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 /* monitor files for graceful shutdown (hotplug) */
  35 struct snd_monitor_file {
  36         struct file *file;
  37         const struct file_operations *disconnected_f_op;
  38         struct list_head shutdown_list; /* still need to shutdown */
  39         struct list_head list;  /* link of monitor files */
  40 };
  41
  42 static DEFINE_SPINLOCK(shutdown_lock);
  43 static LIST_HEAD(shutdown_files);
  44
  45 static const struct file_operations snd_shutdown_f_ops;
  46
  47 static unsigned int snd_cards_lock;     /* locked for registering/using */
  48 struct snd_card *snd_cards[SNDRV_CARDS];
  49 EXPORT_SYMBOL(snd_cards);
  50
  51 static DEFINE_MUTEX(snd_card_mutex);
  52
  53 static char *slots[SNDRV_CARDS];
  54 module_param_array(slots, charp, NULL, 0444);
  55 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
  56
  57 /* return non-zero if the given index is reserved for the given
  58  * module via slots option
  59  */
  60 static int module_slot_match(struct module *module, int idx)
  61 {
  62         int match = 1;
  63 #ifdef MODULE
  64         const char *s1, *s2;
  65
  66         if (!module || !module->name || !slots[idx])
  67                 return 0;
  68
  69         s1 = module->name;
  70         s2 = slots[idx];
  71         if (*s2 == '!') {
  72                 match = 0; /* negative match */
  73                 s2++;
  74         }
  75         /* compare module name strings
  76          * hyphens are handled as equivalent with underscore
  77          */
  78         for (;;) {
  79                 char c1 = *s1++;
  80                 char c2 = *s2++;
  81                 if (c1 == '-')
  82                         c1 = '_';
  83                 if (c2 == '-')
  84                         c2 = '_';
  85                 if (c1 != c2)
  86                         return !match;
  87                 if (!c1)
  88                         break;
  89         }
  90 #endif /* MODULE */
  91         return match;
  92 }
  93
  94 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  95 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  96 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
  97 #endif
  98
  99 #ifdef CONFIG_PROC_FS
 100 static void snd_card_id_read(struct snd_info_entry *entry,
 101                              struct snd_info_buffer *buffer)
 102 {
 103         snd_iprintf(buffer, "%s\n", entry->card->id);
 104 }
 105
 106 static inline int init_info_for_card(struct snd_card *card)
 107 {
 108         int err;
 109         struct snd_info_entry *entry;
 110
 111         if ((err = snd_info_card_register(card)) < 0) {
 112                 snd_printd("unable to create card info\n");
 113                 return err;
 114         }
 115         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 116                 snd_printd("unable to create card entry\n");
 117                 return err;
 118         }
 119         entry->c.text.read = snd_card_id_read;
 120         if (snd_info_register(entry) < 0) {
 121                 snd_info_free_entry(entry);
 122                 entry = NULL;
 123         }
 124         card->proc_id = entry;
 125         return 0;
 126 }
 127 #else /* !CONFIG_PROC_FS */
 128 #define init_info_for_card(card)
 129 #endif
 130
 131 /**
 132  *  snd_card_create - create and initialize a soundcard structure
 133  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
 134  *  @xid: card identification (ASCII string)
 135  *  @module: top level module for locking
 136  *  @extra_size: allocate this extra size after the main soundcard structure
 137  *  @card_ret: the pointer to store the created card instance
 138  *
 139  *  Creates and initializes a soundcard structure.
 140  *
 141  *  The function allocates snd_card instance via kzalloc with the given
 142  *  space for the driver to use freely.  The allocated struct is stored
 143  *  in the given card_ret pointer.
 144  *
 145  *  Returns zero if successful or a negative error code.
 146  */
 147 int snd_card_create(int idx, const char *xid,
 148                     struct module *module, int extra_size,
 149                     struct snd_card **card_ret)
 150 {
 151         struct snd_card *card;
 152         int err, idx2;
 153
 154         if (snd_BUG_ON(!card_ret))
 155                 return -EINVAL;
 156         *card_ret = NULL;
 157
 158         if (extra_size < 0)
 159                 extra_size = 0;
 160         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
 161         if (!card)
 162                 return -ENOMEM;
 163         if (xid)
 164                 strlcpy(card->id, xid, sizeof(card->id));
 165         err = 0;
 166         mutex_lock(&snd_card_mutex);
 167         if (idx < 0) {
 168                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 169                         /* idx == -1 == 0xffff means: take any free slot */
 170                         if (~snd_cards_lock & idx & 1<<idx2) {
 171                                 if (module_slot_match(module, idx2)) {
 172                                         idx = idx2;
 173                                         break;
 174                                 }
 175                         }
 176         }
 177         if (idx < 0) {
 178                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 179                         /* idx == -1 == 0xffff means: take any free slot */
 180                         if (~snd_cards_lock & idx & 1<<idx2) {
 181                                 if (!slots[idx2] || !*slots[idx2]) {
 182                                         idx = idx2;
 183                                         break;
 184                                 }
 185                         }
 186         }
 187         if (idx < 0)
 188                 err = -ENODEV;
 189         else if (idx < snd_ecards_limit) {
 190                 if (snd_cards_lock & (1 << idx))
 191                         err = -EBUSY;   /* invalid */
 192         } else if (idx >= SNDRV_CARDS)
 193                 err = -ENODEV;
 194         if (err < 0) {
 195                 mutex_unlock(&snd_card_mutex);
 196                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
 197                          idx, snd_ecards_limit - 1, err);
 198                 goto __error;
 199         }
 200         snd_cards_lock |= 1 << idx;             /* lock it */
 201         if (idx >= snd_ecards_limit)
 202                 snd_ecards_limit = idx + 1; /* increase the limit */
 203         mutex_unlock(&snd_card_mutex);
 204         card->number = idx;
 205         card->module = module;
 206         INIT_LIST_HEAD(&card->devices);
 207         init_rwsem(&card->controls_rwsem);
 208         rwlock_init(&card->ctl_files_rwlock);
 209         INIT_LIST_HEAD(&card->controls);
 210         INIT_LIST_HEAD(&card->ctl_files);
 211         spin_lock_init(&card->files_lock);
 212         INIT_LIST_HEAD(&card->files_list);
 213         init_waitqueue_head(&card->shutdown_sleep);
 214 #ifdef CONFIG_PM
 215         mutex_init(&card->power_lock);
 216         init_waitqueue_head(&card->power_sleep);
 217 #endif
 218         /* the control interface cannot be accessed from the user space until */
 219         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 220         err = snd_ctl_create(card);
 221         if (err < 0) {
 222                 snd_printk(KERN_ERR "unable to register control minors\n");
 223                 goto __error;
 224         }
 225         err = snd_info_card_create(card);
 226         if (err < 0) {
 227                 snd_printk(KERN_ERR "unable to create card info\n");
 228                 goto __error_ctl;
 229         }
 230         if (extra_size > 0)
 231                 card->private_data = (char *)card + sizeof(struct snd_card);
 232         *card_ret = card;
 233         return 0;
 234
 235       __error_ctl:
 236         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 237       __error:
 238         kfree(card);
 239         return err;
 240 }
 241 EXPORT_SYMBOL(snd_card_create);
 242
 243 /* return non-zero if a card is already locked */
 244 int snd_card_locked(int card)
 245 {
 246         int locked;
 247
 248         mutex_lock(&snd_card_mutex);
 249         locked = snd_cards_lock & (1 << card);
 250         mutex_unlock(&snd_card_mutex);
 251         return locked;
 252 }
 253
 254 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 255 {
 256         return -ENODEV;
 257 }
 258
 259 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 260                                    size_t count, loff_t *offset)
 261 {
 262         return -ENODEV;
 263 }
 264
 265 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 266                                     size_t count, loff_t *offset)
 267 {
 268         return -ENODEV;
 269 }
 270
 271 static int snd_disconnect_release(struct inode *inode, struct file *file)
 272 {
 273         struct snd_monitor_file *df = NULL, *_df;
 274
 275         spin_lock(&shutdown_lock);
 276         list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 277                 if (_df->file == file) {
 278                         df = _df;
 279                         list_del_init(&df->shutdown_list);
 280                         break;
 281                 }
 282         }
 283         spin_unlock(&shutdown_lock);
 284
 285         if (likely(df)) {
 286                 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
 287                         df->disconnected_f_op->fasync(-1, file, 0);
 288                 return df->disconnected_f_op->release(inode, file);
 289         }
 290
 291         panic("%s(%p, %p) failed!", __func__, inode, file);
 292 }
 293
 294 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 295 {
 296         return POLLERR | POLLNVAL;
 297 }
 298
 299 static long snd_disconnect_ioctl(struct file *file,
 300                                  unsigned int cmd, unsigned long arg)
 301 {
 302         return -ENODEV;
 303 }
 304
 305 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 306 {
 307         return -ENODEV;
 308 }
 309
 310 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 311 {
 312         return -ENODEV;
 313 }
 314
 315 static const struct file_operations snd_shutdown_f_ops =
 316 {
 317         .owner =        THIS_MODULE,
 318         .llseek =       snd_disconnect_llseek,
 319         .read =         snd_disconnect_read,
 320         .write =        snd_disconnect_write,
 321         .release =      snd_disconnect_release,
 322         .poll =         snd_disconnect_poll,
 323         .unlocked_ioctl = snd_disconnect_ioctl,
 324 #ifdef CONFIG_COMPAT
 325         .compat_ioctl = snd_disconnect_ioctl,
 326 #endif
 327         .mmap =         snd_disconnect_mmap,
 328         .fasync =       snd_disconnect_fasync
 329 };
 330
 331 /**
 332  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 333  *  @card: soundcard structure
 334  *
 335  *  Disconnects all APIs from the file-operations (user space).
 336  *
 337  *  Returns zero, otherwise a negative error code.
 338  *
 339  *  Note: The current implementation replaces all active file->f_op with special
 340  *        dummy file operations (they do nothing except release).
 341  */
 342 int snd_card_disconnect(struct snd_card *card)
 343 {
 344         struct snd_monitor_file *mfile;
 345         int err;
 346
 347         if (!card)
 348                 return -EINVAL;
 349
 350         spin_lock(&card->files_lock);
 351         if (card->shutdown) {
 352                 spin_unlock(&card->files_lock);
 353                 return 0;
 354         }
 355         card->shutdown = 1;
 356         spin_unlock(&card->files_lock);
 357
 358         /* phase 1: disable fops (user space) operations for ALSA API */
 359         mutex_lock(&snd_card_mutex);
 360         snd_cards[card->number] = NULL;
 361         snd_cards_lock &= ~(1 << card->number);
 362         mutex_unlock(&snd_card_mutex);
 363
 364         /* phase 2: replace file->f_op with special dummy operations */
 365
 366         spin_lock(&card->files_lock);
 367         list_for_each_entry(mfile, &card->files_list, list) {
 368                 /* it's critical part, use endless loop */
 369                 /* we have no room to fail */
 370                 mfile->disconnected_f_op = mfile->file->f_op;
 371
 372                 spin_lock(&shutdown_lock);
 373                 list_add(&mfile->shutdown_list, &shutdown_files);
 374                 spin_unlock(&shutdown_lock);
 375
 376                 mfile->file->f_op = &snd_shutdown_f_ops;
 377                 fops_get(mfile->file->f_op);
 378         }
 379         spin_unlock(&card->files_lock);
 380
 381         /* phase 3: notify all connected devices about disconnection */
 382         /* at this point, they cannot respond to any calls except release() */
 383
 384 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 385         if (snd_mixer_oss_notify_callback)
 386                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 387 #endif
 388
 389         /* notify all devices that we are disconnected */
 390         err = snd_device_disconnect_all(card);
 391         if (err < 0)
 392                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 393
 394         snd_info_card_disconnect(card);
 395         if (card->card_dev) {
 396                 device_unregister(card->card_dev);
 397                 card->card_dev = NULL;
 398         }
 399 #ifdef CONFIG_PM
 400         wake_up(&card->power_sleep);
 401 #endif
 402         return 0;
 403 }
 404
 405 EXPORT_SYMBOL(snd_card_disconnect);
 406
 407 /**
 408  *  snd_card_free - frees given soundcard structure
 409  *  @card: soundcard structure
 410  *
 411  *  This function releases the soundcard structure and the all assigned
 412  *  devices automatically.  That is, you don't have to release the devices
 413  *  by yourself.
 414  *
 415  *  Returns zero. Frees all associated devices and frees the control
 416  *  interface associated to given soundcard.
 417  */
 418 static int snd_card_do_free(struct snd_card *card)
 419 {
 420 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 421         if (snd_mixer_oss_notify_callback)
 422                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 423 #endif
 424         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 425                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 426                 /* Fatal, but this situation should never occur */
 427         }
 428         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 429                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 430                 /* Fatal, but this situation should never occur */
 431         }
 432         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 433                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 434                 /* Fatal, but this situation should never occur */
 435         }
 436         if (card->private_free)
 437                 card->private_free(card);
 438         snd_info_free_entry(card->proc_id);
 439         if (snd_info_card_free(card) < 0) {
 440                 snd_printk(KERN_WARNING "unable to free card info\n");
 441                 /* Not fatal error */
 442         }
 443         kfree(card);
 444         return 0;
 445 }
 446
 447 int snd_card_free_when_closed(struct snd_card *card)
 448 {
 449         int free_now = 0;
 450         int ret = snd_card_disconnect(card);
 451         if (ret)
 452                 return ret;
 453
 454         spin_lock(&card->files_lock);
 455         if (list_empty(&card->files_list))
 456                 free_now = 1;
 457         else
 458                 card->free_on_last_close = 1;
 459         spin_unlock(&card->files_lock);
 460
 461         if (free_now)
 462                 snd_card_do_free(card);
 463         return 0;
 464 }
 465
 466 EXPORT_SYMBOL(snd_card_free_when_closed);
 467
 468 int snd_card_free(struct snd_card *card)
 469 {
 470         int ret = snd_card_disconnect(card);
 471         if (ret)
 472                 return ret;
 473
 474         /* wait, until all devices are ready for the free operation */
 475         wait_event(card->shutdown_sleep, list_empty(&card->files_list));
 476         snd_card_do_free(card);
 477         return 0;
 478 }
 479
 480 EXPORT_SYMBOL(snd_card_free);
 481
 482 static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)
 483 {
 484         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 485         const char *spos, *src;
 486         char *id;
 487
 488         if (nid == NULL) {
 489                 id = card->shortname;
 490                 spos = src = id;
 491                 while (*id != '\0') {
 492                         if (*id == ' ')
 493                                 spos = id + 1;
 494                         id++;
 495                 }
 496         } else {
 497                 spos = src = nid;
 498         }
 499         id = card->id;
 500         while (*spos != '\0' && !isalnum(*spos))
 501                 spos++;
 502         if (isdigit(*spos))
 503                 *id++ = isalpha(src[0]) ? src[0] : 'D';
 504         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 505                 if (isalnum(*spos))
 506                         *id++ = *spos;
 507                 spos++;
 508         }
 509         *id = '\0';
 510
 511         id = card->id;
 512
 513         if (*id == '\0')
 514                 strcpy(id, "Default");
 515
 516         while (1) {
 517                 if (loops-- == 0) {
 518                         snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
 519                         strcpy(card->id, card->proc_root->name);
 520                         return;
 521                 }
 522                 if (!snd_info_check_reserved_words(id))
 523                         goto __change;
 524                 for (i = 0; i < snd_ecards_limit; i++) {
 525                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 526                                 goto __change;
 527                 }
 528                 break;
 529
 530               __change:
 531                 len = strlen(id);
 532                 if (idx_flag) {
 533                         if (id[len-1] != '9')
 534                                 id[len-1]++;
 535                         else
 536                                 id[len-1] = 'A';
 537                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 538                         strcat(id, "_1");
 539                         idx_flag++;
 540                 } else {
 541                         spos = id + len - 2;
 542                         if ((size_t)len <= sizeof(card->id) - 2)
 543                                 spos++;
 544                         *(char *)spos++ = '_';
 545                         *(char *)spos++ = '1';
 546                         *(char *)spos++ = '\0';
 547                         idx_flag++;
 548                 }
 549         }
 550 }
 551
 552 /**
 553  *  snd_card_set_id - set card identification name
 554  *  @card: soundcard structure
 555  *  @nid: new identification string
 556  *
 557  *  This function sets the card identification and checks for name
 558  *  collisions.
 559  */
 560 void snd_card_set_id(struct snd_card *card, const char *nid)
 561 {
 562         /* check if user specified own card->id */
 563         if (card->id[0] != '\0')
 564                 return;
 565         mutex_lock(&snd_card_mutex);
 566         snd_card_set_id_no_lock(card, nid);
 567         mutex_unlock(&snd_card_mutex);
 568 }
 569 EXPORT_SYMBOL(snd_card_set_id);
 570
 571 static ssize_t
 572 card_id_show_attr(struct device *dev,
 573                   struct device_attribute *attr, char *buf)
 574 {
 575         struct snd_card *card = dev_get_drvdata(dev);
 576         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 577 }
 578
 579 static ssize_t
 580 card_id_store_attr(struct device *dev, struct device_attribute *attr,
 581                    const char *buf, size_t count)
 582 {
 583         struct snd_card *card = dev_get_drvdata(dev);
 584         char buf1[sizeof(card->id)];
 585         size_t copy = count > sizeof(card->id) - 1 ?
 586                                         sizeof(card->id) - 1 : count;
 587         size_t idx;
 588         int c;
 589
 590         for (idx = 0; idx < copy; idx++) {
 591                 c = buf[idx];
 592                 if (!isalnum(c) && c != '_' && c != '-')
 593                         return -EINVAL;
 594         }
 595         memcpy(buf1, buf, copy);
 596         buf1[copy] = '\0';
 597         mutex_lock(&snd_card_mutex);
 598         if (!snd_info_check_reserved_words(buf1)) {
 599              __exist:
 600                 mutex_unlock(&snd_card_mutex);
 601                 return -EEXIST;
 602         }
 603         for (idx = 0; idx < snd_ecards_limit; idx++) {
 604                 if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) {
 605                         if (card == snd_cards[idx])
 606                                 goto __ok;
 607                         else
 608                                 goto __exist;
 609                 }
 610         }
 611         strcpy(card->id, buf1);
 612         snd_info_card_id_change(card);
 613 __ok:
 614         mutex_unlock(&snd_card_mutex);
 615
 616         return count;
 617 }
 618
 619 static struct device_attribute card_id_attrs =
 620         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 621
 622 static ssize_t
 623 card_number_show_attr(struct device *dev,
 624                      struct device_attribute *attr, char *buf)
 625 {
 626         struct snd_card *card = dev_get_drvdata(dev);
 627         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 628 }
 629
 630 static struct device_attribute card_number_attrs =
 631         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 632
 633 /**
 634  *  snd_card_register - register the soundcard
 635  *  @card: soundcard structure
 636  *
 637  *  This function registers all the devices assigned to the soundcard.
 638  *  Until calling this, the ALSA control interface is blocked from the
 639  *  external accesses.  Thus, you should call this function at the end
 640  *  of the initialization of the card.
 641  *
 642  *  Returns zero otherwise a negative error code if the registration failed.
 643  */
 644 int snd_card_register(struct snd_card *card)
 645 {
 646         int err;
 647
 648         if (snd_BUG_ON(!card))
 649                 return -EINVAL;
 650
 651         if (!card->card_dev) {
 652                 card->card_dev = device_create(sound_class, card->dev,
 653                                                MKDEV(0, 0), card,
 654                                                "card%i", card->number);
 655                 if (IS_ERR(card->card_dev))
 656                         card->card_dev = NULL;
 657         }
 658
 659         if ((err = snd_device_register_all(card)) < 0)
 660                 return err;
 661         mutex_lock(&snd_card_mutex);
 662         if (snd_cards[card->number]) {
 663                 /* already registered */
 664                 mutex_unlock(&snd_card_mutex);
 665                 return 0;
 666         }
 667         snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id);
 668         snd_cards[card->number] = card;
 669         mutex_unlock(&snd_card_mutex);
 670         init_info_for_card(card);
 671 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 672         if (snd_mixer_oss_notify_callback)
 673                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 674 #endif
 675         if (card->card_dev) {
 676                 err = device_create_file(card->card_dev, &card_id_attrs);
 677                 if (err < 0)
 678                         return err;
 679                 err = device_create_file(card->card_dev, &card_number_attrs);
 680                 if (err < 0)
 681                         return err;
 682         }
 683
 684         return 0;
 685 }
 686
 687 EXPORT_SYMBOL(snd_card_register);
 688
 689 #ifdef CONFIG_PROC_FS
 690 static struct snd_info_entry *snd_card_info_entry;
 691
 692 static void snd_card_info_read(struct snd_info_entry *entry,
 693                                struct snd_info_buffer *buffer)
 694 {
 695         int idx, count;
 696         struct snd_card *card;
 697
 698         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 699                 mutex_lock(&snd_card_mutex);
 700                 if ((card = snd_cards[idx]) != NULL) {
 701                         count++;
 702                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 703                                         idx,
 704                                         card->id,
 705                                         card->driver,
 706                                         card->shortname);
 707                         snd_iprintf(buffer, "                      %s\n",
 708                                         card->longname);
 709                 }
 710                 mutex_unlock(&snd_card_mutex);
 711         }
 712         if (!count)
 713                 snd_iprintf(buffer, "--- no soundcards ---\n");
 714 }
 715
 716 #ifdef CONFIG_SND_OSSEMUL
 717
 718 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 719 {
 720         int idx, count;
 721         struct snd_card *card;
 722
 723         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 724                 mutex_lock(&snd_card_mutex);
 725                 if ((card = snd_cards[idx]) != NULL) {
 726                         count++;
 727                         snd_iprintf(buffer, "%s\n", card->longname);
 728                 }
 729                 mutex_unlock(&snd_card_mutex);
 730         }
 731         if (!count) {
 732                 snd_iprintf(buffer, "--- no soundcards ---\n");
 733         }
 734 }
 735
 736 #endif
 737
 738 #ifdef MODULE
 739 static struct snd_info_entry *snd_card_module_info_entry;
 740 static void snd_card_module_info_read(struct snd_info_entry *entry,
 741                                       struct snd_info_buffer *buffer)
 742 {
 743         int idx;
 744         struct snd_card *card;
 745
 746         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 747                 mutex_lock(&snd_card_mutex);
 748                 if ((card = snd_cards[idx]) != NULL)
 749                         snd_iprintf(buffer, "%2i %s\n",
 750                                     idx, card->module->name);
 751                 mutex_unlock(&snd_card_mutex);
 752         }
 753 }
 754 #endif
 755
 756 int __init snd_card_info_init(void)
 757 {
 758         struct snd_info_entry *entry;
 759
 760         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 761         if (! entry)
 762                 return -ENOMEM;
 763         entry->c.text.read = snd_card_info_read;
 764         if (snd_info_register(entry) < 0) {
 765                 snd_info_free_entry(entry);
 766                 return -ENOMEM;
 767         }
 768         snd_card_info_entry = entry;
 769
 770 #ifdef MODULE
 771         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 772         if (entry) {
 773                 entry->c.text.read = snd_card_module_info_read;
 774                 if (snd_info_register(entry) < 0)
 775                         snd_info_free_entry(entry);
 776                 else
 777                         snd_card_module_info_entry = entry;
 778         }
 779 #endif
 780
 781         return 0;
 782 }
 783
 784 int __exit snd_card_info_done(void)
 785 {
 786         snd_info_free_entry(snd_card_info_entry);
 787 #ifdef MODULE
 788         snd_info_free_entry(snd_card_module_info_entry);
 789 #endif
 790         return 0;
 791 }
 792
 793 #endif /* CONFIG_PROC_FS */
 794
 795 /**
 796  *  snd_component_add - add a component string
 797  *  @card: soundcard structure
 798  *  @component: the component id string
 799  *
 800  *  This function adds the component id string to the supported list.
 801  *  The component can be referred from the alsa-lib.
 802  *
 803  *  Returns zero otherwise a negative error code.
 804  */
 805
 806 int snd_component_add(struct snd_card *card, const char *component)
 807 {
 808         char *ptr;
 809         int len = strlen(component);
 810
 811         ptr = strstr(card->components, component);
 812         if (ptr != NULL) {
 813                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 814                         return 1;
 815         }
 816         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 817                 snd_BUG();
 818                 return -ENOMEM;
 819         }
 820         if (card->components[0] != '\0')
 821                 strcat(card->components, " ");
 822         strcat(card->components, component);
 823         return 0;
 824 }
 825
 826 EXPORT_SYMBOL(snd_component_add);
 827
 828 /**
 829  *  snd_card_file_add - add the file to the file list of the card
 830  *  @card: soundcard structure
 831  *  @file: file pointer
 832  *
 833  *  This function adds the file to the file linked-list of the card.
 834  *  This linked-list is used to keep tracking the connection state,
 835  *  and to avoid the release of busy resources by hotplug.
 836  *
 837  *  Returns zero or a negative error code.
 838  */
 839 int snd_card_file_add(struct snd_card *card, struct file *file)
 840 {
 841         struct snd_monitor_file *mfile;
 842
 843         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 844         if (mfile == NULL)
 845                 return -ENOMEM;
 846         mfile->file = file;
 847         mfile->disconnected_f_op = NULL;
 848         INIT_LIST_HEAD(&mfile->shutdown_list);
 849         spin_lock(&card->files_lock);
 850         if (card->shutdown) {
 851                 spin_unlock(&card->files_lock);
 852                 kfree(mfile);
 853                 return -ENODEV;
 854         }
 855         list_add(&mfile->list, &card->files_list);
 856         spin_unlock(&card->files_lock);
 857         return 0;
 858 }
 859
 860 EXPORT_SYMBOL(snd_card_file_add);
 861
 862 /**
 863  *  snd_card_file_remove - remove the file from the file list
 864  *  @card: soundcard structure
 865  *  @file: file pointer
 866  *
 867  *  This function removes the file formerly added to the card via
 868  *  snd_card_file_add() function.
 869  *  If all files are removed and snd_card_free_when_closed() was
 870  *  called beforehand, it processes the pending release of
 871  *  resources.
 872  *
 873  *  Returns zero or a negative error code.
 874  */
 875 int snd_card_file_remove(struct snd_card *card, struct file *file)
 876 {
 877         struct snd_monitor_file *mfile, *found = NULL;
 878         int last_close = 0;
 879
 880         spin_lock(&card->files_lock);
 881         list_for_each_entry(mfile, &card->files_list, list) {
 882                 if (mfile->file == file) {
 883                         list_del(&mfile->list);
 884                         spin_lock(&shutdown_lock);
 885                         list_del(&mfile->shutdown_list);
 886                         spin_unlock(&shutdown_lock);
 887                         if (mfile->disconnected_f_op)
 888                                 fops_put(mfile->disconnected_f_op);
 889                         found = mfile;
 890                         break;
 891                 }
 892         }
 893         if (list_empty(&card->files_list))
 894                 last_close = 1;
 895         spin_unlock(&card->files_lock);
 896         if (last_close) {
 897                 wake_up(&card->shutdown_sleep);
 898                 if (card->free_on_last_close)
 899                         snd_card_do_free(card);
 900         }
 901         if (!found) {
 902                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 903                 return -ENOENT;
 904         }
 905         kfree(found);
 906         return 0;
 907 }
 908
 909 EXPORT_SYMBOL(snd_card_file_remove);
 910
 911 #ifdef CONFIG_PM
 912 /**
 913  *  snd_power_wait - wait until the power-state is changed.
 914  *  @card: soundcard structure
 915  *  @power_state: expected power state
 916  *
 917  *  Waits until the power-state is changed.
 918  *
 919  *  Note: the power lock must be active before call.
 920  */
 921 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 922 {
 923         wait_queue_t wait;
 924         int result = 0;
 925
 926         /* fastpath */
 927         if (snd_power_get_state(card) == power_state)
 928                 return 0;
 929         init_waitqueue_entry(&wait, current);
 930         add_wait_queue(&card->power_sleep, &wait);
 931         while (1) {
 932                 if (card->shutdown) {
 933                         result = -ENODEV;
 934                         break;
 935                 }
 936                 if (snd_power_get_state(card) == power_state)
 937                         break;
 938                 set_current_state(TASK_UNINTERRUPTIBLE);
 939                 snd_power_unlock(card);
 940                 schedule_timeout(30 * HZ);
 941                 snd_power_lock(card);
 942         }
 943         remove_wait_queue(&card->power_sleep, &wait);
 944         return result;
 945 }
 946
 947 EXPORT_SYMBOL(snd_power_wait);
 948 #endif /* CONFIG_PM */