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