git.oblomov.eu Git - linux-2.6/blob - sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   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/threads.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/slab.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/time.h>
  29 #include <sound/core.h>
  30 #include <sound/minors.h>
  31 #include <sound/info.h>
  32 #include <sound/control.h>
  33
  34 /* max number of user-defined controls */
  35 #define MAX_USER_CONTROLS       32
  36
  37 struct snd_kctl_ioctl {
  38         struct list_head list;          /* list of all ioctls */
  39         snd_kctl_ioctl_func_t fioctl;
  40 };
  41
  42 static DECLARE_RWSEM(snd_ioctl_rwsem);
  43 static LIST_HEAD(snd_control_ioctls);
  44 #ifdef CONFIG_COMPAT
  45 static LIST_HEAD(snd_control_compat_ioctls);
  46 #endif
  47
  48 static int snd_ctl_open(struct inode *inode, struct file *file)
  49 {
  50         int cardnum = SNDRV_MINOR_CARD(iminor(inode));
  51         unsigned long flags;
  52         struct snd_card *card;
  53         struct snd_ctl_file *ctl;
  54         int err;
  55
  56         card = snd_cards[cardnum];
  57         if (!card) {
  58                 err = -ENODEV;
  59                 goto __error1;
  60         }
  61         err = snd_card_file_add(card, file);
  62         if (err < 0) {
  63                 err = -ENODEV;
  64                 goto __error1;
  65         }
  66         if (!try_module_get(card->module)) {
  67                 err = -EFAULT;
  68                 goto __error2;
  69         }
  70         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  71         if (ctl == NULL) {
  72                 err = -ENOMEM;
  73                 goto __error;
  74         }
  75         INIT_LIST_HEAD(&ctl->events);
  76         init_waitqueue_head(&ctl->change_sleep);
  77         spin_lock_init(&ctl->read_lock);
  78         ctl->card = card;
  79         ctl->pid = current->pid;
  80         file->private_data = ctl;
  81         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  82         list_add_tail(&ctl->list, &card->ctl_files);
  83         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  84         return 0;
  85
  86       __error:
  87         module_put(card->module);
  88       __error2:
  89         snd_card_file_remove(card, file);
  90       __error1:
  91         return err;
  92 }
  93
  94 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  95 {
  96         struct snd_kctl_event *cread;
  97
  98         spin_lock(&ctl->read_lock);
  99         while (!list_empty(&ctl->events)) {
 100                 cread = snd_kctl_event(ctl->events.next);
 101                 list_del(&cread->list);
 102                 kfree(cread);
 103         }
 104         spin_unlock(&ctl->read_lock);
 105 }
 106
 107 static int snd_ctl_release(struct inode *inode, struct file *file)
 108 {
 109         unsigned long flags;
 110         struct list_head *list;
 111         struct snd_card *card;
 112         struct snd_ctl_file *ctl;
 113         struct snd_kcontrol *control;
 114         unsigned int idx;
 115
 116         ctl = file->private_data;
 117         fasync_helper(-1, file, 0, &ctl->fasync);
 118         file->private_data = NULL;
 119         card = ctl->card;
 120         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 121         list_del(&ctl->list);
 122         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 123         down_write(&card->controls_rwsem);
 124         list_for_each(list, &card->controls) {
 125                 control = snd_kcontrol(list);
 126                 for (idx = 0; idx < control->count; idx++)
 127                         if (control->vd[idx].owner == ctl)
 128                                 control->vd[idx].owner = NULL;
 129         }
 130         up_write(&card->controls_rwsem);
 131         snd_ctl_empty_read_queue(ctl);
 132         kfree(ctl);
 133         module_put(card->module);
 134         snd_card_file_remove(card, file);
 135         return 0;
 136 }
 137
 138 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 139                     struct snd_ctl_elem_id *id)
 140 {
 141         unsigned long flags;
 142         struct list_head *flist;
 143         struct snd_ctl_file *ctl;
 144         struct snd_kctl_event *ev;
 145
 146         snd_assert(card != NULL && id != NULL, return);
 147         read_lock(&card->ctl_files_rwlock);
 148 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 149         card->mixer_oss_change_count++;
 150 #endif
 151         list_for_each(flist, &card->ctl_files) {
 152                 struct list_head *elist;
 153                 ctl = snd_ctl_file(flist);
 154                 if (!ctl->subscribed)
 155                         continue;
 156                 spin_lock_irqsave(&ctl->read_lock, flags);
 157                 list_for_each(elist, &ctl->events) {
 158                         ev = snd_kctl_event(elist);
 159                         if (ev->id.numid == id->numid) {
 160                                 ev->mask |= mask;
 161                                 goto _found;
 162                         }
 163                 }
 164                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 165                 if (ev) {
 166                         ev->id = *id;
 167                         ev->mask = mask;
 168                         list_add_tail(&ev->list, &ctl->events);
 169                 } else {
 170                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 171                 }
 172         _found:
 173                 wake_up(&ctl->change_sleep);
 174                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 175                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 176         }
 177         read_unlock(&card->ctl_files_rwlock);
 178 }
 179
 180 /**
 181  * snd_ctl_new - create a control instance from the template
 182  * @control: the control template
 183  * @access: the default control access
 184  *
 185  * Allocates a new struct snd_kcontrol instance and copies the given template
 186  * to the new instance. It does not copy volatile data (access).
 187  *
 188  * Returns the pointer of the new instance, or NULL on failure.
 189  */
 190 struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control, unsigned int access)
 191 {
 192         struct snd_kcontrol *kctl;
 193         unsigned int idx;
 194
 195         snd_assert(control != NULL, return NULL);
 196         snd_assert(control->count > 0, return NULL);
 197         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 198         if (kctl == NULL)
 199                 return NULL;
 200         *kctl = *control;
 201         for (idx = 0; idx < kctl->count; idx++)
 202                 kctl->vd[idx].access = access;
 203         return kctl;
 204 }
 205
 206 /**
 207  * snd_ctl_new1 - create a control instance from the template
 208  * @ncontrol: the initialization record
 209  * @private_data: the private data to set
 210  *
 211  * Allocates a new struct snd_kcontrol instance and initialize from the given
 212  * template.  When the access field of ncontrol is 0, it's assumed as
 213  * READWRITE access. When the count field is 0, it's assumes as one.
 214  *
 215  * Returns the pointer of the newly generated instance, or NULL on failure.
 216  */
 217 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 218                                   void *private_data)
 219 {
 220         struct snd_kcontrol kctl;
 221         unsigned int access;
 222
 223         snd_assert(ncontrol != NULL, return NULL);
 224         snd_assert(ncontrol->info != NULL, return NULL);
 225         memset(&kctl, 0, sizeof(kctl));
 226         kctl.id.iface = ncontrol->iface;
 227         kctl.id.device = ncontrol->device;
 228         kctl.id.subdevice = ncontrol->subdevice;
 229         if (ncontrol->name)
 230                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 231         kctl.id.index = ncontrol->index;
 232         kctl.count = ncontrol->count ? ncontrol->count : 1;
 233         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 234                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 235                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
 236         kctl.info = ncontrol->info;
 237         kctl.get = ncontrol->get;
 238         kctl.put = ncontrol->put;
 239         kctl.private_value = ncontrol->private_value;
 240         kctl.private_data = private_data;
 241         return snd_ctl_new(&kctl, access);
 242 }
 243
 244 /**
 245  * snd_ctl_free_one - release the control instance
 246  * @kcontrol: the control instance
 247  *
 248  * Releases the control instance created via snd_ctl_new()
 249  * or snd_ctl_new1().
 250  * Don't call this after the control was added to the card.
 251  */
 252 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 253 {
 254         if (kcontrol) {
 255                 if (kcontrol->private_free)
 256                         kcontrol->private_free(kcontrol);
 257                 kfree(kcontrol);
 258         }
 259 }
 260
 261 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 262                                        unsigned int count)
 263 {
 264         struct list_head *list;
 265         struct snd_kcontrol *kctl;
 266
 267         list_for_each(list, &card->controls) {
 268                 kctl = snd_kcontrol(list);
 269                 if ((kctl->id.numid <= card->last_numid &&
 270                      kctl->id.numid + kctl->count > card->last_numid) ||
 271                     (kctl->id.numid <= card->last_numid + count - 1 &&
 272                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 273                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 274         }
 275         return card->last_numid;
 276 }
 277
 278 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 279 {
 280         unsigned int last_numid, iter = 100000;
 281
 282         last_numid = card->last_numid;
 283         while (last_numid != snd_ctl_hole_check(card, count)) {
 284                 if (--iter == 0) {
 285                         /* this situation is very unlikely */
 286                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 287                         return -ENOMEM;
 288                 }
 289                 last_numid = card->last_numid;
 290         }
 291         return 0;
 292 }
 293
 294 /**
 295  * snd_ctl_add - add the control instance to the card
 296  * @card: the card instance
 297  * @kcontrol: the control instance to add
 298  *
 299  * Adds the control instance created via snd_ctl_new() or
 300  * snd_ctl_new1() to the given card. Assigns also an unique
 301  * numid used for fast search.
 302  *
 303  * Returns zero if successful, or a negative error code on failure.
 304  *
 305  * It frees automatically the control which cannot be added.
 306  */
 307 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 308 {
 309         struct snd_ctl_elem_id id;
 310         unsigned int idx;
 311
 312         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 313         snd_assert(kcontrol->info != NULL, return -EINVAL);
 314         id = kcontrol->id;
 315         down_write(&card->controls_rwsem);
 316         if (snd_ctl_find_id(card, &id)) {
 317                 up_write(&card->controls_rwsem);
 318                 snd_ctl_free_one(kcontrol);
 319                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 320                                         id.iface,
 321                                         id.device,
 322                                         id.subdevice,
 323                                         id.name,
 324                                         id.index);
 325                 return -EBUSY;
 326         }
 327         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 328                 up_write(&card->controls_rwsem);
 329                 snd_ctl_free_one(kcontrol);
 330                 return -ENOMEM;
 331         }
 332         list_add_tail(&kcontrol->list, &card->controls);
 333         card->controls_count += kcontrol->count;
 334         kcontrol->id.numid = card->last_numid + 1;
 335         card->last_numid += kcontrol->count;
 336         up_write(&card->controls_rwsem);
 337         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 338                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 339         return 0;
 340 }
 341
 342 /**
 343  * snd_ctl_remove - remove the control from the card and release it
 344  * @card: the card instance
 345  * @kcontrol: the control instance to remove
 346  *
 347  * Removes the control from the card and then releases the instance.
 348  * You don't need to call snd_ctl_free_one(). You must be in
 349  * the write lock - down_write(&card->controls_rwsem).
 350  *
 351  * Returns 0 if successful, or a negative error code on failure.
 352  */
 353 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 354 {
 355         struct snd_ctl_elem_id id;
 356         unsigned int idx;
 357
 358         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 359         list_del(&kcontrol->list);
 360         card->controls_count -= kcontrol->count;
 361         id = kcontrol->id;
 362         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 363                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 364         snd_ctl_free_one(kcontrol);
 365         return 0;
 366 }
 367
 368 /**
 369  * snd_ctl_remove_id - remove the control of the given id and release it
 370  * @card: the card instance
 371  * @id: the control id to remove
 372  *
 373  * Finds the control instance with the given id, removes it from the
 374  * card list and releases it.
 375  *
 376  * Returns 0 if successful, or a negative error code on failure.
 377  */
 378 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 379 {
 380         struct snd_kcontrol *kctl;
 381         int ret;
 382
 383         down_write(&card->controls_rwsem);
 384         kctl = snd_ctl_find_id(card, id);
 385         if (kctl == NULL) {
 386                 up_write(&card->controls_rwsem);
 387                 return -ENOENT;
 388         }
 389         ret = snd_ctl_remove(card, kctl);
 390         up_write(&card->controls_rwsem);
 391         return ret;
 392 }
 393
 394 /**
 395  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 396  * @file: active control handle
 397  * @id: the control id to remove
 398  *
 399  * Finds the control instance with the given id, removes it from the
 400  * card list and releases it.
 401  *
 402  * Returns 0 if successful, or a negative error code on failure.
 403  */
 404 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 405                                       struct snd_ctl_elem_id *id)
 406 {
 407         struct snd_card *card = file->card;
 408         struct snd_kcontrol *kctl;
 409         int idx, ret;
 410
 411         down_write(&card->controls_rwsem);
 412         kctl = snd_ctl_find_id(card, id);
 413         if (kctl == NULL) {
 414                 up_write(&card->controls_rwsem);
 415                 return -ENOENT;
 416         }
 417         for (idx = 0; idx < kctl->count; idx++)
 418                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 419                         up_write(&card->controls_rwsem);
 420                         return -EBUSY;
 421                 }
 422         ret = snd_ctl_remove(card, kctl);
 423         up_write(&card->controls_rwsem);
 424         return ret;
 425 }
 426
 427 /**
 428  * snd_ctl_rename_id - replace the id of a control on the card
 429  * @card: the card instance
 430  * @src_id: the old id
 431  * @dst_id: the new id
 432  *
 433  * Finds the control with the old id from the card, and replaces the
 434  * id with the new one.
 435  *
 436  * Returns zero if successful, or a negative error code on failure.
 437  */
 438 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 439                       struct snd_ctl_elem_id *dst_id)
 440 {
 441         struct snd_kcontrol *kctl;
 442
 443         down_write(&card->controls_rwsem);
 444         kctl = snd_ctl_find_id(card, src_id);
 445         if (kctl == NULL) {
 446                 up_write(&card->controls_rwsem);
 447                 return -ENOENT;
 448         }
 449         kctl->id = *dst_id;
 450         kctl->id.numid = card->last_numid + 1;
 451         card->last_numid += kctl->count;
 452         up_write(&card->controls_rwsem);
 453         return 0;
 454 }
 455
 456 /**
 457  * snd_ctl_find_numid - find the control instance with the given number-id
 458  * @card: the card instance
 459  * @numid: the number-id to search
 460  *
 461  * Finds the control instance with the given number-id from the card.
 462  *
 463  * Returns the pointer of the instance if found, or NULL if not.
 464  *
 465  * The caller must down card->controls_rwsem before calling this function
 466  * (if the race condition can happen).
 467  */
 468 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 469 {
 470         struct list_head *list;
 471         struct snd_kcontrol *kctl;
 472
 473         snd_assert(card != NULL && numid != 0, return NULL);
 474         list_for_each(list, &card->controls) {
 475                 kctl = snd_kcontrol(list);
 476                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 477                         return kctl;
 478         }
 479         return NULL;
 480 }
 481
 482 /**
 483  * snd_ctl_find_id - find the control instance with the given id
 484  * @card: the card instance
 485  * @id: the id to search
 486  *
 487  * Finds the control instance with the given id from the card.
 488  *
 489  * Returns the pointer of the instance if found, or NULL if not.
 490  *
 491  * The caller must down card->controls_rwsem before calling this function
 492  * (if the race condition can happen).
 493  */
 494 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 495                                      struct snd_ctl_elem_id *id)
 496 {
 497         struct list_head *list;
 498         struct snd_kcontrol *kctl;
 499
 500         snd_assert(card != NULL && id != NULL, return NULL);
 501         if (id->numid != 0)
 502                 return snd_ctl_find_numid(card, id->numid);
 503         list_for_each(list, &card->controls) {
 504                 kctl = snd_kcontrol(list);
 505                 if (kctl->id.iface != id->iface)
 506                         continue;
 507                 if (kctl->id.device != id->device)
 508                         continue;
 509                 if (kctl->id.subdevice != id->subdevice)
 510                         continue;
 511                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 512                         continue;
 513                 if (kctl->id.index > id->index)
 514                         continue;
 515                 if (kctl->id.index + kctl->count <= id->index)
 516                         continue;
 517                 return kctl;
 518         }
 519         return NULL;
 520 }
 521
 522 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 523                              unsigned int cmd, void __user *arg)
 524 {
 525         struct snd_ctl_card_info *info;
 526
 527         info = kzalloc(sizeof(*info), GFP_KERNEL);
 528         if (! info)
 529                 return -ENOMEM;
 530         down_read(&snd_ioctl_rwsem);
 531         info->card = card->number;
 532         strlcpy(info->id, card->id, sizeof(info->id));
 533         strlcpy(info->driver, card->driver, sizeof(info->driver));
 534         strlcpy(info->name, card->shortname, sizeof(info->name));
 535         strlcpy(info->longname, card->longname, sizeof(info->longname));
 536         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 537         strlcpy(info->components, card->components, sizeof(info->components));
 538         up_read(&snd_ioctl_rwsem);
 539         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 540                 kfree(info);
 541                 return -EFAULT;
 542         }
 543         kfree(info);
 544         return 0;
 545 }
 546
 547 static int snd_ctl_elem_list(struct snd_card *card,
 548                              struct snd_ctl_elem_list __user *_list)
 549 {
 550         struct list_head *plist;
 551         struct snd_ctl_elem_list list;
 552         struct snd_kcontrol *kctl;
 553         struct snd_ctl_elem_id *dst, *id;
 554         unsigned int offset, space, first, jidx;
 555
 556         if (copy_from_user(&list, _list, sizeof(list)))
 557                 return -EFAULT;
 558         offset = list.offset;
 559         space = list.space;
 560         first = 0;
 561         /* try limit maximum space */
 562         if (space > 16384)
 563                 return -ENOMEM;
 564         if (space > 0) {
 565                 /* allocate temporary buffer for atomic operation */
 566                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 567                 if (dst == NULL)
 568                         return -ENOMEM;
 569                 down_read(&card->controls_rwsem);
 570                 list.count = card->controls_count;
 571                 plist = card->controls.next;
 572                 while (plist != &card->controls) {
 573                         if (offset == 0)
 574                                 break;
 575                         kctl = snd_kcontrol(plist);
 576                         if (offset < kctl->count)
 577                                 break;
 578                         offset -= kctl->count;
 579                         plist = plist->next;
 580                 }
 581                 list.used = 0;
 582                 id = dst;
 583                 while (space > 0 && plist != &card->controls) {
 584                         kctl = snd_kcontrol(plist);
 585                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 586                                 snd_ctl_build_ioff(id, kctl, jidx);
 587                                 id++;
 588                                 space--;
 589                                 list.used++;
 590                         }
 591                         plist = plist->next;
 592                         offset = 0;
 593                 }
 594                 up_read(&card->controls_rwsem);
 595                 if (list.used > 0 &&
 596                     copy_to_user(list.pids, dst,
 597                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 598                         vfree(dst);
 599                         return -EFAULT;
 600                 }
 601                 vfree(dst);
 602         } else {
 603                 down_read(&card->controls_rwsem);
 604                 list.count = card->controls_count;
 605                 up_read(&card->controls_rwsem);
 606         }
 607         if (copy_to_user(_list, &list, sizeof(list)))
 608                 return -EFAULT;
 609         return 0;
 610 }
 611
 612 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 613                              struct snd_ctl_elem_info *info)
 614 {
 615         struct snd_card *card = ctl->card;
 616         struct snd_kcontrol *kctl;
 617         struct snd_kcontrol_volatile *vd;
 618         unsigned int index_offset;
 619         int result;
 620
 621         down_read(&card->controls_rwsem);
 622         kctl = snd_ctl_find_id(card, &info->id);
 623         if (kctl == NULL) {
 624                 up_read(&card->controls_rwsem);
 625                 return -ENOENT;
 626         }
 627 #ifdef CONFIG_SND_DEBUG
 628         info->access = 0;
 629 #endif
 630         result = kctl->info(kctl, info);
 631         if (result >= 0) {
 632                 snd_assert(info->access == 0, );
 633                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 634                 vd = &kctl->vd[index_offset];
 635                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 636                 info->access = vd->access;
 637                 if (vd->owner) {
 638                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 639                         if (vd->owner == ctl)
 640                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 641                         info->owner = vd->owner_pid;
 642                 } else {
 643                         info->owner = -1;
 644                 }
 645         }
 646         up_read(&card->controls_rwsem);
 647         return result;
 648 }
 649
 650 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 651                                   struct snd_ctl_elem_info __user *_info)
 652 {
 653         struct snd_ctl_elem_info info;
 654         int result;
 655
 656         if (copy_from_user(&info, _info, sizeof(info)))
 657                 return -EFAULT;
 658         result = snd_ctl_elem_info(ctl, &info);
 659         if (result >= 0)
 660                 if (copy_to_user(_info, &info, sizeof(info)))
 661                         return -EFAULT;
 662         return result;
 663 }
 664
 665 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
 666 {
 667         struct snd_kcontrol *kctl;
 668         struct snd_kcontrol_volatile *vd;
 669         unsigned int index_offset;
 670         int result, indirect;
 671
 672         down_read(&card->controls_rwsem);
 673         kctl = snd_ctl_find_id(card, &control->id);
 674         if (kctl == NULL) {
 675                 result = -ENOENT;
 676         } else {
 677                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 678                 vd = &kctl->vd[index_offset];
 679                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 680                 if (control->indirect != indirect) {
 681                         result = -EACCES;
 682                 } else {
 683                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 684                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 685                                 result = kctl->get(kctl, control);
 686                         } else {
 687                                 result = -EPERM;
 688                         }
 689                 }
 690         }
 691         up_read(&card->controls_rwsem);
 692         return result;
 693 }
 694
 695 static int snd_ctl_elem_read_user(struct snd_card *card,
 696                                   struct snd_ctl_elem_value __user *_control)
 697 {
 698         struct snd_ctl_elem_value *control;
 699         int result;
 700
 701         control = kmalloc(sizeof(*control), GFP_KERNEL);
 702         if (control == NULL)
 703                 return -ENOMEM;
 704         if (copy_from_user(control, _control, sizeof(*control))) {
 705                 kfree(control);
 706                 return -EFAULT;
 707         }
 708         result = snd_ctl_elem_read(card, control);
 709         if (result >= 0)
 710                 if (copy_to_user(_control, control, sizeof(*control)))
 711                         result = -EFAULT;
 712         kfree(control);
 713         return result;
 714 }
 715
 716 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 717                        struct snd_ctl_elem_value *control)
 718 {
 719         struct snd_kcontrol *kctl;
 720         struct snd_kcontrol_volatile *vd;
 721         unsigned int index_offset;
 722         int result, indirect;
 723
 724         down_read(&card->controls_rwsem);
 725         kctl = snd_ctl_find_id(card, &control->id);
 726         if (kctl == NULL) {
 727                 result = -ENOENT;
 728         } else {
 729                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 730                 vd = &kctl->vd[index_offset];
 731                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 732                 if (control->indirect != indirect) {
 733                         result = -EACCES;
 734                 } else {
 735                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 736                             kctl->put == NULL ||
 737                             (file && vd->owner != NULL && vd->owner != file)) {
 738                                 result = -EPERM;
 739                         } else {
 740                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 741                                 result = kctl->put(kctl, control);
 742                         }
 743                         if (result > 0) {
 744                                 up_read(&card->controls_rwsem);
 745                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 746                                 return 0;
 747                         }
 748                 }
 749         }
 750         up_read(&card->controls_rwsem);
 751         return result;
 752 }
 753
 754 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 755                                    struct snd_ctl_elem_value __user *_control)
 756 {
 757         struct snd_ctl_elem_value *control;
 758         int result;
 759
 760         control = kmalloc(sizeof(*control), GFP_KERNEL);
 761         if (control == NULL)
 762                 return -ENOMEM;
 763         if (copy_from_user(control, _control, sizeof(*control))) {
 764                 kfree(control);
 765                 return -EFAULT;
 766         }
 767         result = snd_ctl_elem_write(file->card, file, control);
 768         if (result >= 0)
 769                 if (copy_to_user(_control, control, sizeof(*control)))
 770                         result = -EFAULT;
 771         kfree(control);
 772         return result;
 773 }
 774
 775 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 776                              struct snd_ctl_elem_id __user *_id)
 777 {
 778         struct snd_card *card = file->card;
 779         struct snd_ctl_elem_id id;
 780         struct snd_kcontrol *kctl;
 781         struct snd_kcontrol_volatile *vd;
 782         int result;
 783
 784         if (copy_from_user(&id, _id, sizeof(id)))
 785                 return -EFAULT;
 786         down_write(&card->controls_rwsem);
 787         kctl = snd_ctl_find_id(card, &id);
 788         if (kctl == NULL) {
 789                 result = -ENOENT;
 790         } else {
 791                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 792                 if (vd->owner != NULL)
 793                         result = -EBUSY;
 794                 else {
 795                         vd->owner = file;
 796                         vd->owner_pid = current->pid;
 797                         result = 0;
 798                 }
 799         }
 800         up_write(&card->controls_rwsem);
 801         return result;
 802 }
 803
 804 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 805                                struct snd_ctl_elem_id __user *_id)
 806 {
 807         struct snd_card *card = file->card;
 808         struct snd_ctl_elem_id id;
 809         struct snd_kcontrol *kctl;
 810         struct snd_kcontrol_volatile *vd;
 811         int result;
 812
 813         if (copy_from_user(&id, _id, sizeof(id)))
 814                 return -EFAULT;
 815         down_write(&card->controls_rwsem);
 816         kctl = snd_ctl_find_id(card, &id);
 817         if (kctl == NULL) {
 818                 result = -ENOENT;
 819         } else {
 820                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 821                 if (vd->owner == NULL)
 822                         result = -EINVAL;
 823                 else if (vd->owner != file)
 824                         result = -EPERM;
 825                 else {
 826                         vd->owner = NULL;
 827                         vd->owner_pid = 0;
 828                         result = 0;
 829                 }
 830         }
 831         up_write(&card->controls_rwsem);
 832         return result;
 833 }
 834
 835 struct user_element {
 836         struct snd_ctl_elem_info info;
 837         void *elem_data;                /* element data */
 838         unsigned long elem_data_size;   /* size of element data in bytes */
 839         void *priv_data;                /* private data (like strings for enumerated type) */
 840         unsigned long priv_data_size;   /* size of private data in bytes */
 841 };
 842
 843 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 844                                   struct snd_ctl_elem_info *uinfo)
 845 {
 846         struct user_element *ue = kcontrol->private_data;
 847
 848         *uinfo = ue->info;
 849         return 0;
 850 }
 851
 852 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 853                                  struct snd_ctl_elem_value *ucontrol)
 854 {
 855         struct user_element *ue = kcontrol->private_data;
 856
 857         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 858         return 0;
 859 }
 860
 861 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 862                                  struct snd_ctl_elem_value *ucontrol)
 863 {
 864         int change;
 865         struct user_element *ue = kcontrol->private_data;
 866
 867         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 868         if (change)
 869                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 870         return change;
 871 }
 872
 873 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 874 {
 875         kfree(kcontrol->private_data);
 876 }
 877
 878 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 879                             struct snd_ctl_elem_info *info, int replace)
 880 {
 881         struct snd_card *card = file->card;
 882         struct snd_kcontrol kctl, *_kctl;
 883         unsigned int access;
 884         long private_size;
 885         struct user_element *ue;
 886         int idx, err;
 887
 888         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 889                 return -ENOMEM;
 890         if (info->count > 1024)
 891                 return -EINVAL;
 892         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 893                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 894                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE));
 895         info->id.numid = 0;
 896         memset(&kctl, 0, sizeof(kctl));
 897         down_write(&card->controls_rwsem);
 898         _kctl = snd_ctl_find_id(card, &info->id);
 899         err = 0;
 900         if (_kctl) {
 901                 if (replace)
 902                         err = snd_ctl_remove(card, _kctl);
 903                 else
 904                         err = -EBUSY;
 905         } else {
 906                 if (replace)
 907                         err = -ENOENT;
 908         }
 909         up_write(&card->controls_rwsem);
 910         if (err < 0)
 911                 return err;
 912         memcpy(&kctl.id, &info->id, sizeof(info->id));
 913         kctl.count = info->owner ? info->owner : 1;
 914         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 915         kctl.info = snd_ctl_elem_user_info;
 916         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 917                 kctl.get = snd_ctl_elem_user_get;
 918         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 919                 kctl.put = snd_ctl_elem_user_put;
 920         switch (info->type) {
 921         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 922                 private_size = sizeof(char);
 923                 if (info->count > 128)
 924                         return -EINVAL;
 925                 break;
 926         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 927                 private_size = sizeof(long);
 928                 if (info->count > 128)
 929                         return -EINVAL;
 930                 break;
 931         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 932                 private_size = sizeof(long long);
 933                 if (info->count > 64)
 934                         return -EINVAL;
 935                 break;
 936         case SNDRV_CTL_ELEM_TYPE_BYTES:
 937                 private_size = sizeof(unsigned char);
 938                 if (info->count > 512)
 939                         return -EINVAL;
 940                 break;
 941         case SNDRV_CTL_ELEM_TYPE_IEC958:
 942                 private_size = sizeof(struct snd_aes_iec958);
 943                 if (info->count != 1)
 944                         return -EINVAL;
 945                 break;
 946         default:
 947                 return -EINVAL;
 948         }
 949         private_size *= info->count;
 950         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
 951         if (ue == NULL)
 952                 return -ENOMEM;
 953         ue->info = *info;
 954         ue->elem_data = (char *)ue + sizeof(*ue);
 955         ue->elem_data_size = private_size;
 956         kctl.private_free = snd_ctl_elem_user_free;
 957         _kctl = snd_ctl_new(&kctl, access);
 958         if (_kctl == NULL) {
 959                 kfree(_kctl->private_data);
 960                 return -ENOMEM;
 961         }
 962         _kctl->private_data = ue;
 963         for (idx = 0; idx < _kctl->count; idx++)
 964                 _kctl->vd[idx].owner = file;
 965         err = snd_ctl_add(card, _kctl);
 966         if (err < 0) {
 967                 snd_ctl_free_one(_kctl);
 968                 return err;
 969         }
 970
 971         down_write(&card->controls_rwsem);
 972         card->user_ctl_count++;
 973         up_write(&card->controls_rwsem);
 974
 975         return 0;
 976 }
 977
 978 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
 979                                  struct snd_ctl_elem_info __user *_info, int replace)
 980 {
 981         struct snd_ctl_elem_info info;
 982         if (copy_from_user(&info, _info, sizeof(info)))
 983                 return -EFAULT;
 984         return snd_ctl_elem_add(file, &info, replace);
 985 }
 986
 987 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
 988                                struct snd_ctl_elem_id __user *_id)
 989 {
 990         struct snd_ctl_elem_id id;
 991         int err;
 992
 993         if (copy_from_user(&id, _id, sizeof(id)))
 994                 return -EFAULT;
 995         err = snd_ctl_remove_unlocked_id(file, &id);
 996         if (! err) {
 997                 struct snd_card *card = file->card;
 998                 down_write(&card->controls_rwsem);
 999                 card->user_ctl_count--;
1000                 up_write(&card->controls_rwsem);
1001         }
1002         return err;
1003 }
1004
1005 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1006 {
1007         int subscribe;
1008         if (get_user(subscribe, ptr))
1009                 return -EFAULT;
1010         if (subscribe < 0) {
1011                 subscribe = file->subscribed;
1012                 if (put_user(subscribe, ptr))
1013                         return -EFAULT;
1014                 return 0;
1015         }
1016         if (subscribe) {
1017                 file->subscribed = 1;
1018                 return 0;
1019         } else if (file->subscribed) {
1020                 snd_ctl_empty_read_queue(file);
1021                 file->subscribed = 0;
1022         }
1023         return 0;
1024 }
1025
1026 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1027 {
1028         struct snd_ctl_file *ctl;
1029         struct snd_card *card;
1030         struct list_head *list;
1031         struct snd_kctl_ioctl *p;
1032         void __user *argp = (void __user *)arg;
1033         int __user *ip = argp;
1034         int err;
1035
1036         ctl = file->private_data;
1037         card = ctl->card;
1038         snd_assert(card != NULL, return -ENXIO);
1039         switch (cmd) {
1040         case SNDRV_CTL_IOCTL_PVERSION:
1041                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1042         case SNDRV_CTL_IOCTL_CARD_INFO:
1043                 return snd_ctl_card_info(card, ctl, cmd, argp);
1044         case SNDRV_CTL_IOCTL_ELEM_LIST:
1045                 return snd_ctl_elem_list(ctl->card, argp);
1046         case SNDRV_CTL_IOCTL_ELEM_INFO:
1047                 return snd_ctl_elem_info_user(ctl, argp);
1048         case SNDRV_CTL_IOCTL_ELEM_READ:
1049                 return snd_ctl_elem_read_user(ctl->card, argp);
1050         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1051                 return snd_ctl_elem_write_user(ctl, argp);
1052         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1053                 return snd_ctl_elem_lock(ctl, argp);
1054         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1055                 return snd_ctl_elem_unlock(ctl, argp);
1056         case SNDRV_CTL_IOCTL_ELEM_ADD:
1057                 return snd_ctl_elem_add_user(ctl, argp, 0);
1058         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1059                 return snd_ctl_elem_add_user(ctl, argp, 1);
1060         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1061                 return snd_ctl_elem_remove(ctl, argp);
1062         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1063                 return snd_ctl_subscribe_events(ctl, ip);
1064         case SNDRV_CTL_IOCTL_POWER:
1065                 return -ENOPROTOOPT;
1066         case SNDRV_CTL_IOCTL_POWER_STATE:
1067 #ifdef CONFIG_PM
1068                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1069 #else
1070                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1071 #endif
1072         }
1073         down_read(&snd_ioctl_rwsem);
1074         list_for_each(list, &snd_control_ioctls) {
1075                 p = list_entry(list, struct snd_kctl_ioctl, list);
1076                 err = p->fioctl(card, ctl, cmd, arg);
1077                 if (err != -ENOIOCTLCMD) {
1078                         up_read(&snd_ioctl_rwsem);
1079                         return err;
1080                 }
1081         }
1082         up_read(&snd_ioctl_rwsem);
1083         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1084         return -ENOTTY;
1085 }
1086
1087 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1088                             size_t count, loff_t * offset)
1089 {
1090         struct snd_ctl_file *ctl;
1091         int err = 0;
1092         ssize_t result = 0;
1093
1094         ctl = file->private_data;
1095         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1096         if (!ctl->subscribed)
1097                 return -EBADFD;
1098         if (count < sizeof(struct snd_ctl_event))
1099                 return -EINVAL;
1100         spin_lock_irq(&ctl->read_lock);
1101         while (count >= sizeof(struct snd_ctl_event)) {
1102                 struct snd_ctl_event ev;
1103                 struct snd_kctl_event *kev;
1104                 while (list_empty(&ctl->events)) {
1105                         wait_queue_t wait;
1106                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1107                                 err = -EAGAIN;
1108                                 goto __end_lock;
1109                         }
1110                         init_waitqueue_entry(&wait, current);
1111                         add_wait_queue(&ctl->change_sleep, &wait);
1112                         set_current_state(TASK_INTERRUPTIBLE);
1113                         spin_unlock_irq(&ctl->read_lock);
1114                         schedule();
1115                         remove_wait_queue(&ctl->change_sleep, &wait);
1116                         if (signal_pending(current))
1117                                 return result > 0 ? result : -ERESTARTSYS;
1118                         spin_lock_irq(&ctl->read_lock);
1119                 }
1120                 kev = snd_kctl_event(ctl->events.next);
1121                 ev.type = SNDRV_CTL_EVENT_ELEM;
1122                 ev.data.elem.mask = kev->mask;
1123                 ev.data.elem.id = kev->id;
1124                 list_del(&kev->list);
1125                 spin_unlock_irq(&ctl->read_lock);
1126                 kfree(kev);
1127                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1128                         err = -EFAULT;
1129                         goto __end;
1130                 }
1131                 spin_lock_irq(&ctl->read_lock);
1132                 buffer += sizeof(struct snd_ctl_event);
1133                 count -= sizeof(struct snd_ctl_event);
1134                 result += sizeof(struct snd_ctl_event);
1135         }
1136       __end_lock:
1137         spin_unlock_irq(&ctl->read_lock);
1138       __end:
1139         return result > 0 ? result : err;
1140 }
1141
1142 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1143 {
1144         unsigned int mask;
1145         struct snd_ctl_file *ctl;
1146
1147         ctl = file->private_data;
1148         if (!ctl->subscribed)
1149                 return 0;
1150         poll_wait(file, &ctl->change_sleep, wait);
1151
1152         mask = 0;
1153         if (!list_empty(&ctl->events))
1154                 mask |= POLLIN | POLLRDNORM;
1155
1156         return mask;
1157 }
1158
1159 /*
1160  * register the device-specific control-ioctls.
1161  * called from each device manager like pcm.c, hwdep.c, etc.
1162  */
1163 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1164 {
1165         struct snd_kctl_ioctl *pn;
1166
1167         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1168         if (pn == NULL)
1169                 return -ENOMEM;
1170         pn->fioctl = fcn;
1171         down_write(&snd_ioctl_rwsem);
1172         list_add_tail(&pn->list, lists);
1173         up_write(&snd_ioctl_rwsem);
1174         return 0;
1175 }
1176
1177 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1178 {
1179         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1180 }
1181
1182 #ifdef CONFIG_COMPAT
1183 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1184 {
1185         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1186 }
1187 #endif
1188
1189 /*
1190  * de-register the device-specific control-ioctls.
1191  */
1192 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1193                                      struct list_head *lists)
1194 {
1195         struct list_head *list;
1196         struct snd_kctl_ioctl *p;
1197
1198         snd_assert(fcn != NULL, return -EINVAL);
1199         down_write(&snd_ioctl_rwsem);
1200         list_for_each(list, lists) {
1201                 p = list_entry(list, struct snd_kctl_ioctl, list);
1202                 if (p->fioctl == fcn) {
1203                         list_del(&p->list);
1204                         up_write(&snd_ioctl_rwsem);
1205                         kfree(p);
1206                         return 0;
1207                 }
1208         }
1209         up_write(&snd_ioctl_rwsem);
1210         snd_BUG();
1211         return -EINVAL;
1212 }
1213
1214 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1215 {
1216         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1217 }
1218
1219 #ifdef CONFIG_COMPAT
1220 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1221 {
1222         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1223 }
1224
1225 #endif
1226
1227 static int snd_ctl_fasync(int fd, struct file * file, int on)
1228 {
1229         struct snd_ctl_file *ctl;
1230         int err;
1231         ctl = file->private_data;
1232         err = fasync_helper(fd, file, on, &ctl->fasync);
1233         if (err < 0)
1234                 return err;
1235         return 0;
1236 }
1237
1238 /*
1239  * ioctl32 compat
1240  */
1241 #ifdef CONFIG_COMPAT
1242 #include "control_compat.c"
1243 #else
1244 #define snd_ctl_ioctl_compat    NULL
1245 #endif
1246
1247 /*
1248  *  INIT PART
1249  */
1250
1251 static struct file_operations snd_ctl_f_ops =
1252 {
1253         .owner =        THIS_MODULE,
1254         .read =         snd_ctl_read,
1255         .open =         snd_ctl_open,
1256         .release =      snd_ctl_release,
1257         .poll =         snd_ctl_poll,
1258         .unlocked_ioctl =       snd_ctl_ioctl,
1259         .compat_ioctl = snd_ctl_ioctl_compat,
1260         .fasync =       snd_ctl_fasync,
1261 };
1262
1263 static struct snd_minor snd_ctl_reg =
1264 {
1265         .comment =      "ctl",
1266         .f_ops =        &snd_ctl_f_ops,
1267 };
1268
1269 /*
1270  * registration of the control device
1271  */
1272 static int snd_ctl_dev_register(struct snd_device *device)
1273 {
1274         struct snd_card *card = device->device_data;
1275         int err, cardnum;
1276         char name[16];
1277
1278         snd_assert(card != NULL, return -ENXIO);
1279         cardnum = card->number;
1280         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1281         sprintf(name, "controlC%i", cardnum);
1282         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL,
1283                                         card, 0, &snd_ctl_reg, name)) < 0)
1284                 return err;
1285         return 0;
1286 }
1287
1288 /*
1289  * disconnection of the control device
1290  */
1291 static int snd_ctl_dev_disconnect(struct snd_device *device)
1292 {
1293         struct snd_card *card = device->device_data;
1294         struct list_head *flist;
1295         struct snd_ctl_file *ctl;
1296
1297         down_read(&card->controls_rwsem);
1298         list_for_each(flist, &card->ctl_files) {
1299                 ctl = snd_ctl_file(flist);
1300                 wake_up(&ctl->change_sleep);
1301                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1302         }
1303         up_read(&card->controls_rwsem);
1304         return 0;
1305 }
1306
1307 /*
1308  * free all controls
1309  */
1310 static int snd_ctl_dev_free(struct snd_device *device)
1311 {
1312         struct snd_card *card = device->device_data;
1313         struct snd_kcontrol *control;
1314
1315         down_write(&card->controls_rwsem);
1316         while (!list_empty(&card->controls)) {
1317                 control = snd_kcontrol(card->controls.next);
1318                 snd_ctl_remove(card, control);
1319         }
1320         up_write(&card->controls_rwsem);
1321         return 0;
1322 }
1323
1324 /*
1325  * de-registration of the control device
1326  */
1327 static int snd_ctl_dev_unregister(struct snd_device *device)
1328 {
1329         struct snd_card *card = device->device_data;
1330         int err, cardnum;
1331
1332         snd_assert(card != NULL, return -ENXIO);
1333         cardnum = card->number;
1334         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1335         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL, card, 0)) < 0)
1336                 return err;
1337         return snd_ctl_dev_free(device);
1338 }
1339
1340 /*
1341  * create control core:
1342  * called from init.c
1343  */
1344 int snd_ctl_create(struct snd_card *card)
1345 {
1346         static struct snd_device_ops ops = {
1347                 .dev_free = snd_ctl_dev_free,
1348                 .dev_register = snd_ctl_dev_register,
1349                 .dev_disconnect = snd_ctl_dev_disconnect,
1350                 .dev_unregister = snd_ctl_dev_unregister
1351         };
1352
1353         snd_assert(card != NULL, return -ENXIO);
1354         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1355 }