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