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