sound/core/init.c

   1 /*
   2  *  Initialization routines
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/sched.h>
  25 #include <linux/file.h>
  26 #include <linux/slab.h>
  27 #include <linux/time.h>
  28 #include <linux/ctype.h>
  29 #include <linux/pci.h>
  30 #include <linux/pm.h>
  31 #include <sound/core.h>
  32 #include <sound/control.h>
  33 #include <sound/info.h>
  34
  35 struct snd_shutdown_f_ops {
  36         struct file_operations f_ops;
  37         struct snd_shutdown_f_ops *next;
  38 };
  39
  40 unsigned int snd_cards_lock = 0;        /* locked for registering/using */
  41 snd_card_t *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
  42 rwlock_t snd_card_rwlock = RW_LOCK_UNLOCKED;
  43
  44 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  45 int (*snd_mixer_oss_notify_callback)(snd_card_t *card, int free_flag);
  46 #endif
  47
  48 static void snd_card_id_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
  49 {
  50         snd_iprintf(buffer, "%s\n", entry->card->id);
  51 }
  52
  53 static void snd_card_free_thread(void * __card);
  54
  55 /**
  56  *  snd_card_new - create and initialize a soundcard structure
  57  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
  58  *  @xid: card identification (ASCII string)
  59  *  @module: top level module for locking
  60  *  @extra_size: allocate this extra size after the main soundcard structure
  61  *
  62  *  Creates and initializes a soundcard structure.
  63  *
  64  *  Returns kmallocated snd_card_t structure. Creates the ALSA control interface
  65  *  (which is blocked until snd_card_register function is called).
  66  */
  67 snd_card_t *snd_card_new(int idx, const char *xid,
  68                          struct module *module, int extra_size)
  69 {
  70         snd_card_t *card;
  71         int err;
  72
  73         if (extra_size < 0)
  74                 extra_size = 0;
  75         card = kcalloc(1, sizeof(*card) + extra_size, GFP_KERNEL);
  76         if (card == NULL)
  77                 return NULL;
  78         if (xid) {
  79                 if (!snd_info_check_reserved_words(xid))
  80                         goto __error;
  81                 strlcpy(card->id, xid, sizeof(card->id));
  82         }
  83         err = 0;
  84         write_lock(&snd_card_rwlock);
  85         if (idx < 0) {
  86                 int idx2;
  87                 for (idx2 = 0; idx2 < snd_ecards_limit; idx2++)
  88                         if (!(snd_cards_lock & (1 << idx2))) {
  89                                 idx = idx2;
  90                                 break;
  91                         }
  92                 if (idx < 0 && snd_ecards_limit < SNDRV_CARDS)
  93                         /* for dynamically additional devices like hotplug:
  94                          * increment the limit if still free slot exists.
  95                          */
  96                         idx = snd_ecards_limit++;
  97         } else if (idx < snd_ecards_limit) {
  98                 if (snd_cards_lock & (1 << idx))
  99                         err = -ENODEV;  /* invalid */
 100         } else if (idx < SNDRV_CARDS)
 101                 snd_ecards_limit = idx + 1; /* increase the limit */
 102         else
 103                 err = -ENODEV;
 104         if (idx < 0 || err < 0) {
 105                 write_unlock(&snd_card_rwlock);
 106                 snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
 107                 goto __error;
 108         }
 109         snd_cards_lock |= 1 << idx;             /* lock it */
 110         write_unlock(&snd_card_rwlock);
 111         card->number = idx;
 112         card->module = module;
 113         INIT_LIST_HEAD(&card->devices);
 114         init_rwsem(&card->controls_rwsem);
 115         rwlock_init(&card->ctl_files_rwlock);
 116         INIT_LIST_HEAD(&card->controls);
 117         INIT_LIST_HEAD(&card->ctl_files);
 118         spin_lock_init(&card->files_lock);
 119         init_waitqueue_head(&card->shutdown_sleep);
 120         INIT_WORK(&card->free_workq, snd_card_free_thread, card);
 121 #ifdef CONFIG_PM
 122         init_MUTEX(&card->power_lock);
 123         init_waitqueue_head(&card->power_sleep);
 124 #endif
 125         /* the control interface cannot be accessed from the user space until */
 126         /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 127         if ((err = snd_ctl_create(card)) < 0) {
 128                 snd_printd("unable to register control minors\n");
 129                 goto __error;
 130         }
 131         if ((err = snd_info_card_create(card)) < 0) {
 132                 snd_printd("unable to create card info\n");
 133                 goto __error_ctl;
 134         }
 135         if (extra_size > 0)
 136                 card->private_data = (char *)card + sizeof(snd_card_t);
 137         return card;
 138
 139       __error_ctl:
 140         snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 141       __error:
 142         kfree(card);
 143         return NULL;
 144 }
 145
 146 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 147 {
 148         return POLLERR | POLLNVAL;
 149 }
 150
 151 /**
 152  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 153  *  @card: soundcard structure
 154  *
 155  *  Disconnects all APIs from the file-operations (user space).
 156  *
 157  *  Returns zero, otherwise a negative error code.
 158  *
 159  *  Note: The current implementation replaces all active file->f_op with special
 160  *        dummy file operations (they do nothing except release).
 161  */
 162 int snd_card_disconnect(snd_card_t * card)
 163 {
 164         struct snd_monitor_file *mfile;
 165         struct file *file;
 166         struct snd_shutdown_f_ops *s_f_ops;
 167         struct file_operations *f_ops, *old_f_ops;
 168         int err;
 169
 170         spin_lock(&card->files_lock);
 171         if (card->shutdown) {
 172                 spin_unlock(&card->files_lock);
 173                 return 0;
 174         }
 175         card->shutdown = 1;
 176         spin_unlock(&card->files_lock);
 177
 178         /* phase 1: disable fops (user space) operations for ALSA API */
 179         write_lock(&snd_card_rwlock);
 180         snd_cards[card->number] = NULL;
 181         write_unlock(&snd_card_rwlock);
 182
 183         /* phase 2: replace file->f_op with special dummy operations */
 184
 185         spin_lock(&card->files_lock);
 186         mfile = card->files;
 187         while (mfile) {
 188                 file = mfile->file;
 189
 190                 /* it's critical part, use endless loop */
 191                 /* we have no room to fail */
 192                 s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
 193                 if (s_f_ops == NULL)
 194                         panic("Atomic allocation failed for snd_shutdown_f_ops!");
 195
 196                 f_ops = &s_f_ops->f_ops;
 197
 198                 memset(f_ops, 0, sizeof(*f_ops));
 199                 f_ops->owner = file->f_op->owner;
 200                 f_ops->release = file->f_op->release;
 201                 f_ops->poll = snd_disconnect_poll;
 202
 203                 s_f_ops->next = card->s_f_ops;
 204                 card->s_f_ops = s_f_ops;
 205
 206                 f_ops = fops_get(f_ops);
 207
 208                 old_f_ops = file->f_op;
 209                 file->f_op = f_ops;     /* must be atomic */
 210                 fops_put(old_f_ops);
 211
 212                 mfile = mfile->next;
 213         }
 214         spin_unlock(&card->files_lock);
 215
 216         /* phase 3: notify all connected devices about disconnection */
 217         /* at this point, they cannot respond to any calls except release() */
 218
 219 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 220         if (snd_mixer_oss_notify_callback)
 221                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 222 #endif
 223
 224         /* notify all devices that we are disconnected */
 225         err = snd_device_disconnect_all(card);
 226         if (err < 0)
 227                 snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 228
 229         return 0;
 230 }
 231
 232 /**
 233  *  snd_card_free - frees given soundcard structure
 234  *  @card: soundcard structure
 235  *
 236  *  This function releases the soundcard structure and the all assigned
 237  *  devices automatically.  That is, you don't have to release the devices
 238  *  by yourself.
 239  *
 240  *  Returns zero. Frees all associated devices and frees the control
 241  *  interface associated to given soundcard.
 242  */
 243 int snd_card_free(snd_card_t * card)
 244 {
 245         struct snd_shutdown_f_ops *s_f_ops;
 246
 247         if (card == NULL)
 248                 return -EINVAL;
 249         write_lock(&snd_card_rwlock);
 250         snd_cards[card->number] = NULL;
 251         write_unlock(&snd_card_rwlock);
 252
 253 #ifdef CONFIG_PM
 254         wake_up(&card->power_sleep);
 255 #ifdef CONFIG_ISA
 256         if (card->pm_dev) {
 257                 pm_unregister(card->pm_dev);
 258                 card->pm_dev = NULL;
 259         }
 260 #endif
 261 #endif
 262
 263         /* wait, until all devices are ready for the free operation */
 264         wait_event(card->shutdown_sleep, card->files == NULL);
 265
 266 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 267         if (snd_mixer_oss_notify_callback)
 268                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 269 #endif
 270         if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 271                 snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 272                 /* Fatal, but this situation should never occur */
 273         }
 274         if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 275                 snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 276                 /* Fatal, but this situation should never occur */
 277         }
 278         if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 279                 snd_printk(KERN_ERR "unable to free all devices (post)\n");
 280                 /* Fatal, but this situation should never occur */
 281         }
 282         if (card->private_free)
 283                 card->private_free(card);
 284         if (card->proc_id)
 285                 snd_info_unregister(card->proc_id);
 286         if (snd_info_card_free(card) < 0) {
 287                 snd_printk(KERN_WARNING "unable to free card info\n");
 288                 /* Not fatal error */
 289         }
 290         while (card->s_f_ops) {
 291                 s_f_ops = card->s_f_ops;
 292                 card->s_f_ops = s_f_ops->next;
 293                 kfree(s_f_ops);
 294         }
 295         write_lock(&snd_card_rwlock);
 296         snd_cards_lock &= ~(1 << card->number);
 297         write_unlock(&snd_card_rwlock);
 298         kfree(card);
 299         return 0;
 300 }
 301
 302 static void snd_card_free_thread(void * __card)
 303 {
 304         snd_card_t *card = __card;
 305         struct module * module = card->module;
 306
 307         if (!try_module_get(module)) {
 308                 snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
 309                 module = NULL;
 310         }
 311
 312         snd_card_free(card);
 313
 314         module_put(module);
 315 }
 316
 317 /**
 318  *  snd_card_free_in_thread - call snd_card_free() in thread
 319  *  @card: soundcard structure
 320  *
 321  *  This function schedules the call of snd_card_free() function in a
 322  *  work queue.  When all devices are released (non-busy), the work
 323  *  is woken up and calls snd_card_free().
 324  *
 325  *  When a card can be disconnected at any time by hotplug service,
 326  *  this function should be used in disconnect (or detach) callback
 327  *  instead of calling snd_card_free() directly.
 328  *
 329  *  Returns - zero otherwise a negative error code if the start of thread failed.
 330  */
 331 int snd_card_free_in_thread(snd_card_t * card)
 332 {
 333         if (card->files == NULL) {
 334                 snd_card_free(card);
 335                 return 0;
 336         }
 337
 338         if (schedule_work(&card->free_workq))
 339                 return 0;
 340
 341         snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
 342         /* try to free the structure immediately */
 343         snd_card_free(card);
 344         return -EFAULT;
 345 }
 346
 347 static void choose_default_id(snd_card_t * card)
 348 {
 349         int i, len, idx_flag = 0, loops = 8;
 350         char *id, *spos;
 351
 352         id = spos = card->shortname;
 353         while (*id != '\0') {
 354                 if (*id == ' ')
 355                         spos = id + 1;
 356                 id++;
 357         }
 358         id = card->id;
 359         while (*spos != '\0' && !isalnum(*spos))
 360                 spos++;
 361         if (isdigit(*spos))
 362                 *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 363         while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 364                 if (isalnum(*spos))
 365                         *id++ = *spos;
 366                 spos++;
 367         }
 368         *id = '\0';
 369
 370         id = card->id;
 371
 372         if (*id == '\0')
 373                 strcpy(id, "default");
 374
 375         while (1) {
 376                 if (loops-- == 0) {
 377                         snd_printk(KERN_ERR "unable to choose default card id (%s)", id);
 378                         strcpy(card->id, card->proc_root->name);
 379                         return;
 380                 }
 381                 if (!snd_info_check_reserved_words(id))
 382                         goto __change;
 383                 for (i = 0; i < snd_ecards_limit; i++) {
 384                         if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 385                                 goto __change;
 386                 }
 387                 break;
 388
 389               __change:
 390                 len = strlen(id);
 391                 if (idx_flag)
 392                         id[len-1]++;
 393                 else if ((size_t)len <= sizeof(card->id) - 3) {
 394                         strcat(id, "_1");
 395                         idx_flag++;
 396                 } else {
 397                         spos = id + len - 2;
 398                         if ((size_t)len <= sizeof(card->id) - 2)
 399                                 spos++;
 400                         *spos++ = '_';
 401                         *spos++ = '1';
 402                         *spos++ = '\0';
 403                         idx_flag++;
 404                 }
 405         }
 406 }
 407
 408 /**
 409  *  snd_card_register - register the soundcard
 410  *  @card: soundcard structure
 411  *
 412  *  This function registers all the devices assigned to the soundcard.
 413  *  Until calling this, the ALSA control interface is blocked from the
 414  *  external accesses.  Thus, you should call this function at the end
 415  *  of the initialization of the card.
 416  *
 417  *  Returns zero otherwise a negative error code if the registrain failed.
 418  */
 419 int snd_card_register(snd_card_t * card)
 420 {
 421         int err;
 422         snd_info_entry_t *entry;
 423
 424         snd_runtime_check(card != NULL, return -EINVAL);
 425         if ((err = snd_device_register_all(card)) < 0)
 426                 return err;
 427         write_lock(&snd_card_rwlock);
 428         if (snd_cards[card->number]) {
 429                 /* already registered */
 430                 write_unlock(&snd_card_rwlock);
 431                 return 0;
 432         }
 433         if (card->id[0] == '\0')
 434                 choose_default_id(card);
 435         snd_cards[card->number] = card;
 436         write_unlock(&snd_card_rwlock);
 437         if ((err = snd_info_card_register(card)) < 0) {
 438                 snd_printd("unable to create card info\n");
 439                 goto __skip_info;
 440         }
 441         if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 442                 snd_printd("unable to create card entry\n");
 443                 goto __skip_info;
 444         }
 445         entry->c.text.read_size = PAGE_SIZE;
 446         entry->c.text.read = snd_card_id_read;
 447         if (snd_info_register(entry) < 0) {
 448                 snd_info_free_entry(entry);
 449                 entry = NULL;
 450         }
 451         card->proc_id = entry;
 452       __skip_info:
 453 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 454         if (snd_mixer_oss_notify_callback)
 455                 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 456 #endif
 457         return 0;
 458 }
 459
 460 static snd_info_entry_t *snd_card_info_entry = NULL;
 461
 462 static void snd_card_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 463 {
 464         int idx, count;
 465         snd_card_t *card;
 466
 467         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 468                 read_lock(&snd_card_rwlock);
 469                 if ((card = snd_cards[idx]) != NULL) {
 470                         count++;
 471                         snd_iprintf(buffer, "%i [%-15s]: %s - %s\n",
 472                                         idx,
 473                                         card->id,
 474                                         card->driver,
 475                                         card->shortname);
 476                         snd_iprintf(buffer, "                     %s\n",
 477                                         card->longname);
 478                 }
 479                 read_unlock(&snd_card_rwlock);
 480         }
 481         if (!count)
 482                 snd_iprintf(buffer, "--- no soundcards ---\n");
 483 }
 484
 485 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
 486
 487 void snd_card_info_read_oss(snd_info_buffer_t * buffer)
 488 {
 489         int idx, count;
 490         snd_card_t *card;
 491
 492         for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 493                 read_lock(&snd_card_rwlock);
 494                 if ((card = snd_cards[idx]) != NULL) {
 495                         count++;
 496                         snd_iprintf(buffer, "%s\n", card->longname);
 497                 }
 498                 read_unlock(&snd_card_rwlock);
 499         }
 500         if (!count) {
 501                 snd_iprintf(buffer, "--- no soundcards ---\n");
 502         }
 503 }
 504
 505 #endif
 506
 507 #ifdef MODULE
 508 static snd_info_entry_t *snd_card_module_info_entry;
 509 static void snd_card_module_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
 510 {
 511         int idx;
 512         snd_card_t *card;
 513
 514         for (idx = 0; idx < SNDRV_CARDS; idx++) {
 515                 read_lock(&snd_card_rwlock);
 516                 if ((card = snd_cards[idx]) != NULL)
 517                         snd_iprintf(buffer, "%i %s\n", idx, card->module->name);
 518                 read_unlock(&snd_card_rwlock);
 519         }
 520 }
 521 #endif
 522
 523 int __init snd_card_info_init(void)
 524 {
 525         snd_info_entry_t *entry;
 526
 527         entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 528         snd_runtime_check(entry != NULL, return -ENOMEM);
 529         entry->c.text.read_size = PAGE_SIZE;
 530         entry->c.text.read = snd_card_info_read;
 531         if (snd_info_register(entry) < 0) {
 532                 snd_info_free_entry(entry);
 533                 return -ENOMEM;
 534         }
 535         snd_card_info_entry = entry;
 536
 537 #ifdef MODULE
 538         entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 539         if (entry) {
 540                 entry->c.text.read_size = PAGE_SIZE;
 541                 entry->c.text.read = snd_card_module_info_read;
 542                 if (snd_info_register(entry) < 0)
 543                         snd_info_free_entry(entry);
 544                 else
 545                         snd_card_module_info_entry = entry;
 546         }
 547 #endif
 548
 549         return 0;
 550 }
 551
 552 int __exit snd_card_info_done(void)
 553 {
 554         if (snd_card_info_entry)
 555                 snd_info_unregister(snd_card_info_entry);
 556 #ifdef MODULE
 557         if (snd_card_module_info_entry)
 558                 snd_info_unregister(snd_card_module_info_entry);
 559 #endif
 560         return 0;
 561 }
 562
 563 /**
 564  *  snd_component_add - add a component string
 565  *  @card: soundcard structure
 566  *  @component: the component id string
 567  *
 568  *  This function adds the component id string to the supported list.
 569  *  The component can be referred from the alsa-lib.
 570  *
 571  *  Returns zero otherwise a negative error code.
 572  */
 573
 574 int snd_component_add(snd_card_t *card, const char *component)
 575 {
 576         char *ptr;
 577         int len = strlen(component);
 578
 579         ptr = strstr(card->components, component);
 580         if (ptr != NULL) {
 581                 if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 582                         return 1;
 583         }
 584         if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 585                 snd_BUG();
 586                 return -ENOMEM;
 587         }
 588         if (card->components[0] != '\0')
 589                 strcat(card->components, " ");
 590         strcat(card->components, component);
 591         return 0;
 592 }
 593
 594 /**
 595  *  snd_card_file_add - add the file to the file list of the card
 596  *  @card: soundcard structure
 597  *  @file: file pointer
 598  *
 599  *  This function adds the file to the file linked-list of the card.
 600  *  This linked-list is used to keep tracking the connection state,
 601  *  and to avoid the release of busy resources by hotplug.
 602  *
 603  *  Returns zero or a negative error code.
 604  */
 605 int snd_card_file_add(snd_card_t *card, struct file *file)
 606 {
 607         struct snd_monitor_file *mfile;
 608
 609         mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 610         if (mfile == NULL)
 611                 return -ENOMEM;
 612         mfile->file = file;
 613         mfile->next = NULL;
 614         spin_lock(&card->files_lock);
 615         if (card->shutdown) {
 616                 spin_unlock(&card->files_lock);
 617                 kfree(mfile);
 618                 return -ENODEV;
 619         }
 620         mfile->next = card->files;
 621         card->files = mfile;
 622         spin_unlock(&card->files_lock);
 623         return 0;
 624 }
 625
 626 /**
 627  *  snd_card_file_remove - remove the file from the file list
 628  *  @card: soundcard structure
 629  *  @file: file pointer
 630  *
 631  *  This function removes the file formerly added to the card via
 632  *  snd_card_file_add() function.
 633  *  If all files are removed and the release of the card is
 634  *  scheduled, it will wake up the the thread to call snd_card_free()
 635  *  (see snd_card_free_in_thread() function).
 636  *
 637  *  Returns zero or a negative error code.
 638  */
 639 int snd_card_file_remove(snd_card_t *card, struct file *file)
 640 {
 641         struct snd_monitor_file *mfile, *pfile = NULL;
 642
 643         spin_lock(&card->files_lock);
 644         mfile = card->files;
 645         while (mfile) {
 646                 if (mfile->file == file) {
 647                         if (pfile)
 648                                 pfile->next = mfile->next;
 649                         else
 650                                 card->files = mfile->next;
 651                         break;
 652                 }
 653                 pfile = mfile;
 654                 mfile = mfile->next;
 655         }
 656         spin_unlock(&card->files_lock);
 657         if (card->files == NULL)
 658                 wake_up(&card->shutdown_sleep);
 659         if (!mfile) {
 660                 snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 661                 return -ENOENT;
 662         }
 663         kfree(mfile);
 664         return 0;
 665 }
 666
 667 #ifdef CONFIG_PM
 668 /**
 669  *  snd_power_wait - wait until the power-state is changed.
 670  *  @card: soundcard structure
 671  *  @power_state: expected power state
 672  *  @file: file structure for the O_NONBLOCK check (optional)
 673  *
 674  *  Waits until the power-state is changed.
 675  *
 676  *  Note: the power lock must be active before call.
 677  */
 678 int snd_power_wait(snd_card_t *card, unsigned int power_state, struct file *file)
 679 {
 680         wait_queue_t wait;
 681         int result = 0;
 682
 683         /* fastpath */
 684         if (snd_power_get_state(card) == power_state)
 685                 return 0;
 686         init_waitqueue_entry(&wait, current);
 687         add_wait_queue(&card->power_sleep, &wait);
 688         while (1) {
 689                 if (card->shutdown) {
 690                         result = -ENODEV;
 691                         break;
 692                 }
 693                 if (snd_power_get_state(card) == power_state)
 694                         break;
 695 #if 0 /* block all devices */
 696                 if (file && (file->f_flags & O_NONBLOCK)) {
 697                         result = -EAGAIN;
 698                         break;
 699                 }
 700 #endif
 701                 set_current_state(TASK_UNINTERRUPTIBLE);
 702                 snd_power_unlock(card);
 703                 schedule_timeout(30 * HZ);
 704                 snd_power_lock(card);
 705         }
 706         remove_wait_queue(&card->power_sleep, &wait);
 707         return result;
 708 }
 709
 710 /**
 711  * snd_card_set_pm_callback - set the PCI power-management callbacks
 712  * @card: soundcard structure
 713  * @suspend: suspend callback function
 714  * @resume: resume callback function
 715  * @private_data: private data to pass to the callback functions
 716  *
 717  * Sets the power-management callback functions of the card.
 718  * These callbacks are called from ALSA's common PCI suspend/resume
 719  * handler and from the control API.
 720  */
 721 int snd_card_set_pm_callback(snd_card_t *card,
 722                              int (*suspend)(snd_card_t *, unsigned int),
 723                              int (*resume)(snd_card_t *, unsigned int),
 724                              void *private_data)
 725 {
 726         card->pm_suspend = suspend;
 727         card->pm_resume = resume;
 728         card->pm_private_data = private_data;
 729         return 0;
 730 }
 731
 732 static int snd_generic_pm_callback(struct pm_dev *dev, pm_request_t rqst, void *data)
 733 {
 734         snd_card_t *card = dev->data;
 735
 736         switch (rqst) {
 737         case PM_SUSPEND:
 738                 if (card->power_state == SNDRV_CTL_POWER_D3hot)
 739                         break;
 740                 /* FIXME: the correct state value? */
 741                 card->pm_suspend(card, 0);
 742                 snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
 743                 break;
 744         case PM_RESUME:
 745                 if (card->power_state == SNDRV_CTL_POWER_D0)
 746                         break;
 747                 /* FIXME: the correct state value? */
 748                 card->pm_resume(card, 0);
 749                 snd_power_change_state(card, SNDRV_CTL_POWER_D0);
 750                 break;
 751         }
 752         return 0;
 753 }
 754
 755 /**
 756  * snd_card_set_dev_pm_callback - set the generic power-management callbacks
 757  * @card: soundcard structure
 758  * @type: PM device type (PM_XXX)
 759  * @suspend: suspend callback function
 760  * @resume: resume callback function
 761  * @private_data: private data to pass to the callback functions
 762  *
 763  * Registers the power-management and sets the lowlevel callbacks for
 764  * the given card with the given PM type.  These callbacks are called
 765  * from the ALSA's common PM handler and from the control API.
 766  */
 767 int snd_card_set_dev_pm_callback(snd_card_t *card, int type,
 768                                  int (*suspend)(snd_card_t *, unsigned int),
 769                                  int (*resume)(snd_card_t *, unsigned int),
 770                                  void *private_data)
 771 {
 772         card->pm_dev = pm_register(type, 0, snd_generic_pm_callback);
 773         if (! card->pm_dev)
 774                 return -ENOMEM;
 775         card->pm_dev->data = card;
 776         snd_card_set_pm_callback(card, suspend, resume, private_data);
 777         return 0;
 778 }
 779
 780 #ifdef CONFIG_PCI
 781 int snd_card_pci_suspend(struct pci_dev *dev, u32 state)
 782 {
 783         snd_card_t *card = pci_get_drvdata(dev);
 784         int err;
 785         if (! card || ! card->pm_suspend)
 786                 return 0;
 787         if (card->power_state == SNDRV_CTL_POWER_D3hot)
 788                 return 0;
 789         /* FIXME: correct state value? */
 790         err = card->pm_suspend(card, 0);
 791         pci_save_state(dev);
 792         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
 793         return err;
 794 }
 795
 796 int snd_card_pci_resume(struct pci_dev *dev)
 797 {
 798         snd_card_t *card = pci_get_drvdata(dev);
 799         if (! card || ! card->pm_resume)
 800                 return 0;
 801         if (card->power_state == SNDRV_CTL_POWER_D0)
 802                 return 0;
 803         /* restore the PCI config space */
 804         pci_restore_state(dev);
 805         /* FIXME: correct state value? */
 806         card->pm_resume(card, 0);
 807         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
 808         return 0;
 809 }
 810 #endif
 811
 812 #endif /* CONFIG_PM */