */
 358
 359         spin_lock(&card->files_lock);
 360         list_for_each_entry(mfile, &card->files_list, list) {
 361                 file = mfile->file;
 362
 363                 /* it's critical part, use endless loop */
 364                 /* we have no room to fail */
 365                 mfile->disconnected_f_op = mfile->file->f_op;
 366
 367                 spin_lock(&shutdown_lock);
 368                 list_add(&mfile->shutdown_list, &shutdown_files);
 369                 spin_unlock(&shutdown_lock);
 370
 371                 mfile->file->f_op = &snd_shutdown_f_ops;
 372                 fops_get(mfile->file->f_op);
 373         }
 374         spin_unlock(&card->files_lock);
 375
 376         /* phase 3: notify all connected devices about disconnection */
 377         /* at this point, they cannot respond to any calls except release() */
 378
 379 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 380         if (snd_mixer_oss_notify_callback)
 381                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 382 #endif
 383
 384         /* notify all devices that we are disconnected */
 385         err = snd_device_disconnect_all(card);
 386         if (err < 0)
 387                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 388
 389         snd_info_card_disconnect(card);
 390 #ifndef CONFIG_SYSFS_DEPRECATED
 391         if (card->card_dev) {
 392                 device_unregister(card->card_dev);
 393                 card->card_dev = NULL;
 394         }
 395 #endif
 396 #ifdef CONFIG_PM
 397         wake_up(&card->power_sleep);
 398 #endif
 399         return 0;
 400 }
 401
 402 EXPORT_SYMBOL(snd_card_disconnect);
 403
 404 /**
 405  *  snd_card_free - frees given soundcard structure
 406  *  @card: soundcard structure
 407  *
 408  *  This function releases the soundcard structure and the all assigned
 409  *  devices automatically.  That is, you don't have to release the devices
 410  *  by yourself.
 411  *
 412  *  Returns zero. Frees all associated devices and frees the control
 413  *  interface associated to given soundcard.
 414  */
 415 static int snd_card_do_free(struct snd_card *card)
 416 {
 417 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 418         if (snd_mixer_oss_notify_callback)
 419                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 420 #endif
 421         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 422                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 423                 /* Fatal, but this situation should never occur */
 424         }
 425         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 426                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 427                 /* Fatal, but this situation should never occur */
 428         }
 429         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 430                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 431                 /* Fatal, but this situation should never occur */
 432         }
 433         if (card->private_free)
 434                 card->private_free(card);
 435         snd_info_free_entry(card->proc_id);
 436         if (snd_info_card_free(card) < 0) {
 437                 snd_printk(KERN_WARNING "unable to free card info\n");
 438                 /* Not fatal error */
 439         }
 440         kfree(card);
 441         return 0;
 442 }
 443
 444 int snd_card_free_when_closed(struct snd_card *card)
 445 {
 446         int free_now = 0;
 447         int ret = snd_card_disconnect(card);
 448         if (ret)
 449                 return ret;
 450
 451         spin_lock(&card->files_lock);
 452         if (list_empty(&card->files_list))
 453                 free_now = 1;
 454         else
 455                 card->free_on_last_close = 1;
 456         spin_unlock(&card->files_lock);
 457
 458         if (free_now)
 459                 snd_card_do_free(card);
 460         return 0;
 461 }
 462
 463 EXPORT_SYMBOL(snd_card_free_when_closed);
 464
 465 int snd_card_free(struct snd_card *card)
 466 {
 467         int ret = snd_card_disconnect(card);
 468         if (ret)
 469                 return ret;
 470
 471         /* wait, until all devices are ready for the free operation */
 472         wait_event(card->shutdown_sleep, list_empty(&card->files_list));
 473         snd_card_do_free(card);
 474         return 0;
 475 }
 476
 477 EXPORT_SYMBOL(snd_card_free);
 478
 479 /**
 480  *  snd_card_set_id - set card identification name
 481  *  @card: soundcard structure
 482  *  @nid: new identification string
 483  *
 484  *  This function sets the card identification and checks for name
 485  *  collisions.
 486  */
 487 void snd_card_set_id(struct snd_card *card, const char *nid)
 488 {
 489         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 490         const char *spos, *src;
 491         char *id;
 492
 493         /* check if user specified own card->id */
 494         if (card->id[0] != '\0')
 495                 return;
 496         if (nid == NULL) {
 497                 id = card->shortname;
 498                 spos = src = id;
 499                 while (*id != '\0') {
 500                         if (*id == ' ')
 501                                 spos = id + 1;
 502                         id++;
 503                 }
 504         } else {
 505                 spos = src = nid;
 506         }
 507         id = card->id;
 508         while (*spos != '\0' && !isalnum(*spos))
 509                 spos++;
 510         if (isdigit(*spos))
 511                 *id++ = isalpha(src[0]) ? src[0] : 'D';
 512         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 513                 if (isalnum(*spos))
 514                         *id++ = *spos;
 515                 spos++;
 516         }
 517         *id = '\0';
 518
 519         id = card->id;
 520
 521         if (*id == '\0')
 522                 strcpy(id, "default");
 523
 524         while (1) {
 525                 if (loops-- == 0) {
 526                         snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
 527                         strcpy(card->id, card->proc_root->name);
 528                         return;
 529                 }
 530                 if (!snd_info_check_reserved_words(id))
 531                         goto __change;
 532                 mutex_lock(&snd_card_mutex);
 533                 for (i = 0; i < snd_ecards_limit; i++) {
 534                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id)) {
 535                                 mutex_unlock(&snd_card_mutex);
 536                                 goto __change;
 537                         }
 538                 }
 539                 mutex_unlock(&snd_card_mutex);
 540                 break;
 541
 542               __change:
 543                 len = strlen(id);
 544                 if (idx_flag) {
 545                         if (id[len-1] != '9')
 546                                 id[len-1]++;
 547                         else
 548                                 id[len-1] = 'A';
 549                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 550                         strcat(id, "_1");
 551                         idx_flag++;
 552                 } else {
 553                         spos = id + len - 2;
 554                         if ((size_t)len <= sizeof(card->id) - 2)
 555                                 spos++;
 556                         *(char *)spos++ = '_';
 557                         *(char *)spos++ = '1';
 558                         *(char *)spos++ = '\0';
 559                         idx_flag++;
 560                 }
 561         }
 562 }
 563
 564 EXPORT_SYMBOL(snd_card_set_id);
 565
 566 #ifndef CONFIG_SYSFS_DEPRECATED
 567 static ssize_t
 568 card_id_show_attr(struct device *dev,
 569                   struct device_attribute *attr, char *buf)
 570 {
 571         struct snd_card *card = dev_get_drvdata(dev);
 572         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 573 }
 574
 575 static ssize_t
 576 card_id_store_attr(struct device *dev, struct device_attribute *attr,
 577                    const char *buf, size_t count)
 578 {
 579         struct snd_card *card = dev_get_drvdata(dev);
 580         char buf1[sizeof(card->id)];
 581         size_t copy = count > sizeof(card->id) - 1 ?
 582                                         sizeof(card->id) - 1 : count;
 583         size_t idx;
 584         int c;
 585
 586         for (idx = 0; idx < copy; idx++) {
 587                 c = buf[idx];
 588                 if (!isalnum(c) && c != '_' && c != '-')
 589                         return -EINVAL;
 590         }
 591         memcpy(buf1, buf, copy);
 592         buf1[copy] = '\0';
 593         mutex_lock(&snd_card_mutex);
 594         if (!snd_info_check_reserved_words(buf1)) {
 595              __exist:
 596                 mutex_unlock(&snd_card_mutex);
 597                 return -EEXIST;
 598         }
 599         for (idx = 0; idx < snd_ecards_limit; idx++) {
 600                 if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1))
 601                         goto __exist;
 602         }
 603         strcpy(card->id, buf1);
 604         snd_info_card_id_change(card);
 605         mutex_unlock(&snd_card_mutex);
 606
 607         return count;
 608 }
 609
 610 static struct device_attribute card_id_attrs =
 611         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 612
 613 static ssize_t
 614 card_number_show_attr(struct device *dev,
 615                      struct device_attribute *attr, char *buf)
 616 {
 617         struct snd_card *card = dev_get_drvdata(dev);
 618         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 619 }
 620
 621 static struct device_attribute card_number_attrs =
 622         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 623 #endif /* CONFIG_SYSFS_DEPRECATED */
 624
 625 /**
 626  *  snd_card_register - register the soundcard
 627  *  @card: soundcard structure
 628  *
 629  *  This function registers all the devices assigned to the soundcard.
 630  *  Until calling this, the ALSA control interface is blocked from the
 631  *  external accesses.  Thus, you should call this function at the end
 632  *  of the initialization of the card.
 633  *
 634  *  Returns zero otherwise a negative error code if the registrain failed.
 635  */
 636 int snd_card_register(struct snd_card *card)
 637 {
 638         int err;
 639
 640         if (snd_BUG_ON(!card))
 641                 return -EINVAL;
 642 #ifndef CONFIG_SYSFS_DEPRECATED
 643         if (!card->card_dev) {
 644                 card->card_dev = device_create(sound_class, card->dev,
 645                                                MKDEV(0, 0), card,
 646                                                "card%i", card->number);
 647                 if (IS_ERR(card->card_dev))
 648                         card->card_dev = NULL;
 649         }
 650 #endif
 651         if ((err = snd_device_register_all(card)) < 0)
 652                 return err;
 653         mutex_lock(&snd_card_mutex);
 654         if (snd_cards[card->number]) {
 655                 /* already registered */
 656                 mutex_unlock(&snd_card_mutex);
 657                 return 0;
 658         }
 659         if (card->id[0] == '\0')
 660                 snd_card_set_id(card, NULL);
 661         snd_cards[card->number] = card;
 662         mutex_unlock(&snd_card_mutex);
 663         init_info_for_card(card);
 664 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 665         if (snd_mixer_oss_notify_callback)
 666                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 667 #endif
 668 #ifndef CONFIG_SYSFS_DEPRECATED
 669         if (card->card_dev) {
 670                 err = device_create_file(card->card_dev, &card_id_attrs);
 671                 if (err < 0)
 672                         return err;
 673                 err = device_create_file(card->card_dev, &card_number_attrs);
 674                 if (err < 0)
 675                         return err;
 676         }
 677 #endif
 678         return 0;
 679 }
 680
 681 EXPORT_SYMBOL(snd_card_register);
 682
 683 #ifdef CONFIG_PROC_FS
 684 static struct snd_info_entry *snd_card_info_entry;
 685
 686 static void snd_card_info_read(struct snd_info_entry *entry,
 687                                struct snd_info_buffer *buffer)
 688 {
 689         int idx, count;
 690         struct snd_card *card;
 691
 692         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 693                 mutex_lock(&snd_card_mutex);
 694                 if ((card = snd_cards[idx]) != NULL) {
 695                         count++;
 696                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 697                                         idx,
 698                                         card->id,
 699                                         card->driver,
 700                                         card->shortname);
 701                         snd_iprintf(buffer, "                      %s\n",
 702                                         card->longname);
 703                 }
 704                 mutex_unlock(&snd_card_mutex);
 705         }
 706         if (!count)
 707                 snd_iprintf(buffer, "--- no soundcards ---\n");
 708 }
 709
 710 #ifdef CONFIG_SND_OSSEMUL
 711
 712 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 713 {
 714         int idx, count;
 715         struct snd_card *card;
 716
 717         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 718                 mutex_lock(&snd_card_mutex);
 719                 if ((card = snd_cards[idx]) != NULL) {
 720                         count++;
 721                         snd_iprintf(buffer, "%s\n", card->longname);
 722                 }
 723                 mutex_unlock(&snd_card_mutex);
 724         }
 725         if (!count) {
 726                 snd_iprintf(buffer, "--- no soundcards ---\n");
 727         }
 728 }
 729
 730 #endif
 731
 732 #ifdef MODULE
 733 static struct snd_info_entry *snd_card_module_info_entry;
 734 static void snd_card_module_info_read(struct snd_info_entry *entry,
 735                                       struct snd_info_buffer *buffer)
 736 {
 737         int idx;
 738         struct snd_card *card;
 739
 740         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 741                 mutex_lock(&snd_card_mutex);
 742                 if ((card = snd_cards[idx]) != NULL)
 743                         snd_iprintf(buffer, "%2i %s\n",
 744                                     idx, card->module->name);
 745                 mutex_unlock(&snd_card_mutex);
 746         }
 747 }
 748 #endif
 749
 750 int __init snd_card_info_init(void)
 751 {
 752         struct snd_info_entry *entry;
 753
 754         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 755         if (! entry)
 756                 return -ENOMEM;
 757         entry->c.text.read = snd_card_info_read;
 758         if (snd_info_register(entry) < 0) {
 759                 snd_info_free_entry(entry);
 760                 return -ENOMEM;
 761         }
 762         snd_card_info_entry = entry;
 763
 764 #ifdef MODULE
 765         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 766         if (entry) {
 767                 entry->c.text.read = snd_card_module_info_read;
 768                 if (snd_info_register(entry) < 0)
 769                         snd_info_free_entry(entry);
 770                 else
 771                         snd_card_module_info_entry = entry;
 772         }
 773 #endif
 774
 775         return 0;
 776 }
 777
 778 int __exit snd_card_info_done(void)
 779 {
 780         snd_info_free_entry(snd_card_info_entry);
 781 #ifdef MODULE
 782         snd_info_free_entry(snd_card_module_info_entry);
 783 #endif
 784         return 0;
 785 }
 786
 787 #endif /* CONFIG_PROC_FS */
 788
 789 /**
 790  *  snd_component_add - add a component string
 791  *  @card: soundcard structure
 792  *  @component: the component id string
 793  *
 794  *  This function adds the component id string to the supported list.
 795  *  The component can be referred from the alsa-lib.
 796  *
 797  *  Returns zero otherwise a negative error code.
 798  */
 799
 800 int snd_component_add(struct snd_card *card, const char *component)
 801 {
 802         char *ptr;
 803         int len = strlen(component);
 804
 805         ptr = strstr(card->components, component);
 806         if (ptr != NULL) {
 807                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 808                         return 1;
 809         }
 810         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 811                 snd_BUG();
 812                 return -ENOMEM;
 813         }
 814         if (card->components[0] != '\0')
 815                 strcat(card->components, " ");
 816         strcat(card->components, component);
 817         return 0;
 818 }
 819
 820 EXPORT_SYMBOL(snd_component_add);
 821
 822 /**
 823  *  snd_card_file_add - add the file to the file list of the card
 824  *  @card: soundcard structure
 825  *  @file: file pointer
 826  *
 827  *  This function adds the file to the file linked-list of the card.
 828  *  This linked-list is used to keep tracking the connection state,
 829  *  and to avoid the release of busy resources by hotplug.
 830  *
 831  *  Returns zero or a negative error code.
 832  */
 833 int snd_card_file_add(struct snd_card *card, struct file *file)
 834 {
 835         struct snd_monitor_file *mfile;
 836
 837         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 838         if (mfile == NULL)
 839                 return -ENOMEM;
 840         mfile->file = file;
 841         mfile->disconnected_f_op = NULL;
 842         spin_lock(&card->files_lock);
 843         if (card->shutdown) {
 844                 spin_unlock(&card->files_lock);
 845                 kfree(mfile);
 846                 return -ENODEV;
 847         }
 848         list_add(&mfile->list, &card->files_list);
 849         spin_unlock(&card->files_lock);
 850         return 0;
 851 }
 852
 853 EXPORT_SYMBOL(snd_card_file_add);
 854
 855 /**
 856  *  snd_card_file_remove - remove the file from the file list
 857  *  @card: soundcard structure
 858  *  @file: file pointer
 859  *
 860  *  This function removes the file formerly added to the card via
 861  *  snd_card_file_add() function.
 862  *  If all files are removed and snd_card_free_when_closed() was
 863  *  called beforehand, it processes the pending release of
 864  *  resources.
 865  *
 866  *  Returns zero or a negative error code.
 867  */
 868 int snd_card_file_remove(struct snd_card *card, struct file *file)
 869 {
 870         struct snd_monitor_file *mfile, *found = NULL;
 871         int last_close = 0;
 872
 873         spin_lock(&card->files_lock);
 874         list_for_each_entry(mfile, &card->files_list, list) {
 875                 if (mfile->file == file) {
 876                         list_del(&mfile->list);
 877                         if (mfile->disconnected_f_op)
 878                                 fops_put(mfile->disconnected_f_op);
 879                         found = mfile;
 880                         break;
 881                 }
 882         }
 883         if (list_empty(&card->files_list))
 884                 last_close = 1;
 885         spin_unlock(&card->files_lock);
 886         if (last_close) {
 887                 wake_up(&card->shutdown_sleep);
 888                 if (card->free_on_last_close)
 889                         snd_card_do_free(card);
 890         }
 891         if (!found) {
 892                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 893                 return -ENOENT;
 894         }
 895         kfree(found);
 896         return 0;
 897 }
 898
 899 EXPORT_SYMBOL(snd_card_file_remove);
 900
 901 #ifdef CONFIG_PM
 902 /**
 903  *  snd_power_wait - wait until the power-state is changed.
 904  *  @card: soundcard structure
 905  *  @power_state: expected power state
 906  *
 907  *  Waits until the power-state is changed.
 908  *
 909  *  Note: the power lock must be active before call.
 910  */
 911 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 912 {
 913         wait_queue_t wait;
 914         int result = 0;
 915
 916         /* fastpath */
 917         if (snd_power_get_state(card) == power_state)
 918                 return 0;
 919         init_waitqueue_entry(&wait, current);
 920         add_wait_queue(&card->power_sleep, &wait);
 921         while (1) {
 922                 if (card->shutdown) {
 923                         result = -ENODEV;
 924                         break;
 925                 }
 926                 if (snd_power_get_state(card) == power_state)
 927                         break;
 928                 set_current_state(TASK_UNINTERRUPTIBLE);
 929                 snd_power_unlock(card);
 930                 schedule_timeout(30 * HZ);
 931                 snd_power_lock(card);
 932         }
 933         remove_wait_queue(&card->power_sleep, &wait);
 934         return result;
 935 }
 936
 937 EXPORT_SYMBOL(snd_power_wait);
 938 #endif /* CONFIG_PM */