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