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