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         struct file *file;
 346         int err;
 347
 348         if (!card)
 349                 return -EINVAL;
 350
 351         spin_lock(&card->files_lock);
 352         if (card->shutdown) {
 353                 spin_unlock(&card->files_lock);
 354                 return 0;
 355         }
 356         card->shutdown = 1;
 357         spin_unlock(&card->files_lock);
 358
 359         /* phase 1: disable fops (user space) operations for ALSA API */
 360         mutex_lock(&snd_card_mutex);
 361         snd_cards[card->number] = NULL;
 362         snd_cards_lock &= ~(1 << card->number);
 363         mutex_unlock(&snd_card_mutex);
 364
 365         /* phase 2: replace file->f_op with special dummy operations */
 366
 367         spin_lock(&card->files_lock);
 368         list_for_each_entry(mfile, &card->files_list, list) {
 369                 file = mfile->file;
 370
 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 #ifndef CONFIG_SYSFS_DEPRECATED
 399         if (card->card_dev) {
 400                 device_unregister(card->card_dev);
 401                 card->card_dev = NULL;
 402         }
 403 #endif
 404 #ifdef CONFIG_PM
 405         wake_up(&card->power_sleep);
 406 #endif
 407         return 0;
 408 }
 409
 410 EXPORT_SYMBOL(snd_card_disconnect);
 411
 412 /**
 413  *  snd_card_free - frees given soundcard structure
 414  *  @card: soundcard structure
 415  *
 416  *  This function releases the soundcard structure and the all assigned
 417  *  devices automatically.  That is, you don't have to release the devices
 418  *  by yourself.
 419  *
 420  *  Returns zero. Frees all associated devices and frees the control
 421  *  interface associated to given soundcard.
 422  */
 423 static int snd_card_do_free(struct snd_card *card)
 424 {
 425 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 426         if (snd_mixer_oss_notify_callback)
 427                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 428 #endif
 429         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 430                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 431                 /* Fatal, but this situation should never occur */
 432         }
 433         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 434                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 435                 /* Fatal, but this situation should never occur */
 436         }
 437         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 438                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 439                 /* Fatal, but this situation should never occur */
 440         }
 441         if (card->private_free)
 442                 card->private_free(card);
 443         snd_info_free_entry(card->proc_id);
 444         if (snd_info_card_free(card) < 0) {
 445                 snd_printk(KERN_WARNING "unable to free card info\n");
 446                 /* Not fatal error */
 447         }
 448         kfree(card);
 449         return 0;
 450 }
 451
 452 int snd_card_free_when_closed(struct snd_card *card)
 453 {
 454         int free_now = 0;
 455         int ret = snd_card_disconnect(card);
 456         if (ret)
 457                 return ret;
 458
 459         spin_lock(&card->files_lock);
 460         if (list_empty(&card->files_list))
 461                 free_now = 1;
 462         else
 463                 card->free_on_last_close = 1;
 464         spin_unlock(&card->files_lock);
 465
 466         if (free_now)
 467                 snd_card_do_free(card);
 468         return 0;
 469 }
 470
 471 EXPORT_SYMBOL(snd_card_free_when_closed);
 472
 473 int snd_card_free(struct snd_card *card)
 474 {
 475         int ret = snd_card_disconnect(card);
 476         if (ret)
 477                 return ret;
 478
 479         /* wait, until all devices are ready for the free operation */
 480         wait_event(card->shutdown_sleep, list_empty(&card->files_list));
 481         snd_card_do_free(card);
 482         return 0;
 483 }
 484
 485 EXPORT_SYMBOL(snd_card_free);
 486
 487 static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)
 488 {
 489         int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 490         const char *spos, *src;
 491         char *id;
 492
 493         if (nid == NULL) {
 494                 id = card->shortname;
 495                 spos = src = id;
 496                 while (*id != '\0') {
 497                         if (*id == ' ')
 498                                 spos = id + 1;
 499                         id++;
 500                 }
 501         } else {
 502                 spos = src = nid;
 503         }
 504         id = card->id;
 505         while (*spos != '\0' && !isalnum(*spos))
 506                 spos++;
 507         if (isdigit(*spos))
 508                 *id++ = isalpha(src[0]) ? src[0] : 'D';
 509         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 510                 if (isalnum(*spos))
 511                         *id++ = *spos;
 512                 spos++;
 513         }
 514         *id = '\0';
 515
 516         id = card->id;
 517
 518         if (*id == '\0')
 519                 strcpy(id, "default");
 520
 521         while (1) {
 522                 if (loops-- == 0) {
 523                         snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
 524                         strcpy(card->id, card->proc_root->name);
 525                         return;
 526                 }
 527                 if (!snd_info_check_reserved_words(id))
 528                         goto __change;
 529                 for (i = 0; i < snd_ecards_limit; i++) {
 530                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 531                                 goto __change;
 532                 }
 533                 break;
 534
 535               __change:
 536                 len = strlen(id);
 537                 if (idx_flag) {
 538                         if (id[len-1] != '9')
 539                                 id[len-1]++;
 540                         else
 541                                 id[len-1] = 'A';
 542                 } else if ((size_t)len <= sizeof(card->id) - 3) {
 543                         strcat(id, "_1");
 544                         idx_flag++;
 545                 } else {
 546                         spos = id + len - 2;
 547                         if ((size_t)len <= sizeof(card->id) - 2)
 548                                 spos++;
 549                         *(char *)spos++ = '_';
 550                         *(char *)spos++ = '1';
 551                         *(char *)spos++ = '\0';
 552                         idx_flag++;
 553                 }
 554         }
 555 }
 556
 557 /**
 558  *  snd_card_set_id - set card identification name
 559  *  @card: soundcard structure
 560  *  @nid: new identification string
 561  *
 562  *  This function sets the card identification and checks for name
 563  *  collisions.
 564  */
 565 void snd_card_set_id(struct snd_card *card, const char *nid)
 566 {
 567         /* check if user specified own card->id */
 568         if (card->id[0] != '\0')
 569                 return;
 570         mutex_lock(&snd_card_mutex);
 571         snd_card_set_id_no_lock(card, nid);
 572         mutex_unlock(&snd_card_mutex);
 573 }
 574 EXPORT_SYMBOL(snd_card_set_id);
 575
 576 #ifndef CONFIG_SYSFS_DEPRECATED
 577 static ssize_t
 578 card_id_show_attr(struct device *dev,
 579                   struct device_attribute *attr, char *buf)
 580 {
 581         struct snd_card *card = dev_get_drvdata(dev);
 582         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 583 }
 584
 585 static ssize_t
 586 card_id_store_attr(struct device *dev, struct device_attribute *attr,
 587                    const char *buf, size_t count)
 588 {
 589         struct snd_card *card = dev_get_drvdata(dev);
 590         char buf1[sizeof(card->id)];
 591         size_t copy = count > sizeof(card->id) - 1 ?
 592                                         sizeof(card->id) - 1 : count;
 593         size_t idx;
 594         int c;
 595
 596         for (idx = 0; idx < copy; idx++) {
 597                 c = buf[idx];
 598                 if (!isalnum(c) && c != '_' && c != '-')
 599                         return -EINVAL;
 600         }
 601         memcpy(buf1, buf, copy);
 602         buf1[copy] = '\0';
 603         mutex_lock(&snd_card_mutex);
 604         if (!snd_info_check_reserved_words(buf1)) {
 605              __exist:
 606                 mutex_unlock(&snd_card_mutex);
 607                 return -EEXIST;
 608         }
 609         for (idx = 0; idx < snd_ecards_limit; idx++) {
 610                 if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1))
 611                         goto __exist;
 612         }
 613         strcpy(card->id, buf1);
 614         snd_info_card_id_change(card);
 615         mutex_unlock(&snd_card_mutex);
 616
 617         return count;
 618 }
 619
 620 static struct device_attribute card_id_attrs =
 621         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 622
 623 static ssize_t
 624 card_number_show_attr(struct device *dev,
 625                      struct device_attribute *attr, char *buf)
 626 {
 627         struct snd_card *card = dev_get_drvdata(dev);
 628         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 629 }
 630
 631 static struct device_attribute card_number_attrs =
 632         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 633 #endif /* CONFIG_SYSFS_DEPRECATED */
 634
 635 /**
 636  *  snd_card_register - register the soundcard
 637  *  @card: soundcard structure
 638  *
 639  *  This function registers all the devices assigned to the soundcard.
 640  *  Until calling this, the ALSA control interface is blocked from the
 641  *  external accesses.  Thus, you should call this function at the end
 642  *  of the initialization of the card.
 643  *
 644  *  Returns zero otherwise a negative error code if the registrain failed.
 645  */
 646 int snd_card_register(struct snd_card *card)
 647 {
 648         int err;
 649
 650         if (snd_BUG_ON(!card))
 651                 return -EINVAL;
 652 #ifndef CONFIG_SYSFS_DEPRECATED
 653         if (!card->card_dev) {
 654                 card->card_dev = device_create(sound_class, card->dev,
 655                                                MKDEV(0, 0), card,
 656                                                "card%i", card->number);
 657                 if (IS_ERR(card->card_dev))
 658                         card->card_dev = NULL;
 659         }
 660 #endif
 661         if ((err = snd_device_register_all(card)) < 0)
 662                 return err;
 663         mutex_lock(&snd_card_mutex);
 664         if (snd_cards[card->number]) {
 665                 /* already registered */
 666                 mutex_unlock(&snd_card_mutex);
 667                 return 0;
 668         }
 669         snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id);
 670         snd_cards[card->number] = card;
 671         mutex_unlock(&snd_card_mutex);
 672         init_info_for_card(card);
 673 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 674         if (snd_mixer_oss_notify_callback)
 675                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 676 #endif
 677 #ifndef CONFIG_SYSFS_DEPRECATED
 678         if (card->card_dev) {
 679                 err = device_create_file(card->card_dev, &card_id_attrs);
 680                 if (err < 0)
 681                         return err;
 682                 err = device_create_file(card->card_dev, &card_number_attrs);
 683                 if (err < 0)
 684                         return err;
 685         }
 686 #endif
 687         return 0;
 688 }
 689
 690 EXPORT_SYMBOL(snd_card_register);
 691
 692 #ifdef CONFIG_PROC_FS
 693 static struct snd_info_entry *snd_card_info_entry;
 694
 695 static void snd_card_info_read(struct snd_info_entry *entry,
 696                                struct snd_info_buffer *buffer)
 697 {
 698         int idx, count;
 699         struct snd_card *card;
 700
 701         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 702                 mutex_lock(&snd_card_mutex);
 703                 if ((card = snd_cards[idx]) != NULL) {
 704                         count++;
 705                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 706                                         idx,
 707                                         card->id,
 708                                         card->driver,
 709                                         card->shortname);
 710                         snd_iprintf(buffer, "                      %s\n",
 711                                         card->longname);
 712                 }
 713                 mutex_unlock(&snd_card_mutex);
 714         }
 715         if (!count)
 716                 snd_iprintf(buffer, "--- no soundcards ---\n");
 717 }
 718
 719 #ifdef CONFIG_SND_OSSEMUL
 720
 721 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 722 {
 723         int idx, count;
 724         struct snd_card *card;
 725
 726         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 727                 mutex_lock(&snd_card_mutex);
 728                 if ((card = snd_cards[idx]) != NULL) {
 729                         count++;
 730                         snd_iprintf(buffer, "%s\n", card->longname);
 731                 }
 732                 mutex_unlock(&snd_card_mutex);
 733         }
 734         if (!count) {
 735                 snd_iprintf(buffer, "--- no soundcards ---\n");
 736         }
 737 }
 738
 739 #endif
 740
 741 #ifdef MODULE
 742 static struct snd_info_entry *snd_card_module_info_entry;
 743 static void snd_card_module_info_read(struct snd_info_entry *entry,
 744                                       struct snd_info_buffer *buffer)
 745 {
 746         int idx;
 747         struct snd_card *card;
 748
 749         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 750                 mutex_lock(&snd_card_mutex);
 751                 if ((card = snd_cards[idx]) != NULL)
 752                         snd_iprintf(buffer, "%2i %s\n",
 753                                     idx, card->module->name);
 754                 mutex_unlock(&snd_card_mutex);
 755         }
 756 }
 757 #endif
 758
 759 int __init snd_card_info_init(void)
 760 {
 761         struct snd_info_entry *entry;
 762
 763         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 764         if (! entry)
 765                 return -ENOMEM;
 766         entry->c.text.read = snd_card_info_read;
 767         if (snd_info_register(entry) < 0) {
 768                 snd_info_free_entry(entry);
 769                 return -ENOMEM;
 770         }
 771         snd_card_info_entry = entry;
 772
 773 #ifdef MODULE
 774         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 775         if (entry) {
 776                 entry->c.text.read = snd_card_module_info_read;
 777                 if (snd_info_register(entry) < 0)
 778                         snd_info_free_entry(entry);
 779                 else
 780                         snd_card_module_info_entry = entry;
 781         }
 782 #endif
 783
 784         return 0;
 785 }
 786
 787 int __exit snd_card_info_done(void)
 788 {
 789         snd_info_free_entry(snd_card_info_entry);
 790 #ifdef MODULE
 791         snd_info_free_entry(snd_card_module_info_entry);
 792 #endif
 793         return 0;
 794 }
 795
 796 #endif /* CONFIG_PROC_FS */
 797
 798 /**
 799  *  snd_component_add - add a component string
 800  *  @card: soundcard structure
 801  *  @component: the component id string
 802  *
 803  *  This function adds the component id string to the supported list.
 804  *  The component can be referred from the alsa-lib.
 805  *
 806  *  Returns zero otherwise a negative error code.
 807  */
 808
 809 int snd_component_add(struct snd_card *card, const char *component)
 810 {
 811         char *ptr;
 812         int len = strlen(component);
 813
 814         ptr = strstr(card->components, component);
 815         if (ptr != NULL) {
 816                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 817                         return 1;
 818         }
 819         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 820                 snd_BUG();
 821                 return -ENOMEM;
 822         }
 823         if (card->components[0] != '\0')
 824                 strcat(card->components, " ");
 825         strcat(card->components, component);
 826         return 0;
 827 }
 828
 829 EXPORT_SYMBOL(snd_component_add);
 830
 831 /**
 832  *  snd_card_file_add - add the file to the file list of the card
 833  *  @card: soundcard structure
 834  *  @file: file pointer
 835  *
 836  *  This function adds the file to the file linked-list of the card.
 837  *  This linked-list is used to keep tracking the connection state,
 838  *  and to avoid the release of busy resources by hotplug.
 839  *
 840  *  Returns zero or a negative error code.
 841  */
 842 int snd_card_file_add(struct snd_card *card, struct file *file)
 843 {
 844         struct snd_monitor_file *mfile;
 845
 846         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 847         if (mfile == NULL)
 848                 return -ENOMEM;
 849         mfile->file = file;
 850         mfile->disconnected_f_op = NULL;
 851         spin_lock(&card->files_lock);
 852         if (card->shutdown) {
 853                 spin_unlock(&card->files_lock);
 854                 kfree(mfile);
 855                 return -ENODEV;
 856         }
 857         list_add(&mfile->list, &card->files_list);
 858         spin_unlock(&card->files_lock);
 859         return 0;
 860 }
 861
 862 EXPORT_SYMBOL(snd_card_file_add);
 863
 864 /**
 865  *  snd_card_file_remove - remove the file from the file list
 866  *  @card: soundcard structure
 867  *  @file: file pointer
 868  *
 869  *  This function removes the file formerly added to the card via
 870  *  snd_card_file_add() function.
 871  *  If all files are removed and snd_card_free_when_closed() was
 872  *  called beforehand, it processes the pending release of
 873  *  resources.
 874  *
 875  *  Returns zero or a negative error code.
 876  */
 877 int snd_card_file_remove(struct snd_card *card, struct file *file)
 878 {
 879         struct snd_monitor_file *mfile, *found = NULL;
 880         int last_close = 0;
 881
 882         spin_lock(&card->files_lock);
 883         list_for_each_entry(mfile, &card->files_list, list) {
 884                 if (mfile->file == file) {
 885                         list_del(&mfile->list);
 886                         if (mfile->disconnected_f_op)
 887                                 fops_put(mfile->disconnected_f_op);
 888                         found = mfile;
 889                         break;
 890                 }
 891         }
 892         if (list_empty(&card->files_list))
 893                 last_close = 1;
 894         spin_unlock(&card->files_lock);
 895         if (last_close) {
 896                 wake_up(&card->shutdown_sleep);
 897                 if (card->free_on_last_close)
 898                         snd_card_do_free(card);
 899         }
 900         if (!found) {
 901                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 902                 return -ENOENT;
 903         }
 904         kfree(found);
 905         return 0;
 906 }
 907
 908 EXPORT_SYMBOL(snd_card_file_remove);
 909
 910 #ifdef CONFIG_PM
 911 /**
 912  *  snd_power_wait - wait until the power-state is changed.
 913  *  @card: soundcard structure
 914  *  @power_state: expected power state
 915  *
 916  *  Waits until the power-state is changed.
 917  *
 918  *  Note: the power lock must be active before call.
 919  */
 920 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 921 {
 922         wait_queue_t wait;
 923         int result = 0;
 924
 925         /* fastpath */
 926         if (snd_power_get_state(card) == power_state)
 927                 return 0;
 928         init_waitqueue_entry(&wait, current);
 929         add_wait_queue(&card->power_sleep, &wait);
 930         while (1) {
 931                 if (card->shutdown) {
 932                         result = -ENODEV;
 933                         break;
 934                 }
 935                 if (snd_power_get_state(card) == power_state)
 936                         break;
 937                 set_current_state(TASK_UNINTERRUPTIBLE);
 938                 snd_power_unlock(card);
 939                 schedule_timeout(30 * HZ);
 940                 snd_power_lock(card);
 941         }
 942         remove_wait_queue(&card->power_sleep, &wait);
 943         return result;
 944 }
 945
 946 EXPORT_SYMBOL(snd_power_wait);
 947 #endif /* CONFIG_PM */