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/module.h>
  25 #include <linux/file.h>
  26 #include <linux/slab.h>
  27 #include <linux/time.h>
  28 #include <linux/ctype.h>
  29 #include <linux/pm.h>
  30
  31 #include <sound/core.h>
  32 #include <sound/control.h>
  33 #include <sound/info.h>
  34
  35 /* monitor files for graceful shutdown (hotplug) */
  36 struct snd_monitor_file {
  37         struct file *file;
  38         const struct file_operations *disconnected_f_op;
  39         struct list_head shutdown_list; /* still need to shutdown */
  40         struct list_head list;  /* link of monitor files */
  41 };
  42
  43 static DEFINE_SPINLOCK(shutdown_lock);
  44 static LIST_HEAD(shutdown_files);
  45
  46 static const struct file_operations snd_shutdown_f_ops;
  47
  48 static unsigned int snd_cards_lock;     /* locked for registering/using */
  49 struct snd_card *snd_cards[SNDRV_CARDS];
  50 EXPORT_SYMBOL(snd_cards);
  51
  52 static DEFINE_MUTEX(snd_card_mutex);
  53
  54 static char *slots[SNDRV_CARDS];
  55 module_param_array(slots, charp, NULL, 0444);
  56 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
  57
  58 /* return non-zero if the given index is reserved for the given
  59  * module via slots option
  60  */
  61 static int module_slot_match(struct module *module, int idx)
  62 {
  63         int match = 1;
  64 #ifdef MODULE
  65         const char *s1, *s2;
  66
  67         if (!module || !module->name || !slots[idx])
  68                 return 0;
  69
  70         s1 = module->name;
  71         s2 = slots[idx];
  72         if (*s2 == '!') {
  73                 match = 0; /* negative match */
  74                 s2++;
  75         }
  76         /* compare module name strings
  77          * hyphens are handled as equivalent with underscore
  78          */
  79         for (;;) {
  80                 char c1 = *s1++;
  81                 char c2 = *s2++;
  82                 if (c1 == '-')
  83                         c1 = '_';
  84                 if (c2 == '-')
  85                         c2 = '_';
  86                 if (c1 != c2)
  87                         return !match;
  88                 if (!c1)
  89                         break;
  90         }
  91 #endif /* MODULE */
  92         return match;
  93 }
  94
  95 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  96 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  97 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
  98 #endif
  99
 100 #ifdef CONFIG_PROC_FS
 101 static void snd_card_id_read(struct snd_info_entry *entry,
 102                              struct snd_info_buffer *buffer)
 103 {
 104         snd_iprintf(buffer, "%s\n", entry->card->id);
 105 }
 106
 107 static inline int init_info_for_card(struct snd_card *card)
 108 {
 109         int err;
 110         struct snd_info_entry *entry;
 111
 112         if ((err = snd_info_card_register(card)) < 0) {
 113                 snd_printd("unable to create card info\n");
 114                 return err;
 115         }
 116         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 117                 snd_printd("unable to create card entry\n");
 118                 return err;
 119         }
 120         entry->c.text.read = snd_card_id_read;
 121         if (snd_info_register(entry) < 0) {
 122                 snd_info_free_entry(entry);
 123                 entry = NULL;
 124         }
 125         card->proc_id = entry;
 126         return 0;
 127 }
 128 #else /* !CONFIG_PROC_FS */
 129 #define init_info_for_card(card)
 130 #endif
 131
 132 /**
 133  *  snd_card_create - create and initialize a soundcard structure
 134  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
 135  *  @xid: card identification (ASCII string)
 136  *  @module: top level module for locking
 137  *  @extra_size: allocate this extra size after the main soundcard structure
 138  *  @card_ret: the pointer to store the created card instance
 139  *
 140  *  Creates and initializes a soundcard structure.
 141  *
 142  *  The function allocates snd_card instance via kzalloc with the given
 143  *  space for the driver to use freely.  The allocated struct is stored
 144  *  in the given card_ret pointer.
 145  *
 146  *  Returns zero if successful or a negative error code.
 147  */
 148 int snd_card_create(int idx, const char *xid,
 149                     struct module *module, int extra_size,
 150                     struct snd_card **card_ret)
 151 {
 152         struct snd_card *card;
 153         int err, idx2;
 154
 155         if (snd_BUG_ON(!card_ret))
 156                 return -EINVAL;
 157         *card_ret = NULL;
 158
 159         if (extra_size < 0)
 160                 extra_size = 0;
 161         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
 162         if (!card)
 163                 return -ENOMEM;
 164         if (xid)
 165                 strlcpy(card->id, xid, sizeof(card->id));
 166         err = 0;
 167         mutex_lock(&snd_card_mutex);
 168         if (idx < 0) {
 169                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 170                         /* idx == -1 == 0xffff means: take any free slot */
 171                         if (~snd_cards_lock & idx & 1<<idx2) {
 172                                 if (module_slot_match(module, idx2)) {
 173                                         idx = idx2;
 174                                         break;
 175                                 }
 176                         }
 177         }
 178         if (idx < 0) {
 179                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 180                         /* idx == -1 == 0xffff means: take any free slot */
 181                         if (~snd_cards_lock & idx & 1<<idx2) {
 182                                 if (!slots[idx2] || !*slots[idx2]) {
 183                                         idx = idx2;
 184                                         break;
 185                                 }
 186                         }
 187         }
 188         if (idx < 0)
 189                 err = -ENODEV;
 190         else if (idx < snd_ecards_limit) {
 191                 if (snd_cards_lock & (1 << idx))
 192                         err = -EBUSY;   /* invalid */
 193         } else if (idx >= SNDRV_CARDS)
 194                 err = -ENODEV;
 195         if (err < 0) {
 196                 mutex_unlock(&snd_card_mutex);
 197                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
 198                          idx, snd_ecards_limit - 1, err);
 199                 goto __error;
 200         }
 201         snd_cards_lock |= 1 << idx;             /* lock it */
 202         if (idx >= snd_ecards_limit)
 203                 snd_ecards_limit = idx + 1; /* increase the limit */
 204         mutex_unlock(&snd_card_mutex);
 205         card->number = idx;
 206         card->module = module;
 207         INIT_LIST_HEAD(&card->devices);
 208         init_rwsem(&card->controls_rwsem);
 209         rwlock_init(&card->ctl_files_rwlock);
 210         mutex_init(&card->user_ctl_lock);
 211         INIT_LIST_HEAD(&card->controls);
 212         INIT_LIST_HEAD(&card->ctl_files);
 213         spin_lock_init(&card->files_lock);
 214         INIT_LIST_HEAD(&card->files_list);
 215         init_waitqueue_head(&card->shutdown_sleep);
 216         atomic_set(&card->refcount, 0);
 217 #ifdef CONFIG_PM
 218         mutex_init(&card->power_lock);
 219         init_waitqueue_head(&card->power_sleep);
 220 #endif
 221         /* the control interface cannot be accessed from the user space until */
 222         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 223         err = snd_ctl_create(card);
 224         if (err < 0) {
 225                 snd_printk(KERN_ERR "unable to register control minors\n");
 226                 goto __error;
 227         }
 228         err = snd_info_card_create(card);
 229         if (err < 0) {
 230                 snd_printk(KERN_ERR "unable to create card info\n");
 231                 goto __error_ctl;
 232         }
 233         if (extra_size > 0)
 234                 card->private_data = (char *)card + sizeof(struct snd_card);
 235         *card_ret = card;
 236         return 0;
 237
 238       __error_ctl:
 239         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 240       __error:
 241         kfree(card);
 242         return err;
 243 }
 244 EXPORT_SYMBOL(snd_card_create);
 245
 246 /* return non-zero if a card is already locked */
 247 int snd_card_locked(int card)
 248 {
 249         int locked;
 250
 251         mutex_lock(&snd_card_mutex);
 252         locked = snd_cards_lock & (1 << card);
 253         mutex_unlock(&snd_card_mutex);
 254         return locked;
 255 }
 256
 257 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 258 {
 259         return -ENODEV;
 260 }
 261
 262 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 263                                    size_t count, loff_t *offset)
 264 {
 265         return -ENODEV;
 266 }
 267
 268 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 269                                     size_t count, loff_t *offset)
 270 {
 271         return -ENODEV;
 272 }
 273
 274 static int snd_disconnect_release(struct inode *inode, struct file *file)
 275 {
 276         struct snd_monitor_file *df = NULL, *_df;
 277
 278         spin_lock(&shutdown_lock);
 279         list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 280                 if (_df->file == file) {
 281                         df = _df;
 282                         list_del_init(&df->shutdown_list);
 283                         break;
 284                 }
 285         }
 286         spin_unlock(&shutdown_lock);
 287
 288         if (likely(df)) {
 289                 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
 290                         df->disconnected_f_op->fasync(-1, file, 0);
 291                 return df->disconnected_f_op->release(inode, file);
 292         }
 293
 294         panic("%s(%p, %p) failed!", __func__, inode, file);
 295 }
 296
 297 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 298 {
 299         return POLLERR | POLLNVAL;
 300 }
 301
 302 static long snd_disconnect_ioctl(struct file *file,
 303                                  unsigned int cmd, unsigned long arg)
 304 {
 305         return -ENODEV;
 306 }
 307
 308 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 309 {
 310         return -ENODEV;
 311 }
 312
 313 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 314 {
 315         return -ENODEV;
 316 }
 317
 318 static const struct file_operations snd_shutdown_f_ops =
 319 {
 320         .owner =        THIS_MODULE,
 321         .llseek =       snd_disconnect_llseek,
 322         .read =         snd_disconnect_read,
 323         .write =        snd_disconnect_write,
 324         .release =      snd_disconnect_release,
 325         .poll =         snd_disconnect_poll,
 326         .unlocked_ioctl = snd_disconnect_ioctl,
 327 #ifdef CONFIG_COMPAT
 328         .compat_ioctl = snd_disconnect_ioctl,
 329 #endif
 330         .mmap =         snd_disconnect_mmap,
 331         .fasync =       snd_disconnect_fasync
 332 };
 333
 334 /**
 335  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 336  *  @card: soundcard structure
 337  *
 338  *  Disconnects all APIs from the file-operations (user space).
 339  *
 340  *  Returns zero, otherwise a negative error code.
 341  *
 342  *  Note: The current implementation replaces all active file->f_op with special
 343  *        dummy file operations (they do nothing except release).
 344  */
 345 int snd_card_disconnect(struct snd_card *card)
 346 {
 347         struct snd_monitor_file *mfile;
 348         int err;
 349
 350         if (!card)
 351                 return -EINVAL;
 352
 353         spin_lock(&card->files_lock);
 354         if (card->shutdown) {
 355                 spin_unlock(&card->files_lock);
 356                 return 0;
 357         }
 358         card->shutdown = 1;
 359         spin_unlock(&card->files_lock);
 360
 361         /* phase 1: disable fops (user space) operations for ALSA API */
 362         mutex_lock(&snd_card_mutex);
 363         snd_cards[card->number] = NULL;
 364         snd_cards_lock &= ~(1 << card->number);
 365         mutex_unlock(&snd_card_mutex);
 366
 367         /* phase 2: replace file->f_op with special dummy operations */
 368
 369         spin_lock(&card->files_lock);
 370         list_for_each_entry(mfile, &card->files_list, list) {
 371                 /* it's critical part, use endless loop */
 372                 /* we have no room to fail */
 373                 mfile->disconnected_f_op = mfile->file->f_op;
 374
 375                 spin_lock(&shutdown_lock);
 376                 list_add(&mfile->shutdown_list, &shutdown_files);
 377                 spin_unlock(&shutdown_lock);
 378
 379                 mfile->file->f_op = &snd_shutdown_f_ops;
 380                 fops_get(mfile->file->f_op);
 381         }
 382         spin_unlock(&card->files_lock);
 383
 384         /* phase 3: notify all connected devices about disconnection */
 385         /* at this point, they cannot respond to any calls except release() */
 386
 387 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 388         if (snd_mixer_oss_notify_callback)
 389                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 390 #endif
 391
 392         /* notify all devices that we are disconnected */
 393         err = snd_device_disconnect_all(card);
 394         if (err < 0)
 395                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 396
 397         snd_info_card_disconnect(card);
 398         if (card->card_dev) {
 399                 device_unregister(card->card_dev);
 400                 card->card_dev = NULL;
 401         }
 402 #ifdef CONFIG_PM
 403         wake_up(&card->power_sleep);
 404 #endif
 405         return 0;
 406 }
 407
 408 EXPORT_SYMBOL(snd_card_disconnect);
 409
 410 /**
 411  *  snd_card_free - frees given soundcard structure
 412  *  @card: soundcard structure
 413  *
 414  *  This function releases the soundcard structure and the all assigned
 415  *  devices automatically.  That is, you don't have to release the devices
 416  *  by yourself.
 417  *
 418  *  Returns zero. Frees all associated devices and frees the control
 419  *  interface associated to given soundcard.
 420  */
 421 static int snd_card_do_free(struct snd_card *card)
 422 {
 423 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 424         if (snd_mixer_oss_notify_callback)
 425                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 426 #endif
 427         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 428                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 429                 /* Fatal, but this situation should never occur */
 430         }
 431         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 432                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 433                 /* Fatal, but this situation should never occur */
 434         }
 435         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 436                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 437                 /* Fatal, but this situation should never occur */
 438         }
 439         if (card->private_free)
 440                 card->private_free(card);
 441         snd_info_free_entry(card->proc_id);
 442         if (snd_info_card_free(card) < 0) {
 443                 snd_printk(KERN_WARNING "unable to free card info\n");
 444                 /* Not fatal error */
 445         }
 446         kfree(card);
 447         return 0;
 448 }
 449
 450 /**
 451  * snd_card_unref - release the reference counter
 452  * @card: the card instance
 453  *
 454  * Decrements the reference counter.  When it reaches to zero, wake up
 455  * the sleeper and call the destructor if needed.
 456  */
 457 void snd_card_unref(struct snd_card *card)
 458 {
 459         if (atomic_dec_and_test(&card->refcount)) {
 460                 wake_up(&card->shutdown_sleep);
 461                 if (card->free_on_last_close)
 462                         snd_card_do_free(card);
 463         }
 464 }
 465 EXPORT_SYMBOL(snd_card_unref);
 466
 467 int snd_card_free_when_closed(struct snd_card *card)
 468 {
 469         int ret;
 470
 471         atomic_inc(&card->refcount);
 472         ret = snd_card_disconnect(card);
 473         if (ret) {
 474                 atomic_dec(&card->refcount);
 475                 return ret;
 476         }
 477
 478         card->free_on_last_close = 1;
 479         if (atomic_dec_and_test(&card->refcount))
 480                 snd_card_do_free(card);
 481         return 0;
 482 }
 483
 484 EXPORT_SYMBOL(snd_card_free_when_closed);
 485
 486 int snd_card_free(struct snd_card *card)
 487 {
 488         int ret = snd_card_disconnect(card);
 489         if (ret)
 490                 return ret;
 491
 492         /* wait, until all devices are ready for the free operation */
 493         wait_event(card->shutdown_sleep, !atomic_read(&card->refcount));
 494         snd_card_do_free(card);
 495         return 0;
 496 }
 497
 498 EXPORT_SYMBOL(snd_card_free);
 499
 500 static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)
 501 {
 502         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 503         const char *spos, *src;
 504         char *id;
 505
 506         if (nid == NULL) {
 507                 id = card->shortname;
 508                 spos = src = id;
 509                 while (*id != '\0') {
 510                         if (*id == ' ')
 511                                 spos = id + 1;
 512                         id++;
 513                 }
 514         } else {
 515                 spos = src = nid;
 516         }
 517         id = card->id;
 518         while (*spos != '\0' && !isalnum(*spos))
 519                 spos++;
 520         if (isdigit(*spos))
 521                 *id++ = isalpha(src[0]) ? src[0] : 'D';
 522         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 523                 if (isalnum(*spos))
 524                         *id++ = *spos;
 525                 spos++;
 526         }
 527         *id = '\0';
 528
 529         id = card->id;
 530
 531         if (*id == '\0')
 532                 strcpy(id, "Default");
 533
 534         while (1) {
 535                 if (loops-- == 0) {
 536                         snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
 537                         strcpy(card->id, card->proc_root->name);
 538                         return;
 539                 }
 540                 if (!snd_info_check_reserved_words(id))
 541                         goto __change;
 542                 for (i = 0; i < snd_ecards_limit; i++) {
 543                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 544                                 goto __change;
 545                 }
 546                 break;
 547
 548               __change:
 549                 len = strlen(id);
 550                 if (idx_flag) {
 551                         if (id[len-1] != '9')
 552                                 id[len-1]++;
 553                         else
 554                                 id[len-1] = 'A';
 555                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 556                         strcat(id, "_1");
 557                         idx_flag++;
 558                 } else {
 559                         spos = id + len - 2;
 560                         if ((size_t)len <= sizeof(card->id) - 2)
 561                                 spos++;
 562                         *(char *)spos++ = '_';
 563                         *(char *)spos++ = '1';
 564                         *(char *)spos++ = '\0';
 565                         idx_flag++;
 566                 }
 567         }
 568 }
 569
 570 /**
 571  *  snd_card_set_id - set card identification name
 572  *  @card: soundcard structure
 573  *  @nid: new identification string
 574  *
 575  *  This function sets the card identification and checks for name
 576  *  collisions.
 577  */
 578 void snd_card_set_id(struct snd_card *card, const char *nid)
 579 {
 580         /* check if user specified own card->id */
 581         if (card->id[0] != '\0')
 582                 return;
 583         mutex_lock(&snd_card_mutex);
 584         snd_card_set_id_no_lock(card, nid);
 585         mutex_unlock(&snd_card_mutex);
 586 }
 587 EXPORT_SYMBOL(snd_card_set_id);
 588
 589 static ssize_t
 590 card_id_show_attr(struct device *dev,
 591                   struct device_attribute *attr, char *buf)
 592 {
 593         struct snd_card *card = dev_get_drvdata(dev);
 594         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 595 }
 596
 597 static ssize_t
 598 card_id_store_attr(struct device *dev, struct device_attribute *attr,
 599                    const char *buf, size_t count)
 600 {
 601         struct snd_card *card = dev_get_drvdata(dev);
 602         char buf1[sizeof(card->id)];
 603         size_t copy = count > sizeof(card->id) - 1 ?
 604                                         sizeof(card->id) - 1 : count;
 605         size_t idx;
 606         int c;
 607
 608         for (idx = 0; idx < copy; idx++) {
 609                 c = buf[idx];
 610                 if (!isalnum(c) && c != '_' && c != '-')
 611                         return -EINVAL;
 612         }
 613         memcpy(buf1, buf, copy);
 614         buf1[copy] = '\0';
 615         mutex_lock(&snd_card_mutex);
 616         if (!snd_info_check_reserved_words(buf1)) {
 617              __exist:
 618                 mutex_unlock(&snd_card_mutex);
 619                 return -EEXIST;
 620         }
 621         for (idx = 0; idx < snd_ecards_limit; idx++) {
 622                 if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) {
 623                         if (card == snd_cards[idx])
 624                                 goto __ok;
 625                         else
 626                                 goto __exist;
 627                 }
 628         }
 629         strcpy(card->id, buf1);
 630         snd_info_card_id_change(card);
 631 __ok:
 632         mutex_unlock(&snd_card_mutex);
 633
 634         return count;
 635 }
 636
 637 static struct device_attribute card_id_attrs =
 638         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 639
 640 static ssize_t
 641 card_number_show_attr(struct device *dev,
 642                      struct device_attribute *attr, char *buf)
 643 {
 644         struct snd_card *card = dev_get_drvdata(dev);
 645         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 646 }
 647
 648 static struct device_attribute card_number_attrs =
 649         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 650
 651 /**
 652  *  snd_card_register - register the soundcard
 653  *  @card: soundcard structure
 654  *
 655  *  This function registers all the devices assigned to the soundcard.
 656  *  Until calling this, the ALSA control interface is blocked from the
 657  *  external accesses.  Thus, you should call this function at the end
 658  *  of the initialization of the card.
 659  *
 660  *  Returns zero otherwise a negative error code if the registration failed.
 661  */
 662 int snd_card_register(struct snd_card *card)
 663 {
 664         int err;
 665
 666         if (snd_BUG_ON(!card))
 667                 return -EINVAL;
 668
 669         if (!card->card_dev) {
 670                 card->card_dev = device_create(sound_class, card->dev,
 671                                                MKDEV(0, 0), card,
 672                                                "card%i", card->number);
 673                 if (IS_ERR(card->card_dev))
 674                         card->card_dev = NULL;
 675         }
 676
 677         if ((err = snd_device_register_all(card)) < 0)
 678                 return err;
 679         mutex_lock(&snd_card_mutex);
 680         if (snd_cards[card->number]) {
 681                 /* already registered */
 682                 mutex_unlock(&snd_card_mutex);
 683                 return 0;
 684         }
 685         snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id);
 686         snd_cards[card->number] = card;
 687         mutex_unlock(&snd_card_mutex);
 688         init_info_for_card(card);
 689 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 690         if (snd_mixer_oss_notify_callback)
 691                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 692 #endif
 693         if (card->card_dev) {
 694                 err = device_create_file(card->card_dev, &card_id_attrs);
 695                 if (err < 0)
 696                         return err;
 697                 err = device_create_file(card->card_dev, &card_number_attrs);
 698                 if (err < 0)
 699                         return err;
 700         }
 701
 702         return 0;
 703 }
 704
 705 EXPORT_SYMBOL(snd_card_register);
 706
 707 #ifdef CONFIG_PROC_FS
 708 static struct snd_info_entry *snd_card_info_entry;
 709
 710 static void snd_card_info_read(struct snd_info_entry *entry,
 711                                struct snd_info_buffer *buffer)
 712 {
 713         int idx, count;
 714         struct snd_card *card;
 715
 716         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 717                 mutex_lock(&snd_card_mutex);
 718                 if ((card = snd_cards[idx]) != NULL) {
 719                         count++;
 720                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 721                                         idx,
 722                                         card->id,
 723                                         card->driver,
 724                                         card->shortname);
 725                         snd_iprintf(buffer, "                      %s\n",
 726                                         card->longname);
 727                 }
 728                 mutex_unlock(&snd_card_mutex);
 729         }
 730         if (!count)
 731                 snd_iprintf(buffer, "--- no soundcards ---\n");
 732 }
 733
 734 #ifdef CONFIG_SND_OSSEMUL
 735
 736 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 737 {
 738         int idx, count;
 739         struct snd_card *card;
 740
 741         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 742                 mutex_lock(&snd_card_mutex);
 743                 if ((card = snd_cards[idx]) != NULL) {
 744                         count++;
 745                         snd_iprintf(buffer, "%s\n", card->longname);
 746                 }
 747                 mutex_unlock(&snd_card_mutex);
 748         }
 749         if (!count) {
 750                 snd_iprintf(buffer, "--- no soundcards ---\n");
 751         }
 752 }
 753
 754 #endif
 755
 756 #ifdef MODULE
 757 static struct snd_info_entry *snd_card_module_info_entry;
 758 static void snd_card_module_info_read(struct snd_info_entry *entry,
 759                                       struct snd_info_buffer *buffer)
 760 {
 761         int idx;
 762         struct snd_card *card;
 763
 764         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 765                 mutex_lock(&snd_card_mutex);
 766                 if ((card = snd_cards[idx]) != NULL)
 767                         snd_iprintf(buffer, "%2i %s\n",
 768                                     idx, card->module->name);
 769                 mutex_unlock(&snd_card_mutex);
 770         }
 771 }
 772 #endif
 773
 774 int __init snd_card_info_init(void)
 775 {
 776         struct snd_info_entry *entry;
 777
 778         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 779         if (! entry)
 780                 return -ENOMEM;
 781         entry->c.text.read = snd_card_info_read;
 782         if (snd_info_register(entry) < 0) {
 783                 snd_info_free_entry(entry);
 784                 return -ENOMEM;
 785         }
 786         snd_card_info_entry = entry;
 787
 788 #ifdef MODULE
 789         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 790         if (entry) {
 791                 entry->c.text.read = snd_card_module_info_read;
 792                 if (snd_info_register(entry) < 0)
 793                         snd_info_free_entry(entry);
 794                 else
 795                         snd_card_module_info_entry = entry;
 796         }
 797 #endif
 798
 799         return 0;
 800 }
 801
 802 int __exit snd_card_info_done(void)
 803 {
 804         snd_info_free_entry(snd_card_info_entry);
 805 #ifdef MODULE
 806         snd_info_free_entry(snd_card_module_info_entry);
 807 #endif
 808         return 0;
 809 }
 810
 811 #endif /* CONFIG_PROC_FS */
 812
 813 /**
 814  *  snd_component_add - add a component string
 815  *  @card: soundcard structure
 816  *  @component: the component id string
 817  *
 818  *  This function adds the component id string to the supported list.
 819  *  The component can be referred from the alsa-lib.
 820  *
 821  *  Returns zero otherwise a negative error code.
 822  */
 823
 824 int snd_component_add(struct snd_card *card, const char *component)
 825 {
 826         char *ptr;
 827         int len = strlen(component);
 828
 829         ptr = strstr(card->components, component);
 830         if (ptr != NULL) {
 831                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 832                         return 1;
 833         }
 834         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 835                 snd_BUG();
 836                 return -ENOMEM;
 837         }
 838         if (card->components[0] != '\0')
 839                 strcat(card->components, " ");
 840         strcat(card->components, component);
 841         return 0;
 842 }
 843
 844 EXPORT_SYMBOL(snd_component_add);
 845
 846 /**
 847  *  snd_card_file_add - add the file to the file list of the card
 848  *  @card: soundcard structure
 849  *  @file: file pointer
 850  *
 851  *  This function adds the file to the file linked-list of the card.
 852  *  This linked-list is used to keep tracking the connection state,
 853  *  and to avoid the release of busy resources by hotplug.
 854  *
 855  *  Returns zero or a negative error code.
 856  */
 857 int snd_card_file_add(struct snd_card *card, struct file *file)
 858 {
 859         struct snd_monitor_file *mfile;
 860
 861         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 862         if (mfile == NULL)
 863                 return -ENOMEM;
 864         mfile->file = file;
 865         mfile->disconnected_f_op = NULL;
 866         INIT_LIST_HEAD(&mfile->shutdown_list);
 867         spin_lock(&card->files_lock);
 868         if (card->shutdown) {
 869                 spin_unlock(&card->files_lock);
 870                 kfree(mfile);
 871                 return -ENODEV;
 872         }
 873         list_add(&mfile->list, &card->files_list);
 874         atomic_inc(&card->refcount);
 875         spin_unlock(&card->files_lock);
 876         return 0;
 877 }
 878
 879 EXPORT_SYMBOL(snd_card_file_add);
 880
 881 /**
 882  *  snd_card_file_remove - remove the file from the file list
 883  *  @card: soundcard structure
 884  *  @file: file pointer
 885  *
 886  *  This function removes the file formerly added to the card via
 887  *  snd_card_file_add() function.
 888  *  If all files are removed and snd_card_free_when_closed() was
 889  *  called beforehand, it processes the pending release of
 890  *  resources.
 891  *
 892  *  Returns zero or a negative error code.
 893  */
 894 int snd_card_file_remove(struct snd_card *card, struct file *file)
 895 {
 896         struct snd_monitor_file *mfile, *found = NULL;
 897
 898         spin_lock(&card->files_lock);
 899         list_for_each_entry(mfile, &card->files_list, list) {
 900                 if (mfile->file == file) {
 901                         list_del(&mfile->list);
 902                         spin_lock(&shutdown_lock);
 903                         list_del(&mfile->shutdown_list);
 904                         spin_unlock(&shutdown_lock);
 905                         if (mfile->disconnected_f_op)
 906                                 fops_put(mfile->disconnected_f_op);
 907                         found = mfile;
 908                         break;
 909                 }
 910         }
 911         spin_unlock(&card->files_lock);
 912         if (!found) {
 913                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 914                 return -ENOENT;
 915         }
 916         kfree(found);
 917         snd_card_unref(card);
 918         return 0;
 919 }
 920
 921 EXPORT_SYMBOL(snd_card_file_remove);
 922
 923 #ifdef CONFIG_PM
 924 /**
 925  *  snd_power_wait - wait until the power-state is changed.
 926  *  @card: soundcard structure
 927  *  @power_state: expected power state
 928  *
 929  *  Waits until the power-state is changed.
 930  *
 931  *  Note: the power lock must be active before call.
 932  */
 933 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 934 {
 935         wait_queue_t wait;
 936         int result = 0;
 937
 938         /* fastpath */
 939         if (snd_power_get_state(card) == power_state)
 940                 return 0;
 941         init_waitqueue_entry(&wait, current);
 942         add_wait_queue(&card->power_sleep, &wait);
 943         while (1) {
 944                 if (card->shutdown) {
 945                         result = -ENODEV;
 946                         break;
 947                 }
 948                 if (snd_power_get_state(card) == power_state)
 949                         break;
 950                 set_current_state(TASK_UNINTERRUPTIBLE);
 951                 snd_power_unlock(card);
 952                 schedule_timeout(30 * HZ);
 953                 snd_power_lock(card);
 954         }
 955         remove_wait_queue(&card->power_sleep, &wait);
 956         return result;
 957 }
 958
 959 EXPORT_SYMBOL(snd_power_wait);
 960 #endif /* CONFIG_PM */