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         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_entry(control, &card->controls, list)
 124                 for (idx = 0; idx < control->count; idx++)
 125                         if (control->vd[idx].owner == ctl)
 126                                 control->vd[idx].owner = NULL;
 127         up_write(&card->controls_rwsem);
 128         snd_ctl_empty_read_queue(ctl);
 129         kfree(ctl);
 130         module_put(card->module);
 131         snd_card_file_remove(card, file);
 132         return 0;
 133 }
 134
 135 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 136                     struct snd_ctl_elem_id *id)
 137 {
 138         unsigned long flags;
 139         struct snd_ctl_file *ctl;
 140         struct snd_kctl_event *ev;
 141
 142         if (snd_BUG_ON(!card || !id))
 143                 return;
 144         read_lock(&card->ctl_files_rwlock);
 145 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 146         card->mixer_oss_change_count++;
 147 #endif
 148         list_for_each_entry(ctl, &card->ctl_files, list) {
 149                 if (!ctl->subscribed)
 150                         continue;
 151                 spin_lock_irqsave(&ctl->read_lock, flags);
 152                 list_for_each_entry(ev, &ctl->events, list) {
 153                         if (ev->id.numid == id->numid) {
 154                                 ev->mask |= mask;
 155                                 goto _found;
 156                         }
 157                 }
 158                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 159                 if (ev) {
 160                         ev->id = *id;
 161                         ev->mask = mask;
 162                         list_add_tail(&ev->list, &ctl->events);
 163                 } else {
 164                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 165                 }
 166         _found:
 167                 wake_up(&ctl->change_sleep);
 168                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 169                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 170         }
 171         read_unlock(&card->ctl_files_rwlock);
 172 }
 173
 174 EXPORT_SYMBOL(snd_ctl_notify);
 175
 176 /**
 177  * snd_ctl_new - create a control instance from the template
 178  * @control: the control template
 179  * @access: the default control access
 180  *
 181  * Allocates a new struct snd_kcontrol instance and copies the given template
 182  * to the new instance. It does not copy volatile data (access).
 183  *
 184  * Returns the pointer of the new instance, or NULL on failure.
 185  */
 186 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 187                                         unsigned int access)
 188 {
 189         struct snd_kcontrol *kctl;
 190         unsigned int idx;
 191
 192         if (snd_BUG_ON(!control || !control->count))
 193                 return NULL;
 194         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 195         if (kctl == NULL) {
 196                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 197                 return NULL;
 198         }
 199         *kctl = *control;
 200         for (idx = 0; idx < kctl->count; idx++)
 201                 kctl->vd[idx].access = access;
 202         return kctl;
 203 }
 204
 205 /**
 206  * snd_ctl_new1 - create a control instance from the template
 207  * @ncontrol: the initialization record
 208  * @private_data: the private data to set
 209  *
 210  * Allocates a new struct snd_kcontrol instance and initialize from the given
 211  * template.  When the access field of ncontrol is 0, it's assumed as
 212  * READWRITE access. When the count field is 0, it's assumes as one.
 213  *
 214  * Returns the pointer of the newly generated instance, or NULL on failure.
 215  */
 216 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 217                                   void *private_data)
 218 {
 219         struct snd_kcontrol kctl;
 220         unsigned int access;
 221
 222         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 223                 return NULL;
 224         memset(&kctl, 0, sizeof(kctl));
 225         kctl.id.iface = ncontrol->iface;
 226         kctl.id.device = ncontrol->device;
 227         kctl.id.subdevice = ncontrol->subdevice;
 228         if (ncontrol->name)
 229                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 230         kctl.id.index = ncontrol->index;
 231         kctl.count = ncontrol->count ? ncontrol->count : 1;
 232         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 233                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 234                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 235                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 236                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 237         kctl.info = ncontrol->info;
 238         kctl.get = ncontrol->get;
 239         kctl.put = ncontrol->put;
 240         kctl.tlv.p = ncontrol->tlv.p;
 241         kctl.private_value = ncontrol->private_value;
 242         kctl.private_data = private_data;
 243         return snd_ctl_new(&kctl, access);
 244 }
 245
 246 EXPORT_SYMBOL(snd_ctl_new1);
 247
 248 /**
 249  * snd_ctl_free_one - release the control instance
 250  * @kcontrol: the control instance
 251  *
 252  * Releases the control instance created via snd_ctl_new()
 253  * or snd_ctl_new1().
 254  * Don't call this after the control was added to the card.
 255  */
 256 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 257 {
 258         if (kcontrol) {
 259                 if (kcontrol->private_free)
 260                         kcontrol->private_free(kcontrol);
 261                 kfree(kcontrol);
 262         }
 263 }
 264
 265 EXPORT_SYMBOL(snd_ctl_free_one);
 266
 267 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 268                                        unsigned int count)
 269 {
 270         struct snd_kcontrol *kctl;
 271
 272         list_for_each_entry(kctl, &card->controls, list) {
 273                 if ((kctl->id.numid <= card->last_numid &&
 274                      kctl->id.numid + kctl->count > card->last_numid) ||
 275                     (kctl->id.numid <= card->last_numid + count - 1 &&
 276                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 277                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 278         }
 279         return card->last_numid;
 280 }
 281
 282 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 283 {
 284         unsigned int last_numid, iter = 100000;
 285
 286         last_numid = card->last_numid;
 287         while (last_numid != snd_ctl_hole_check(card, count)) {
 288                 if (--iter == 0) {
 289                         /* this situation is very unlikely */
 290                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 291                         return -ENOMEM;
 292                 }
 293                 last_numid = card->last_numid;
 294         }
 295         return 0;
 296 }
 297
 298 /**
 299  * snd_ctl_add - add the control instance to the card
 300  * @card: the card instance
 301  * @kcontrol: the control instance to add
 302  *
 303  * Adds the control instance created via snd_ctl_new() or
 304  * snd_ctl_new1() to the given card. Assigns also an unique
 305  * numid used for fast search.
 306  *
 307  * Returns zero if successful, or a negative error code on failure.
 308  *
 309  * It frees automatically the control which cannot be added.
 310  */
 311 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 312 {
 313         struct snd_ctl_elem_id id;
 314         unsigned int idx;
 315         int err = -EINVAL;
 316
 317         if (! kcontrol)
 318                 return err;
 319         if (snd_BUG_ON(!card || !kcontrol->info))
 320                 goto error;
 321         id = kcontrol->id;
 322         down_write(&card->controls_rwsem);
 323         if (snd_ctl_find_id(card, &id)) {
 324                 up_write(&card->controls_rwsem);
 325                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 326                                         id.iface,
 327                                         id.device,
 328                                         id.subdevice,
 329                                         id.name,
 330                                         id.index);
 331                 err = -EBUSY;
 332                 goto error;
 333         }
 334         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 335                 up_write(&card->controls_rwsem);
 336                 err = -ENOMEM;
 337                 goto error;
 338         }
 339         list_add_tail(&kcontrol->list, &card->controls);
 340         card->controls_count += kcontrol->count;
 341         kcontrol->id.numid = card->last_numid + 1;
 342         card->last_numid += kcontrol->count;
 343         up_write(&card->controls_rwsem);
 344         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 345                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 346         return 0;
 347
 348  error:
 349         snd_ctl_free_one(kcontrol);
 350         return err;
 351 }
 352
 353 EXPORT_SYMBOL(snd_ctl_add);
 354
 355 /**
 356  * snd_ctl_remove - remove the control from the card and release it
 357  * @card: the card instance
 358  * @kcontrol: the control instance to remove
 359  *
 360  * Removes the control from the card and then releases the instance.
 361  * You don't need to call snd_ctl_free_one(). You must be in
 362  * the write lock - down_write(&card->controls_rwsem).
 363  *
 364  * Returns 0 if successful, or a negative error code on failure.
 365  */
 366 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 367 {
 368         struct snd_ctl_elem_id id;
 369         unsigned int idx;
 370
 371         if (snd_BUG_ON(!card || !kcontrol))
 372                 return -EINVAL;
 373         list_del(&kcontrol->list);
 374         card->controls_count -= kcontrol->count;
 375         id = kcontrol->id;
 376         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 377                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 378         snd_ctl_free_one(kcontrol);
 379         return 0;
 380 }
 381
 382 EXPORT_SYMBOL(snd_ctl_remove);
 383
 384 /**
 385  * snd_ctl_remove_id - remove the control of the given id and release it
 386  * @card: the card instance
 387  * @id: the control id to remove
 388  *
 389  * Finds the control instance with the given id, removes it from the
 390  * card list and releases it.
 391  *
 392  * Returns 0 if successful, or a negative error code on failure.
 393  */
 394 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 395 {
 396         struct snd_kcontrol *kctl;
 397         int ret;
 398
 399         down_write(&card->controls_rwsem);
 400         kctl = snd_ctl_find_id(card, id);
 401         if (kctl == NULL) {
 402                 up_write(&card->controls_rwsem);
 403                 return -ENOENT;
 404         }
 405         ret = snd_ctl_remove(card, kctl);
 406         up_write(&card->controls_rwsem);
 407         return ret;
 408 }
 409
 410 EXPORT_SYMBOL(snd_ctl_remove_id);
 411
 412 /**
 413  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 414  * @file: active control handle
 415  * @id: the control id to remove
 416  *
 417  * Finds the control instance with the given id, removes it from the
 418  * card list and releases it.
 419  *
 420  * Returns 0 if successful, or a negative error code on failure.
 421  */
 422 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 423                                       struct snd_ctl_elem_id *id)
 424 {
 425         struct snd_card *card = file->card;
 426         struct snd_kcontrol *kctl;
 427         int idx, ret;
 428
 429         down_write(&card->controls_rwsem);
 430         kctl = snd_ctl_find_id(card, id);
 431         if (kctl == NULL) {
 432                 up_write(&card->controls_rwsem);
 433                 return -ENOENT;
 434         }
 435         for (idx = 0; idx < kctl->count; idx++)
 436                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 437                         up_write(&card->controls_rwsem);
 438                         return -EBUSY;
 439                 }
 440         ret = snd_ctl_remove(card, kctl);
 441         up_write(&card->controls_rwsem);
 442         return ret;
 443 }
 444
 445 /**
 446  * snd_ctl_rename_id - replace the id of a control on the card
 447  * @card: the card instance
 448  * @src_id: the old id
 449  * @dst_id: the new id
 450  *
 451  * Finds the control with the old id from the card, and replaces the
 452  * id with the new one.
 453  *
 454  * Returns zero if successful, or a negative error code on failure.
 455  */
 456 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 457                       struct snd_ctl_elem_id *dst_id)
 458 {
 459         struct snd_kcontrol *kctl;
 460
 461         down_write(&card->controls_rwsem);
 462         kctl = snd_ctl_find_id(card, src_id);
 463         if (kctl == NULL) {
 464                 up_write(&card->controls_rwsem);
 465                 return -ENOENT;
 466         }
 467         kctl->id = *dst_id;
 468         kctl->id.numid = card->last_numid + 1;
 469         card->last_numid += kctl->count;
 470         up_write(&card->controls_rwsem);
 471         return 0;
 472 }
 473
 474 EXPORT_SYMBOL(snd_ctl_rename_id);
 475
 476 /**
 477  * snd_ctl_find_numid - find the control instance with the given number-id
 478  * @card: the card instance
 479  * @numid: the number-id to search
 480  *
 481  * Finds the control instance with the given number-id from the card.
 482  *
 483  * Returns the pointer of the instance if found, or NULL if not.
 484  *
 485  * The caller must down card->controls_rwsem before calling this function
 486  * (if the race condition can happen).
 487  */
 488 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 489 {
 490         struct snd_kcontrol *kctl;
 491
 492         if (snd_BUG_ON(!card || !numid))
 493                 return NULL;
 494         list_for_each_entry(kctl, &card->controls, list) {
 495                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 496                         return kctl;
 497         }
 498         return NULL;
 499 }
 500
 501 EXPORT_SYMBOL(snd_ctl_find_numid);
 502
 503 /**
 504  * snd_ctl_find_id - find the control instance with the given id
 505  * @card: the card instance
 506  * @id: the id to search
 507  *
 508  * Finds the control instance with the given id from the card.
 509  *
 510  * Returns the pointer of the instance if found, or NULL if not.
 511  *
 512  * The caller must down card->controls_rwsem before calling this function
 513  * (if the race condition can happen).
 514  */
 515 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 516                                      struct snd_ctl_elem_id *id)
 517 {
 518         struct snd_kcontrol *kctl;
 519
 520         if (snd_BUG_ON(!card || !id))
 521                 return NULL;
 522         if (id->numid != 0)
 523                 return snd_ctl_find_numid(card, id->numid);
 524         list_for_each_entry(kctl, &card->controls, list) {
 525                 if (kctl->id.iface != id->iface)
 526                         continue;
 527                 if (kctl->id.device != id->device)
 528                         continue;
 529                 if (kctl->id.subdevice != id->subdevice)
 530                         continue;
 531                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 532                         continue;
 533                 if (kctl->id.index > id->index)
 534                         continue;
 535                 if (kctl->id.index + kctl->count <= id->index)
 536                         continue;
 537                 return kctl;
 538         }
 539         return NULL;
 540 }
 541
 542 EXPORT_SYMBOL(snd_ctl_find_id);
 543
 544 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 545                              unsigned int cmd, void __user *arg)
 546 {
 547         struct snd_ctl_card_info *info;
 548
 549         info = kzalloc(sizeof(*info), GFP_KERNEL);
 550         if (! info)
 551                 return -ENOMEM;
 552         down_read(&snd_ioctl_rwsem);
 553         info->card = card->number;
 554         strlcpy(info->id, card->id, sizeof(info->id));
 555         strlcpy(info->driver, card->driver, sizeof(info->driver));
 556         strlcpy(info->name, card->shortname, sizeof(info->name));
 557         strlcpy(info->longname, card->longname, sizeof(info->longname));
 558         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 559         strlcpy(info->components, card->components, sizeof(info->components));
 560         up_read(&snd_ioctl_rwsem);
 561         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 562                 kfree(info);
 563                 return -EFAULT;
 564         }
 565         kfree(info);
 566         return 0;
 567 }
 568
 569 static int snd_ctl_elem_list(struct snd_card *card,
 570                              struct snd_ctl_elem_list __user *_list)
 571 {
 572         struct list_head *plist;
 573         struct snd_ctl_elem_list list;
 574         struct snd_kcontrol *kctl;
 575         struct snd_ctl_elem_id *dst, *id;
 576         unsigned int offset, space, first, jidx;
 577
 578         if (copy_from_user(&list, _list, sizeof(list)))
 579                 return -EFAULT;
 580         offset = list.offset;
 581         space = list.space;
 582         first = 0;
 583         /* try limit maximum space */
 584         if (space > 16384)
 585                 return -ENOMEM;
 586         if (space > 0) {
 587                 /* allocate temporary buffer for atomic operation */
 588                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 589                 if (dst == NULL)
 590                         return -ENOMEM;
 591                 down_read(&card->controls_rwsem);
 592                 list.count = card->controls_count;
 593                 plist = card->controls.next;
 594                 while (plist != &card->controls) {
 595                         if (offset == 0)
 596                                 break;
 597                         kctl = snd_kcontrol(plist);
 598                         if (offset < kctl->count)
 599                                 break;
 600                         offset -= kctl->count;
 601                         plist = plist->next;
 602                 }
 603                 list.used = 0;
 604                 id = dst;
 605                 while (space > 0 && plist != &card->controls) {
 606                         kctl = snd_kcontrol(plist);
 607                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 608                                 snd_ctl_build_ioff(id, kctl, jidx);
 609                                 id++;
 610                                 space--;
 611                                 list.used++;
 612                         }
 613                         plist = plist->next;
 614                         offset = 0;
 615                 }
 616                 up_read(&card->controls_rwsem);
 617                 if (list.used > 0 &&
 618                     copy_to_user(list.pids, dst,
 619                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 620                         vfree(dst);
 621                         return -EFAULT;
 622                 }
 623                 vfree(dst);
 624         } else {
 625                 down_read(&card->controls_rwsem);
 626                 list.count = card->controls_count;
 627                 up_read(&card->controls_rwsem);
 628         }
 629         if (copy_to_user(_list, &list, sizeof(list)))
 630                 return -EFAULT;
 631         return 0;
 632 }
 633
 634 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 635                              struct snd_ctl_elem_info *info)
 636 {
 637         struct snd_card *card = ctl->card;
 638         struct snd_kcontrol *kctl;
 639         struct snd_kcontrol_volatile *vd;
 640         unsigned int index_offset;
 641         int result;
 642
 643         down_read(&card->controls_rwsem);
 644         kctl = snd_ctl_find_id(card, &info->id);
 645         if (kctl == NULL) {
 646                 up_read(&card->controls_rwsem);
 647                 return -ENOENT;
 648         }
 649 #ifdef CONFIG_SND_DEBUG
 650         info->access = 0;
 651 #endif
 652         result = kctl->info(kctl, info);
 653         if (result >= 0) {
 654                 snd_BUG_ON(info->access);
 655                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 656                 vd = &kctl->vd[index_offset];
 657                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 658                 info->access = vd->access;
 659                 if (vd->owner) {
 660                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 661                         if (vd->owner == ctl)
 662                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 663                         info->owner = vd->owner_pid;
 664                 } else {
 665                         info->owner = -1;
 666                 }
 667         }
 668         up_read(&card->controls_rwsem);
 669         return result;
 670 }
 671
 672 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 673                                   struct snd_ctl_elem_info __user *_info)
 674 {
 675         struct snd_ctl_elem_info info;
 676         int result;
 677
 678         if (copy_from_user(&info, _info, sizeof(info)))
 679                 return -EFAULT;
 680         snd_power_lock(ctl->card);
 681         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 682         if (result >= 0)
 683                 result = snd_ctl_elem_info(ctl, &info);
 684         snd_power_unlock(ctl->card);
 685         if (result >= 0)
 686                 if (copy_to_user(_info, &info, sizeof(info)))
 687                         return -EFAULT;
 688         return result;
 689 }
 690
 691 static int snd_ctl_elem_read(struct snd_card *card,
 692                              struct snd_ctl_elem_value *control)
 693 {
 694         struct snd_kcontrol *kctl;
 695         struct snd_kcontrol_volatile *vd;
 696         unsigned int index_offset;
 697         int result;
 698
 699         down_read(&card->controls_rwsem);
 700         kctl = snd_ctl_find_id(card, &control->id);
 701         if (kctl == NULL) {
 702                 result = -ENOENT;
 703         } else {
 704                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 705                 vd = &kctl->vd[index_offset];
 706                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 707                     kctl->get != NULL) {
 708                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 709                         result = kctl->get(kctl, control);
 710                 } else
 711                         result = -EPERM;
 712         }
 713         up_read(&card->controls_rwsem);
 714         return result;
 715 }
 716
 717 static int snd_ctl_elem_read_user(struct snd_card *card,
 718                                   struct snd_ctl_elem_value __user *_control)
 719 {
 720         struct snd_ctl_elem_value *control;
 721         int result;
 722
 723         control = kmalloc(sizeof(*control), GFP_KERNEL);
 724         if (control == NULL)
 725                 return -ENOMEM;
 726         if (copy_from_user(control, _control, sizeof(*control))) {
 727                 kfree(control);
 728                 return -EFAULT;
 729         }
 730         snd_power_lock(card);
 731         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 732         if (result >= 0)
 733                 result = snd_ctl_elem_read(card, control);
 734         snd_power_unlock(card);
 735         if (result >= 0)
 736                 if (copy_to_user(_control, control, sizeof(*control)))
 737                         result = -EFAULT;
 738         kfree(control);
 739         return result;
 740 }
 741
 742 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 743                               struct snd_ctl_elem_value *control)
 744 {
 745         struct snd_kcontrol *kctl;
 746         struct snd_kcontrol_volatile *vd;
 747         unsigned int index_offset;
 748         int result;
 749
 750         down_read(&card->controls_rwsem);
 751         kctl = snd_ctl_find_id(card, &control->id);
 752         if (kctl == NULL) {
 753                 result = -ENOENT;
 754         } else {
 755                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 756                 vd = &kctl->vd[index_offset];
 757                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 758                     kctl->put == NULL ||
 759                     (file && vd->owner && vd->owner != file)) {
 760                         result = -EPERM;
 761                 } else {
 762                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 763                         result = kctl->put(kctl, control);
 764                 }
 765                 if (result > 0) {
 766                         up_read(&card->controls_rwsem);
 767                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 768                                        &control->id);
 769                         return 0;
 770                 }
 771         }
 772         up_read(&card->controls_rwsem);
 773         return result;
 774 }
 775
 776 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 777                                    struct snd_ctl_elem_value __user *_control)
 778 {
 779         struct snd_ctl_elem_value *control;
 780         struct snd_card *card;
 781         int result;
 782
 783         control = kmalloc(sizeof(*control), GFP_KERNEL);
 784         if (control == NULL)
 785                 return -ENOMEM;
 786         if (copy_from_user(control, _control, sizeof(*control))) {
 787                 kfree(control);
 788                 return -EFAULT;
 789         }
 790         card = file->card;
 791         snd_power_lock(card);
 792         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 793         if (result >= 0)
 794                 result = snd_ctl_elem_write(card, file, control);
 795         snd_power_unlock(card);
 796         if (result >= 0)
 797                 if (copy_to_user(_control, control, sizeof(*control)))
 798                         result = -EFAULT;
 799         kfree(control);
 800         return result;
 801 }
 802
 803 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 804                              struct snd_ctl_elem_id __user *_id)
 805 {
 806         struct snd_card *card = file->card;
 807         struct snd_ctl_elem_id id;
 808         struct snd_kcontrol *kctl;
 809         struct snd_kcontrol_volatile *vd;
 810         int result;
 811
 812         if (copy_from_user(&id, _id, sizeof(id)))
 813                 return -EFAULT;
 814         down_write(&card->controls_rwsem);
 815         kctl = snd_ctl_find_id(card, &id);
 816         if (kctl == NULL) {
 817                 result = -ENOENT;
 818         } else {
 819                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 820                 if (vd->owner != NULL)
 821                         result = -EBUSY;
 822                 else {
 823                         vd->owner = file;
 824                         vd->owner_pid = current->pid;
 825                         result = 0;
 826                 }
 827         }
 828         up_write(&card->controls_rwsem);
 829         return result;
 830 }
 831
 832 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 833                                struct snd_ctl_elem_id __user *_id)
 834 {
 835         struct snd_card *card = file->card;
 836         struct snd_ctl_elem_id id;
 837         struct snd_kcontrol *kctl;
 838         struct snd_kcontrol_volatile *vd;
 839         int result;
 840
 841         if (copy_from_user(&id, _id, sizeof(id)))
 842                 return -EFAULT;
 843         down_write(&card->controls_rwsem);
 844         kctl = snd_ctl_find_id(card, &id);
 845         if (kctl == NULL) {
 846                 result = -ENOENT;
 847         } else {
 848                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 849                 if (vd->owner == NULL)
 850                         result = -EINVAL;
 851                 else if (vd->owner != file)
 852                         result = -EPERM;
 853                 else {
 854                         vd->owner = NULL;
 855                         vd->owner_pid = 0;
 856                         result = 0;
 857                 }
 858         }
 859         up_write(&card->controls_rwsem);
 860         return result;
 861 }
 862
 863 struct user_element {
 864         struct snd_ctl_elem_info info;
 865         void *elem_data;                /* element data */
 866         unsigned long elem_data_size;   /* size of element data in bytes */
 867         void *tlv_data;                 /* TLV data */
 868         unsigned long tlv_data_size;    /* TLV data size */
 869         void *priv_data;                /* private data (like strings for enumerated type) */
 870         unsigned long priv_data_size;   /* size of private data in bytes */
 871 };
 872
 873 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 874                                   struct snd_ctl_elem_info *uinfo)
 875 {
 876         struct user_element *ue = kcontrol->private_data;
 877
 878         *uinfo = ue->info;
 879         return 0;
 880 }
 881
 882 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 883                                  struct snd_ctl_elem_value *ucontrol)
 884 {
 885         struct user_element *ue = kcontrol->private_data;
 886
 887         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 888         return 0;
 889 }
 890
 891 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 892                                  struct snd_ctl_elem_value *ucontrol)
 893 {
 894         int change;
 895         struct user_element *ue = kcontrol->private_data;
 896
 897         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 898         if (change)
 899                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 900         return change;
 901 }
 902
 903 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 904                                  int op_flag,
 905                                  unsigned int size,
 906                                  unsigned int __user *tlv)
 907 {
 908         struct user_element *ue = kcontrol->private_data;
 909         int change = 0;
 910         void *new_data;
 911
 912         if (op_flag > 0) {
 913                 if (size > 1024 * 128)  /* sane value */
 914                         return -EINVAL;
 915                 new_data = kmalloc(size, GFP_KERNEL);
 916                 if (new_data == NULL)
 917                         return -ENOMEM;
 918                 if (copy_from_user(new_data, tlv, size)) {
 919                         kfree(new_data);
 920                         return -EFAULT;
 921                 }
 922                 change = ue->tlv_data_size != size;
 923                 if (!change)
 924                         change = memcmp(ue->tlv_data, new_data, size);
 925                 kfree(ue->tlv_data);
 926                 ue->tlv_data = new_data;
 927                 ue->tlv_data_size = size;
 928         } else {
 929                 if (! ue->tlv_data_size || ! ue->tlv_data)
 930                         return -ENXIO;
 931                 if (size < ue->tlv_data_size)
 932                         return -ENOSPC;
 933                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 934                         return -EFAULT;
 935         }
 936         return change;
 937 }
 938
 939 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 940 {
 941         struct user_element *ue = kcontrol->private_data;
 942         if (ue->tlv_data)
 943                 kfree(ue->tlv_data);
 944         kfree(ue);
 945 }
 946
 947 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 948                             struct snd_ctl_elem_info *info, int replace)
 949 {
 950         struct snd_card *card = file->card;
 951         struct snd_kcontrol kctl, *_kctl;
 952         unsigned int access;
 953         long private_size;
 954         struct user_element *ue;
 955         int idx, err;
 956
 957         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 958                 return -ENOMEM;
 959         if (info->count > 1024)
 960                 return -EINVAL;
 961         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 962                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 963                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 964                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 965         info->id.numid = 0;
 966         memset(&kctl, 0, sizeof(kctl));
 967         down_write(&card->controls_rwsem);
 968         _kctl = snd_ctl_find_id(card, &info->id);
 969         err = 0;
 970         if (_kctl) {
 971                 if (replace)
 972                         err = snd_ctl_remove(card, _kctl);
 973                 else
 974                         err = -EBUSY;
 975         } else {
 976                 if (replace)
 977                         err = -ENOENT;
 978         }
 979         up_write(&card->controls_rwsem);
 980         if (err < 0)
 981                 return err;
 982         memcpy(&kctl.id, &info->id, sizeof(info->id));
 983         kctl.count = info->owner ? info->owner : 1;
 984         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 985         kctl.info = snd_ctl_elem_user_info;
 986         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 987                 kctl.get = snd_ctl_elem_user_get;
 988         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 989                 kctl.put = snd_ctl_elem_user_put;
 990         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 991                 kctl.tlv.c = snd_ctl_elem_user_tlv;
 992                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 993         }
 994         switch (info->type) {
 995         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 996         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 997                 private_size = sizeof(long);
 998                 if (info->count > 128)
 999                         return -EINVAL;
1000                 break;
1001         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1002                 private_size = sizeof(long long);
1003                 if (info->count > 64)
1004                         return -EINVAL;
1005                 break;
1006         case SNDRV_CTL_ELEM_TYPE_BYTES:
1007                 private_size = sizeof(unsigned char);
1008                 if (info->count > 512)
1009                         return -EINVAL;
1010                 break;
1011         case SNDRV_CTL_ELEM_TYPE_IEC958:
1012                 private_size = sizeof(struct snd_aes_iec958);
1013                 if (info->count != 1)
1014                         return -EINVAL;
1015                 break;
1016         default:
1017                 return -EINVAL;
1018         }
1019         private_size *= info->count;
1020         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1021         if (ue == NULL)
1022                 return -ENOMEM;
1023         ue->info = *info;
1024         ue->info.access = 0;
1025         ue->elem_data = (char *)ue + sizeof(*ue);
1026         ue->elem_data_size = private_size;
1027         kctl.private_free = snd_ctl_elem_user_free;
1028         _kctl = snd_ctl_new(&kctl, access);
1029         if (_kctl == NULL) {
1030                 kfree(ue);
1031                 return -ENOMEM;
1032         }
1033         _kctl->private_data = ue;
1034         for (idx = 0; idx < _kctl->count; idx++)
1035                 _kctl->vd[idx].owner = file;
1036         err = snd_ctl_add(card, _kctl);
1037         if (err < 0)
1038                 return err;
1039
1040         down_write(&card->controls_rwsem);
1041         card->user_ctl_count++;
1042         up_write(&card->controls_rwsem);
1043
1044         return 0;
1045 }
1046
1047 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1048                                  struct snd_ctl_elem_info __user *_info, int replace)
1049 {
1050         struct snd_ctl_elem_info info;
1051         if (copy_from_user(&info, _info, sizeof(info)))
1052                 return -EFAULT;
1053         return snd_ctl_elem_add(file, &info, replace);
1054 }
1055
1056 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1057                                struct snd_ctl_elem_id __user *_id)
1058 {
1059         struct snd_ctl_elem_id id;
1060         int err;
1061
1062         if (copy_from_user(&id, _id, sizeof(id)))
1063                 return -EFAULT;
1064         err = snd_ctl_remove_unlocked_id(file, &id);
1065         if (! err) {
1066                 struct snd_card *card = file->card;
1067                 down_write(&card->controls_rwsem);
1068                 card->user_ctl_count--;
1069                 up_write(&card->controls_rwsem);
1070         }
1071         return err;
1072 }
1073
1074 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1075 {
1076         int subscribe;
1077         if (get_user(subscribe, ptr))
1078                 return -EFAULT;
1079         if (subscribe < 0) {
1080                 subscribe = file->subscribed;
1081                 if (put_user(subscribe, ptr))
1082                         return -EFAULT;
1083                 return 0;
1084         }
1085         if (subscribe) {
1086                 file->subscribed = 1;
1087                 return 0;
1088         } else if (file->subscribed) {
1089                 snd_ctl_empty_read_queue(file);
1090                 file->subscribed = 0;
1091         }
1092         return 0;
1093 }
1094
1095 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1096                              struct snd_ctl_tlv __user *_tlv,
1097                              int op_flag)
1098 {
1099         struct snd_card *card = file->card;
1100         struct snd_ctl_tlv tlv;
1101         struct snd_kcontrol *kctl;
1102         struct snd_kcontrol_volatile *vd;
1103         unsigned int len;
1104         int err = 0;
1105
1106         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1107                 return -EFAULT;
1108         if (tlv.length < sizeof(unsigned int) * 3)
1109                 return -EINVAL;
1110         down_read(&card->controls_rwsem);
1111         kctl = snd_ctl_find_numid(card, tlv.numid);
1112         if (kctl == NULL) {
1113                 err = -ENOENT;
1114                 goto __kctl_end;
1115         }
1116         if (kctl->tlv.p == NULL) {
1117                 err = -ENXIO;
1118                 goto __kctl_end;
1119         }
1120         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1121         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1122             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1123             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1124                 err = -ENXIO;
1125                 goto __kctl_end;
1126         }
1127         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1128                 if (file && vd->owner != NULL && vd->owner != file) {
1129                         err = -EPERM;
1130                         goto __kctl_end;
1131                 }
1132                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1133                 if (err > 0) {
1134                         up_read(&card->controls_rwsem);
1135                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1136                         return 0;
1137                 }
1138         } else {
1139                 if (op_flag) {
1140                         err = -ENXIO;
1141                         goto __kctl_end;
1142                 }
1143                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1144                 if (tlv.length < len) {
1145                         err = -ENOMEM;
1146                         goto __kctl_end;
1147                 }
1148                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1149                         err = -EFAULT;
1150         }
1151       __kctl_end:
1152         up_read(&card->controls_rwsem);
1153         return err;
1154 }
1155
1156 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1157 {
1158         struct snd_ctl_file *ctl;
1159         struct snd_card *card;
1160         struct snd_kctl_ioctl *p;
1161         void __user *argp = (void __user *)arg;
1162         int __user *ip = argp;
1163         int err;
1164
1165         ctl = file->private_data;
1166         card = ctl->card;
1167         if (snd_BUG_ON(!card))
1168                 return -ENXIO;
1169         switch (cmd) {
1170         case SNDRV_CTL_IOCTL_PVERSION:
1171                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1172         case SNDRV_CTL_IOCTL_CARD_INFO:
1173                 return snd_ctl_card_info(card, ctl, cmd, argp);
1174         case SNDRV_CTL_IOCTL_ELEM_LIST:
1175                 return snd_ctl_elem_list(card, argp);
1176         case SNDRV_CTL_IOCTL_ELEM_INFO:
1177                 return snd_ctl_elem_info_user(ctl, argp);
1178         case SNDRV_CTL_IOCTL_ELEM_READ:
1179                 return snd_ctl_elem_read_user(card, argp);
1180         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1181                 return snd_ctl_elem_write_user(ctl, argp);
1182         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1183                 return snd_ctl_elem_lock(ctl, argp);
1184         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1185                 return snd_ctl_elem_unlock(ctl, argp);
1186         case SNDRV_CTL_IOCTL_ELEM_ADD:
1187                 return snd_ctl_elem_add_user(ctl, argp, 0);
1188         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1189                 return snd_ctl_elem_add_user(ctl, argp, 1);
1190         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1191                 return snd_ctl_elem_remove(ctl, argp);
1192         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1193                 return snd_ctl_subscribe_events(ctl, ip);
1194         case SNDRV_CTL_IOCTL_TLV_READ:
1195                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1196         case SNDRV_CTL_IOCTL_TLV_WRITE:
1197                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1198         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1199                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1200         case SNDRV_CTL_IOCTL_POWER:
1201                 return -ENOPROTOOPT;
1202         case SNDRV_CTL_IOCTL_POWER_STATE:
1203 #ifdef CONFIG_PM
1204                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1205 #else
1206                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1207 #endif
1208         }
1209         down_read(&snd_ioctl_rwsem);
1210         list_for_each_entry(p, &snd_control_ioctls, list) {
1211                 err = p->fioctl(card, ctl, cmd, arg);
1212                 if (err != -ENOIOCTLCMD) {
1213                         up_read(&snd_ioctl_rwsem);
1214                         return err;
1215                 }
1216         }
1217         up_read(&snd_ioctl_rwsem);
1218         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1219         return -ENOTTY;
1220 }
1221
1222 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1223                             size_t count, loff_t * offset)
1224 {
1225         struct snd_ctl_file *ctl;
1226         int err = 0;
1227         ssize_t result = 0;
1228
1229         ctl = file->private_data;
1230         if (snd_BUG_ON(!ctl || !ctl->card))
1231                 return -ENXIO;
1232         if (!ctl->subscribed)
1233                 return -EBADFD;
1234         if (count < sizeof(struct snd_ctl_event))
1235                 return -EINVAL;
1236         spin_lock_irq(&ctl->read_lock);
1237         while (count >= sizeof(struct snd_ctl_event)) {
1238                 struct snd_ctl_event ev;
1239                 struct snd_kctl_event *kev;
1240                 while (list_empty(&ctl->events)) {
1241                         wait_queue_t wait;
1242                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1243                                 err = -EAGAIN;
1244                                 goto __end_lock;
1245                         }
1246                         init_waitqueue_entry(&wait, current);
1247                         add_wait_queue(&ctl->change_sleep, &wait);
1248                         set_current_state(TASK_INTERRUPTIBLE);
1249                         spin_unlock_irq(&ctl->read_lock);
1250                         schedule();
1251                         remove_wait_queue(&ctl->change_sleep, &wait);
1252                         if (signal_pending(current))
1253                                 return -ERESTARTSYS;
1254                         spin_lock_irq(&ctl->read_lock);
1255                 }
1256                 kev = snd_kctl_event(ctl->events.next);
1257                 ev.type = SNDRV_CTL_EVENT_ELEM;
1258                 ev.data.elem.mask = kev->mask;
1259                 ev.data.elem.id = kev->id;
1260                 list_del(&kev->list);
1261                 spin_unlock_irq(&ctl->read_lock);
1262                 kfree(kev);
1263                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1264                         err = -EFAULT;
1265                         goto __end;
1266                 }
1267                 spin_lock_irq(&ctl->read_lock);
1268                 buffer += sizeof(struct snd_ctl_event);
1269                 count -= sizeof(struct snd_ctl_event);
1270                 result += sizeof(struct snd_ctl_event);
1271         }
1272       __end_lock:
1273         spin_unlock_irq(&ctl->read_lock);
1274       __end:
1275         return result > 0 ? result : err;
1276 }
1277
1278 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1279 {
1280         unsigned int mask;
1281         struct snd_ctl_file *ctl;
1282
1283         ctl = file->private_data;
1284         if (!ctl->subscribed)
1285                 return 0;
1286         poll_wait(file, &ctl->change_sleep, wait);
1287
1288         mask = 0;
1289         if (!list_empty(&ctl->events))
1290                 mask |= POLLIN | POLLRDNORM;
1291
1292         return mask;
1293 }
1294
1295 /*
1296  * register the device-specific control-ioctls.
1297  * called from each device manager like pcm.c, hwdep.c, etc.
1298  */
1299 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1300 {
1301         struct snd_kctl_ioctl *pn;
1302
1303         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1304         if (pn == NULL)
1305                 return -ENOMEM;
1306         pn->fioctl = fcn;
1307         down_write(&snd_ioctl_rwsem);
1308         list_add_tail(&pn->list, lists);
1309         up_write(&snd_ioctl_rwsem);
1310         return 0;
1311 }
1312
1313 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1314 {
1315         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1316 }
1317
1318 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1319
1320 #ifdef CONFIG_COMPAT
1321 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1322 {
1323         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1324 }
1325
1326 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1327 #endif
1328
1329 /*
1330  * de-register the device-specific control-ioctls.
1331  */
1332 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1333                                      struct list_head *lists)
1334 {
1335         struct snd_kctl_ioctl *p;
1336
1337         if (snd_BUG_ON(!fcn))
1338                 return -EINVAL;
1339         down_write(&snd_ioctl_rwsem);
1340         list_for_each_entry(p, lists, list) {
1341                 if (p->fioctl == fcn) {
1342                         list_del(&p->list);
1343                         up_write(&snd_ioctl_rwsem);
1344                         kfree(p);
1345                         return 0;
1346                 }
1347         }
1348         up_write(&snd_ioctl_rwsem);
1349         snd_BUG();
1350         return -EINVAL;
1351 }
1352
1353 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1354 {
1355         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1356 }
1357
1358 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1359
1360 #ifdef CONFIG_COMPAT
1361 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1362 {
1363         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1364 }
1365
1366 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1367 #endif
1368
1369 static int snd_ctl_fasync(int fd, struct file * file, int on)
1370 {
1371         struct snd_ctl_file *ctl;
1372         int err;
1373         ctl = file->private_data;
1374         err = fasync_helper(fd, file, on, &ctl->fasync);
1375         if (err < 0)
1376                 return err;
1377         return 0;
1378 }
1379
1380 /*
1381  * ioctl32 compat
1382  */
1383 #ifdef CONFIG_COMPAT
1384 #include "control_compat.c"
1385 #else
1386 #define snd_ctl_ioctl_compat    NULL
1387 #endif
1388
1389 /*
1390  *  INIT PART
1391  */
1392
1393 static const struct file_operations snd_ctl_f_ops =
1394 {
1395         .owner =        THIS_MODULE,
1396         .read =         snd_ctl_read,
1397         .open =         snd_ctl_open,
1398         .release =      snd_ctl_release,
1399         .poll =         snd_ctl_poll,
1400         .unlocked_ioctl =       snd_ctl_ioctl,
1401         .compat_ioctl = snd_ctl_ioctl_compat,
1402         .fasync =       snd_ctl_fasync,
1403 };
1404
1405 /*
1406  * registration of the control device
1407  */
1408 static int snd_ctl_dev_register(struct snd_device *device)
1409 {
1410         struct snd_card *card = device->device_data;
1411         int err, cardnum;
1412         char name[16];
1413
1414         if (snd_BUG_ON(!card))
1415                 return -ENXIO;
1416         cardnum = card->number;
1417         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1418                 return -ENXIO;
1419         sprintf(name, "controlC%i", cardnum);
1420         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1421                                        &snd_ctl_f_ops, card, name)) < 0)
1422                 return err;
1423         return 0;
1424 }
1425
1426 /*
1427  * disconnection of the control device
1428  */
1429 static int snd_ctl_dev_disconnect(struct snd_device *device)
1430 {
1431         struct snd_card *card = device->device_data;
1432         struct snd_ctl_file *ctl;
1433         int err, cardnum;
1434
1435         if (snd_BUG_ON(!card))
1436                 return -ENXIO;
1437         cardnum = card->number;
1438         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1439                 return -ENXIO;
1440
1441         read_lock(&card->ctl_files_rwlock);
1442         list_for_each_entry(ctl, &card->ctl_files, list) {
1443                 wake_up(&ctl->change_sleep);
1444                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1445         }
1446         read_unlock(&card->ctl_files_rwlock);
1447
1448         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1449                                          card, -1)) < 0)
1450                 return err;
1451         return 0;
1452 }
1453
1454 /*
1455  * free all controls
1456  */
1457 static int snd_ctl_dev_free(struct snd_device *device)
1458 {
1459         struct snd_card *card = device->device_data;
1460         struct snd_kcontrol *control;
1461
1462         down_write(&card->controls_rwsem);
1463         while (!list_empty(&card->controls)) {
1464                 control = snd_kcontrol(card->controls.next);
1465                 snd_ctl_remove(card, control);
1466         }
1467         up_write(&card->controls_rwsem);
1468         return 0;
1469 }
1470
1471 /*
1472  * create control core:
1473  * called from init.c
1474  */
1475 int snd_ctl_create(struct snd_card *card)
1476 {
1477         static struct snd_device_ops ops = {
1478                 .dev_free = snd_ctl_dev_free,
1479                 .dev_register = snd_ctl_dev_register,
1480                 .dev_disconnect = snd_ctl_dev_disconnect,
1481         };
1482
1483         if (snd_BUG_ON(!card))
1484                 return -ENXIO;
1485         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1486 }
1487
1488 /*
1489  * Frequently used control callbacks
1490  */
1491 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1492                               struct snd_ctl_elem_info *uinfo)
1493 {
1494         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1495         uinfo->count = 1;
1496         uinfo->value.integer.min = 0;
1497         uinfo->value.integer.max = 1;
1498         return 0;
1499 }
1500
1501 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1502
1503 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1504                                 struct snd_ctl_elem_info *uinfo)
1505 {
1506         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1507         uinfo->count = 2;
1508         uinfo->value.integer.min = 0;
1509         uinfo->value.integer.max = 1;
1510         return 0;
1511 }
1512
1513 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);