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         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         int err = -EINVAL;
 313
 314         if (! kcontrol)
 315                 return err;
 316         snd_assert(card != NULL, goto error);
 317         snd_assert(kcontrol->info != NULL, goto error);
 318         id = kcontrol->id;
 319         down_write(&card->controls_rwsem);
 320         if (snd_ctl_find_id(card, &id)) {
 321                 up_write(&card->controls_rwsem);
 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                 err = -EBUSY;
 329                 goto error;
 330         }
 331         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 332                 up_write(&card->controls_rwsem);
 333                 err = -ENOMEM;
 334                 goto error;
 335         }
 336         list_add_tail(&kcontrol->list, &card->controls);
 337         card->controls_count += kcontrol->count;
 338         kcontrol->id.numid = card->last_numid + 1;
 339         card->last_numid += kcontrol->count;
 340         up_write(&card->controls_rwsem);
 341         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 342                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 343         return 0;
 344
 345  error:
 346         snd_ctl_free_one(kcontrol);
 347         return err;
 348 }
 349
 350 /**
 351  * snd_ctl_remove - remove the control from the card and release it
 352  * @card: the card instance
 353  * @kcontrol: the control instance to remove
 354  *
 355  * Removes the control from the card and then releases the instance.
 356  * You don't need to call snd_ctl_free_one(). You must be in
 357  * the write lock - down_write(&card->controls_rwsem).
 358  *
 359  * Returns 0 if successful, or a negative error code on failure.
 360  */
 361 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 362 {
 363         struct snd_ctl_elem_id id;
 364         unsigned int idx;
 365
 366         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 367         list_del(&kcontrol->list);
 368         card->controls_count -= kcontrol->count;
 369         id = kcontrol->id;
 370         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 371                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 372         snd_ctl_free_one(kcontrol);
 373         return 0;
 374 }
 375
 376 /**
 377  * snd_ctl_remove_id - remove the control of the given id and release it
 378  * @card: the card instance
 379  * @id: the control id to remove
 380  *
 381  * Finds the control instance with the given id, removes it from the
 382  * card list and releases it.
 383  *
 384  * Returns 0 if successful, or a negative error code on failure.
 385  */
 386 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 387 {
 388         struct snd_kcontrol *kctl;
 389         int ret;
 390
 391         down_write(&card->controls_rwsem);
 392         kctl = snd_ctl_find_id(card, id);
 393         if (kctl == NULL) {
 394                 up_write(&card->controls_rwsem);
 395                 return -ENOENT;
 396         }
 397         ret = snd_ctl_remove(card, kctl);
 398         up_write(&card->controls_rwsem);
 399         return ret;
 400 }
 401
 402 /**
 403  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 404  * @file: active control handle
 405  * @id: the control id to remove
 406  *
 407  * Finds the control instance with the given id, removes it from the
 408  * card list and releases it.
 409  *
 410  * Returns 0 if successful, or a negative error code on failure.
 411  */
 412 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 413                                       struct snd_ctl_elem_id *id)
 414 {
 415         struct snd_card *card = file->card;
 416         struct snd_kcontrol *kctl;
 417         int idx, ret;
 418
 419         down_write(&card->controls_rwsem);
 420         kctl = snd_ctl_find_id(card, id);
 421         if (kctl == NULL) {
 422                 up_write(&card->controls_rwsem);
 423                 return -ENOENT;
 424         }
 425         for (idx = 0; idx < kctl->count; idx++)
 426                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 427                         up_write(&card->controls_rwsem);
 428                         return -EBUSY;
 429                 }
 430         ret = snd_ctl_remove(card, kctl);
 431         up_write(&card->controls_rwsem);
 432         return ret;
 433 }
 434
 435 /**
 436  * snd_ctl_rename_id - replace the id of a control on the card
 437  * @card: the card instance
 438  * @src_id: the old id
 439  * @dst_id: the new id
 440  *
 441  * Finds the control with the old id from the card, and replaces the
 442  * id with the new one.
 443  *
 444  * Returns zero if successful, or a negative error code on failure.
 445  */
 446 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 447                       struct snd_ctl_elem_id *dst_id)
 448 {
 449         struct snd_kcontrol *kctl;
 450
 451         down_write(&card->controls_rwsem);
 452         kctl = snd_ctl_find_id(card, src_id);
 453         if (kctl == NULL) {
 454                 up_write(&card->controls_rwsem);
 455                 return -ENOENT;
 456         }
 457         kctl->id = *dst_id;
 458         kctl->id.numid = card->last_numid + 1;
 459         card->last_numid += kctl->count;
 460         up_write(&card->controls_rwsem);
 461         return 0;
 462 }
 463
 464 /**
 465  * snd_ctl_find_numid - find the control instance with the given number-id
 466  * @card: the card instance
 467  * @numid: the number-id to search
 468  *
 469  * Finds the control instance with the given number-id from the card.
 470  *
 471  * Returns the pointer of the instance if found, or NULL if not.
 472  *
 473  * The caller must down card->controls_rwsem before calling this function
 474  * (if the race condition can happen).
 475  */
 476 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 477 {
 478         struct list_head *list;
 479         struct snd_kcontrol *kctl;
 480
 481         snd_assert(card != NULL && numid != 0, return NULL);
 482         list_for_each(list, &card->controls) {
 483                 kctl = snd_kcontrol(list);
 484                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 485                         return kctl;
 486         }
 487         return NULL;
 488 }
 489
 490 /**
 491  * snd_ctl_find_id - find the control instance with the given id
 492  * @card: the card instance
 493  * @id: the id to search
 494  *
 495  * Finds the control instance with the given id from the card.
 496  *
 497  * Returns the pointer of the instance if found, or NULL if not.
 498  *
 499  * The caller must down card->controls_rwsem before calling this function
 500  * (if the race condition can happen).
 501  */
 502 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 503                                      struct snd_ctl_elem_id *id)
 504 {
 505         struct list_head *list;
 506         struct snd_kcontrol *kctl;
 507
 508         snd_assert(card != NULL && id != NULL, return NULL);
 509         if (id->numid != 0)
 510                 return snd_ctl_find_numid(card, id->numid);
 511         list_for_each(list, &card->controls) {
 512                 kctl = snd_kcontrol(list);
 513                 if (kctl->id.iface != id->iface)
 514                         continue;
 515                 if (kctl->id.device != id->device)
 516                         continue;
 517                 if (kctl->id.subdevice != id->subdevice)
 518                         continue;
 519                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 520                         continue;
 521                 if (kctl->id.index > id->index)
 522                         continue;
 523                 if (kctl->id.index + kctl->count <= id->index)
 524                         continue;
 525                 return kctl;
 526         }
 527         return NULL;
 528 }
 529
 530 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 531                              unsigned int cmd, void __user *arg)
 532 {
 533         struct snd_ctl_card_info *info;
 534
 535         info = kzalloc(sizeof(*info), GFP_KERNEL);
 536         if (! info)
 537                 return -ENOMEM;
 538         down_read(&snd_ioctl_rwsem);
 539         info->card = card->number;
 540         strlcpy(info->id, card->id, sizeof(info->id));
 541         strlcpy(info->driver, card->driver, sizeof(info->driver));
 542         strlcpy(info->name, card->shortname, sizeof(info->name));
 543         strlcpy(info->longname, card->longname, sizeof(info->longname));
 544         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 545         strlcpy(info->components, card->components, sizeof(info->components));
 546         up_read(&snd_ioctl_rwsem);
 547         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 548                 kfree(info);
 549                 return -EFAULT;
 550         }
 551         kfree(info);
 552         return 0;
 553 }
 554
 555 static int snd_ctl_elem_list(struct snd_card *card,
 556                              struct snd_ctl_elem_list __user *_list)
 557 {
 558         struct list_head *plist;
 559         struct snd_ctl_elem_list list;
 560         struct snd_kcontrol *kctl;
 561         struct snd_ctl_elem_id *dst, *id;
 562         unsigned int offset, space, first, jidx;
 563
 564         if (copy_from_user(&list, _list, sizeof(list)))
 565                 return -EFAULT;
 566         offset = list.offset;
 567         space = list.space;
 568         first = 0;
 569         /* try limit maximum space */
 570         if (space > 16384)
 571                 return -ENOMEM;
 572         if (space > 0) {
 573                 /* allocate temporary buffer for atomic operation */
 574                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 575                 if (dst == NULL)
 576                         return -ENOMEM;
 577                 down_read(&card->controls_rwsem);
 578                 list.count = card->controls_count;
 579                 plist = card->controls.next;
 580                 while (plist != &card->controls) {
 581                         if (offset == 0)
 582                                 break;
 583                         kctl = snd_kcontrol(plist);
 584                         if (offset < kctl->count)
 585                                 break;
 586                         offset -= kctl->count;
 587                         plist = plist->next;
 588                 }
 589                 list.used = 0;
 590                 id = dst;
 591                 while (space > 0 && plist != &card->controls) {
 592                         kctl = snd_kcontrol(plist);
 593                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 594                                 snd_ctl_build_ioff(id, kctl, jidx);
 595                                 id++;
 596                                 space--;
 597                                 list.used++;
 598                         }
 599                         plist = plist->next;
 600                         offset = 0;
 601                 }
 602                 up_read(&card->controls_rwsem);
 603                 if (list.used > 0 &&
 604                     copy_to_user(list.pids, dst,
 605                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 606                         vfree(dst);
 607                         return -EFAULT;
 608                 }
 609                 vfree(dst);
 610         } else {
 611                 down_read(&card->controls_rwsem);
 612                 list.count = card->controls_count;
 613                 up_read(&card->controls_rwsem);
 614         }
 615         if (copy_to_user(_list, &list, sizeof(list)))
 616                 return -EFAULT;
 617         return 0;
 618 }
 619
 620 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 621                              struct snd_ctl_elem_info *info)
 622 {
 623         struct snd_card *card = ctl->card;
 624         struct snd_kcontrol *kctl;
 625         struct snd_kcontrol_volatile *vd;
 626         unsigned int index_offset;
 627         int result;
 628
 629         down_read(&card->controls_rwsem);
 630         kctl = snd_ctl_find_id(card, &info->id);
 631         if (kctl == NULL) {
 632                 up_read(&card->controls_rwsem);
 633                 return -ENOENT;
 634         }
 635 #ifdef CONFIG_SND_DEBUG
 636         info->access = 0;
 637 #endif
 638         result = kctl->info(kctl, info);
 639         if (result >= 0) {
 640                 snd_assert(info->access == 0, );
 641                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 642                 vd = &kctl->vd[index_offset];
 643                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 644                 info->access = vd->access;
 645                 if (vd->owner) {
 646                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 647                         if (vd->owner == ctl)
 648                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 649                         info->owner = vd->owner_pid;
 650                 } else {
 651                         info->owner = -1;
 652                 }
 653         }
 654         up_read(&card->controls_rwsem);
 655         return result;
 656 }
 657
 658 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 659                                   struct snd_ctl_elem_info __user *_info)
 660 {
 661         struct snd_ctl_elem_info info;
 662         int result;
 663
 664         if (copy_from_user(&info, _info, sizeof(info)))
 665                 return -EFAULT;
 666         snd_power_lock(ctl->card);
 667         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 668         if (result >= 0)
 669                 result = snd_ctl_elem_info(ctl, &info);
 670         snd_power_unlock(ctl->card);
 671         if (result >= 0)
 672                 if (copy_to_user(_info, &info, sizeof(info)))
 673                         return -EFAULT;
 674         return result;
 675 }
 676
 677 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
 678 {
 679         struct snd_kcontrol *kctl;
 680         struct snd_kcontrol_volatile *vd;
 681         unsigned int index_offset;
 682         int result, indirect;
 683
 684         down_read(&card->controls_rwsem);
 685         kctl = snd_ctl_find_id(card, &control->id);
 686         if (kctl == NULL) {
 687                 result = -ENOENT;
 688         } else {
 689                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 690                 vd = &kctl->vd[index_offset];
 691                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 692                 if (control->indirect != indirect) {
 693                         result = -EACCES;
 694                 } else {
 695                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 696                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 697                                 result = kctl->get(kctl, control);
 698                         } else {
 699                                 result = -EPERM;
 700                         }
 701                 }
 702         }
 703         up_read(&card->controls_rwsem);
 704         return result;
 705 }
 706
 707 static int snd_ctl_elem_read_user(struct snd_card *card,
 708                                   struct snd_ctl_elem_value __user *_control)
 709 {
 710         struct snd_ctl_elem_value *control;
 711         int result;
 712
 713         control = kmalloc(sizeof(*control), GFP_KERNEL);
 714         if (control == NULL)
 715                 return -ENOMEM;
 716         if (copy_from_user(control, _control, sizeof(*control))) {
 717                 kfree(control);
 718                 return -EFAULT;
 719         }
 720         snd_power_lock(card);
 721         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 722         if (result >= 0)
 723                 result = snd_ctl_elem_read(card, control);
 724         snd_power_unlock(card);
 725         if (result >= 0)
 726                 if (copy_to_user(_control, control, sizeof(*control)))
 727                         result = -EFAULT;
 728         kfree(control);
 729         return result;
 730 }
 731
 732 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 733                        struct snd_ctl_elem_value *control)
 734 {
 735         struct snd_kcontrol *kctl;
 736         struct snd_kcontrol_volatile *vd;
 737         unsigned int index_offset;
 738         int result, indirect;
 739
 740         down_read(&card->controls_rwsem);
 741         kctl = snd_ctl_find_id(card, &control->id);
 742         if (kctl == NULL) {
 743                 result = -ENOENT;
 744         } else {
 745                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 746                 vd = &kctl->vd[index_offset];
 747                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 748                 if (control->indirect != indirect) {
 749                         result = -EACCES;
 750                 } else {
 751                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 752                             kctl->put == NULL ||
 753                             (file && vd->owner != NULL && vd->owner != file)) {
 754                                 result = -EPERM;
 755                         } else {
 756                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 757                                 result = kctl->put(kctl, control);
 758                         }
 759                         if (result > 0) {
 760                                 up_read(&card->controls_rwsem);
 761                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 762                                 return 0;
 763                         }
 764                 }
 765         }
 766         up_read(&card->controls_rwsem);
 767         return result;
 768 }
 769
 770 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 771                                    struct snd_ctl_elem_value __user *_control)
 772 {
 773         struct snd_ctl_elem_value *control;
 774         struct snd_card *card;
 775         int result;
 776
 777         control = kmalloc(sizeof(*control), GFP_KERNEL);
 778         if (control == NULL)
 779                 return -ENOMEM;
 780         if (copy_from_user(control, _control, sizeof(*control))) {
 781                 kfree(control);
 782                 return -EFAULT;
 783         }
 784         card = file->card;
 785         snd_power_lock(card);
 786         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 787         if (result >= 0)
 788                 result = snd_ctl_elem_write(card, file, control);
 789         snd_power_unlock(card);
 790         if (result >= 0)
 791                 if (copy_to_user(_control, control, sizeof(*control)))
 792                         result = -EFAULT;
 793         kfree(control);
 794         return result;
 795 }
 796
 797 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 798                              struct snd_ctl_elem_id __user *_id)
 799 {
 800         struct snd_card *card = file->card;
 801         struct snd_ctl_elem_id id;
 802         struct snd_kcontrol *kctl;
 803         struct snd_kcontrol_volatile *vd;
 804         int result;
 805
 806         if (copy_from_user(&id, _id, sizeof(id)))
 807                 return -EFAULT;
 808         down_write(&card->controls_rwsem);
 809         kctl = snd_ctl_find_id(card, &id);
 810         if (kctl == NULL) {
 811                 result = -ENOENT;
 812         } else {
 813                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 814                 if (vd->owner != NULL)
 815                         result = -EBUSY;
 816                 else {
 817                         vd->owner = file;
 818                         vd->owner_pid = current->pid;
 819                         result = 0;
 820                 }
 821         }
 822         up_write(&card->controls_rwsem);
 823         return result;
 824 }
 825
 826 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 827                                struct snd_ctl_elem_id __user *_id)
 828 {
 829         struct snd_card *card = file->card;
 830         struct snd_ctl_elem_id id;
 831         struct snd_kcontrol *kctl;
 832         struct snd_kcontrol_volatile *vd;
 833         int result;
 834
 835         if (copy_from_user(&id, _id, sizeof(id)))
 836                 return -EFAULT;
 837         down_write(&card->controls_rwsem);
 838         kctl = snd_ctl_find_id(card, &id);
 839         if (kctl == NULL) {
 840                 result = -ENOENT;
 841         } else {
 842                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 843                 if (vd->owner == NULL)
 844                         result = -EINVAL;
 845                 else if (vd->owner != file)
 846                         result = -EPERM;
 847                 else {
 848                         vd->owner = NULL;
 849                         vd->owner_pid = 0;
 850                         result = 0;
 851                 }
 852         }
 853         up_write(&card->controls_rwsem);
 854         return result;
 855 }
 856
 857 struct user_element {
 858         struct snd_ctl_elem_info info;
 859         void *elem_data;                /* element data */
 860         unsigned long elem_data_size;   /* size of element data in bytes */
 861         void *priv_data;                /* private data (like strings for enumerated type) */
 862         unsigned long priv_data_size;   /* size of private data in bytes */
 863 };
 864
 865 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 866                                   struct snd_ctl_elem_info *uinfo)
 867 {
 868         struct user_element *ue = kcontrol->private_data;
 869
 870         *uinfo = ue->info;
 871         return 0;
 872 }
 873
 874 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 875                                  struct snd_ctl_elem_value *ucontrol)
 876 {
 877         struct user_element *ue = kcontrol->private_data;
 878
 879         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 880         return 0;
 881 }
 882
 883 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 884                                  struct snd_ctl_elem_value *ucontrol)
 885 {
 886         int change;
 887         struct user_element *ue = kcontrol->private_data;
 888
 889         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 890         if (change)
 891                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 892         return change;
 893 }
 894
 895 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 896 {
 897         kfree(kcontrol->private_data);
 898 }
 899
 900 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 901                             struct snd_ctl_elem_info *info, int replace)
 902 {
 903         struct snd_card *card = file->card;
 904         struct snd_kcontrol kctl, *_kctl;
 905         unsigned int access;
 906         long private_size;
 907         struct user_element *ue;
 908         int idx, err;
 909
 910         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 911                 return -ENOMEM;
 912         if (info->count > 1024)
 913                 return -EINVAL;
 914         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 915                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 916                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE));
 917         info->id.numid = 0;
 918         memset(&kctl, 0, sizeof(kctl));
 919         down_write(&card->controls_rwsem);
 920         _kctl = snd_ctl_find_id(card, &info->id);
 921         err = 0;
 922         if (_kctl) {
 923                 if (replace)
 924                         err = snd_ctl_remove(card, _kctl);
 925                 else
 926                         err = -EBUSY;
 927         } else {
 928                 if (replace)
 929                         err = -ENOENT;
 930         }
 931         up_write(&card->controls_rwsem);
 932         if (err < 0)
 933                 return err;
 934         memcpy(&kctl.id, &info->id, sizeof(info->id));
 935         kctl.count = info->owner ? info->owner : 1;
 936         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 937         kctl.info = snd_ctl_elem_user_info;
 938         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 939                 kctl.get = snd_ctl_elem_user_get;
 940         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 941                 kctl.put = snd_ctl_elem_user_put;
 942         switch (info->type) {
 943         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 944                 private_size = sizeof(char);
 945                 if (info->count > 128)
 946                         return -EINVAL;
 947                 break;
 948         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 949                 private_size = sizeof(long);
 950                 if (info->count > 128)
 951                         return -EINVAL;
 952                 break;
 953         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 954                 private_size = sizeof(long long);
 955                 if (info->count > 64)
 956                         return -EINVAL;
 957                 break;
 958         case SNDRV_CTL_ELEM_TYPE_BYTES:
 959                 private_size = sizeof(unsigned char);
 960                 if (info->count > 512)
 961                         return -EINVAL;
 962                 break;
 963         case SNDRV_CTL_ELEM_TYPE_IEC958:
 964                 private_size = sizeof(struct snd_aes_iec958);
 965                 if (info->count != 1)
 966                         return -EINVAL;
 967                 break;
 968         default:
 969                 return -EINVAL;
 970         }
 971         private_size *= info->count;
 972         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
 973         if (ue == NULL)
 974                 return -ENOMEM;
 975         ue->info = *info;
 976         ue->elem_data = (char *)ue + sizeof(*ue);
 977         ue->elem_data_size = private_size;
 978         kctl.private_free = snd_ctl_elem_user_free;
 979         _kctl = snd_ctl_new(&kctl, access);
 980         if (_kctl == NULL) {
 981                 kfree(ue);
 982                 return -ENOMEM;
 983         }
 984         _kctl->private_data = ue;
 985         for (idx = 0; idx < _kctl->count; idx++)
 986                 _kctl->vd[idx].owner = file;
 987         err = snd_ctl_add(card, _kctl);
 988         if (err < 0)
 989                 return err;
 990
 991         down_write(&card->controls_rwsem);
 992         card->user_ctl_count++;
 993         up_write(&card->controls_rwsem);
 994
 995         return 0;
 996 }
 997
 998 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
 999                                  struct snd_ctl_elem_info __user *_info, int replace)
1000 {
1001         struct snd_ctl_elem_info info;
1002         if (copy_from_user(&info, _info, sizeof(info)))
1003                 return -EFAULT;
1004         return snd_ctl_elem_add(file, &info, replace);
1005 }
1006
1007 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1008                                struct snd_ctl_elem_id __user *_id)
1009 {
1010         struct snd_ctl_elem_id id;
1011         int err;
1012
1013         if (copy_from_user(&id, _id, sizeof(id)))
1014                 return -EFAULT;
1015         err = snd_ctl_remove_unlocked_id(file, &id);
1016         if (! err) {
1017                 struct snd_card *card = file->card;
1018                 down_write(&card->controls_rwsem);
1019                 card->user_ctl_count--;
1020                 up_write(&card->controls_rwsem);
1021         }
1022         return err;
1023 }
1024
1025 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1026 {
1027         int subscribe;
1028         if (get_user(subscribe, ptr))
1029                 return -EFAULT;
1030         if (subscribe < 0) {
1031                 subscribe = file->subscribed;
1032                 if (put_user(subscribe, ptr))
1033                         return -EFAULT;
1034                 return 0;
1035         }
1036         if (subscribe) {
1037                 file->subscribed = 1;
1038                 return 0;
1039         } else if (file->subscribed) {
1040                 snd_ctl_empty_read_queue(file);
1041                 file->subscribed = 0;
1042         }
1043         return 0;
1044 }
1045
1046 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1047 {
1048         struct snd_ctl_file *ctl;
1049         struct snd_card *card;
1050         struct list_head *list;
1051         struct snd_kctl_ioctl *p;
1052         void __user *argp = (void __user *)arg;
1053         int __user *ip = argp;
1054         int err;
1055
1056         ctl = file->private_data;
1057         card = ctl->card;
1058         snd_assert(card != NULL, return -ENXIO);
1059         switch (cmd) {
1060         case SNDRV_CTL_IOCTL_PVERSION:
1061                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1062         case SNDRV_CTL_IOCTL_CARD_INFO:
1063                 return snd_ctl_card_info(card, ctl, cmd, argp);
1064         case SNDRV_CTL_IOCTL_ELEM_LIST:
1065                 return snd_ctl_elem_list(ctl->card, argp);
1066         case SNDRV_CTL_IOCTL_ELEM_INFO:
1067                 return snd_ctl_elem_info_user(ctl, argp);
1068         case SNDRV_CTL_IOCTL_ELEM_READ:
1069                 return snd_ctl_elem_read_user(ctl->card, argp);
1070         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1071                 return snd_ctl_elem_write_user(ctl, argp);
1072         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1073                 return snd_ctl_elem_lock(ctl, argp);
1074         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1075                 return snd_ctl_elem_unlock(ctl, argp);
1076         case SNDRV_CTL_IOCTL_ELEM_ADD:
1077                 return snd_ctl_elem_add_user(ctl, argp, 0);
1078         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1079                 return snd_ctl_elem_add_user(ctl, argp, 1);
1080         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1081                 return snd_ctl_elem_remove(ctl, argp);
1082         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1083                 return snd_ctl_subscribe_events(ctl, ip);
1084         case SNDRV_CTL_IOCTL_POWER:
1085                 return -ENOPROTOOPT;
1086         case SNDRV_CTL_IOCTL_POWER_STATE:
1087 #ifdef CONFIG_PM
1088                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1089 #else
1090                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1091 #endif
1092         }
1093         down_read(&snd_ioctl_rwsem);
1094         list_for_each(list, &snd_control_ioctls) {
1095                 p = list_entry(list, struct snd_kctl_ioctl, list);
1096                 err = p->fioctl(card, ctl, cmd, arg);
1097                 if (err != -ENOIOCTLCMD) {
1098                         up_read(&snd_ioctl_rwsem);
1099                         return err;
1100                 }
1101         }
1102         up_read(&snd_ioctl_rwsem);
1103         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1104         return -ENOTTY;
1105 }
1106
1107 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1108                             size_t count, loff_t * offset)
1109 {
1110         struct snd_ctl_file *ctl;
1111         int err = 0;
1112         ssize_t result = 0;
1113
1114         ctl = file->private_data;
1115         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1116         if (!ctl->subscribed)
1117                 return -EBADFD;
1118         if (count < sizeof(struct snd_ctl_event))
1119                 return -EINVAL;
1120         spin_lock_irq(&ctl->read_lock);
1121         while (count >= sizeof(struct snd_ctl_event)) {
1122                 struct snd_ctl_event ev;
1123                 struct snd_kctl_event *kev;
1124                 while (list_empty(&ctl->events)) {
1125                         wait_queue_t wait;
1126                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1127                                 err = -EAGAIN;
1128                                 goto __end_lock;
1129                         }
1130                         init_waitqueue_entry(&wait, current);
1131                         add_wait_queue(&ctl->change_sleep, &wait);
1132                         set_current_state(TASK_INTERRUPTIBLE);
1133                         spin_unlock_irq(&ctl->read_lock);
1134                         schedule();
1135                         remove_wait_queue(&ctl->change_sleep, &wait);
1136                         if (signal_pending(current))
1137                                 return result > 0 ? result : -ERESTARTSYS;
1138                         spin_lock_irq(&ctl->read_lock);
1139                 }
1140                 kev = snd_kctl_event(ctl->events.next);
1141                 ev.type = SNDRV_CTL_EVENT_ELEM;
1142                 ev.data.elem.mask = kev->mask;
1143                 ev.data.elem.id = kev->id;
1144                 list_del(&kev->list);
1145                 spin_unlock_irq(&ctl->read_lock);
1146                 kfree(kev);
1147                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1148                         err = -EFAULT;
1149                         goto __end;
1150                 }
1151                 spin_lock_irq(&ctl->read_lock);
1152                 buffer += sizeof(struct snd_ctl_event);
1153                 count -= sizeof(struct snd_ctl_event);
1154                 result += sizeof(struct snd_ctl_event);
1155         }
1156       __end_lock:
1157         spin_unlock_irq(&ctl->read_lock);
1158       __end:
1159         return result > 0 ? result : err;
1160 }
1161
1162 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1163 {
1164         unsigned int mask;
1165         struct snd_ctl_file *ctl;
1166
1167         ctl = file->private_data;
1168         if (!ctl->subscribed)
1169                 return 0;
1170         poll_wait(file, &ctl->change_sleep, wait);
1171
1172         mask = 0;
1173         if (!list_empty(&ctl->events))
1174                 mask |= POLLIN | POLLRDNORM;
1175
1176         return mask;
1177 }
1178
1179 /*
1180  * register the device-specific control-ioctls.
1181  * called from each device manager like pcm.c, hwdep.c, etc.
1182  */
1183 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1184 {
1185         struct snd_kctl_ioctl *pn;
1186
1187         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1188         if (pn == NULL)
1189                 return -ENOMEM;
1190         pn->fioctl = fcn;
1191         down_write(&snd_ioctl_rwsem);
1192         list_add_tail(&pn->list, lists);
1193         up_write(&snd_ioctl_rwsem);
1194         return 0;
1195 }
1196
1197 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1198 {
1199         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1200 }
1201
1202 #ifdef CONFIG_COMPAT
1203 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1204 {
1205         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1206 }
1207 #endif
1208
1209 /*
1210  * de-register the device-specific control-ioctls.
1211  */
1212 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1213                                      struct list_head *lists)
1214 {
1215         struct list_head *list;
1216         struct snd_kctl_ioctl *p;
1217
1218         snd_assert(fcn != NULL, return -EINVAL);
1219         down_write(&snd_ioctl_rwsem);
1220         list_for_each(list, lists) {
1221                 p = list_entry(list, struct snd_kctl_ioctl, list);
1222                 if (p->fioctl == fcn) {
1223                         list_del(&p->list);
1224                         up_write(&snd_ioctl_rwsem);
1225                         kfree(p);
1226                         return 0;
1227                 }
1228         }
1229         up_write(&snd_ioctl_rwsem);
1230         snd_BUG();
1231         return -EINVAL;
1232 }
1233
1234 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1235 {
1236         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1237 }
1238
1239 #ifdef CONFIG_COMPAT
1240 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1241 {
1242         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1243 }
1244
1245 #endif
1246
1247 static int snd_ctl_fasync(int fd, struct file * file, int on)
1248 {
1249         struct snd_ctl_file *ctl;
1250         int err;
1251         ctl = file->private_data;
1252         err = fasync_helper(fd, file, on, &ctl->fasync);
1253         if (err < 0)
1254                 return err;
1255         return 0;
1256 }
1257
1258 /*
1259  * ioctl32 compat
1260  */
1261 #ifdef CONFIG_COMPAT
1262 #include "control_compat.c"
1263 #else
1264 #define snd_ctl_ioctl_compat    NULL
1265 #endif
1266
1267 /*
1268  *  INIT PART
1269  */
1270
1271 static struct file_operations snd_ctl_f_ops =
1272 {
1273         .owner =        THIS_MODULE,
1274         .read =         snd_ctl_read,
1275         .open =         snd_ctl_open,
1276         .release =      snd_ctl_release,
1277         .poll =         snd_ctl_poll,
1278         .unlocked_ioctl =       snd_ctl_ioctl,
1279         .compat_ioctl = snd_ctl_ioctl_compat,
1280         .fasync =       snd_ctl_fasync,
1281 };
1282
1283 /*
1284  * registration of the control device
1285  */
1286 static int snd_ctl_dev_register(struct snd_device *device)
1287 {
1288         struct snd_card *card = device->device_data;
1289         int err, cardnum;
1290         char name[16];
1291
1292         snd_assert(card != NULL, return -ENXIO);
1293         cardnum = card->number;
1294         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1295         sprintf(name, "controlC%i", cardnum);
1296         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1297                                        &snd_ctl_f_ops, card, name)) < 0)
1298                 return err;
1299         return 0;
1300 }
1301
1302 /*
1303  * disconnection of the control device
1304  */
1305 static int snd_ctl_dev_disconnect(struct snd_device *device)
1306 {
1307         struct snd_card *card = device->device_data;
1308         struct list_head *flist;
1309         struct snd_ctl_file *ctl;
1310
1311         down_read(&card->controls_rwsem);
1312         list_for_each(flist, &card->ctl_files) {
1313                 ctl = snd_ctl_file(flist);
1314                 wake_up(&ctl->change_sleep);
1315                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1316         }
1317         up_read(&card->controls_rwsem);
1318         return 0;
1319 }
1320
1321 /*
1322  * free all controls
1323  */
1324 static int snd_ctl_dev_free(struct snd_device *device)
1325 {
1326         struct snd_card *card = device->device_data;
1327         struct snd_kcontrol *control;
1328
1329         down_write(&card->controls_rwsem);
1330         while (!list_empty(&card->controls)) {
1331                 control = snd_kcontrol(card->controls.next);
1332                 snd_ctl_remove(card, control);
1333         }
1334         up_write(&card->controls_rwsem);
1335         return 0;
1336 }
1337
1338 /*
1339  * de-registration of the control device
1340  */
1341 static int snd_ctl_dev_unregister(struct snd_device *device)
1342 {
1343         struct snd_card *card = device->device_data;
1344         int err, cardnum;
1345
1346         snd_assert(card != NULL, return -ENXIO);
1347         cardnum = card->number;
1348         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1349         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1350                                          card, -1)) < 0)
1351                 return err;
1352         return snd_ctl_dev_free(device);
1353 }
1354
1355 /*
1356  * create control core:
1357  * called from init.c
1358  */
1359 int snd_ctl_create(struct snd_card *card)
1360 {
1361         static struct snd_device_ops ops = {
1362                 .dev_free = snd_ctl_dev_free,
1363                 .dev_register = snd_ctl_dev_register,
1364                 .dev_disconnect = snd_ctl_dev_disconnect,
1365                 .dev_unregister = snd_ctl_dev_unregister
1366         };
1367
1368         snd_assert(card != NULL, return -ENXIO);
1369         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1370 }