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                 return df->disconnected_f_op->release(inode, file);
 269
 270         panic("%s(%p, %p) failed!", __func__, inode, file);
 271 }
 272
 273 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 274 {
 275         return POLLERR | POLLNVAL;
 276 }
 277
 278 static long snd_disconnect_ioctl(struct file *file,
 279                                  unsigned int cmd, unsigned long arg)
 280 {
 281         return -ENODEV;
 282 }
 283
 284 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 285 {
 286         return -ENODEV;
 287 }
 288
 289 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 290 {
 291         return -ENODEV;
 292 }
 293
 294 static const struct file_operations snd_shutdown_f_ops =
 295 {
 296         .owner =        THIS_MODULE,
 297         .llseek =       snd_disconnect_llseek,
 298         .read =         snd_disconnect_read,
 299         .write =        snd_disconnect_write,
 300         .release =      snd_disconnect_release,
 301         .poll =         snd_disconnect_poll,
 302         .unlocked_ioctl = snd_disconnect_ioctl,
 303 #ifdef CONFIG_COMPAT
 304         .compat_ioctl = snd_disconnect_ioctl,
 305 #endif
 306         .mmap =         snd_disconnect_mmap,
 307         .fasync =       snd_disconnect_fasync
 308 };
 309
 310 /**
 311  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 312  *  @card: soundcard structure
 313  *
 314  *  Disconnects all APIs from the file-operations (user space).
 315  *
 316  *  Returns zero, otherwise a negative error code.
 317  *
 318  *  Note: The current implementation replaces all active file->f_op with special
 319  *        dummy file operations (they do nothing except release).
 320  */
 321 int snd_card_disconnect(struct snd_card *card)
 322 {
 323         struct snd_monitor_file *mfile;
 324         struct file *file;
 325         int err;
 326
 327         if (!card)
 328                 return -EINVAL;
 329
 330         spin_lock(&card->files_lock);
 331         if (card->shutdown) {
 332                 spin_unlock(&card->files_lock);
 333                 return 0;
 334         }
 335         card->shutdown = 1;
 336         spin_unlock(&card->files_lock);
 337
 338         /* phase 1: disable fops (user space) operations for ALSA API */
 339         mutex_lock(&snd_card_mutex);
 340         snd_cards[card->number] = NULL;
 341         snd_cards_lock &= ~(1 << card->number);
 342         mutex_unlock(&snd_card_mutex);
 343
 344         /* phase 2: replace file->f_op with special dummy operations */
 345
 346         spin_lock(&card->files_lock);
 347         mfile = card->files;
 348         while (mfile) {
 349                 file = mfile->file;
 350
 351                 /* it's critical part, use endless loop */
 352                 /* we have no room to fail */
 353                 mfile->disconnected_f_op = mfile->file->f_op;
 354
 355                 spin_lock(&shutdown_lock);
 356                 list_add(&mfile->shutdown_list, &shutdown_files);
 357                 spin_unlock(&shutdown_lock);
 358
 359                 mfile->file->f_op = &snd_shutdown_f_ops;
 360                 fops_get(mfile->file->f_op);
 361
 362                 mfile = mfile->next;
 363         }
 364         spin_unlock(&card->files_lock);
 365
 366         /* phase 3: notify all connected devices about disconnection */
 367         /* at this point, they cannot respond to any calls except release() */
 368
 369 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 370         if (snd_mixer_oss_notify_callback)
 371                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 372 #endif
 373
 374         /* notify all devices that we are disconnected */
 375         err = snd_device_disconnect_all(card);
 376         if (err < 0)
 377                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 378
 379         snd_info_card_disconnect(card);
 380 #ifndef CONFIG_SYSFS_DEPRECATED
 381         if (card->card_dev) {
 382                 device_unregister(card->card_dev);
 383                 card->card_dev = NULL;
 384         }
 385 #endif
 386 #ifdef CONFIG_PM
 387         wake_up(&card->power_sleep);
 388 #endif
 389         return 0;
 390 }
 391
 392 EXPORT_SYMBOL(snd_card_disconnect);
 393
 394 /**
 395  *  snd_card_free - frees given soundcard structure
 396  *  @card: soundcard structure
 397  *
 398  *  This function releases the soundcard structure and the all assigned
 399  *  devices automatically.  That is, you don't have to release the devices
 400  *  by yourself.
 401  *
 402  *  Returns zero. Frees all associated devices and frees the control
 403  *  interface associated to given soundcard.
 404  */
 405 static int snd_card_do_free(struct snd_card *card)
 406 {
 407 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 408         if (snd_mixer_oss_notify_callback)
 409                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 410 #endif
 411         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 412                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 413                 /* Fatal, but this situation should never occur */
 414         }
 415         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 416                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 417                 /* Fatal, but this situation should never occur */
 418         }
 419         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 420                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 421                 /* Fatal, but this situation should never occur */
 422         }
 423         if (card->private_free)
 424                 card->private_free(card);
 425         snd_info_free_entry(card->proc_id);
 426         if (snd_info_card_free(card) < 0) {
 427                 snd_printk(KERN_WARNING "unable to free card info\n");
 428                 /* Not fatal error */
 429         }
 430         kfree(card);
 431         return 0;
 432 }
 433
 434 int snd_card_free_when_closed(struct snd_card *card)
 435 {
 436         int free_now = 0;
 437         int ret = snd_card_disconnect(card);
 438         if (ret)
 439                 return ret;
 440
 441         spin_lock(&card->files_lock);
 442         if (card->files == NULL)
 443                 free_now = 1;
 444         else
 445                 card->free_on_last_close = 1;
 446         spin_unlock(&card->files_lock);
 447
 448         if (free_now)
 449                 snd_card_do_free(card);
 450         return 0;
 451 }
 452
 453 EXPORT_SYMBOL(snd_card_free_when_closed);
 454
 455 int snd_card_free(struct snd_card *card)
 456 {
 457         int ret = snd_card_disconnect(card);
 458         if (ret)
 459                 return ret;
 460
 461         /* wait, until all devices are ready for the free operation */
 462         wait_event(card->shutdown_sleep, card->files == NULL);
 463         snd_card_do_free(card);
 464         return 0;
 465 }
 466
 467 EXPORT_SYMBOL(snd_card_free);
 468
 469 static void choose_default_id(struct snd_card *card)
 470 {
 471         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 472         char *id, *spos;
 473
 474         id = spos = card->shortname;
 475         while (*id != '\0') {
 476                 if (*id == ' ')
 477                         spos = id + 1;
 478                 id++;
 479         }
 480         id = card->id;
 481         while (*spos != '\0' && !isalnum(*spos))
 482                 spos++;
 483         if (isdigit(*spos))
 484                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 485         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 486                 if (isalnum(*spos))
 487                         *id++ = *spos;
 488                 spos++;
 489         }
 490         *id = '\0';
 491
 492         id = card->id;
 493
 494         if (*id == '\0')
 495                 strcpy(id, "default");
 496
 497         while (1) {
 498                 if (loops-- == 0) {
 499                         snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
 500                         strcpy(card->id, card->proc_root->name);
 501                         return;
 502                 }
 503                 if (!snd_info_check_reserved_words(id))
 504                         goto __change;
 505                 for (i = 0; i < snd_ecards_limit; i++) {
 506                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 507                                 goto __change;
 508                 }
 509                 break;
 510
 511               __change:
 512                 len = strlen(id);
 513                 if (idx_flag) {
 514                         if (id[len-1] != '9')
 515                                 id[len-1]++;
 516                         else
 517                                 id[len-1] = 'A';
 518                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 519                         strcat(id, "_1");
 520                         idx_flag++;
 521                 } else {
 522                         spos = id + len - 2;
 523                         if ((size_t)len <= sizeof(card->id) - 2)
 524                                 spos++;
 525                         *spos++ = '_';
 526                         *spos++ = '1';
 527                         *spos++ = '\0';
 528                         idx_flag++;
 529                 }
 530         }
 531 }
 532
 533 /**
 534  *  snd_card_register - register the soundcard
 535  *  @card: soundcard structure
 536  *
 537  *  This function registers all the devices assigned to the soundcard.
 538  *  Until calling this, the ALSA control interface is blocked from the
 539  *  external accesses.  Thus, you should call this function at the end
 540  *  of the initialization of the card.
 541  *
 542  *  Returns zero otherwise a negative error code if the registrain failed.
 543  */
 544 int snd_card_register(struct snd_card *card)
 545 {
 546         int err;
 547
 548         snd_assert(card != NULL, return -EINVAL);
 549 #ifndef CONFIG_SYSFS_DEPRECATED
 550         if (!card->card_dev) {
 551                 card->card_dev = device_create(sound_class, card->dev, 0,
 552                                                "card%i", card->number);
 553                 if (IS_ERR(card->card_dev))
 554                         card->card_dev = NULL;
 555         }
 556 #endif
 557         if ((err = snd_device_register_all(card)) < 0)
 558                 return err;
 559         mutex_lock(&snd_card_mutex);
 560         if (snd_cards[card->number]) {
 561                 /* already registered */
 562                 mutex_unlock(&snd_card_mutex);
 563                 return 0;
 564         }
 565         if (card->id[0] == '\0')
 566                 choose_default_id(card);
 567         snd_cards[card->number] = card;
 568         mutex_unlock(&snd_card_mutex);
 569         init_info_for_card(card);
 570 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 571         if (snd_mixer_oss_notify_callback)
 572                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 573 #endif
 574         return 0;
 575 }
 576
 577 EXPORT_SYMBOL(snd_card_register);
 578
 579 #ifdef CONFIG_PROC_FS
 580 static struct snd_info_entry *snd_card_info_entry;
 581
 582 static void snd_card_info_read(struct snd_info_entry *entry,
 583                                struct snd_info_buffer *buffer)
 584 {
 585         int idx, count;
 586         struct snd_card *card;
 587
 588         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 589                 mutex_lock(&snd_card_mutex);
 590                 if ((card = snd_cards[idx]) != NULL) {
 591                         count++;
 592                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 593                                         idx,
 594                                         card->id,
 595                                         card->driver,
 596                                         card->shortname);
 597                         snd_iprintf(buffer, "                      %s\n",
 598                                         card->longname);
 599                 }
 600                 mutex_unlock(&snd_card_mutex);
 601         }
 602         if (!count)
 603                 snd_iprintf(buffer, "--- no soundcards ---\n");
 604 }
 605
 606 #ifdef CONFIG_SND_OSSEMUL
 607
 608 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 609 {
 610         int idx, count;
 611         struct snd_card *card;
 612
 613         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 614                 mutex_lock(&snd_card_mutex);
 615                 if ((card = snd_cards[idx]) != NULL) {
 616                         count++;
 617                         snd_iprintf(buffer, "%s\n", card->longname);
 618                 }
 619                 mutex_unlock(&snd_card_mutex);
 620         }
 621         if (!count) {
 622                 snd_iprintf(buffer, "--- no soundcards ---\n");
 623         }
 624 }
 625
 626 #endif
 627
 628 #ifdef MODULE
 629 static struct snd_info_entry *snd_card_module_info_entry;
 630 static void snd_card_module_info_read(struct snd_info_entry *entry,
 631                                       struct snd_info_buffer *buffer)
 632 {
 633         int idx;
 634         struct snd_card *card;
 635
 636         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 637                 mutex_lock(&snd_card_mutex);
 638                 if ((card = snd_cards[idx]) != NULL)
 639                         snd_iprintf(buffer, "%2i %s\n",
 640                                     idx, card->module->name);
 641                 mutex_unlock(&snd_card_mutex);
 642         }
 643 }
 644 #endif
 645
 646 int __init snd_card_info_init(void)
 647 {
 648         struct snd_info_entry *entry;
 649
 650         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 651         if (! entry)
 652                 return -ENOMEM;
 653         entry->c.text.read = snd_card_info_read;
 654         if (snd_info_register(entry) < 0) {
 655                 snd_info_free_entry(entry);
 656                 return -ENOMEM;
 657         }
 658         snd_card_info_entry = entry;
 659
 660 #ifdef MODULE
 661         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 662         if (entry) {
 663                 entry->c.text.read = snd_card_module_info_read;
 664                 if (snd_info_register(entry) < 0)
 665                         snd_info_free_entry(entry);
 666                 else
 667                         snd_card_module_info_entry = entry;
 668         }
 669 #endif
 670
 671         return 0;
 672 }
 673
 674 int __exit snd_card_info_done(void)
 675 {
 676         snd_info_free_entry(snd_card_info_entry);
 677 #ifdef MODULE
 678         snd_info_free_entry(snd_card_module_info_entry);
 679 #endif
 680         return 0;
 681 }
 682
 683 #endif /* CONFIG_PROC_FS */
 684
 685 /**
 686  *  snd_component_add - add a component string
 687  *  @card: soundcard structure
 688  *  @component: the component id string
 689  *
 690  *  This function adds the component id string to the supported list.
 691  *  The component can be referred from the alsa-lib.
 692  *
 693  *  Returns zero otherwise a negative error code.
 694  */
 695
 696 int snd_component_add(struct snd_card *card, const char *component)
 697 {
 698         char *ptr;
 699         int len = strlen(component);
 700
 701         ptr = strstr(card->components, component);
 702         if (ptr != NULL) {
 703                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 704                         return 1;
 705         }
 706         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 707                 snd_BUG();
 708                 return -ENOMEM;
 709         }
 710         if (card->components[0] != '\0')
 711                 strcat(card->components, " ");
 712         strcat(card->components, component);
 713         return 0;
 714 }
 715
 716 EXPORT_SYMBOL(snd_component_add);
 717
 718 /**
 719  *  snd_card_file_add - add the file to the file list of the card
 720  *  @card: soundcard structure
 721  *  @file: file pointer
 722  *
 723  *  This function adds the file to the file linked-list of the card.
 724  *  This linked-list is used to keep tracking the connection state,
 725  *  and to avoid the release of busy resources by hotplug.
 726  *
 727  *  Returns zero or a negative error code.
 728  */
 729 int snd_card_file_add(struct snd_card *card, struct file *file)
 730 {
 731         struct snd_monitor_file *mfile;
 732
 733         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 734         if (mfile == NULL)
 735                 return -ENOMEM;
 736         mfile->file = file;
 737         mfile->disconnected_f_op = NULL;
 738         mfile->next = NULL;
 739         spin_lock(&card->files_lock);
 740         if (card->shutdown) {
 741                 spin_unlock(&card->files_lock);
 742                 kfree(mfile);
 743                 return -ENODEV;
 744         }
 745         mfile->next = card->files;
 746         card->files = mfile;
 747         spin_unlock(&card->files_lock);
 748         return 0;
 749 }
 750
 751 EXPORT_SYMBOL(snd_card_file_add);
 752
 753 /**
 754  *  snd_card_file_remove - remove the file from the file list
 755  *  @card: soundcard structure
 756  *  @file: file pointer
 757  *
 758  *  This function removes the file formerly added to the card via
 759  *  snd_card_file_add() function.
 760  *  If all files are removed and snd_card_free_when_closed() was
 761  *  called beforehand, it processes the pending release of
 762  *  resources.
 763  *
 764  *  Returns zero or a negative error code.
 765  */
 766 int snd_card_file_remove(struct snd_card *card, struct file *file)
 767 {
 768         struct snd_monitor_file *mfile, *pfile = NULL;
 769         int last_close = 0;
 770
 771         spin_lock(&card->files_lock);
 772         mfile = card->files;
 773         while (mfile) {
 774                 if (mfile->file == file) {
 775                         if (pfile)
 776                                 pfile->next = mfile->next;
 777                         else
 778                                 card->files = mfile->next;
 779                         break;
 780                 }
 781                 pfile = mfile;
 782                 mfile = mfile->next;
 783         }
 784         if (mfile && mfile->disconnected_f_op) {
 785                 fops_put(mfile->disconnected_f_op);
 786                 spin_lock(&shutdown_lock);
 787                 list_del(&mfile->shutdown_list);
 788                 spin_unlock(&shutdown_lock);
 789         }
 790         if (card->files == NULL)
 791                 last_close = 1;
 792         spin_unlock(&card->files_lock);
 793         if (last_close) {
 794                 wake_up(&card->shutdown_sleep);
 795                 if (card->free_on_last_close)
 796                         snd_card_do_free(card);
 797         }
 798         if (!mfile) {
 799                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 800                 return -ENOENT;
 801         }
 802         kfree(mfile);
 803         return 0;
 804 }
 805
 806 EXPORT_SYMBOL(snd_card_file_remove);
 807
 808 #ifdef CONFIG_PM
 809 /**
 810  *  snd_power_wait - wait until the power-state is changed.
 811  *  @card: soundcard structure
 812  *  @power_state: expected power state
 813  *
 814  *  Waits until the power-state is changed.
 815  *
 816  *  Note: the power lock must be active before call.
 817  */
 818 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 819 {
 820         wait_queue_t wait;
 821         int result = 0;
 822
 823         /* fastpath */
 824         if (snd_power_get_state(card) == power_state)
 825                 return 0;
 826         init_waitqueue_entry(&wait, current);
 827         add_wait_queue(&card->power_sleep, &wait);
 828         while (1) {
 829                 if (card->shutdown) {
 830                         result = -ENODEV;
 831                         break;
 832                 }
 833                 if (snd_power_get_state(card) == power_state)
 834                         break;
 835                 set_current_state(TASK_UNINTERRUPTIBLE);
 836                 snd_power_unlock(card);
 837                 schedule_timeout(30 * HZ);
 838                 snd_power_lock(card);
 839         }
 840         remove_wait_queue(&card->power_sleep, &wait);
 841         return result;
 842 }
 843
 844 EXPORT_SYMBOL(snd_power_wait);
 845 #endif /* CONFIG_PM */