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/device.h>
  26 #include <linux/file.h>
  27 #include <linux/slab.h>
  28 #include <linux/time.h>
  29 #include <linux/ctype.h>
  30 #include <linux/pm.h>
  31
  32 #include <sound/core.h>
  33 #include <sound/control.h>
  34 #include <sound/info.h>
  35
  36 /* monitor files for graceful shutdown (hotplug) */
  37 struct snd_monitor_file {
  38         struct file *file;
  39         const struct file_operations *disconnected_f_op;
  40         struct list_head shutdown_list; /* still need to shutdown */
  41         struct list_head list;  /* link of monitor files */
  42 };
  43
  44 static DEFINE_SPINLOCK(shutdown_lock);
  45 static LIST_HEAD(shutdown_files);
  46
  47 static const struct file_operations snd_shutdown_f_ops;
  48
  49 /* locked for registering/using */
  50 static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
  51 struct snd_card *snd_cards[SNDRV_CARDS];
  52 EXPORT_SYMBOL(snd_cards);
  53
  54 static DEFINE_MUTEX(snd_card_mutex);
  55
  56 static char *slots[SNDRV_CARDS];
  57 module_param_array(slots, charp, NULL, 0444);
  58 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
  59
  60 /* return non-zero if the given index is reserved for the given
  61  * module via slots option
  62  */
  63 static int module_slot_match(struct module *module, int idx)
  64 {
  65         int match = 1;
  66 #ifdef MODULE
  67         const char *s1, *s2;
  68
  69         if (!module || !*module->name || !slots[idx])
  70                 return 0;
  71
  72         s1 = module->name;
  73         s2 = slots[idx];
  74         if (*s2 == '!') {
  75                 match = 0; /* negative match */
  76                 s2++;
  77         }
  78         /* compare module name strings
  79          * hyphens are handled as equivalent with underscore
  80          */
  81         for (;;) {
  82                 char c1 = *s1++;
  83                 char c2 = *s2++;
  84                 if (c1 == '-')
  85                         c1 = '_';
  86                 if (c2 == '-')
  87                         c2 = '_';
  88                 if (c1 != c2)
  89                         return !match;
  90                 if (!c1)
  91                         break;
  92         }
  93 #endif /* MODULE */
  94         return match;
  95 }
  96
  97 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  98 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  99 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
 100 #endif
 101
 102 #ifdef CONFIG_PROC_FS
 103 static void snd_card_id_read(struct snd_info_entry *entry,
 104                              struct snd_info_buffer *buffer)
 105 {
 106         snd_iprintf(buffer, "%s\n", entry->card->id);
 107 }
 108
 109 static inline int init_info_for_card(struct snd_card *card)
 110 {
 111         int err;
 112         struct snd_info_entry *entry;
 113
 114         if ((err = snd_info_card_register(card)) < 0) {
 115                 snd_printd("unable to create card info\n");
 116                 return err;
 117         }
 118         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 119                 snd_printd("unable to create card entry\n");
 120                 return err;
 121         }
 122         entry->c.text.read = snd_card_id_read;
 123         if (snd_info_register(entry) < 0) {
 124                 snd_info_free_entry(entry);
 125                 entry = NULL;
 126         }
 127         card->proc_id = entry;
 128         return 0;
 129 }
 130 #else /* !CONFIG_PROC_FS */
 131 #define init_info_for_card(card)
 132 #endif
 133
 134 /**
 135  *  snd_card_create - create and initialize a soundcard structure
 136  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
 137  *  @xid: card identification (ASCII string)
 138  *  @module: top level module for locking
 139  *  @extra_size: allocate this extra size after the main soundcard structure
 140  *  @card_ret: the pointer to store the created card instance
 141  *
 142  *  Creates and initializes a soundcard structure.
 143  *
 144  *  The function allocates snd_card instance via kzalloc with the given
 145  *  space for the driver to use freely.  The allocated struct is stored
 146  *  in the given card_ret pointer.
 147  *
 148  *  Return: Zero if successful or a negative error code.
 149  */
 150 int snd_card_create(int idx, const char *xid,
 151                     struct module *module, int extra_size,
 152                     struct snd_card **card_ret)
 153 {
 154         struct snd_card *card;
 155         int err, idx2;
 156
 157         if (snd_BUG_ON(!card_ret))
 158                 return -EINVAL;
 159         *card_ret = NULL;
 160
 161         if (extra_size < 0)
 162                 extra_size = 0;
 163         card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
 164         if (!card)
 165                 return -ENOMEM;
 166         if (xid)
 167                 strlcpy(card->id, xid, sizeof(card->id));
 168         err = 0;
 169         mutex_lock(&snd_card_mutex);
 170         if (idx < 0) {
 171                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
 172                         /* idx == -1 == 0xffff means: take any free slot */
 173                         if (idx2 < sizeof(int) && !(idx & (1U << idx2)))
 174                                 continue;
 175                         if (!test_bit(idx2, snd_cards_lock)) {
 176                                 if (module_slot_match(module, idx2)) {
 177                                         idx = idx2;
 178                                         break;
 179                                 }
 180                         }
 181                 }
 182         }
 183         if (idx < 0) {
 184                 for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
 185                         /* idx == -1 == 0xffff means: take any free slot */
 186                         if (idx2 < sizeof(int) && !(idx & (1U << idx2)))
 187                                 continue;
 188                         if (!test_bit(idx2, snd_cards_lock)) {
 189                                 if (!slots[idx2] || !*slots[idx2]) {
 190                                         idx = idx2;
 191                                         break;
 192                                 }
 193                         }
 194                 }
 195         }
 196         if (idx < 0)
 197                 err = -ENODEV;
 198         else if (idx < snd_ecards_limit) {
 199                 if (test_bit(idx, snd_cards_lock))
 200                         err = -EBUSY;   /* invalid */
 201         } else if (idx >= SNDRV_CARDS)
 202                 err = -ENODEV;
 203         if (err < 0) {
 204                 mutex_unlock(&snd_card_mutex);
 205                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
 206                          idx, snd_ecards_limit - 1, err);
 207                 goto __error;
 208         }
 209         set_bit(idx, snd_cards_lock);           /* lock it */
 210         if (idx >= snd_ecards_limit)
 211                 snd_ecards_limit = idx + 1; /* increase the limit */
 212         mutex_unlock(&snd_card_mutex);
 213         card->number = idx;
 214         card->module = module;
 215         INIT_LIST_HEAD(&card->devices);
 216         init_rwsem(&card->controls_rwsem);
 217         rwlock_init(&card->ctl_files_rwlock);
 218         INIT_LIST_HEAD(&card->controls);
 219         INIT_LIST_HEAD(&card->ctl_files);
 220         spin_lock_init(&card->files_lock);
 221         INIT_LIST_HEAD(&card->files_list);
 222         init_waitqueue_head(&card->shutdown_sleep);
 223         atomic_set(&card->refcount, 0);
 224 #ifdef CONFIG_PM
 225         mutex_init(&card->power_lock);
 226         init_waitqueue_head(&card->power_sleep);
 227 #endif
 228         /* the control interface cannot be accessed from the user space until */
 229         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 230         err = snd_ctl_create(card);
 231         if (err < 0) {
 232                 snd_printk(KERN_ERR "unable to register control minors\n");
 233                 goto __error;
 234         }
 235         err = snd_info_card_create(card);
 236         if (err < 0) {
 237                 snd_printk(KERN_ERR "unable to create card info\n");
 238                 goto __error_ctl;
 239         }
 240         if (extra_size > 0)
 241                 card->private_data = (char *)card + sizeof(struct snd_card);
 242         *card_ret = card;
 243         return 0;
 244
 245       __error_ctl:
 246         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 247       __error:
 248         kfree(card);
 249         return err;
 250 }
 251 EXPORT_SYMBOL(snd_card_create);
 252
 253 /* return non-zero if a card is already locked */
 254 int snd_card_locked(int card)
 255 {
 256         int locked;
 257
 258         mutex_lock(&snd_card_mutex);
 259         locked = test_bit(card, snd_cards_lock);
 260         mutex_unlock(&snd_card_mutex);
 261         return locked;
 262 }
 263
 264 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 265 {
 266         return -ENODEV;
 267 }
 268
 269 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 270                                    size_t count, loff_t *offset)
 271 {
 272         return -ENODEV;
 273 }
 274
 275 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 276                                     size_t count, loff_t *offset)
 277 {
 278         return -ENODEV;
 279 }
 280
 281 static int snd_disconnect_release(struct inode *inode, struct file *file)
 282 {
 283         struct snd_monitor_file *df = NULL, *_df;
 284
 285         spin_lock(&shutdown_lock);
 286         list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 287                 if (_df->file == file) {
 288                         df = _df;
 289                         list_del_init(&df->shutdown_list);
 290                         break;
 291                 }
 292         }
 293         spin_unlock(&shutdown_lock);
 294
 295         if (likely(df)) {
 296                 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
 297                         df->disconnected_f_op->fasync(-1, file, 0);
 298                 return df->disconnected_f_op->release(inode, file);
 299         }
 300
 301         panic("%s(%p, %p) failed!", __func__, inode, file);
 302 }
 303
 304 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 305 {
 306         return POLLERR | POLLNVAL;
 307 }
 308
 309 static long snd_disconnect_ioctl(struct file *file,
 310                                  unsigned int cmd, unsigned long arg)
 311 {
 312         return -ENODEV;
 313 }
 314
 315 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 316 {
 317         return -ENODEV;
 318 }
 319
 320 static int snd_disconnect_fasync(int fd, struct file *file, int on)
 321 {
 322         return -ENODEV;
 323 }
 324
 325 static const struct file_operations snd_shutdown_f_ops =
 326 {
 327         .owner =        THIS_MODULE,
 328         .llseek =       snd_disconnect_llseek,
 329         .read =         snd_disconnect_read,
 330         .write =        snd_disconnect_write,
 331         .release =      snd_disconnect_release,
 332         .poll =         snd_disconnect_poll,
 333         .unlocked_ioctl = snd_disconnect_ioctl,
 334 #ifdef CONFIG_COMPAT
 335         .compat_ioctl = snd_disconnect_ioctl,
 336 #endif
 337         .mmap =         snd_disconnect_mmap,
 338         .fasync =       snd_disconnect_fasync
 339 };
 340
 341 /**
 342  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 343  *  @card: soundcard structure
 344  *
 345  *  Disconnects all APIs from the file-operations (user space).
 346  *
 347  *  Return: Zero, otherwise a negative error code.
 348  *
 349  *  Note: The current implementation replaces all active file->f_op with special
 350  *        dummy file operations (they do nothing except release).
 351  */
 352 int snd_card_disconnect(struct snd_card *card)
 353 {
 354         struct snd_monitor_file *mfile;
 355         int err;
 356
 357         if (!card)
 358                 return -EINVAL;
 359
 360         spin_lock(&card->files_lock);
 361         if (card->shutdown) {
 362                 spin_unlock(&card->files_lock);
 363                 return 0;
 364         }
 365         card->shutdown = 1;
 366         spin_unlock(&card->files_lock);
 367
 368         /* phase 1: disable fops (user space) operations for ALSA API */
 369         mutex_lock(&snd_card_mutex);
 370         snd_cards[card->number] = NULL;
 371         clear_bit(card->number, snd_cards_lock);
 372         mutex_unlock(&snd_card_mutex);
 373
 374         /* phase 2: replace file->f_op with special dummy operations */
 375
 376         spin_lock(&card->files_lock);
 377         list_for_each_entry(mfile, &card->files_list, list) {
 378                 /* it's critical part, use endless loop */
 379                 /* we have no room to fail */
 380                 mfile->disconnected_f_op = mfile->file->f_op;
 381
 382                 spin_lock(&shutdown_lock);
 383                 list_add(&mfile->shutdown_list, &shutdown_files);
 384                 spin_unlock(&shutdown_lock);
 385
 386                 mfile->file->f_op = &snd_shutdown_f_ops;
 387                 fops_get(mfile->file->f_op);
 388         }
 389         spin_unlock(&card->files_lock);
 390
 391         /* phase 3: notify all connected devices about disconnection */
 392         /* at this point, they cannot respond to any calls except release() */
 393
 394 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 395         if (snd_mixer_oss_notify_callback)
 396                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 397 #endif
 398
 399         /* notify all devices that we are disconnected */
 400         err = snd_device_disconnect_all(card);
 401         if (err < 0)
 402                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 403
 404         snd_info_card_disconnect(card);
 405         if (card->card_dev) {
 406                 device_unregister(card->card_dev);
 407                 card->card_dev = NULL;
 408         }
 409 #ifdef CONFIG_PM
 410         wake_up(&card->power_sleep);
 411 #endif
 412         return 0;
 413 }
 414
 415 EXPORT_SYMBOL(snd_card_disconnect);
 416
 417 /**
 418  *  snd_card_free - frees given soundcard structure
 419  *  @card: soundcard structure
 420  *
 421  *  This function releases the soundcard structure and the all assigned
 422  *  devices automatically.  That is, you don't have to release the devices
 423  *  by yourself.
 424  *
 425  *  Return: Zero. Frees all associated devices and frees the control
 426  *  interface associated to given soundcard.
 427  */
 428 static int snd_card_do_free(struct snd_card *card)
 429 {
 430 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 431         if (snd_mixer_oss_notify_callback)
 432                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 433 #endif
 434         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 435                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 436                 /* Fatal, but this situation should never occur */
 437         }
 438         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 439                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 440                 /* Fatal, but this situation should never occur */
 441         }
 442         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 443                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 444                 /* Fatal, but this situation should never occur */
 445         }
 446         if (card->private_free)
 447                 card->private_free(card);
 448         snd_info_free_entry(card->proc_id);
 449         if (snd_info_card_free(card) < 0) {
 450                 snd_printk(KERN_WARNING "unable to free card info\n");
 451                 /* Not fatal error */
 452         }
 453         kfree(card);
 454         return 0;
 455 }
 456
 457 /**
 458  * snd_card_unref - release the reference counter
 459  * @card: the card instance
 460  *
 461  * Decrements the reference counter.  When it reaches to zero, wake up
 462  * the sleeper and call the destructor if needed.
 463  */
 464 void snd_card_unref(struct snd_card *card)
 465 {
 466         if (atomic_dec_and_test(&card->refcount)) {
 467                 wake_up(&card->shutdown_sleep);
 468                 if (card->free_on_last_close)
 469                         snd_card_do_free(card);
 470         }
 471 }
 472 EXPORT_SYMBOL(snd_card_unref);
 473
 474 int snd_card_free_when_closed(struct snd_card *card)
 475 {
 476         int ret;
 477
 478         atomic_inc(&card->refcount);
 479         ret = snd_card_disconnect(card);
 480         if (ret) {
 481                 atomic_dec(&card->refcount);
 482                 return ret;
 483         }
 484
 485         card->free_on_last_close = 1;
 486         if (atomic_dec_and_test(&card->refcount))
 487                 snd_card_do_free(card);
 488         return 0;
 489 }
 490
 491 EXPORT_SYMBOL(snd_card_free_when_closed);
 492
 493 int snd_card_free(struct snd_card *card)
 494 {
 495         int ret = snd_card_disconnect(card);
 496         if (ret)
 497                 return ret;
 498
 499         /* wait, until all devices are ready for the free operation */
 500         wait_event(card->shutdown_sleep, !atomic_read(&card->refcount));
 501         snd_card_do_free(card);
 502         return 0;
 503 }
 504
 505 EXPORT_SYMBOL(snd_card_free);
 506
 507 /* retrieve the last word of shortname or longname */
 508 static const char *retrieve_id_from_card_name(const char *name)
 509 {
 510         const char *spos = name;
 511
 512         while (*name) {
 513                 if (isspace(*name) && isalnum(name[1]))
 514                         spos = name + 1;
 515                 name++;
 516         }
 517         return spos;
 518 }
 519
 520 /* return true if the given id string doesn't conflict any other card ids */
 521 static bool card_id_ok(struct snd_card *card, const char *id)
 522 {
 523         int i;
 524         if (!snd_info_check_reserved_words(id))
 525                 return false;
 526         for (i = 0; i < snd_ecards_limit; i++) {
 527                 if (snd_cards[i] && snd_cards[i] != card &&
 528                     !strcmp(snd_cards[i]->id, id))
 529                         return false;
 530         }
 531         return true;
 532 }
 533
 534 /* copy to card->id only with valid letters from nid */
 535 static void copy_valid_id_string(struct snd_card *card, const char *src,
 536                                  const char *nid)
 537 {
 538         char *id = card->id;
 539
 540         while (*nid && !isalnum(*nid))
 541                 nid++;
 542         if (isdigit(*nid))
 543                 *id++ = isalpha(*src) ? *src : 'D';
 544         while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 545                 if (isalnum(*nid))
 546                         *id++ = *nid;
 547                 nid++;
 548         }
 549         *id = 0;
 550 }
 551
 552 /* Set card->id from the given string
 553  * If the string conflicts with other ids, add a suffix to make it unique.
 554  */
 555 static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
 556                                     const char *nid)
 557 {
 558         int len, loops;
 559         bool is_default = false;
 560         char *id;
 561
 562         copy_valid_id_string(card, src, nid);
 563         id = card->id;
 564
 565  again:
 566         /* use "Default" for obviously invalid strings
 567          * ("card" conflicts with proc directories)
 568          */
 569         if (!*id || !strncmp(id, "card", 4)) {
 570                 strcpy(id, "Default");
 571                 is_default = true;
 572         }
 573
 574         len = strlen(id);
 575         for (loops = 0; loops < SNDRV_CARDS; loops++) {
 576                 char *spos;
 577                 char sfxstr[5]; /* "_012" */
 578                 int sfxlen;
 579
 580                 if (card_id_ok(card, id))
 581                         return; /* OK */
 582
 583                 /* Add _XYZ suffix */
 584                 sprintf(sfxstr, "_%X", loops + 1);
 585                 sfxlen = strlen(sfxstr);
 586                 if (len + sfxlen >= sizeof(card->id))
 587                         spos = id + sizeof(card->id) - sfxlen - 1;
 588                 else
 589                         spos = id + len;
 590                 strcpy(spos, sfxstr);
 591         }
 592         /* fallback to the default id */
 593         if (!is_default) {
 594                 *id = 0;
 595                 goto again;
 596         }
 597         /* last resort... */
 598         snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
 599         if (card->proc_root->name)
 600                 strcpy(card->id, card->proc_root->name);
 601 }
 602
 603 /**
 604  *  snd_card_set_id - set card identification name
 605  *  @card: soundcard structure
 606  *  @nid: new identification string
 607  *
 608  *  This function sets the card identification and checks for name
 609  *  collisions.
 610  */
 611 void snd_card_set_id(struct snd_card *card, const char *nid)
 612 {
 613         /* check if user specified own card->id */
 614         if (card->id[0] != '\0')
 615                 return;
 616         mutex_lock(&snd_card_mutex);
 617         snd_card_set_id_no_lock(card, nid, nid);
 618         mutex_unlock(&snd_card_mutex);
 619 }
 620 EXPORT_SYMBOL(snd_card_set_id);
 621
 622 static ssize_t
 623 card_id_show_attr(struct device *dev,
 624                   struct device_attribute *attr, char *buf)
 625 {
 626         struct snd_card *card = dev_get_drvdata(dev);
 627         return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 628 }
 629
 630 static ssize_t
 631 card_id_store_attr(struct device *dev, struct device_attribute *attr,
 632                    const char *buf, size_t count)
 633 {
 634         struct snd_card *card = dev_get_drvdata(dev);
 635         char buf1[sizeof(card->id)];
 636         size_t copy = count > sizeof(card->id) - 1 ?
 637                                         sizeof(card->id) - 1 : count;
 638         size_t idx;
 639         int c;
 640
 641         for (idx = 0; idx < copy; idx++) {
 642                 c = buf[idx];
 643                 if (!isalnum(c) && c != '_' && c != '-')
 644                         return -EINVAL;
 645         }
 646         memcpy(buf1, buf, copy);
 647         buf1[copy] = '\0';
 648         mutex_lock(&snd_card_mutex);
 649         if (!card_id_ok(NULL, buf1)) {
 650                 mutex_unlock(&snd_card_mutex);
 651                 return -EEXIST;
 652         }
 653         strcpy(card->id, buf1);
 654         snd_info_card_id_change(card);
 655         mutex_unlock(&snd_card_mutex);
 656
 657         return count;
 658 }
 659
 660 static struct device_attribute card_id_attrs =
 661         __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 662
 663 static ssize_t
 664 card_number_show_attr(struct device *dev,
 665                      struct device_attribute *attr, char *buf)
 666 {
 667         struct snd_card *card = dev_get_drvdata(dev);
 668         return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 669 }
 670
 671 static struct device_attribute card_number_attrs =
 672         __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 673
 674 /**
 675  *  snd_card_register - register the soundcard
 676  *  @card: soundcard structure
 677  *
 678  *  This function registers all the devices assigned to the soundcard.
 679  *  Until calling this, the ALSA control interface is blocked from the
 680  *  external accesses.  Thus, you should call this function at the end
 681  *  of the initialization of the card.
 682  *
 683  *  Return: Zero otherwise a negative error code if the registration failed.
 684  */
 685 int snd_card_register(struct snd_card *card)
 686 {
 687         int err;
 688
 689         if (snd_BUG_ON(!card))
 690                 return -EINVAL;
 691
 692         if (!card->card_dev) {
 693                 card->card_dev = device_create(sound_class, card->dev,
 694                                                MKDEV(0, 0), card,
 695                                                "card%i", card->number);
 696                 if (IS_ERR(card->card_dev))
 697                         card->card_dev = NULL;
 698         }
 699
 700         if ((err = snd_device_register_all(card)) < 0)
 701                 return err;
 702         mutex_lock(&snd_card_mutex);
 703         if (snd_cards[card->number]) {
 704                 /* already registered */
 705                 mutex_unlock(&snd_card_mutex);
 706                 return 0;
 707         }
 708         if (*card->id) {
 709                 /* make a unique id name from the given string */
 710                 char tmpid[sizeof(card->id)];
 711                 memcpy(tmpid, card->id, sizeof(card->id));
 712                 snd_card_set_id_no_lock(card, tmpid, tmpid);
 713         } else {
 714                 /* create an id from either shortname or longname */
 715                 const char *src;
 716                 src = *card->shortname ? card->shortname : card->longname;
 717                 snd_card_set_id_no_lock(card, src,
 718                                         retrieve_id_from_card_name(src));
 719         }
 720         snd_cards[card->number] = card;
 721         mutex_unlock(&snd_card_mutex);
 722         init_info_for_card(card);
 723 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 724         if (snd_mixer_oss_notify_callback)
 725                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 726 #endif
 727         if (card->card_dev) {
 728                 err = device_create_file(card->card_dev, &card_id_attrs);
 729                 if (err < 0)
 730                         return err;
 731                 err = device_create_file(card->card_dev, &card_number_attrs);
 732                 if (err < 0)
 733                         return err;
 734         }
 735
 736         return 0;
 737 }
 738
 739 EXPORT_SYMBOL(snd_card_register);
 740
 741 #ifdef CONFIG_PROC_FS
 742 static struct snd_info_entry *snd_card_info_entry;
 743
 744 static void snd_card_info_read(struct snd_info_entry *entry,
 745                                struct snd_info_buffer *buffer)
 746 {
 747         int idx, count;
 748         struct snd_card *card;
 749
 750         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 751                 mutex_lock(&snd_card_mutex);
 752                 if ((card = snd_cards[idx]) != NULL) {
 753                         count++;
 754                         snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 755                                         idx,
 756                                         card->id,
 757                                         card->driver,
 758                                         card->shortname);
 759                         snd_iprintf(buffer, "                      %s\n",
 760                                         card->longname);
 761                 }
 762                 mutex_unlock(&snd_card_mutex);
 763         }
 764         if (!count)
 765                 snd_iprintf(buffer, "--- no soundcards ---\n");
 766 }
 767
 768 #ifdef CONFIG_SND_OSSEMUL
 769
 770 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 771 {
 772         int idx, count;
 773         struct snd_card *card;
 774
 775         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 776                 mutex_lock(&snd_card_mutex);
 777                 if ((card = snd_cards[idx]) != NULL) {
 778                         count++;
 779                         snd_iprintf(buffer, "%s\n", card->longname);
 780                 }
 781                 mutex_unlock(&snd_card_mutex);
 782         }
 783         if (!count) {
 784                 snd_iprintf(buffer, "--- no soundcards ---\n");
 785         }
 786 }
 787
 788 #endif
 789
 790 #ifdef MODULE
 791 static struct snd_info_entry *snd_card_module_info_entry;
 792 static void snd_card_module_info_read(struct snd_info_entry *entry,
 793                                       struct snd_info_buffer *buffer)
 794 {
 795         int idx;
 796         struct snd_card *card;
 797
 798         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 799                 mutex_lock(&snd_card_mutex);
 800                 if ((card = snd_cards[idx]) != NULL)
 801                         snd_iprintf(buffer, "%2i %s\n",
 802                                     idx, card->module->name);
 803                 mutex_unlock(&snd_card_mutex);
 804         }
 805 }
 806 #endif
 807
 808 int __init snd_card_info_init(void)
 809 {
 810         struct snd_info_entry *entry;
 811
 812         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 813         if (! entry)
 814                 return -ENOMEM;
 815         entry->c.text.read = snd_card_info_read;
 816         if (snd_info_register(entry) < 0) {
 817                 snd_info_free_entry(entry);
 818                 return -ENOMEM;
 819         }
 820         snd_card_info_entry = entry;
 821
 822 #ifdef MODULE
 823         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 824         if (entry) {
 825                 entry->c.text.read = snd_card_module_info_read;
 826                 if (snd_info_register(entry) < 0)
 827                         snd_info_free_entry(entry);
 828                 else
 829                         snd_card_module_info_entry = entry;
 830         }
 831 #endif
 832
 833         return 0;
 834 }
 835
 836 int __exit snd_card_info_done(void)
 837 {
 838         snd_info_free_entry(snd_card_info_entry);
 839 #ifdef MODULE
 840         snd_info_free_entry(snd_card_module_info_entry);
 841 #endif
 842         return 0;
 843 }
 844
 845 #endif /* CONFIG_PROC_FS */
 846
 847 /**
 848  *  snd_component_add - add a component string
 849  *  @card: soundcard structure
 850  *  @component: the component id string
 851  *
 852  *  This function adds the component id string to the supported list.
 853  *  The component can be referred from the alsa-lib.
 854  *
 855  *  Return: Zero otherwise a negative error code.
 856  */
 857
 858 int snd_component_add(struct snd_card *card, const char *component)
 859 {
 860         char *ptr;
 861         int len = strlen(component);
 862
 863         ptr = strstr(card->components, component);
 864         if (ptr != NULL) {
 865                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 866                         return 1;
 867         }
 868         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 869                 snd_BUG();
 870                 return -ENOMEM;
 871         }
 872         if (card->components[0] != '\0')
 873                 strcat(card->components, " ");
 874         strcat(card->components, component);
 875         return 0;
 876 }
 877
 878 EXPORT_SYMBOL(snd_component_add);
 879
 880 /**
 881  *  snd_card_file_add - add the file to the file list of the card
 882  *  @card: soundcard structure
 883  *  @file: file pointer
 884  *
 885  *  This function adds the file to the file linked-list of the card.
 886  *  This linked-list is used to keep tracking the connection state,
 887  *  and to avoid the release of busy resources by hotplug.
 888  *
 889  *  Return: zero or a negative error code.
 890  */
 891 int snd_card_file_add(struct snd_card *card, struct file *file)
 892 {
 893         struct snd_monitor_file *mfile;
 894
 895         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 896         if (mfile == NULL)
 897                 return -ENOMEM;
 898         mfile->file = file;
 899         mfile->disconnected_f_op = NULL;
 900         INIT_LIST_HEAD(&mfile->shutdown_list);
 901         spin_lock(&card->files_lock);
 902         if (card->shutdown) {
 903                 spin_unlock(&card->files_lock);
 904                 kfree(mfile);
 905                 return -ENODEV;
 906         }
 907         list_add(&mfile->list, &card->files_list);
 908         atomic_inc(&card->refcount);
 909         spin_unlock(&card->files_lock);
 910         return 0;
 911 }
 912
 913 EXPORT_SYMBOL(snd_card_file_add);
 914
 915 /**
 916  *  snd_card_file_remove - remove the file from the file list
 917  *  @card: soundcard structure
 918  *  @file: file pointer
 919  *
 920  *  This function removes the file formerly added to the card via
 921  *  snd_card_file_add() function.
 922  *  If all files are removed and snd_card_free_when_closed() was
 923  *  called beforehand, it processes the pending release of
 924  *  resources.
 925  *
 926  *  Return: Zero or a negative error code.
 927  */
 928 int snd_card_file_remove(struct snd_card *card, struct file *file)
 929 {
 930         struct snd_monitor_file *mfile, *found = NULL;
 931
 932         spin_lock(&card->files_lock);
 933         list_for_each_entry(mfile, &card->files_list, list) {
 934                 if (mfile->file == file) {
 935                         list_del(&mfile->list);
 936                         spin_lock(&shutdown_lock);
 937                         list_del(&mfile->shutdown_list);
 938                         spin_unlock(&shutdown_lock);
 939                         if (mfile->disconnected_f_op)
 940                                 fops_put(mfile->disconnected_f_op);
 941                         found = mfile;
 942                         break;
 943                 }
 944         }
 945         spin_unlock(&card->files_lock);
 946         if (!found) {
 947                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 948                 return -ENOENT;
 949         }
 950         kfree(found);
 951         snd_card_unref(card);
 952         return 0;
 953 }
 954
 955 EXPORT_SYMBOL(snd_card_file_remove);
 956
 957 #ifdef CONFIG_PM
 958 /**
 959  *  snd_power_wait - wait until the power-state is changed.
 960  *  @card: soundcard structure
 961  *  @power_state: expected power state
 962  *
 963  *  Waits until the power-state is changed.
 964  *
 965  *  Return: Zero if successful, or a negative error code.
 966  *
 967  *  Note: the power lock must be active before call.
 968  */
 969 int snd_power_wait(struct snd_card *card, unsigned int power_state)
 970 {
 971         wait_queue_t wait;
 972         int result = 0;
 973
 974         /* fastpath */
 975         if (snd_power_get_state(card) == power_state)
 976                 return 0;
 977         init_waitqueue_entry(&wait, current);
 978         add_wait_queue(&card->power_sleep, &wait);
 979         while (1) {
 980                 if (card->shutdown) {
 981                         result = -ENODEV;
 982                         break;
 983                 }
 984                 if (snd_power_get_state(card) == power_state)
 985                         break;
 986                 set_current_state(TASK_UNINTERRUPTIBLE);
 987                 snd_power_unlock(card);
 988                 schedule_timeout(30 * HZ);
 989                 snd_power_lock(card);
 990         }
 991         remove_wait_queue(&card->power_sleep, &wait);
 992         return result;
 993 }
 994
 995 EXPORT_SYMBOL(snd_power_wait);
 996 #endif /* CONFIG_PM */