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