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