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 EXPORT_SYMBOL(snd_ctl_notify);
 180
 181 /**
 182  * snd_ctl_new - create a control instance from the template
 183  * @control: the control template
 184  * @access: the default control access
 185  *
 186  * Allocates a new struct snd_kcontrol instance and copies the given template
 187  * to the new instance. It does not copy volatile data (access).
 188  *
 189  * Returns the pointer of the new instance, or NULL on failure.
 190  */
 191 struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control, unsigned int access)
 192 {
 193         struct snd_kcontrol *kctl;
 194         unsigned int idx;
 195
 196         snd_assert(control != NULL, return NULL);
 197         snd_assert(control->count > 0, return NULL);
 198         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 199         if (kctl == NULL) {
 200                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 201                 return NULL;
 202         }
 203         *kctl = *control;
 204         for (idx = 0; idx < kctl->count; idx++)
 205                 kctl->vd[idx].access = access;
 206         return kctl;
 207 }
 208
 209 EXPORT_SYMBOL(snd_ctl_new);
 210
 211 /**
 212  * snd_ctl_new1 - create a control instance from the template
 213  * @ncontrol: the initialization record
 214  * @private_data: the private data to set
 215  *
 216  * Allocates a new struct snd_kcontrol instance and initialize from the given
 217  * template.  When the access field of ncontrol is 0, it's assumed as
 218  * READWRITE access. When the count field is 0, it's assumes as one.
 219  *
 220  * Returns the pointer of the newly generated instance, or NULL on failure.
 221  */
 222 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 223                                   void *private_data)
 224 {
 225         struct snd_kcontrol kctl;
 226         unsigned int access;
 227
 228         snd_assert(ncontrol != NULL, return NULL);
 229         snd_assert(ncontrol->info != NULL, return NULL);
 230         memset(&kctl, 0, sizeof(kctl));
 231         kctl.id.iface = ncontrol->iface;
 232         kctl.id.device = ncontrol->device;
 233         kctl.id.subdevice = ncontrol->subdevice;
 234         if (ncontrol->name)
 235                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 236         kctl.id.index = ncontrol->index;
 237         kctl.count = ncontrol->count ? ncontrol->count : 1;
 238         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 239                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 240                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
 241         kctl.info = ncontrol->info;
 242         kctl.get = ncontrol->get;
 243         kctl.put = ncontrol->put;
 244         kctl.private_value = ncontrol->private_value;
 245         kctl.private_data = private_data;
 246         return snd_ctl_new(&kctl, access);
 247 }
 248
 249 EXPORT_SYMBOL(snd_ctl_new1);
 250
 251 /**
 252  * snd_ctl_free_one - release the control instance
 253  * @kcontrol: the control instance
 254  *
 255  * Releases the control instance created via snd_ctl_new()
 256  * or snd_ctl_new1().
 257  * Don't call this after the control was added to the card.
 258  */
 259 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 260 {
 261         if (kcontrol) {
 262                 if (kcontrol->private_free)
 263                         kcontrol->private_free(kcontrol);
 264                 kfree(kcontrol);
 265         }
 266 }
 267
 268 EXPORT_SYMBOL(snd_ctl_free_one);
 269
 270 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 271                                        unsigned int count)
 272 {
 273         struct list_head *list;
 274         struct snd_kcontrol *kctl;
 275
 276         list_for_each(list, &card->controls) {
 277                 kctl = snd_kcontrol(list);
 278                 if ((kctl->id.numid <= card->last_numid &&
 279                      kctl->id.numid + kctl->count > card->last_numid) ||
 280                     (kctl->id.numid <= card->last_numid + count - 1 &&
 281                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 282                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 283         }
 284         return card->last_numid;
 285 }
 286
 287 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 288 {
 289         unsigned int last_numid, iter = 100000;
 290
 291         last_numid = card->last_numid;
 292         while (last_numid != snd_ctl_hole_check(card, count)) {
 293                 if (--iter == 0) {
 294                         /* this situation is very unlikely */
 295                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 296                         return -ENOMEM;
 297                 }
 298                 last_numid = card->last_numid;
 299         }
 300         return 0;
 301 }
 302
 303 /**
 304  * snd_ctl_add - add the control instance to the card
 305  * @card: the card instance
 306  * @kcontrol: the control instance to add
 307  *
 308  * Adds the control instance created via snd_ctl_new() or
 309  * snd_ctl_new1() to the given card. Assigns also an unique
 310  * numid used for fast search.
 311  *
 312  * Returns zero if successful, or a negative error code on failure.
 313  *
 314  * It frees automatically the control which cannot be added.
 315  */
 316 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 317 {
 318         struct snd_ctl_elem_id id;
 319         unsigned int idx;
 320         int err = -EINVAL;
 321
 322         if (! kcontrol)
 323                 return err;
 324         snd_assert(card != NULL, goto error);
 325         snd_assert(kcontrol->info != NULL, goto error);
 326         id = kcontrol->id;
 327         down_write(&card->controls_rwsem);
 328         if (snd_ctl_find_id(card, &id)) {
 329                 up_write(&card->controls_rwsem);
 330                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 331                                         id.iface,
 332                                         id.device,
 333                                         id.subdevice,
 334                                         id.name,
 335                                         id.index);
 336                 err = -EBUSY;
 337                 goto error;
 338         }
 339         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 340                 up_write(&card->controls_rwsem);
 341                 err = -ENOMEM;
 342                 goto error;
 343         }
 344         list_add_tail(&kcontrol->list, &card->controls);
 345         card->controls_count += kcontrol->count;
 346         kcontrol->id.numid = card->last_numid + 1;
 347         card->last_numid += kcontrol->count;
 348         up_write(&card->controls_rwsem);
 349         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 350                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 351         return 0;
 352
 353  error:
 354         snd_ctl_free_one(kcontrol);
 355         return err;
 356 }
 357
 358 EXPORT_SYMBOL(snd_ctl_add);
 359
 360 /**
 361  * snd_ctl_remove - remove the control from the card and release it
 362  * @card: the card instance
 363  * @kcontrol: the control instance to remove
 364  *
 365  * Removes the control from the card and then releases the instance.
 366  * You don't need to call snd_ctl_free_one(). You must be in
 367  * the write lock - down_write(&card->controls_rwsem).
 368  *
 369  * Returns 0 if successful, or a negative error code on failure.
 370  */
 371 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 372 {
 373         struct snd_ctl_elem_id id;
 374         unsigned int idx;
 375
 376         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 377         list_del(&kcontrol->list);
 378         card->controls_count -= kcontrol->count;
 379         id = kcontrol->id;
 380         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 381                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 382         snd_ctl_free_one(kcontrol);
 383         return 0;
 384 }
 385
 386 EXPORT_SYMBOL(snd_ctl_remove);
 387
 388 /**
 389  * snd_ctl_remove_id - remove the control of the given id and release it
 390  * @card: the card instance
 391  * @id: the control id to remove
 392  *
 393  * Finds the control instance with the given id, removes it from the
 394  * card list and releases it.
 395  *
 396  * Returns 0 if successful, or a negative error code on failure.
 397  */
 398 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 399 {
 400         struct snd_kcontrol *kctl;
 401         int ret;
 402
 403         down_write(&card->controls_rwsem);
 404         kctl = snd_ctl_find_id(card, id);
 405         if (kctl == NULL) {
 406                 up_write(&card->controls_rwsem);
 407                 return -ENOENT;
 408         }
 409         ret = snd_ctl_remove(card, kctl);
 410         up_write(&card->controls_rwsem);
 411         return ret;
 412 }
 413
 414 EXPORT_SYMBOL(snd_ctl_remove_id);
 415
 416 /**
 417  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 418  * @file: active control handle
 419  * @id: the control id to remove
 420  *
 421  * Finds the control instance with the given id, removes it from the
 422  * card list and releases it.
 423  *
 424  * Returns 0 if successful, or a negative error code on failure.
 425  */
 426 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 427                                       struct snd_ctl_elem_id *id)
 428 {
 429         struct snd_card *card = file->card;
 430         struct snd_kcontrol *kctl;
 431         int idx, ret;
 432
 433         down_write(&card->controls_rwsem);
 434         kctl = snd_ctl_find_id(card, id);
 435         if (kctl == NULL) {
 436                 up_write(&card->controls_rwsem);
 437                 return -ENOENT;
 438         }
 439         for (idx = 0; idx < kctl->count; idx++)
 440                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 441                         up_write(&card->controls_rwsem);
 442                         return -EBUSY;
 443                 }
 444         ret = snd_ctl_remove(card, kctl);
 445         up_write(&card->controls_rwsem);
 446         return ret;
 447 }
 448
 449 /**
 450  * snd_ctl_rename_id - replace the id of a control on the card
 451  * @card: the card instance
 452  * @src_id: the old id
 453  * @dst_id: the new id
 454  *
 455  * Finds the control with the old id from the card, and replaces the
 456  * id with the new one.
 457  *
 458  * Returns zero if successful, or a negative error code on failure.
 459  */
 460 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 461                       struct snd_ctl_elem_id *dst_id)
 462 {
 463         struct snd_kcontrol *kctl;
 464
 465         down_write(&card->controls_rwsem);
 466         kctl = snd_ctl_find_id(card, src_id);
 467         if (kctl == NULL) {
 468                 up_write(&card->controls_rwsem);
 469                 return -ENOENT;
 470         }
 471         kctl->id = *dst_id;
 472         kctl->id.numid = card->last_numid + 1;
 473         card->last_numid += kctl->count;
 474         up_write(&card->controls_rwsem);
 475         return 0;
 476 }
 477
 478 EXPORT_SYMBOL(snd_ctl_rename_id);
 479
 480 /**
 481  * snd_ctl_find_numid - find the control instance with the given number-id
 482  * @card: the card instance
 483  * @numid: the number-id to search
 484  *
 485  * Finds the control instance with the given number-id from the card.
 486  *
 487  * Returns the pointer of the instance if found, or NULL if not.
 488  *
 489  * The caller must down card->controls_rwsem before calling this function
 490  * (if the race condition can happen).
 491  */
 492 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 493 {
 494         struct list_head *list;
 495         struct snd_kcontrol *kctl;
 496
 497         snd_assert(card != NULL && numid != 0, return NULL);
 498         list_for_each(list, &card->controls) {
 499                 kctl = snd_kcontrol(list);
 500                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 501                         return kctl;
 502         }
 503         return NULL;
 504 }
 505
 506 EXPORT_SYMBOL(snd_ctl_find_numid);
 507
 508 /**
 509  * snd_ctl_find_id - find the control instance with the given id
 510  * @card: the card instance
 511  * @id: the id to search
 512  *
 513  * Finds the control instance with the given id from the card.
 514  *
 515  * Returns the pointer of the instance if found, or NULL if not.
 516  *
 517  * The caller must down card->controls_rwsem before calling this function
 518  * (if the race condition can happen).
 519  */
 520 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 521                                      struct snd_ctl_elem_id *id)
 522 {
 523         struct list_head *list;
 524         struct snd_kcontrol *kctl;
 525
 526         snd_assert(card != NULL && id != NULL, return NULL);
 527         if (id->numid != 0)
 528                 return snd_ctl_find_numid(card, id->numid);
 529         list_for_each(list, &card->controls) {
 530                 kctl = snd_kcontrol(list);
 531                 if (kctl->id.iface != id->iface)
 532                         continue;
 533                 if (kctl->id.device != id->device)
 534                         continue;
 535                 if (kctl->id.subdevice != id->subdevice)
 536                         continue;
 537                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 538                         continue;
 539                 if (kctl->id.index > id->index)
 540                         continue;
 541                 if (kctl->id.index + kctl->count <= id->index)
 542                         continue;
 543                 return kctl;
 544         }
 545         return NULL;
 546 }
 547
 548 EXPORT_SYMBOL(snd_ctl_find_id);
 549
 550 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 551                              unsigned int cmd, void __user *arg)
 552 {
 553         struct snd_ctl_card_info *info;
 554
 555         info = kzalloc(sizeof(*info), GFP_KERNEL);
 556         if (! info)
 557                 return -ENOMEM;
 558         down_read(&snd_ioctl_rwsem);
 559         info->card = card->number;
 560         strlcpy(info->id, card->id, sizeof(info->id));
 561         strlcpy(info->driver, card->driver, sizeof(info->driver));
 562         strlcpy(info->name, card->shortname, sizeof(info->name));
 563         strlcpy(info->longname, card->longname, sizeof(info->longname));
 564         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 565         strlcpy(info->components, card->components, sizeof(info->components));
 566         up_read(&snd_ioctl_rwsem);
 567         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 568                 kfree(info);
 569                 return -EFAULT;
 570         }
 571         kfree(info);
 572         return 0;
 573 }
 574
 575 static int snd_ctl_elem_list(struct snd_card *card,
 576                              struct snd_ctl_elem_list __user *_list)
 577 {
 578         struct list_head *plist;
 579         struct snd_ctl_elem_list list;
 580         struct snd_kcontrol *kctl;
 581         struct snd_ctl_elem_id *dst, *id;
 582         unsigned int offset, space, first, jidx;
 583
 584         if (copy_from_user(&list, _list, sizeof(list)))
 585                 return -EFAULT;
 586         offset = list.offset;
 587         space = list.space;
 588         first = 0;
 589         /* try limit maximum space */
 590         if (space > 16384)
 591                 return -ENOMEM;
 592         if (space > 0) {
 593                 /* allocate temporary buffer for atomic operation */
 594                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 595                 if (dst == NULL)
 596                         return -ENOMEM;
 597                 down_read(&card->controls_rwsem);
 598                 list.count = card->controls_count;
 599                 plist = card->controls.next;
 600                 while (plist != &card->controls) {
 601                         if (offset == 0)
 602                                 break;
 603                         kctl = snd_kcontrol(plist);
 604                         if (offset < kctl->count)
 605                                 break;
 606                         offset -= kctl->count;
 607                         plist = plist->next;
 608                 }
 609                 list.used = 0;
 610                 id = dst;
 611                 while (space > 0 && plist != &card->controls) {
 612                         kctl = snd_kcontrol(plist);
 613                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 614                                 snd_ctl_build_ioff(id, kctl, jidx);
 615                                 id++;
 616                                 space--;
 617                                 list.used++;
 618                         }
 619                         plist = plist->next;
 620                         offset = 0;
 621                 }
 622                 up_read(&card->controls_rwsem);
 623                 if (list.used > 0 &&
 624                     copy_to_user(list.pids, dst,
 625                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 626                         vfree(dst);
 627                         return -EFAULT;
 628                 }
 629                 vfree(dst);
 630         } else {
 631                 down_read(&card->controls_rwsem);
 632                 list.count = card->controls_count;
 633                 up_read(&card->controls_rwsem);
 634         }
 635         if (copy_to_user(_list, &list, sizeof(list)))
 636                 return -EFAULT;
 637         return 0;
 638 }
 639
 640 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 641                              struct snd_ctl_elem_info *info)
 642 {
 643         struct snd_card *card = ctl->card;
 644         struct snd_kcontrol *kctl;
 645         struct snd_kcontrol_volatile *vd;
 646         unsigned int index_offset;
 647         int result;
 648
 649         down_read(&card->controls_rwsem);
 650         kctl = snd_ctl_find_id(card, &info->id);
 651         if (kctl == NULL) {
 652                 up_read(&card->controls_rwsem);
 653                 return -ENOENT;
 654         }
 655 #ifdef CONFIG_SND_DEBUG
 656         info->access = 0;
 657 #endif
 658         result = kctl->info(kctl, info);
 659         if (result >= 0) {
 660                 snd_assert(info->access == 0, );
 661                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 662                 vd = &kctl->vd[index_offset];
 663                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 664                 info->access = vd->access;
 665                 if (vd->owner) {
 666                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 667                         if (vd->owner == ctl)
 668                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 669                         info->owner = vd->owner_pid;
 670                 } else {
 671                         info->owner = -1;
 672                 }
 673         }
 674         up_read(&card->controls_rwsem);
 675         return result;
 676 }
 677
 678 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 679                                   struct snd_ctl_elem_info __user *_info)
 680 {
 681         struct snd_ctl_elem_info info;
 682         int result;
 683
 684         if (copy_from_user(&info, _info, sizeof(info)))
 685                 return -EFAULT;
 686         snd_power_lock(ctl->card);
 687         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 688         if (result >= 0)
 689                 result = snd_ctl_elem_info(ctl, &info);
 690         snd_power_unlock(ctl->card);
 691         if (result >= 0)
 692                 if (copy_to_user(_info, &info, sizeof(info)))
 693                         return -EFAULT;
 694         return result;
 695 }
 696
 697 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
 698 {
 699         struct snd_kcontrol *kctl;
 700         struct snd_kcontrol_volatile *vd;
 701         unsigned int index_offset;
 702         int result, indirect;
 703
 704         down_read(&card->controls_rwsem);
 705         kctl = snd_ctl_find_id(card, &control->id);
 706         if (kctl == NULL) {
 707                 result = -ENOENT;
 708         } else {
 709                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 710                 vd = &kctl->vd[index_offset];
 711                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 712                 if (control->indirect != indirect) {
 713                         result = -EACCES;
 714                 } else {
 715                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 716                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 717                                 result = kctl->get(kctl, control);
 718                         } else {
 719                                 result = -EPERM;
 720                         }
 721                 }
 722         }
 723         up_read(&card->controls_rwsem);
 724         return result;
 725 }
 726
 727 EXPORT_SYMBOL(snd_ctl_elem_read);
 728
 729 static int snd_ctl_elem_read_user(struct snd_card *card,
 730                                   struct snd_ctl_elem_value __user *_control)
 731 {
 732         struct snd_ctl_elem_value *control;
 733         int result;
 734
 735         control = kmalloc(sizeof(*control), GFP_KERNEL);
 736         if (control == NULL)
 737                 return -ENOMEM;
 738         if (copy_from_user(control, _control, sizeof(*control))) {
 739                 kfree(control);
 740                 return -EFAULT;
 741         }
 742         snd_power_lock(card);
 743         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 744         if (result >= 0)
 745                 result = snd_ctl_elem_read(card, control);
 746         snd_power_unlock(card);
 747         if (result >= 0)
 748                 if (copy_to_user(_control, control, sizeof(*control)))
 749                         result = -EFAULT;
 750         kfree(control);
 751         return result;
 752 }
 753
 754 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 755                        struct snd_ctl_elem_value *control)
 756 {
 757         struct snd_kcontrol *kctl;
 758         struct snd_kcontrol_volatile *vd;
 759         unsigned int index_offset;
 760         int result, indirect;
 761
 762         down_read(&card->controls_rwsem);
 763         kctl = snd_ctl_find_id(card, &control->id);
 764         if (kctl == NULL) {
 765                 result = -ENOENT;
 766         } else {
 767                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 768                 vd = &kctl->vd[index_offset];
 769                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 770                 if (control->indirect != indirect) {
 771                         result = -EACCES;
 772                 } else {
 773                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 774                             kctl->put == NULL ||
 775                             (file && vd->owner != NULL && vd->owner != file)) {
 776                                 result = -EPERM;
 777                         } else {
 778                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 779                                 result = kctl->put(kctl, control);
 780                         }
 781                         if (result > 0) {
 782                                 up_read(&card->controls_rwsem);
 783                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 784                                 return 0;
 785                         }
 786                 }
 787         }
 788         up_read(&card->controls_rwsem);
 789         return result;
 790 }
 791
 792 EXPORT_SYMBOL(snd_ctl_elem_write);
 793
 794 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 795                                    struct snd_ctl_elem_value __user *_control)
 796 {
 797         struct snd_ctl_elem_value *control;
 798         struct snd_card *card;
 799         int result;
 800
 801         control = kmalloc(sizeof(*control), GFP_KERNEL);
 802         if (control == NULL)
 803                 return -ENOMEM;
 804         if (copy_from_user(control, _control, sizeof(*control))) {
 805                 kfree(control);
 806                 return -EFAULT;
 807         }
 808         card = file->card;
 809         snd_power_lock(card);
 810         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 811         if (result >= 0)
 812                 result = snd_ctl_elem_write(card, file, control);
 813         snd_power_unlock(card);
 814         if (result >= 0)
 815                 if (copy_to_user(_control, control, sizeof(*control)))
 816                         result = -EFAULT;
 817         kfree(control);
 818         return result;
 819 }
 820
 821 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 822                              struct snd_ctl_elem_id __user *_id)
 823 {
 824         struct snd_card *card = file->card;
 825         struct snd_ctl_elem_id id;
 826         struct snd_kcontrol *kctl;
 827         struct snd_kcontrol_volatile *vd;
 828         int result;
 829
 830         if (copy_from_user(&id, _id, sizeof(id)))
 831                 return -EFAULT;
 832         down_write(&card->controls_rwsem);
 833         kctl = snd_ctl_find_id(card, &id);
 834         if (kctl == NULL) {
 835                 result = -ENOENT;
 836         } else {
 837                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 838                 if (vd->owner != NULL)
 839                         result = -EBUSY;
 840                 else {
 841                         vd->owner = file;
 842                         vd->owner_pid = current->pid;
 843                         result = 0;
 844                 }
 845         }
 846         up_write(&card->controls_rwsem);
 847         return result;
 848 }
 849
 850 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 851                                struct snd_ctl_elem_id __user *_id)
 852 {
 853         struct snd_card *card = file->card;
 854         struct snd_ctl_elem_id id;
 855         struct snd_kcontrol *kctl;
 856         struct snd_kcontrol_volatile *vd;
 857         int result;
 858
 859         if (copy_from_user(&id, _id, sizeof(id)))
 860                 return -EFAULT;
 861         down_write(&card->controls_rwsem);
 862         kctl = snd_ctl_find_id(card, &id);
 863         if (kctl == NULL) {
 864                 result = -ENOENT;
 865         } else {
 866                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 867                 if (vd->owner == NULL)
 868                         result = -EINVAL;
 869                 else if (vd->owner != file)
 870                         result = -EPERM;
 871                 else {
 872                         vd->owner = NULL;
 873                         vd->owner_pid = 0;
 874                         result = 0;
 875                 }
 876         }
 877         up_write(&card->controls_rwsem);
 878         return result;
 879 }
 880
 881 struct user_element {
 882         struct snd_ctl_elem_info info;
 883         void *elem_data;                /* element data */
 884         unsigned long elem_data_size;   /* size of element data in bytes */
 885         void *priv_data;                /* private data (like strings for enumerated type) */
 886         unsigned long priv_data_size;   /* size of private data in bytes */
 887 };
 888
 889 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 890                                   struct snd_ctl_elem_info *uinfo)
 891 {
 892         struct user_element *ue = kcontrol->private_data;
 893
 894         *uinfo = ue->info;
 895         return 0;
 896 }
 897
 898 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 899                                  struct snd_ctl_elem_value *ucontrol)
 900 {
 901         struct user_element *ue = kcontrol->private_data;
 902
 903         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 904         return 0;
 905 }
 906
 907 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 908                                  struct snd_ctl_elem_value *ucontrol)
 909 {
 910         int change;
 911         struct user_element *ue = kcontrol->private_data;
 912
 913         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 914         if (change)
 915                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 916         return change;
 917 }
 918
 919 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 920 {
 921         kfree(kcontrol->private_data);
 922 }
 923
 924 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 925                             struct snd_ctl_elem_info *info, int replace)
 926 {
 927         struct snd_card *card = file->card;
 928         struct snd_kcontrol kctl, *_kctl;
 929         unsigned int access;
 930         long private_size;
 931         struct user_element *ue;
 932         int idx, err;
 933
 934         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 935                 return -ENOMEM;
 936         if (info->count > 1024)
 937                 return -EINVAL;
 938         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 939                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 940                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE));
 941         info->id.numid = 0;
 942         memset(&kctl, 0, sizeof(kctl));
 943         down_write(&card->controls_rwsem);
 944         _kctl = snd_ctl_find_id(card, &info->id);
 945         err = 0;
 946         if (_kctl) {
 947                 if (replace)
 948                         err = snd_ctl_remove(card, _kctl);
 949                 else
 950                         err = -EBUSY;
 951         } else {
 952                 if (replace)
 953                         err = -ENOENT;
 954         }
 955         up_write(&card->controls_rwsem);
 956         if (err < 0)
 957                 return err;
 958         memcpy(&kctl.id, &info->id, sizeof(info->id));
 959         kctl.count = info->owner ? info->owner : 1;
 960         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 961         kctl.info = snd_ctl_elem_user_info;
 962         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 963                 kctl.get = snd_ctl_elem_user_get;
 964         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 965                 kctl.put = snd_ctl_elem_user_put;
 966         switch (info->type) {
 967         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 968                 private_size = sizeof(char);
 969                 if (info->count > 128)
 970                         return -EINVAL;
 971                 break;
 972         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 973                 private_size = sizeof(long);
 974                 if (info->count > 128)
 975                         return -EINVAL;
 976                 break;
 977         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 978                 private_size = sizeof(long long);
 979                 if (info->count > 64)
 980                         return -EINVAL;
 981                 break;
 982         case SNDRV_CTL_ELEM_TYPE_BYTES:
 983                 private_size = sizeof(unsigned char);
 984                 if (info->count > 512)
 985                         return -EINVAL;
 986                 break;
 987         case SNDRV_CTL_ELEM_TYPE_IEC958:
 988                 private_size = sizeof(struct snd_aes_iec958);
 989                 if (info->count != 1)
 990                         return -EINVAL;
 991                 break;
 992         default:
 993                 return -EINVAL;
 994         }
 995         private_size *= info->count;
 996         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
 997         if (ue == NULL)
 998                 return -ENOMEM;
 999         ue->info = *info;
1000         ue->elem_data = (char *)ue + sizeof(*ue);
1001         ue->elem_data_size = private_size;
1002         kctl.private_free = snd_ctl_elem_user_free;
1003         _kctl = snd_ctl_new(&kctl, access);
1004         if (_kctl == NULL) {
1005                 kfree(ue);
1006                 return -ENOMEM;
1007         }
1008         _kctl->private_data = ue;
1009         for (idx = 0; idx < _kctl->count; idx++)
1010                 _kctl->vd[idx].owner = file;
1011         err = snd_ctl_add(card, _kctl);
1012         if (err < 0)
1013                 return err;
1014
1015         down_write(&card->controls_rwsem);
1016         card->user_ctl_count++;
1017         up_write(&card->controls_rwsem);
1018
1019         return 0;
1020 }
1021
1022 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1023                                  struct snd_ctl_elem_info __user *_info, int replace)
1024 {
1025         struct snd_ctl_elem_info info;
1026         if (copy_from_user(&info, _info, sizeof(info)))
1027                 return -EFAULT;
1028         return snd_ctl_elem_add(file, &info, replace);
1029 }
1030
1031 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1032                                struct snd_ctl_elem_id __user *_id)
1033 {
1034         struct snd_ctl_elem_id id;
1035         int err;
1036
1037         if (copy_from_user(&id, _id, sizeof(id)))
1038                 return -EFAULT;
1039         err = snd_ctl_remove_unlocked_id(file, &id);
1040         if (! err) {
1041                 struct snd_card *card = file->card;
1042                 down_write(&card->controls_rwsem);
1043                 card->user_ctl_count--;
1044                 up_write(&card->controls_rwsem);
1045         }
1046         return err;
1047 }
1048
1049 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1050 {
1051         int subscribe;
1052         if (get_user(subscribe, ptr))
1053                 return -EFAULT;
1054         if (subscribe < 0) {
1055                 subscribe = file->subscribed;
1056                 if (put_user(subscribe, ptr))
1057                         return -EFAULT;
1058                 return 0;
1059         }
1060         if (subscribe) {
1061                 file->subscribed = 1;
1062                 return 0;
1063         } else if (file->subscribed) {
1064                 snd_ctl_empty_read_queue(file);
1065                 file->subscribed = 0;
1066         }
1067         return 0;
1068 }
1069
1070 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1071 {
1072         struct snd_ctl_file *ctl;
1073         struct snd_card *card;
1074         struct list_head *list;
1075         struct snd_kctl_ioctl *p;
1076         void __user *argp = (void __user *)arg;
1077         int __user *ip = argp;
1078         int err;
1079
1080         ctl = file->private_data;
1081         card = ctl->card;
1082         snd_assert(card != NULL, return -ENXIO);
1083         switch (cmd) {
1084         case SNDRV_CTL_IOCTL_PVERSION:
1085                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1086         case SNDRV_CTL_IOCTL_CARD_INFO:
1087                 return snd_ctl_card_info(card, ctl, cmd, argp);
1088         case SNDRV_CTL_IOCTL_ELEM_LIST:
1089                 return snd_ctl_elem_list(ctl->card, argp);
1090         case SNDRV_CTL_IOCTL_ELEM_INFO:
1091                 return snd_ctl_elem_info_user(ctl, argp);
1092         case SNDRV_CTL_IOCTL_ELEM_READ:
1093                 return snd_ctl_elem_read_user(ctl->card, argp);
1094         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1095                 return snd_ctl_elem_write_user(ctl, argp);
1096         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1097                 return snd_ctl_elem_lock(ctl, argp);
1098         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1099                 return snd_ctl_elem_unlock(ctl, argp);
1100         case SNDRV_CTL_IOCTL_ELEM_ADD:
1101                 return snd_ctl_elem_add_user(ctl, argp, 0);
1102         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1103                 return snd_ctl_elem_add_user(ctl, argp, 1);
1104         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1105                 return snd_ctl_elem_remove(ctl, argp);
1106         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1107                 return snd_ctl_subscribe_events(ctl, ip);
1108         case SNDRV_CTL_IOCTL_POWER:
1109                 return -ENOPROTOOPT;
1110         case SNDRV_CTL_IOCTL_POWER_STATE:
1111 #ifdef CONFIG_PM
1112                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1113 #else
1114                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1115 #endif
1116         }
1117         down_read(&snd_ioctl_rwsem);
1118         list_for_each(list, &snd_control_ioctls) {
1119                 p = list_entry(list, struct snd_kctl_ioctl, list);
1120                 err = p->fioctl(card, ctl, cmd, arg);
1121                 if (err != -ENOIOCTLCMD) {
1122                         up_read(&snd_ioctl_rwsem);
1123                         return err;
1124                 }
1125         }
1126         up_read(&snd_ioctl_rwsem);
1127         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1128         return -ENOTTY;
1129 }
1130
1131 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1132                             size_t count, loff_t * offset)
1133 {
1134         struct snd_ctl_file *ctl;
1135         int err = 0;
1136         ssize_t result = 0;
1137
1138         ctl = file->private_data;
1139         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1140         if (!ctl->subscribed)
1141                 return -EBADFD;
1142         if (count < sizeof(struct snd_ctl_event))
1143                 return -EINVAL;
1144         spin_lock_irq(&ctl->read_lock);
1145         while (count >= sizeof(struct snd_ctl_event)) {
1146                 struct snd_ctl_event ev;
1147                 struct snd_kctl_event *kev;
1148                 while (list_empty(&ctl->events)) {
1149                         wait_queue_t wait;
1150                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1151                                 err = -EAGAIN;
1152                                 goto __end_lock;
1153                         }
1154                         init_waitqueue_entry(&wait, current);
1155                         add_wait_queue(&ctl->change_sleep, &wait);
1156                         set_current_state(TASK_INTERRUPTIBLE);
1157                         spin_unlock_irq(&ctl->read_lock);
1158                         schedule();
1159                         remove_wait_queue(&ctl->change_sleep, &wait);
1160                         if (signal_pending(current))
1161                                 return result > 0 ? result : -ERESTARTSYS;
1162                         spin_lock_irq(&ctl->read_lock);
1163                 }
1164                 kev = snd_kctl_event(ctl->events.next);
1165                 ev.type = SNDRV_CTL_EVENT_ELEM;
1166                 ev.data.elem.mask = kev->mask;
1167                 ev.data.elem.id = kev->id;
1168                 list_del(&kev->list);
1169                 spin_unlock_irq(&ctl->read_lock);
1170                 kfree(kev);
1171                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1172                         err = -EFAULT;
1173                         goto __end;
1174                 }
1175                 spin_lock_irq(&ctl->read_lock);
1176                 buffer += sizeof(struct snd_ctl_event);
1177                 count -= sizeof(struct snd_ctl_event);
1178                 result += sizeof(struct snd_ctl_event);
1179         }
1180       __end_lock:
1181         spin_unlock_irq(&ctl->read_lock);
1182       __end:
1183         return result > 0 ? result : err;
1184 }
1185
1186 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1187 {
1188         unsigned int mask;
1189         struct snd_ctl_file *ctl;
1190
1191         ctl = file->private_data;
1192         if (!ctl->subscribed)
1193                 return 0;
1194         poll_wait(file, &ctl->change_sleep, wait);
1195
1196         mask = 0;
1197         if (!list_empty(&ctl->events))
1198                 mask |= POLLIN | POLLRDNORM;
1199
1200         return mask;
1201 }
1202
1203 /*
1204  * register the device-specific control-ioctls.
1205  * called from each device manager like pcm.c, hwdep.c, etc.
1206  */
1207 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1208 {
1209         struct snd_kctl_ioctl *pn;
1210
1211         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1212         if (pn == NULL)
1213                 return -ENOMEM;
1214         pn->fioctl = fcn;
1215         down_write(&snd_ioctl_rwsem);
1216         list_add_tail(&pn->list, lists);
1217         up_write(&snd_ioctl_rwsem);
1218         return 0;
1219 }
1220
1221 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1222 {
1223         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1224 }
1225
1226 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1227
1228 #ifdef CONFIG_COMPAT
1229 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1230 {
1231         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1232 }
1233
1234 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1235 #endif
1236
1237 /*
1238  * de-register the device-specific control-ioctls.
1239  */
1240 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1241                                      struct list_head *lists)
1242 {
1243         struct list_head *list;
1244         struct snd_kctl_ioctl *p;
1245
1246         snd_assert(fcn != NULL, return -EINVAL);
1247         down_write(&snd_ioctl_rwsem);
1248         list_for_each(list, lists) {
1249                 p = list_entry(list, struct snd_kctl_ioctl, list);
1250                 if (p->fioctl == fcn) {
1251                         list_del(&p->list);
1252                         up_write(&snd_ioctl_rwsem);
1253                         kfree(p);
1254                         return 0;
1255                 }
1256         }
1257         up_write(&snd_ioctl_rwsem);
1258         snd_BUG();
1259         return -EINVAL;
1260 }
1261
1262 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1263 {
1264         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1265 }
1266
1267 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1268
1269 #ifdef CONFIG_COMPAT
1270 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1271 {
1272         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1273 }
1274
1275 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1276 #endif
1277
1278 static int snd_ctl_fasync(int fd, struct file * file, int on)
1279 {
1280         struct snd_ctl_file *ctl;
1281         int err;
1282         ctl = file->private_data;
1283         err = fasync_helper(fd, file, on, &ctl->fasync);
1284         if (err < 0)
1285                 return err;
1286         return 0;
1287 }
1288
1289 /*
1290  * ioctl32 compat
1291  */
1292 #ifdef CONFIG_COMPAT
1293 #include "control_compat.c"
1294 #else
1295 #define snd_ctl_ioctl_compat    NULL
1296 #endif
1297
1298 /*
1299  *  INIT PART
1300  */
1301
1302 static struct file_operations snd_ctl_f_ops =
1303 {
1304         .owner =        THIS_MODULE,
1305         .read =         snd_ctl_read,
1306         .open =         snd_ctl_open,
1307         .release =      snd_ctl_release,
1308         .poll =         snd_ctl_poll,
1309         .unlocked_ioctl =       snd_ctl_ioctl,
1310         .compat_ioctl = snd_ctl_ioctl_compat,
1311         .fasync =       snd_ctl_fasync,
1312 };
1313
1314 /*
1315  * registration of the control device
1316  */
1317 static int snd_ctl_dev_register(struct snd_device *device)
1318 {
1319         struct snd_card *card = device->device_data;
1320         int err, cardnum;
1321         char name[16];
1322
1323         snd_assert(card != NULL, return -ENXIO);
1324         cardnum = card->number;
1325         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1326         sprintf(name, "controlC%i", cardnum);
1327         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1328                                        &snd_ctl_f_ops, card, name)) < 0)
1329                 return err;
1330         return 0;
1331 }
1332
1333 /*
1334  * disconnection of the control device
1335  */
1336 static int snd_ctl_dev_disconnect(struct snd_device *device)
1337 {
1338         struct snd_card *card = device->device_data;
1339         struct list_head *flist;
1340         struct snd_ctl_file *ctl;
1341
1342         down_read(&card->controls_rwsem);
1343         list_for_each(flist, &card->ctl_files) {
1344                 ctl = snd_ctl_file(flist);
1345                 wake_up(&ctl->change_sleep);
1346                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1347         }
1348         up_read(&card->controls_rwsem);
1349         return 0;
1350 }
1351
1352 /*
1353  * free all controls
1354  */
1355 static int snd_ctl_dev_free(struct snd_device *device)
1356 {
1357         struct snd_card *card = device->device_data;
1358         struct snd_kcontrol *control;
1359
1360         down_write(&card->controls_rwsem);
1361         while (!list_empty(&card->controls)) {
1362                 control = snd_kcontrol(card->controls.next);
1363                 snd_ctl_remove(card, control);
1364         }
1365         up_write(&card->controls_rwsem);
1366         return 0;
1367 }
1368
1369 /*
1370  * de-registration of the control device
1371  */
1372 static int snd_ctl_dev_unregister(struct snd_device *device)
1373 {
1374         struct snd_card *card = device->device_data;
1375         int err, cardnum;
1376
1377         snd_assert(card != NULL, return -ENXIO);
1378         cardnum = card->number;
1379         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1380         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1381                                          card, -1)) < 0)
1382                 return err;
1383         return snd_ctl_dev_free(device);
1384 }
1385
1386 /*
1387  * create control core:
1388  * called from init.c
1389  */
1390 int snd_ctl_create(struct snd_card *card)
1391 {
1392         static struct snd_device_ops ops = {
1393                 .dev_free = snd_ctl_dev_free,
1394                 .dev_register = snd_ctl_dev_register,
1395                 .dev_disconnect = snd_ctl_dev_disconnect,
1396                 .dev_unregister = snd_ctl_dev_unregister
1397         };
1398
1399         snd_assert(card != NULL, return -ENXIO);
1400         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1401 }