SAFE public projects git trees. - safe/jmp/linux-2.6/blob - sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/threads.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/slab.h>
  25 #include <linux/vmalloc.h>
  26 #include <linux/time.h>
  27 #include <sound/core.h>
  28 #include <sound/minors.h>
  29 #include <sound/info.h>
  30 #include <sound/control.h>
  31
  32 /* max number of user-defined controls */
  33 #define MAX_USER_CONTROLS       32
  34
  35 struct snd_kctl_ioctl {
  36         struct list_head list;          /* list of all ioctls */
  37         snd_kctl_ioctl_func_t fioctl;
  38 };
  39
  40 static DECLARE_RWSEM(snd_ioctl_rwsem);
  41 static LIST_HEAD(snd_control_ioctls);
  42 #ifdef CONFIG_COMPAT
  43 static LIST_HEAD(snd_control_compat_ioctls);
  44 #endif
  45
  46 static int snd_ctl_open(struct inode *inode, struct file *file)
  47 {
  48         unsigned long flags;
  49         struct snd_card *card;
  50         struct snd_ctl_file *ctl;
  51         int err;
  52
  53         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  54         if (!card) {
  55                 err = -ENODEV;
  56                 goto __error1;
  57         }
  58         err = snd_card_file_add(card, file);
  59         if (err < 0) {
  60                 err = -ENODEV;
  61                 goto __error1;
  62         }
  63         if (!try_module_get(card->module)) {
  64                 err = -EFAULT;
  65                 goto __error2;
  66         }
  67         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  68         if (ctl == NULL) {
  69                 err = -ENOMEM;
  70                 goto __error;
  71         }
  72         INIT_LIST_HEAD(&ctl->events);
  73         init_waitqueue_head(&ctl->change_sleep);
  74         spin_lock_init(&ctl->read_lock);
  75         ctl->card = card;
  76         ctl->prefer_pcm_subdevice = -1;
  77         ctl->prefer_rawmidi_subdevice = -1;
  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         unsigned long flags;
  96         struct snd_kctl_event *cread;
  97
  98         spin_lock_irqsave(&ctl->read_lock, flags);
  99         while (!list_empty(&ctl->events)) {
 100                 cread = snd_kctl_event(ctl->events.next);
 101                 list_del(&cread->list);
 102                 kfree(cread);
 103         }
 104         spin_unlock_irqrestore(&ctl->read_lock, flags);
 105 }
 106
 107 static int snd_ctl_release(struct inode *inode, struct file *file)
 108 {
 109         unsigned long flags;
 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         file->private_data = NULL;
 117         card = ctl->card;
 118         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 119         list_del(&ctl->list);
 120         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 121         down_write(&card->controls_rwsem);
 122         list_for_each_entry(control, &card->controls, list)
 123                 for (idx = 0; idx < control->count; idx++)
 124                         if (control->vd[idx].owner == ctl)
 125                                 control->vd[idx].owner = NULL;
 126         up_write(&card->controls_rwsem);
 127         snd_ctl_empty_read_queue(ctl);
 128         kfree(ctl);
 129         module_put(card->module);
 130         snd_card_file_remove(card, file);
 131         return 0;
 132 }
 133
 134 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 135                     struct snd_ctl_elem_id *id)
 136 {
 137         unsigned long flags;
 138         struct snd_ctl_file *ctl;
 139         struct snd_kctl_event *ev;
 140
 141         if (snd_BUG_ON(!card || !id))
 142                 return;
 143         read_lock(&card->ctl_files_rwlock);
 144 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 145         card->mixer_oss_change_count++;
 146 #endif
 147         list_for_each_entry(ctl, &card->ctl_files, list) {
 148                 if (!ctl->subscribed)
 149                         continue;
 150                 spin_lock_irqsave(&ctl->read_lock, flags);
 151                 list_for_each_entry(ev, &ctl->events, list) {
 152                         if (ev->id.numid == id->numid) {
 153                                 ev->mask |= mask;
 154                                 goto _found;
 155                         }
 156                 }
 157                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 158                 if (ev) {
 159                         ev->id = *id;
 160                         ev->mask = mask;
 161                         list_add_tail(&ev->list, &ctl->events);
 162                 } else {
 163                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 164                 }
 165         _found:
 166                 wake_up(&ctl->change_sleep);
 167                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 168                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 169         }
 170         read_unlock(&card->ctl_files_rwlock);
 171 }
 172
 173 EXPORT_SYMBOL(snd_ctl_notify);
 174
 175 /**
 176  * snd_ctl_new - create a control instance from the template
 177  * @control: the control template
 178  * @access: the default control access
 179  *
 180  * Allocates a new struct snd_kcontrol instance and copies the given template
 181  * to the new instance. It does not copy volatile data (access).
 182  *
 183  * Returns the pointer of the new instance, or NULL on failure.
 184  */
 185 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 186                                         unsigned int access)
 187 {
 188         struct snd_kcontrol *kctl;
 189         unsigned int idx;
 190
 191         if (snd_BUG_ON(!control || !control->count))
 192                 return NULL;
 193         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 194         if (kctl == NULL) {
 195                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 196                 return NULL;
 197         }
 198         *kctl = *control;
 199         for (idx = 0; idx < kctl->count; idx++)
 200                 kctl->vd[idx].access = access;
 201         return kctl;
 202 }
 203
 204 /**
 205  * snd_ctl_new1 - create a control instance from the template
 206  * @ncontrol: the initialization record
 207  * @private_data: the private data to set
 208  *
 209  * Allocates a new struct snd_kcontrol instance and initialize from the given
 210  * template.  When the access field of ncontrol is 0, it's assumed as
 211  * READWRITE access. When the count field is 0, it's assumes as one.
 212  *
 213  * Returns the pointer of the newly generated instance, or NULL on failure.
 214  */
 215 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 216                                   void *private_data)
 217 {
 218         struct snd_kcontrol kctl;
 219         unsigned int access;
 220
 221         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 222                 return NULL;
 223         memset(&kctl, 0, sizeof(kctl));
 224         kctl.id.iface = ncontrol->iface;
 225         kctl.id.device = ncontrol->device;
 226         kctl.id.subdevice = ncontrol->subdevice;
 227         if (ncontrol->name) {
 228                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 229                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 230                         snd_printk(KERN_WARNING
 231                                    "Control name '%s' truncated to '%s'\n",
 232                                    ncontrol->name, kctl.id.name);
 233         }
 234         kctl.id.index = ncontrol->index;
 235         kctl.count = ncontrol->count ? ncontrol->count : 1;
 236         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 237                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 238                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 239                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 240                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 241         kctl.info = ncontrol->info;
 242         kctl.get = ncontrol->get;
 243         kctl.put = ncontrol->put;
 244         kctl.tlv.p = ncontrol->tlv.p;
 245         kctl.private_value = ncontrol->private_value;
 246         kctl.private_data = private_data;
 247         return snd_ctl_new(&kctl, access);
 248 }
 249
 250 EXPORT_SYMBOL(snd_ctl_new1);
 251
 252 /**
 253  * snd_ctl_free_one - release the control instance
 254  * @kcontrol: the control instance
 255  *
 256  * Releases the control instance created via snd_ctl_new()
 257  * or snd_ctl_new1().
 258  * Don't call this after the control was added to the card.
 259  */
 260 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 261 {
 262         if (kcontrol) {
 263                 if (kcontrol->private_free)
 264                         kcontrol->private_free(kcontrol);
 265                 kfree(kcontrol);
 266         }
 267 }
 268
 269 EXPORT_SYMBOL(snd_ctl_free_one);
 270
 271 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 272                                        unsigned int count)
 273 {
 274         struct snd_kcontrol *kctl;
 275
 276         list_for_each_entry(kctl, &card->controls, list) {
 277                 if ((kctl->id.numid <= card->last_numid &&
 278                      kctl->id.numid + kctl->count > card->last_numid) ||
 279                     (kctl->id.numid <= card->last_numid + count - 1 &&
 280                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 281                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 282         }
 283         return card->last_numid;
 284 }
 285
 286 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 287 {
 288         unsigned int last_numid, iter = 100000;
 289
 290         last_numid = card->last_numid;
 291         while (last_numid != snd_ctl_hole_check(card, count)) {
 292                 if (--iter == 0) {
 293                         /* this situation is very unlikely */
 294                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 295                         return -ENOMEM;
 296                 }
 297                 last_numid = card->last_numid;
 298         }
 299         return 0;
 300 }
 301
 302 /**
 303  * snd_ctl_add - add the control instance to the card
 304  * @card: the card instance
 305  * @kcontrol: the control instance to add
 306  *
 307  * Adds the control instance created via snd_ctl_new() or
 308  * snd_ctl_new1() to the given card. Assigns also an unique
 309  * numid used for fast search.
 310  *
 311  * Returns zero if successful, or a negative error code on failure.
 312  *
 313  * It frees automatically the control which cannot be added.
 314  */
 315 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 316 {
 317         struct snd_ctl_elem_id id;
 318         unsigned int idx;
 319         int err = -EINVAL;
 320
 321         if (! kcontrol)
 322                 return err;
 323         if (snd_BUG_ON(!card || !kcontrol->info))
 324                 goto error;
 325         id = kcontrol->id;
 326         down_write(&card->controls_rwsem);
 327         if (snd_ctl_find_id(card, &id)) {
 328                 up_write(&card->controls_rwsem);
 329                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 330                                         id.iface,
 331                                         id.device,
 332                                         id.subdevice,
 333                                         id.name,
 334                                         id.index);
 335                 err = -EBUSY;
 336                 goto error;
 337         }
 338         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 339                 up_write(&card->controls_rwsem);
 340                 err = -ENOMEM;
 341                 goto error;
 342         }
 343         list_add_tail(&kcontrol->list, &card->controls);
 344         card->controls_count += kcontrol->count;
 345         kcontrol->id.numid = card->last_numid + 1;
 346         card->last_numid += kcontrol->count;
 347         up_write(&card->controls_rwsem);
 348         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 349                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 350         return 0;
 351
 352  error:
 353         snd_ctl_free_one(kcontrol);
 354         return err;
 355 }
 356
 357 EXPORT_SYMBOL(snd_ctl_add);
 358
 359 /**
 360  * snd_ctl_remove - remove the control from the card and release it
 361  * @card: the card instance
 362  * @kcontrol: the control instance to remove
 363  *
 364  * Removes the control from the card and then releases the instance.
 365  * You don't need to call snd_ctl_free_one(). You must be in
 366  * the write lock - down_write(&card->controls_rwsem).
 367  *
 368  * Returns 0 if successful, or a negative error code on failure.
 369  */
 370 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 371 {
 372         struct snd_ctl_elem_id id;
 373         unsigned int idx;
 374
 375         if (snd_BUG_ON(!card || !kcontrol))
 376                 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                 ret = -ENOENT;
 437                 goto error;
 438         }
 439         for (idx = 0; idx < kctl->count; idx++)
 440                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 441                         ret = -EBUSY;
 442                         goto error;
 443                 }
 444         ret = snd_ctl_remove(card, kctl);
 445 error:
 446         up_write(&card->controls_rwsem);
 447         return ret;
 448 }
 449
 450 /**
 451  * snd_ctl_rename_id - replace the id of a control on the card
 452  * @card: the card instance
 453  * @src_id: the old id
 454  * @dst_id: the new id
 455  *
 456  * Finds the control with the old id from the card, and replaces the
 457  * id with the new one.
 458  *
 459  * Returns zero if successful, or a negative error code on failure.
 460  */
 461 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 462                       struct snd_ctl_elem_id *dst_id)
 463 {
 464         struct snd_kcontrol *kctl;
 465
 466         down_write(&card->controls_rwsem);
 467         kctl = snd_ctl_find_id(card, src_id);
 468         if (kctl == NULL) {
 469                 up_write(&card->controls_rwsem);
 470                 return -ENOENT;
 471         }
 472         kctl->id = *dst_id;
 473         kctl->id.numid = card->last_numid + 1;
 474         card->last_numid += kctl->count;
 475         up_write(&card->controls_rwsem);
 476         return 0;
 477 }
 478
 479 EXPORT_SYMBOL(snd_ctl_rename_id);
 480
 481 /**
 482  * snd_ctl_find_numid - find the control instance with the given number-id
 483  * @card: the card instance
 484  * @numid: the number-id to search
 485  *
 486  * Finds the control instance with the given number-id from the card.
 487  *
 488  * Returns the pointer of the instance if found, or NULL if not.
 489  *
 490  * The caller must down card->controls_rwsem before calling this function
 491  * (if the race condition can happen).
 492  */
 493 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 494 {
 495         struct snd_kcontrol *kctl;
 496
 497         if (snd_BUG_ON(!card || !numid))
 498                 return NULL;
 499         list_for_each_entry(kctl, &card->controls, 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 snd_kcontrol *kctl;
 524
 525         if (snd_BUG_ON(!card || !id))
 526                 return NULL;
 527         if (id->numid != 0)
 528                 return snd_ctl_find_numid(card, id->numid);
 529         list_for_each_entry(kctl, &card->controls, list) {
 530                 if (kctl->id.iface != id->iface)
 531                         continue;
 532                 if (kctl->id.device != id->device)
 533                         continue;
 534                 if (kctl->id.subdevice != id->subdevice)
 535                         continue;
 536                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 537                         continue;
 538                 if (kctl->id.index > id->index)
 539                         continue;
 540                 if (kctl->id.index + kctl->count <= id->index)
 541                         continue;
 542                 return kctl;
 543         }
 544         return NULL;
 545 }
 546
 547 EXPORT_SYMBOL(snd_ctl_find_id);
 548
 549 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 550                              unsigned int cmd, void __user *arg)
 551 {
 552         struct snd_ctl_card_info *info;
 553
 554         info = kzalloc(sizeof(*info), GFP_KERNEL);
 555         if (! info)
 556                 return -ENOMEM;
 557         down_read(&snd_ioctl_rwsem);
 558         info->card = card->number;
 559         strlcpy(info->id, card->id, sizeof(info->id));
 560         strlcpy(info->driver, card->driver, sizeof(info->driver));
 561         strlcpy(info->name, card->shortname, sizeof(info->name));
 562         strlcpy(info->longname, card->longname, sizeof(info->longname));
 563         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 564         strlcpy(info->components, card->components, sizeof(info->components));
 565         up_read(&snd_ioctl_rwsem);
 566         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 567                 kfree(info);
 568                 return -EFAULT;
 569         }
 570         kfree(info);
 571         return 0;
 572 }
 573
 574 static int snd_ctl_elem_list(struct snd_card *card,
 575                              struct snd_ctl_elem_list __user *_list)
 576 {
 577         struct list_head *plist;
 578         struct snd_ctl_elem_list list;
 579         struct snd_kcontrol *kctl;
 580         struct snd_ctl_elem_id *dst, *id;
 581         unsigned int offset, space, first, jidx;
 582
 583         if (copy_from_user(&list, _list, sizeof(list)))
 584                 return -EFAULT;
 585         offset = list.offset;
 586         space = list.space;
 587         first = 0;
 588         /* try limit maximum space */
 589         if (space > 16384)
 590                 return -ENOMEM;
 591         if (space > 0) {
 592                 /* allocate temporary buffer for atomic operation */
 593                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 594                 if (dst == NULL)
 595                         return -ENOMEM;
 596                 down_read(&card->controls_rwsem);
 597                 list.count = card->controls_count;
 598                 plist = card->controls.next;
 599                 while (plist != &card->controls) {
 600                         if (offset == 0)
 601                                 break;
 602                         kctl = snd_kcontrol(plist);
 603                         if (offset < kctl->count)
 604                                 break;
 605                         offset -= kctl->count;
 606                         plist = plist->next;
 607                 }
 608                 list.used = 0;
 609                 id = dst;
 610                 while (space > 0 && plist != &card->controls) {
 611                         kctl = snd_kcontrol(plist);
 612                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 613                                 snd_ctl_build_ioff(id, kctl, jidx);
 614                                 id++;
 615                                 space--;
 616                                 list.used++;
 617                         }
 618                         plist = plist->next;
 619                         offset = 0;
 620                 }
 621                 up_read(&card->controls_rwsem);
 622                 if (list.used > 0 &&
 623                     copy_to_user(list.pids, dst,
 624                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 625                         vfree(dst);
 626                         return -EFAULT;
 627                 }
 628                 vfree(dst);
 629         } else {
 630                 down_read(&card->controls_rwsem);
 631                 list.count = card->controls_count;
 632                 up_read(&card->controls_rwsem);
 633         }
 634         if (copy_to_user(_list, &list, sizeof(list)))
 635                 return -EFAULT;
 636         return 0;
 637 }
 638
 639 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 640                              struct snd_ctl_elem_info *info)
 641 {
 642         struct snd_card *card = ctl->card;
 643         struct snd_kcontrol *kctl;
 644         struct snd_kcontrol_volatile *vd;
 645         unsigned int index_offset;
 646         int result;
 647
 648         down_read(&card->controls_rwsem);
 649         kctl = snd_ctl_find_id(card, &info->id);
 650         if (kctl == NULL) {
 651                 up_read(&card->controls_rwsem);
 652                 return -ENOENT;
 653         }
 654 #ifdef CONFIG_SND_DEBUG
 655         info->access = 0;
 656 #endif
 657         result = kctl->info(kctl, info);
 658         if (result >= 0) {
 659                 snd_BUG_ON(info->access);
 660                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 661                 vd = &kctl->vd[index_offset];
 662                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 663                 info->access = vd->access;
 664                 if (vd->owner) {
 665                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 666                         if (vd->owner == ctl)
 667                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 668                         info->owner = vd->owner_pid;
 669                 } else {
 670                         info->owner = -1;
 671                 }
 672         }
 673         up_read(&card->controls_rwsem);
 674         return result;
 675 }
 676
 677 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 678                                   struct snd_ctl_elem_info __user *_info)
 679 {
 680         struct snd_ctl_elem_info info;
 681         int result;
 682
 683         if (copy_from_user(&info, _info, sizeof(info)))
 684                 return -EFAULT;
 685         snd_power_lock(ctl->card);
 686         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 687         if (result >= 0)
 688                 result = snd_ctl_elem_info(ctl, &info);
 689         snd_power_unlock(ctl->card);
 690         if (result >= 0)
 691                 if (copy_to_user(_info, &info, sizeof(info)))
 692                         return -EFAULT;
 693         return result;
 694 }
 695
 696 static int snd_ctl_elem_read(struct snd_card *card,
 697                              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;
 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                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 712                     kctl->get != NULL) {
 713                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 714                         result = kctl->get(kctl, control);
 715                 } else
 716                         result = -EPERM;
 717         }
 718         up_read(&card->controls_rwsem);
 719         return result;
 720 }
 721
 722 static int snd_ctl_elem_read_user(struct snd_card *card,
 723                                   struct snd_ctl_elem_value __user *_control)
 724 {
 725         struct snd_ctl_elem_value *control;
 726         int result;
 727
 728         control = memdup_user(_control, sizeof(*control));
 729         if (IS_ERR(control))
 730                 return PTR_ERR(control);
 731
 732         snd_power_lock(card);
 733         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 734         if (result >= 0)
 735                 result = snd_ctl_elem_read(card, control);
 736         snd_power_unlock(card);
 737         if (result >= 0)
 738                 if (copy_to_user(_control, control, sizeof(*control)))
 739                         result = -EFAULT;
 740         kfree(control);
 741         return result;
 742 }
 743
 744 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 745                               struct snd_ctl_elem_value *control)
 746 {
 747         struct snd_kcontrol *kctl;
 748         struct snd_kcontrol_volatile *vd;
 749         unsigned int index_offset;
 750         int result;
 751
 752         down_read(&card->controls_rwsem);
 753         kctl = snd_ctl_find_id(card, &control->id);
 754         if (kctl == NULL) {
 755                 result = -ENOENT;
 756         } else {
 757                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 758                 vd = &kctl->vd[index_offset];
 759                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 760                     kctl->put == NULL ||
 761                     (file && vd->owner && vd->owner != file)) {
 762                         result = -EPERM;
 763                 } else {
 764                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 765                         result = kctl->put(kctl, control);
 766                 }
 767                 if (result > 0) {
 768                         up_read(&card->controls_rwsem);
 769                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 770                                        &control->id);
 771                         return 0;
 772                 }
 773         }
 774         up_read(&card->controls_rwsem);
 775         return result;
 776 }
 777
 778 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 779                                    struct snd_ctl_elem_value __user *_control)
 780 {
 781         struct snd_ctl_elem_value *control;
 782         struct snd_card *card;
 783         int result;
 784
 785         control = memdup_user(_control, sizeof(*control));
 786         if (IS_ERR(control))
 787                 return PTR_ERR(control);
 788
 789         card = file->card;
 790         snd_power_lock(card);
 791         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 792         if (result >= 0)
 793                 result = snd_ctl_elem_write(card, file, control);
 794         snd_power_unlock(card);
 795         if (result >= 0)
 796                 if (copy_to_user(_control, control, sizeof(*control)))
 797                         result = -EFAULT;
 798         kfree(control);
 799         return result;
 800 }
 801
 802 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 803                              struct snd_ctl_elem_id __user *_id)
 804 {
 805         struct snd_card *card = file->card;
 806         struct snd_ctl_elem_id id;
 807         struct snd_kcontrol *kctl;
 808         struct snd_kcontrol_volatile *vd;
 809         int result;
 810
 811         if (copy_from_user(&id, _id, sizeof(id)))
 812                 return -EFAULT;
 813         down_write(&card->controls_rwsem);
 814         kctl = snd_ctl_find_id(card, &id);
 815         if (kctl == NULL) {
 816                 result = -ENOENT;
 817         } else {
 818                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 819                 if (vd->owner != NULL)
 820                         result = -EBUSY;
 821                 else {
 822                         vd->owner = file;
 823                         vd->owner_pid = current->pid;
 824                         result = 0;
 825                 }
 826         }
 827         up_write(&card->controls_rwsem);
 828         return result;
 829 }
 830
 831 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 832                                struct snd_ctl_elem_id __user *_id)
 833 {
 834         struct snd_card *card = file->card;
 835         struct snd_ctl_elem_id id;
 836         struct snd_kcontrol *kctl;
 837         struct snd_kcontrol_volatile *vd;
 838         int result;
 839
 840         if (copy_from_user(&id, _id, sizeof(id)))
 841                 return -EFAULT;
 842         down_write(&card->controls_rwsem);
 843         kctl = snd_ctl_find_id(card, &id);
 844         if (kctl == NULL) {
 845                 result = -ENOENT;
 846         } else {
 847                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 848                 if (vd->owner == NULL)
 849                         result = -EINVAL;
 850                 else if (vd->owner != file)
 851                         result = -EPERM;
 852                 else {
 853                         vd->owner = NULL;
 854                         vd->owner_pid = 0;
 855                         result = 0;
 856                 }
 857         }
 858         up_write(&card->controls_rwsem);
 859         return result;
 860 }
 861
 862 struct user_element {
 863         struct snd_ctl_elem_info info;
 864         void *elem_data;                /* element data */
 865         unsigned long elem_data_size;   /* size of element data in bytes */
 866         void *tlv_data;                 /* TLV data */
 867         unsigned long tlv_data_size;    /* TLV data size */
 868         void *priv_data;                /* private data (like strings for enumerated type) */
 869         unsigned long priv_data_size;   /* size of private data in bytes */
 870 };
 871
 872 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 873                                   struct snd_ctl_elem_info *uinfo)
 874 {
 875         struct user_element *ue = kcontrol->private_data;
 876
 877         *uinfo = ue->info;
 878         return 0;
 879 }
 880
 881 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 882                                  struct snd_ctl_elem_value *ucontrol)
 883 {
 884         struct user_element *ue = kcontrol->private_data;
 885
 886         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 887         return 0;
 888 }
 889
 890 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 891                                  struct snd_ctl_elem_value *ucontrol)
 892 {
 893         int change;
 894         struct user_element *ue = kcontrol->private_data;
 895
 896         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 897         if (change)
 898                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 899         return change;
 900 }
 901
 902 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 903                                  int op_flag,
 904                                  unsigned int size,
 905                                  unsigned int __user *tlv)
 906 {
 907         struct user_element *ue = kcontrol->private_data;
 908         int change = 0;
 909         void *new_data;
 910
 911         if (op_flag > 0) {
 912                 if (size > 1024 * 128)  /* sane value */
 913                         return -EINVAL;
 914
 915                 new_data = memdup_user(tlv, size);
 916                 if (IS_ERR(new_data))
 917                         return PTR_ERR(new_data);
 918                 change = ue->tlv_data_size != size;
 919                 if (!change)
 920                         change = memcmp(ue->tlv_data, new_data, size);
 921                 kfree(ue->tlv_data);
 922                 ue->tlv_data = new_data;
 923                 ue->tlv_data_size = size;
 924         } else {
 925                 if (! ue->tlv_data_size || ! ue->tlv_data)
 926                         return -ENXIO;
 927                 if (size < ue->tlv_data_size)
 928                         return -ENOSPC;
 929                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 930                         return -EFAULT;
 931         }
 932         return change;
 933 }
 934
 935 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 936 {
 937         struct user_element *ue = kcontrol->private_data;
 938         if (ue->tlv_data)
 939                 kfree(ue->tlv_data);
 940         kfree(ue);
 941 }
 942
 943 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 944                             struct snd_ctl_elem_info *info, int replace)
 945 {
 946         struct snd_card *card = file->card;
 947         struct snd_kcontrol kctl, *_kctl;
 948         unsigned int access;
 949         long private_size;
 950         struct user_element *ue;
 951         int idx, err;
 952
 953         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 954                 return -ENOMEM;
 955         if (info->count < 1)
 956                 return -EINVAL;
 957         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 958                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 959                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 960                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 961         info->id.numid = 0;
 962         memset(&kctl, 0, sizeof(kctl));
 963         down_write(&card->controls_rwsem);
 964         _kctl = snd_ctl_find_id(card, &info->id);
 965         err = 0;
 966         if (_kctl) {
 967                 if (replace)
 968                         err = snd_ctl_remove(card, _kctl);
 969                 else
 970                         err = -EBUSY;
 971         } else {
 972                 if (replace)
 973                         err = -ENOENT;
 974         }
 975         up_write(&card->controls_rwsem);
 976         if (err < 0)
 977                 return err;
 978         memcpy(&kctl.id, &info->id, sizeof(info->id));
 979         kctl.count = info->owner ? info->owner : 1;
 980         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 981         kctl.info = snd_ctl_elem_user_info;
 982         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 983                 kctl.get = snd_ctl_elem_user_get;
 984         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 985                 kctl.put = snd_ctl_elem_user_put;
 986         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 987                 kctl.tlv.c = snd_ctl_elem_user_tlv;
 988                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 989         }
 990         switch (info->type) {
 991         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 992         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 993                 private_size = sizeof(long);
 994                 if (info->count > 128)
 995                         return -EINVAL;
 996                 break;
 997         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 998                 private_size = sizeof(long long);
 999                 if (info->count > 64)
1000                         return -EINVAL;
1001                 break;
1002         case SNDRV_CTL_ELEM_TYPE_BYTES:
1003                 private_size = sizeof(unsigned char);
1004                 if (info->count > 512)
1005                         return -EINVAL;
1006                 break;
1007         case SNDRV_CTL_ELEM_TYPE_IEC958:
1008                 private_size = sizeof(struct snd_aes_iec958);
1009                 if (info->count != 1)
1010                         return -EINVAL;
1011                 break;
1012         default:
1013                 return -EINVAL;
1014         }
1015         private_size *= info->count;
1016         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1017         if (ue == NULL)
1018                 return -ENOMEM;
1019         ue->info = *info;
1020         ue->info.access = 0;
1021         ue->elem_data = (char *)ue + sizeof(*ue);
1022         ue->elem_data_size = private_size;
1023         kctl.private_free = snd_ctl_elem_user_free;
1024         _kctl = snd_ctl_new(&kctl, access);
1025         if (_kctl == NULL) {
1026                 kfree(ue);
1027                 return -ENOMEM;
1028         }
1029         _kctl->private_data = ue;
1030         for (idx = 0; idx < _kctl->count; idx++)
1031                 _kctl->vd[idx].owner = file;
1032         err = snd_ctl_add(card, _kctl);
1033         if (err < 0)
1034                 return err;
1035
1036         down_write(&card->controls_rwsem);
1037         card->user_ctl_count++;
1038         up_write(&card->controls_rwsem);
1039
1040         return 0;
1041 }
1042
1043 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1044                                  struct snd_ctl_elem_info __user *_info, int replace)
1045 {
1046         struct snd_ctl_elem_info info;
1047         if (copy_from_user(&info, _info, sizeof(info)))
1048                 return -EFAULT;
1049         return snd_ctl_elem_add(file, &info, replace);
1050 }
1051
1052 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1053                                struct snd_ctl_elem_id __user *_id)
1054 {
1055         struct snd_ctl_elem_id id;
1056         int err;
1057
1058         if (copy_from_user(&id, _id, sizeof(id)))
1059                 return -EFAULT;
1060         err = snd_ctl_remove_unlocked_id(file, &id);
1061         if (! err) {
1062                 struct snd_card *card = file->card;
1063                 down_write(&card->controls_rwsem);
1064                 card->user_ctl_count--;
1065                 up_write(&card->controls_rwsem);
1066         }
1067         return err;
1068 }
1069
1070 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1071 {
1072         int subscribe;
1073         if (get_user(subscribe, ptr))
1074                 return -EFAULT;
1075         if (subscribe < 0) {
1076                 subscribe = file->subscribed;
1077                 if (put_user(subscribe, ptr))
1078                         return -EFAULT;
1079                 return 0;
1080         }
1081         if (subscribe) {
1082                 file->subscribed = 1;
1083                 return 0;
1084         } else if (file->subscribed) {
1085                 snd_ctl_empty_read_queue(file);
1086                 file->subscribed = 0;
1087         }
1088         return 0;
1089 }
1090
1091 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1092                              struct snd_ctl_tlv __user *_tlv,
1093                              int op_flag)
1094 {
1095         struct snd_card *card = file->card;
1096         struct snd_ctl_tlv tlv;
1097         struct snd_kcontrol *kctl;
1098         struct snd_kcontrol_volatile *vd;
1099         unsigned int len;
1100         int err = 0;
1101
1102         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1103                 return -EFAULT;
1104         if (tlv.length < sizeof(unsigned int) * 3)
1105                 return -EINVAL;
1106         down_read(&card->controls_rwsem);
1107         kctl = snd_ctl_find_numid(card, tlv.numid);
1108         if (kctl == NULL) {
1109                 err = -ENOENT;
1110                 goto __kctl_end;
1111         }
1112         if (kctl->tlv.p == NULL) {
1113                 err = -ENXIO;
1114                 goto __kctl_end;
1115         }
1116         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1117         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1118             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1119             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1120                 err = -ENXIO;
1121                 goto __kctl_end;
1122         }
1123         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1124                 if (file && vd->owner != NULL && vd->owner != file) {
1125                         err = -EPERM;
1126                         goto __kctl_end;
1127                 }
1128                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1129                 if (err > 0) {
1130                         up_read(&card->controls_rwsem);
1131                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1132                         return 0;
1133                 }
1134         } else {
1135                 if (op_flag) {
1136                         err = -ENXIO;
1137                         goto __kctl_end;
1138                 }
1139                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1140                 if (tlv.length < len) {
1141                         err = -ENOMEM;
1142                         goto __kctl_end;
1143                 }
1144                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1145                         err = -EFAULT;
1146         }
1147       __kctl_end:
1148         up_read(&card->controls_rwsem);
1149         return err;
1150 }
1151
1152 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1153 {
1154         struct snd_ctl_file *ctl;
1155         struct snd_card *card;
1156         struct snd_kctl_ioctl *p;
1157         void __user *argp = (void __user *)arg;
1158         int __user *ip = argp;
1159         int err;
1160
1161         ctl = file->private_data;
1162         card = ctl->card;
1163         if (snd_BUG_ON(!card))
1164                 return -ENXIO;
1165         switch (cmd) {
1166         case SNDRV_CTL_IOCTL_PVERSION:
1167                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1168         case SNDRV_CTL_IOCTL_CARD_INFO:
1169                 return snd_ctl_card_info(card, ctl, cmd, argp);
1170         case SNDRV_CTL_IOCTL_ELEM_LIST:
1171                 return snd_ctl_elem_list(card, argp);
1172         case SNDRV_CTL_IOCTL_ELEM_INFO:
1173                 return snd_ctl_elem_info_user(ctl, argp);
1174         case SNDRV_CTL_IOCTL_ELEM_READ:
1175                 return snd_ctl_elem_read_user(card, argp);
1176         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1177                 return snd_ctl_elem_write_user(ctl, argp);
1178         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1179                 return snd_ctl_elem_lock(ctl, argp);
1180         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1181                 return snd_ctl_elem_unlock(ctl, argp);
1182         case SNDRV_CTL_IOCTL_ELEM_ADD:
1183                 return snd_ctl_elem_add_user(ctl, argp, 0);
1184         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1185                 return snd_ctl_elem_add_user(ctl, argp, 1);
1186         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1187                 return snd_ctl_elem_remove(ctl, argp);
1188         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1189                 return snd_ctl_subscribe_events(ctl, ip);
1190         case SNDRV_CTL_IOCTL_TLV_READ:
1191                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1192         case SNDRV_CTL_IOCTL_TLV_WRITE:
1193                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1194         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1195                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1196         case SNDRV_CTL_IOCTL_POWER:
1197                 return -ENOPROTOOPT;
1198         case SNDRV_CTL_IOCTL_POWER_STATE:
1199 #ifdef CONFIG_PM
1200                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1201 #else
1202                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1203 #endif
1204         }
1205         down_read(&snd_ioctl_rwsem);
1206         list_for_each_entry(p, &snd_control_ioctls, list) {
1207                 err = p->fioctl(card, ctl, cmd, arg);
1208                 if (err != -ENOIOCTLCMD) {
1209                         up_read(&snd_ioctl_rwsem);
1210                         return err;
1211                 }
1212         }
1213         up_read(&snd_ioctl_rwsem);
1214         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1215         return -ENOTTY;
1216 }
1217
1218 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1219                             size_t count, loff_t * offset)
1220 {
1221         struct snd_ctl_file *ctl;
1222         int err = 0;
1223         ssize_t result = 0;
1224
1225         ctl = file->private_data;
1226         if (snd_BUG_ON(!ctl || !ctl->card))
1227                 return -ENXIO;
1228         if (!ctl->subscribed)
1229                 return -EBADFD;
1230         if (count < sizeof(struct snd_ctl_event))
1231                 return -EINVAL;
1232         spin_lock_irq(&ctl->read_lock);
1233         while (count >= sizeof(struct snd_ctl_event)) {
1234                 struct snd_ctl_event ev;
1235                 struct snd_kctl_event *kev;
1236                 while (list_empty(&ctl->events)) {
1237                         wait_queue_t wait;
1238                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1239                                 err = -EAGAIN;
1240                                 goto __end_lock;
1241                         }
1242                         init_waitqueue_entry(&wait, current);
1243                         add_wait_queue(&ctl->change_sleep, &wait);
1244                         set_current_state(TASK_INTERRUPTIBLE);
1245                         spin_unlock_irq(&ctl->read_lock);
1246                         schedule();
1247                         remove_wait_queue(&ctl->change_sleep, &wait);
1248                         if (signal_pending(current))
1249                                 return -ERESTARTSYS;
1250                         spin_lock_irq(&ctl->read_lock);
1251                 }
1252                 kev = snd_kctl_event(ctl->events.next);
1253                 ev.type = SNDRV_CTL_EVENT_ELEM;
1254                 ev.data.elem.mask = kev->mask;
1255                 ev.data.elem.id = kev->id;
1256                 list_del(&kev->list);
1257                 spin_unlock_irq(&ctl->read_lock);
1258                 kfree(kev);
1259                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1260                         err = -EFAULT;
1261                         goto __end;
1262                 }
1263                 spin_lock_irq(&ctl->read_lock);
1264                 buffer += sizeof(struct snd_ctl_event);
1265                 count -= sizeof(struct snd_ctl_event);
1266                 result += sizeof(struct snd_ctl_event);
1267         }
1268       __end_lock:
1269         spin_unlock_irq(&ctl->read_lock);
1270       __end:
1271         return result > 0 ? result : err;
1272 }
1273
1274 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1275 {
1276         unsigned int mask;
1277         struct snd_ctl_file *ctl;
1278
1279         ctl = file->private_data;
1280         if (!ctl->subscribed)
1281                 return 0;
1282         poll_wait(file, &ctl->change_sleep, wait);
1283
1284         mask = 0;
1285         if (!list_empty(&ctl->events))
1286                 mask |= POLLIN | POLLRDNORM;
1287
1288         return mask;
1289 }
1290
1291 /*
1292  * register the device-specific control-ioctls.
1293  * called from each device manager like pcm.c, hwdep.c, etc.
1294  */
1295 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1296 {
1297         struct snd_kctl_ioctl *pn;
1298
1299         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1300         if (pn == NULL)
1301                 return -ENOMEM;
1302         pn->fioctl = fcn;
1303         down_write(&snd_ioctl_rwsem);
1304         list_add_tail(&pn->list, lists);
1305         up_write(&snd_ioctl_rwsem);
1306         return 0;
1307 }
1308
1309 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1310 {
1311         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1312 }
1313
1314 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1315
1316 #ifdef CONFIG_COMPAT
1317 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1318 {
1319         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1320 }
1321
1322 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1323 #endif
1324
1325 /*
1326  * de-register the device-specific control-ioctls.
1327  */
1328 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1329                                      struct list_head *lists)
1330 {
1331         struct snd_kctl_ioctl *p;
1332
1333         if (snd_BUG_ON(!fcn))
1334                 return -EINVAL;
1335         down_write(&snd_ioctl_rwsem);
1336         list_for_each_entry(p, lists, list) {
1337                 if (p->fioctl == fcn) {
1338                         list_del(&p->list);
1339                         up_write(&snd_ioctl_rwsem);
1340                         kfree(p);
1341                         return 0;
1342                 }
1343         }
1344         up_write(&snd_ioctl_rwsem);
1345         snd_BUG();
1346         return -EINVAL;
1347 }
1348
1349 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1350 {
1351         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1352 }
1353
1354 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1355
1356 #ifdef CONFIG_COMPAT
1357 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1358 {
1359         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1360 }
1361
1362 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1363 #endif
1364
1365 static int snd_ctl_fasync(int fd, struct file * file, int on)
1366 {
1367         struct snd_ctl_file *ctl;
1368
1369         ctl = file->private_data;
1370         return fasync_helper(fd, file, on, &ctl->fasync);
1371 }
1372
1373 /*
1374  * ioctl32 compat
1375  */
1376 #ifdef CONFIG_COMPAT
1377 #include "control_compat.c"
1378 #else
1379 #define snd_ctl_ioctl_compat    NULL
1380 #endif
1381
1382 /*
1383  *  INIT PART
1384  */
1385
1386 static const struct file_operations snd_ctl_f_ops =
1387 {
1388         .owner =        THIS_MODULE,
1389         .read =         snd_ctl_read,
1390         .open =         snd_ctl_open,
1391         .release =      snd_ctl_release,
1392         .poll =         snd_ctl_poll,
1393         .unlocked_ioctl =       snd_ctl_ioctl,
1394         .compat_ioctl = snd_ctl_ioctl_compat,
1395         .fasync =       snd_ctl_fasync,
1396 };
1397
1398 /*
1399  * registration of the control device
1400  */
1401 static int snd_ctl_dev_register(struct snd_device *device)
1402 {
1403         struct snd_card *card = device->device_data;
1404         int err, cardnum;
1405         char name[16];
1406
1407         if (snd_BUG_ON(!card))
1408                 return -ENXIO;
1409         cardnum = card->number;
1410         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1411                 return -ENXIO;
1412         sprintf(name, "controlC%i", cardnum);
1413         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1414                                        &snd_ctl_f_ops, card, name)) < 0)
1415                 return err;
1416         return 0;
1417 }
1418
1419 /*
1420  * disconnection of the control device
1421  */
1422 static int snd_ctl_dev_disconnect(struct snd_device *device)
1423 {
1424         struct snd_card *card = device->device_data;
1425         struct snd_ctl_file *ctl;
1426         int err, cardnum;
1427
1428         if (snd_BUG_ON(!card))
1429                 return -ENXIO;
1430         cardnum = card->number;
1431         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1432                 return -ENXIO;
1433
1434         read_lock(&card->ctl_files_rwlock);
1435         list_for_each_entry(ctl, &card->ctl_files, list) {
1436                 wake_up(&ctl->change_sleep);
1437                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1438         }
1439         read_unlock(&card->ctl_files_rwlock);
1440
1441         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1442                                          card, -1)) < 0)
1443                 return err;
1444         return 0;
1445 }
1446
1447 /*
1448  * free all controls
1449  */
1450 static int snd_ctl_dev_free(struct snd_device *device)
1451 {
1452         struct snd_card *card = device->device_data;
1453         struct snd_kcontrol *control;
1454
1455         down_write(&card->controls_rwsem);
1456         while (!list_empty(&card->controls)) {
1457                 control = snd_kcontrol(card->controls.next);
1458                 snd_ctl_remove(card, control);
1459         }
1460         up_write(&card->controls_rwsem);
1461         return 0;
1462 }
1463
1464 /*
1465  * create control core:
1466  * called from init.c
1467  */
1468 int snd_ctl_create(struct snd_card *card)
1469 {
1470         static struct snd_device_ops ops = {
1471                 .dev_free = snd_ctl_dev_free,
1472                 .dev_register = snd_ctl_dev_register,
1473                 .dev_disconnect = snd_ctl_dev_disconnect,
1474         };
1475
1476         if (snd_BUG_ON(!card))
1477                 return -ENXIO;
1478         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1479 }
1480
1481 /*
1482  * Frequently used control callbacks
1483  */
1484 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1485                               struct snd_ctl_elem_info *uinfo)
1486 {
1487         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1488         uinfo->count = 1;
1489         uinfo->value.integer.min = 0;
1490         uinfo->value.integer.max = 1;
1491         return 0;
1492 }
1493
1494 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1495
1496 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1497                                 struct snd_ctl_elem_info *uinfo)
1498 {
1499         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1500         uinfo->count = 2;
1501         uinfo->value.integer.min = 0;
1502         uinfo->value.integer.max = 1;
1503         return 0;
1504 }
1505
1506 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);