git.oblomov.eu Git - linux-2.6/blob - sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   3  *  Copyright (c) by Jaroslav Kysela <perex@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                 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_CALLBACK));
 242         kctl.info = ncontrol->info;
 243         kctl.get = ncontrol->get;
 244         kctl.put = ncontrol->put;
 245         kctl.tlv.p = ncontrol->tlv.p;
 246         kctl.private_value = ncontrol->private_value;
 247         kctl.private_data = private_data;
 248         return snd_ctl_new(&kctl, access);
 249 }
 250
 251 EXPORT_SYMBOL(snd_ctl_new1);
 252
 253 /**
 254  * snd_ctl_free_one - release the control instance
 255  * @kcontrol: the control instance
 256  *
 257  * Releases the control instance created via snd_ctl_new()
 258  * or snd_ctl_new1().
 259  * Don't call this after the control was added to the card.
 260  */
 261 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 262 {
 263         if (kcontrol) {
 264                 if (kcontrol->private_free)
 265                         kcontrol->private_free(kcontrol);
 266                 kfree(kcontrol);
 267         }
 268 }
 269
 270 EXPORT_SYMBOL(snd_ctl_free_one);
 271
 272 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 273                                        unsigned int count)
 274 {
 275         struct snd_kcontrol *kctl;
 276
 277         list_for_each_entry(kctl, &card->controls, list) {
 278                 if ((kctl->id.numid <= card->last_numid &&
 279                      kctl->id.numid + kctl->count > card->last_numid) ||
 280                     (kctl->id.numid <= card->last_numid + count - 1 &&
 281                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 282                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 283         }
 284         return card->last_numid;
 285 }
 286
 287 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 288 {
 289         unsigned int last_numid, iter = 100000;
 290
 291         last_numid = card->last_numid;
 292         while (last_numid != snd_ctl_hole_check(card, count)) {
 293                 if (--iter == 0) {
 294                         /* this situation is very unlikely */
 295                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 296                         return -ENOMEM;
 297                 }
 298                 last_numid = card->last_numid;
 299         }
 300         return 0;
 301 }
 302
 303 /**
 304  * snd_ctl_add - add the control instance to the card
 305  * @card: the card instance
 306  * @kcontrol: the control instance to add
 307  *
 308  * Adds the control instance created via snd_ctl_new() or
 309  * snd_ctl_new1() to the given card. Assigns also an unique
 310  * numid used for fast search.
 311  *
 312  * Returns zero if successful, or a negative error code on failure.
 313  *
 314  * It frees automatically the control which cannot be added.
 315  */
 316 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 317 {
 318         struct snd_ctl_elem_id id;
 319         unsigned int idx;
 320         int err = -EINVAL;
 321
 322         if (! kcontrol)
 323                 return err;
 324         if (snd_BUG_ON(!card || !kcontrol->info))
 325                 goto error;
 326         id = kcontrol->id;
 327         down_write(&card->controls_rwsem);
 328         if (snd_ctl_find_id(card, &id)) {
 329                 up_write(&card->controls_rwsem);
 330                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 331                                         id.iface,
 332                                         id.device,
 333                                         id.subdevice,
 334                                         id.name,
 335                                         id.index);
 336                 err = -EBUSY;
 337                 goto error;
 338         }
 339         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 340                 up_write(&card->controls_rwsem);
 341                 err = -ENOMEM;
 342                 goto error;
 343         }
 344         list_add_tail(&kcontrol->list, &card->controls);
 345         card->controls_count += kcontrol->count;
 346         kcontrol->id.numid = card->last_numid + 1;
 347         card->last_numid += kcontrol->count;
 348         up_write(&card->controls_rwsem);
 349         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 350                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 351         return 0;
 352
 353  error:
 354         snd_ctl_free_one(kcontrol);
 355         return err;
 356 }
 357
 358 EXPORT_SYMBOL(snd_ctl_add);
 359
 360 /**
 361  * snd_ctl_remove - remove the control from the card and release it
 362  * @card: the card instance
 363  * @kcontrol: the control instance to remove
 364  *
 365  * Removes the control from the card and then releases the instance.
 366  * You don't need to call snd_ctl_free_one(). You must be in
 367  * the write lock - down_write(&card->controls_rwsem).
 368  *
 369  * Returns 0 if successful, or a negative error code on failure.
 370  */
 371 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 372 {
 373         struct snd_ctl_elem_id id;
 374         unsigned int idx;
 375
 376         if (snd_BUG_ON(!card || !kcontrol))
 377                 return -EINVAL;
 378         list_del(&kcontrol->list);
 379         card->controls_count -= kcontrol->count;
 380         id = kcontrol->id;
 381         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 382                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 383         snd_ctl_free_one(kcontrol);
 384         return 0;
 385 }
 386
 387 EXPORT_SYMBOL(snd_ctl_remove);
 388
 389 /**
 390  * snd_ctl_remove_id - remove the control of the given id and release it
 391  * @card: the card instance
 392  * @id: the control id to remove
 393  *
 394  * Finds the control instance with the given id, removes it from the
 395  * card list and releases it.
 396  *
 397  * Returns 0 if successful, or a negative error code on failure.
 398  */
 399 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 400 {
 401         struct snd_kcontrol *kctl;
 402         int ret;
 403
 404         down_write(&card->controls_rwsem);
 405         kctl = snd_ctl_find_id(card, id);
 406         if (kctl == NULL) {
 407                 up_write(&card->controls_rwsem);
 408                 return -ENOENT;
 409         }
 410         ret = snd_ctl_remove(card, kctl);
 411         up_write(&card->controls_rwsem);
 412         return ret;
 413 }
 414
 415 EXPORT_SYMBOL(snd_ctl_remove_id);
 416
 417 /**
 418  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 419  * @file: active control handle
 420  * @id: the control id to remove
 421  *
 422  * Finds the control instance with the given id, removes it from the
 423  * card list and releases it.
 424  *
 425  * Returns 0 if successful, or a negative error code on failure.
 426  */
 427 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 428                                       struct snd_ctl_elem_id *id)
 429 {
 430         struct snd_card *card = file->card;
 431         struct snd_kcontrol *kctl;
 432         int idx, ret;
 433
 434         down_write(&card->controls_rwsem);
 435         kctl = snd_ctl_find_id(card, id);
 436         if (kctl == NULL) {
 437                 up_write(&card->controls_rwsem);
 438                 return -ENOENT;
 439         }
 440         for (idx = 0; idx < kctl->count; idx++)
 441                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 442                         up_write(&card->controls_rwsem);
 443                         return -EBUSY;
 444                 }
 445         ret = snd_ctl_remove(card, kctl);
 446         up_write(&card->controls_rwsem);
 447         return ret;
 448 }
 449
 450 /**
 451  * snd_ctl_rename_id - replace the id of a control on the card
 452  * @card: the card instance
 453  * @src_id: the old id
 454  * @dst_id: the new id
 455  *
 456  * Finds the control with the old id from the card, and replaces the
 457  * id with the new one.
 458  *
 459  * Returns zero if successful, or a negative error code on failure.
 460  */
 461 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 462                       struct snd_ctl_elem_id *dst_id)
 463 {
 464         struct snd_kcontrol *kctl;
 465
 466         down_write(&card->controls_rwsem);
 467         kctl = snd_ctl_find_id(card, src_id);
 468         if (kctl == NULL) {
 469                 up_write(&card->controls_rwsem);
 470                 return -ENOENT;
 471         }
 472         kctl->id = *dst_id;
 473         kctl->id.numid = card->last_numid + 1;
 474         card->last_numid += kctl->count;
 475         up_write(&card->controls_rwsem);
 476         return 0;
 477 }
 478
 479 EXPORT_SYMBOL(snd_ctl_rename_id);
 480
 481 /**
 482  * snd_ctl_find_numid - find the control instance with the given number-id
 483  * @card: the card instance
 484  * @numid: the number-id to search
 485  *
 486  * Finds the control instance with the given number-id from the card.
 487  *
 488  * Returns the pointer of the instance if found, or NULL if not.
 489  *
 490  * The caller must down card->controls_rwsem before calling this function
 491  * (if the race condition can happen).
 492  */
 493 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 494 {
 495         struct snd_kcontrol *kctl;
 496
 497         if (snd_BUG_ON(!card || !numid))
 498                 return NULL;
 499         list_for_each_entry(kctl, &card->controls, list) {
 500                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 501                         return kctl;
 502         }
 503         return NULL;
 504 }
 505
 506 EXPORT_SYMBOL(snd_ctl_find_numid);
 507
 508 /**
 509  * snd_ctl_find_id - find the control instance with the given id
 510  * @card: the card instance
 511  * @id: the id to search
 512  *
 513  * Finds the control instance with the given id from the card.
 514  *
 515  * Returns the pointer of the instance if found, or NULL if not.
 516  *
 517  * The caller must down card->controls_rwsem before calling this function
 518  * (if the race condition can happen).
 519  */
 520 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 521                                      struct snd_ctl_elem_id *id)
 522 {
 523         struct snd_kcontrol *kctl;
 524
 525         if (snd_BUG_ON(!card || !id))
 526                 return NULL;
 527         if (id->numid != 0)
 528                 return snd_ctl_find_numid(card, id->numid);
 529         list_for_each_entry(kctl, &card->controls, list) {
 530                 if (kctl->id.iface != id->iface)
 531                         continue;
 532                 if (kctl->id.device != id->device)
 533                         continue;
 534                 if (kctl->id.subdevice != id->subdevice)
 535                         continue;
 536                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 537                         continue;
 538                 if (kctl->id.index > id->index)
 539                         continue;
 540                 if (kctl->id.index + kctl->count <= id->index)
 541                         continue;
 542                 return kctl;
 543         }
 544         return NULL;
 545 }
 546
 547 EXPORT_SYMBOL(snd_ctl_find_id);
 548
 549 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 550                              unsigned int cmd, void __user *arg)
 551 {
 552         struct snd_ctl_card_info *info;
 553
 554         info = kzalloc(sizeof(*info), GFP_KERNEL);
 555         if (! info)
 556                 return -ENOMEM;
 557         down_read(&snd_ioctl_rwsem);
 558         info->card = card->number;
 559         strlcpy(info->id, card->id, sizeof(info->id));
 560         strlcpy(info->driver, card->driver, sizeof(info->driver));
 561         strlcpy(info->name, card->shortname, sizeof(info->name));
 562         strlcpy(info->longname, card->longname, sizeof(info->longname));
 563         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 564         strlcpy(info->components, card->components, sizeof(info->components));
 565         up_read(&snd_ioctl_rwsem);
 566         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 567                 kfree(info);
 568                 return -EFAULT;
 569         }
 570         kfree(info);
 571         return 0;
 572 }
 573
 574 static int snd_ctl_elem_list(struct snd_card *card,
 575                              struct snd_ctl_elem_list __user *_list)
 576 {
 577         struct list_head *plist;
 578         struct snd_ctl_elem_list list;
 579         struct snd_kcontrol *kctl;
 580         struct snd_ctl_elem_id *dst, *id;
 581         unsigned int offset, space, first, jidx;
 582
 583         if (copy_from_user(&list, _list, sizeof(list)))
 584                 return -EFAULT;
 585         offset = list.offset;
 586         space = list.space;
 587         first = 0;
 588         /* try limit maximum space */
 589         if (space > 16384)
 590                 return -ENOMEM;
 591         if (space > 0) {
 592                 /* allocate temporary buffer for atomic operation */
 593                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 594                 if (dst == NULL)
 595                         return -ENOMEM;
 596                 down_read(&card->controls_rwsem);
 597                 list.count = card->controls_count;
 598                 plist = card->controls.next;
 599                 while (plist != &card->controls) {
 600                         if (offset == 0)
 601                                 break;
 602                         kctl = snd_kcontrol(plist);
 603                         if (offset < kctl->count)
 604                                 break;
 605                         offset -= kctl->count;
 606                         plist = plist->next;
 607                 }
 608                 list.used = 0;
 609                 id = dst;
 610                 while (space > 0 && plist != &card->controls) {
 611                         kctl = snd_kcontrol(plist);
 612                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 613                                 snd_ctl_build_ioff(id, kctl, jidx);
 614                                 id++;
 615                                 space--;
 616                                 list.used++;
 617                         }
 618                         plist = plist->next;
 619                         offset = 0;
 620                 }
 621                 up_read(&card->controls_rwsem);
 622                 if (list.used > 0 &&
 623                     copy_to_user(list.pids, dst,
 624                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 625                         vfree(dst);
 626                         return -EFAULT;
 627                 }
 628                 vfree(dst);
 629         } else {
 630                 down_read(&card->controls_rwsem);
 631                 list.count = card->controls_count;
 632                 up_read(&card->controls_rwsem);
 633         }
 634         if (copy_to_user(_list, &list, sizeof(list)))
 635                 return -EFAULT;
 636         return 0;
 637 }
 638
 639 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 640                              struct snd_ctl_elem_info *info)
 641 {
 642         struct snd_card *card = ctl->card;
 643         struct snd_kcontrol *kctl;
 644         struct snd_kcontrol_volatile *vd;
 645         unsigned int index_offset;
 646         int result;
 647
 648         down_read(&card->controls_rwsem);
 649         kctl = snd_ctl_find_id(card, &info->id);
 650         if (kctl == NULL) {
 651                 up_read(&card->controls_rwsem);
 652                 return -ENOENT;
 653         }
 654 #ifdef CONFIG_SND_DEBUG
 655         info->access = 0;
 656 #endif
 657         result = kctl->info(kctl, info);
 658         if (result >= 0) {
 659                 snd_BUG_ON(info->access);
 660                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 661                 vd = &kctl->vd[index_offset];
 662                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 663                 info->access = vd->access;
 664                 if (vd->owner) {
 665                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 666                         if (vd->owner == ctl)
 667                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 668                         info->owner = vd->owner_pid;
 669                 } else {
 670                         info->owner = -1;
 671                 }
 672         }
 673         up_read(&card->controls_rwsem);
 674         return result;
 675 }
 676
 677 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 678                                   struct snd_ctl_elem_info __user *_info)
 679 {
 680         struct snd_ctl_elem_info info;
 681         int result;
 682
 683         if (copy_from_user(&info, _info, sizeof(info)))
 684                 return -EFAULT;
 685         snd_power_lock(ctl->card);
 686         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 687         if (result >= 0)
 688                 result = snd_ctl_elem_info(ctl, &info);
 689         snd_power_unlock(ctl->card);
 690         if (result >= 0)
 691                 if (copy_to_user(_info, &info, sizeof(info)))
 692                         return -EFAULT;
 693         return result;
 694 }
 695
 696 static int snd_ctl_elem_read(struct snd_card *card,
 697                              struct snd_ctl_elem_value *control)
 698 {
 699         struct snd_kcontrol *kctl;
 700         struct snd_kcontrol_volatile *vd;
 701         unsigned int index_offset;
 702         int result;
 703
 704         down_read(&card->controls_rwsem);
 705         kctl = snd_ctl_find_id(card, &control->id);
 706         if (kctl == NULL) {
 707                 result = -ENOENT;
 708         } else {
 709                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 710                 vd = &kctl->vd[index_offset];
 711                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 712                     kctl->get != NULL) {
 713                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 714                         result = kctl->get(kctl, control);
 715                 } else
 716                         result = -EPERM;
 717         }
 718         up_read(&card->controls_rwsem);
 719         return result;
 720 }
 721
 722 static int snd_ctl_elem_read_user(struct snd_card *card,
 723                                   struct snd_ctl_elem_value __user *_control)
 724 {
 725         struct snd_ctl_elem_value *control;
 726         int result;
 727
 728         control = kmalloc(sizeof(*control), GFP_KERNEL);
 729         if (control == NULL)
 730                 return -ENOMEM;
 731         if (copy_from_user(control, _control, sizeof(*control))) {
 732                 kfree(control);
 733                 return -EFAULT;
 734         }
 735         snd_power_lock(card);
 736         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 737         if (result >= 0)
 738                 result = snd_ctl_elem_read(card, control);
 739         snd_power_unlock(card);
 740         if (result >= 0)
 741                 if (copy_to_user(_control, control, sizeof(*control)))
 742                         result = -EFAULT;
 743         kfree(control);
 744         return result;
 745 }
 746
 747 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 748                               struct snd_ctl_elem_value *control)
 749 {
 750         struct snd_kcontrol *kctl;
 751         struct snd_kcontrol_volatile *vd;
 752         unsigned int index_offset;
 753         int result;
 754
 755         down_read(&card->controls_rwsem);
 756         kctl = snd_ctl_find_id(card, &control->id);
 757         if (kctl == NULL) {
 758                 result = -ENOENT;
 759         } else {
 760                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 761                 vd = &kctl->vd[index_offset];
 762                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 763                     kctl->put == NULL ||
 764                     (file && vd->owner && vd->owner != file)) {
 765                         result = -EPERM;
 766                 } else {
 767                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 768                         result = kctl->put(kctl, control);
 769                 }
 770                 if (result > 0) {
 771                         up_read(&card->controls_rwsem);
 772                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 773                                        &control->id);
 774                         return 0;
 775                 }
 776         }
 777         up_read(&card->controls_rwsem);
 778         return result;
 779 }
 780
 781 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 782                                    struct snd_ctl_elem_value __user *_control)
 783 {
 784         struct snd_ctl_elem_value *control;
 785         struct snd_card *card;
 786         int result;
 787
 788         control = kmalloc(sizeof(*control), GFP_KERNEL);
 789         if (control == NULL)
 790                 return -ENOMEM;
 791         if (copy_from_user(control, _control, sizeof(*control))) {
 792                 kfree(control);
 793                 return -EFAULT;
 794         }
 795         card = file->card;
 796         snd_power_lock(card);
 797         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 798         if (result >= 0)
 799                 result = snd_ctl_elem_write(card, file, control);
 800         snd_power_unlock(card);
 801         if (result >= 0)
 802                 if (copy_to_user(_control, control, sizeof(*control)))
 803                         result = -EFAULT;
 804         kfree(control);
 805         return result;
 806 }
 807
 808 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 809                              struct snd_ctl_elem_id __user *_id)
 810 {
 811         struct snd_card *card = file->card;
 812         struct snd_ctl_elem_id id;
 813         struct snd_kcontrol *kctl;
 814         struct snd_kcontrol_volatile *vd;
 815         int result;
 816
 817         if (copy_from_user(&id, _id, sizeof(id)))
 818                 return -EFAULT;
 819         down_write(&card->controls_rwsem);
 820         kctl = snd_ctl_find_id(card, &id);
 821         if (kctl == NULL) {
 822                 result = -ENOENT;
 823         } else {
 824                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 825                 if (vd->owner != NULL)
 826                         result = -EBUSY;
 827                 else {
 828                         vd->owner = file;
 829                         vd->owner_pid = current->pid;
 830                         result = 0;
 831                 }
 832         }
 833         up_write(&card->controls_rwsem);
 834         return result;
 835 }
 836
 837 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 838                                struct snd_ctl_elem_id __user *_id)
 839 {
 840         struct snd_card *card = file->card;
 841         struct snd_ctl_elem_id id;
 842         struct snd_kcontrol *kctl;
 843         struct snd_kcontrol_volatile *vd;
 844         int result;
 845
 846         if (copy_from_user(&id, _id, sizeof(id)))
 847                 return -EFAULT;
 848         down_write(&card->controls_rwsem);
 849         kctl = snd_ctl_find_id(card, &id);
 850         if (kctl == NULL) {
 851                 result = -ENOENT;
 852         } else {
 853                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 854                 if (vd->owner == NULL)
 855                         result = -EINVAL;
 856                 else if (vd->owner != file)
 857                         result = -EPERM;
 858                 else {
 859                         vd->owner = NULL;
 860                         vd->owner_pid = 0;
 861                         result = 0;
 862                 }
 863         }
 864         up_write(&card->controls_rwsem);
 865         return result;
 866 }
 867
 868 struct user_element {
 869         struct snd_ctl_elem_info info;
 870         void *elem_data;                /* element data */
 871         unsigned long elem_data_size;   /* size of element data in bytes */
 872         void *tlv_data;                 /* TLV data */
 873         unsigned long tlv_data_size;    /* TLV data size */
 874         void *priv_data;                /* private data (like strings for enumerated type) */
 875         unsigned long priv_data_size;   /* size of private data in bytes */
 876 };
 877
 878 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 879                                   struct snd_ctl_elem_info *uinfo)
 880 {
 881         struct user_element *ue = kcontrol->private_data;
 882
 883         *uinfo = ue->info;
 884         return 0;
 885 }
 886
 887 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 888                                  struct snd_ctl_elem_value *ucontrol)
 889 {
 890         struct user_element *ue = kcontrol->private_data;
 891
 892         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 893         return 0;
 894 }
 895
 896 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 897                                  struct snd_ctl_elem_value *ucontrol)
 898 {
 899         int change;
 900         struct user_element *ue = kcontrol->private_data;
 901
 902         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 903         if (change)
 904                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 905         return change;
 906 }
 907
 908 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 909                                  int op_flag,
 910                                  unsigned int size,
 911                                  unsigned int __user *tlv)
 912 {
 913         struct user_element *ue = kcontrol->private_data;
 914         int change = 0;
 915         void *new_data;
 916
 917         if (op_flag > 0) {
 918                 if (size > 1024 * 128)  /* sane value */
 919                         return -EINVAL;
 920                 new_data = kmalloc(size, GFP_KERNEL);
 921                 if (new_data == NULL)
 922                         return -ENOMEM;
 923                 if (copy_from_user(new_data, tlv, size)) {
 924                         kfree(new_data);
 925                         return -EFAULT;
 926                 }
 927                 change = ue->tlv_data_size != size;
 928                 if (!change)
 929                         change = memcmp(ue->tlv_data, new_data, size);
 930                 kfree(ue->tlv_data);
 931                 ue->tlv_data = new_data;
 932                 ue->tlv_data_size = size;
 933         } else {
 934                 if (! ue->tlv_data_size || ! ue->tlv_data)
 935                         return -ENXIO;
 936                 if (size < ue->tlv_data_size)
 937                         return -ENOSPC;
 938                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 939                         return -EFAULT;
 940         }
 941         return change;
 942 }
 943
 944 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 945 {
 946         struct user_element *ue = kcontrol->private_data;
 947         if (ue->tlv_data)
 948                 kfree(ue->tlv_data);
 949         kfree(ue);
 950 }
 951
 952 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 953                             struct snd_ctl_elem_info *info, int replace)
 954 {
 955         struct snd_card *card = file->card;
 956         struct snd_kcontrol kctl, *_kctl;
 957         unsigned int access;
 958         long private_size;
 959         struct user_element *ue;
 960         int idx, err;
 961
 962         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 963                 return -ENOMEM;
 964         if (info->count > 1024)
 965                 return -EINVAL;
 966         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 967                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 968                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 969                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 970         info->id.numid = 0;
 971         memset(&kctl, 0, sizeof(kctl));
 972         down_write(&card->controls_rwsem);
 973         _kctl = snd_ctl_find_id(card, &info->id);
 974         err = 0;
 975         if (_kctl) {
 976                 if (replace)
 977                         err = snd_ctl_remove(card, _kctl);
 978                 else
 979                         err = -EBUSY;
 980         } else {
 981                 if (replace)
 982                         err = -ENOENT;
 983         }
 984         up_write(&card->controls_rwsem);
 985         if (err < 0)
 986                 return err;
 987         memcpy(&kctl.id, &info->id, sizeof(info->id));
 988         kctl.count = info->owner ? info->owner : 1;
 989         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 990         kctl.info = snd_ctl_elem_user_info;
 991         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 992                 kctl.get = snd_ctl_elem_user_get;
 993         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 994                 kctl.put = snd_ctl_elem_user_put;
 995         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 996                 kctl.tlv.c = snd_ctl_elem_user_tlv;
 997                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 998         }
 999         switch (info->type) {
1000         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1001         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1002                 private_size = sizeof(long);
1003                 if (info->count > 128)
1004                         return -EINVAL;
1005                 break;
1006         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1007                 private_size = sizeof(long long);
1008                 if (info->count > 64)
1009                         return -EINVAL;
1010                 break;
1011         case SNDRV_CTL_ELEM_TYPE_BYTES:
1012                 private_size = sizeof(unsigned char);
1013                 if (info->count > 512)
1014                         return -EINVAL;
1015                 break;
1016         case SNDRV_CTL_ELEM_TYPE_IEC958:
1017                 private_size = sizeof(struct snd_aes_iec958);
1018                 if (info->count != 1)
1019                         return -EINVAL;
1020                 break;
1021         default:
1022                 return -EINVAL;
1023         }
1024         private_size *= info->count;
1025         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1026         if (ue == NULL)
1027                 return -ENOMEM;
1028         ue->info = *info;
1029         ue->info.access = 0;
1030         ue->elem_data = (char *)ue + sizeof(*ue);
1031         ue->elem_data_size = private_size;
1032         kctl.private_free = snd_ctl_elem_user_free;
1033         _kctl = snd_ctl_new(&kctl, access);
1034         if (_kctl == NULL) {
1035                 kfree(ue);
1036                 return -ENOMEM;
1037         }
1038         _kctl->private_data = ue;
1039         for (idx = 0; idx < _kctl->count; idx++)
1040                 _kctl->vd[idx].owner = file;
1041         err = snd_ctl_add(card, _kctl);
1042         if (err < 0)
1043                 return err;
1044
1045         down_write(&card->controls_rwsem);
1046         card->user_ctl_count++;
1047         up_write(&card->controls_rwsem);
1048
1049         return 0;
1050 }
1051
1052 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1053                                  struct snd_ctl_elem_info __user *_info, int replace)
1054 {
1055         struct snd_ctl_elem_info info;
1056         if (copy_from_user(&info, _info, sizeof(info)))
1057                 return -EFAULT;
1058         return snd_ctl_elem_add(file, &info, replace);
1059 }
1060
1061 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1062                                struct snd_ctl_elem_id __user *_id)
1063 {
1064         struct snd_ctl_elem_id id;
1065         int err;
1066
1067         if (copy_from_user(&id, _id, sizeof(id)))
1068                 return -EFAULT;
1069         err = snd_ctl_remove_unlocked_id(file, &id);
1070         if (! err) {
1071                 struct snd_card *card = file->card;
1072                 down_write(&card->controls_rwsem);
1073                 card->user_ctl_count--;
1074                 up_write(&card->controls_rwsem);
1075         }
1076         return err;
1077 }
1078
1079 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1080 {
1081         int subscribe;
1082         if (get_user(subscribe, ptr))
1083                 return -EFAULT;
1084         if (subscribe < 0) {
1085                 subscribe = file->subscribed;
1086                 if (put_user(subscribe, ptr))
1087                         return -EFAULT;
1088                 return 0;
1089         }
1090         if (subscribe) {
1091                 file->subscribed = 1;
1092                 return 0;
1093         } else if (file->subscribed) {
1094                 snd_ctl_empty_read_queue(file);
1095                 file->subscribed = 0;
1096         }
1097         return 0;
1098 }
1099
1100 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1101                              struct snd_ctl_tlv __user *_tlv,
1102                              int op_flag)
1103 {
1104         struct snd_card *card = file->card;
1105         struct snd_ctl_tlv tlv;
1106         struct snd_kcontrol *kctl;
1107         struct snd_kcontrol_volatile *vd;
1108         unsigned int len;
1109         int err = 0;
1110
1111         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1112                 return -EFAULT;
1113         if (tlv.length < sizeof(unsigned int) * 3)
1114                 return -EINVAL;
1115         down_read(&card->controls_rwsem);
1116         kctl = snd_ctl_find_numid(card, tlv.numid);
1117         if (kctl == NULL) {
1118                 err = -ENOENT;
1119                 goto __kctl_end;
1120         }
1121         if (kctl->tlv.p == NULL) {
1122                 err = -ENXIO;
1123                 goto __kctl_end;
1124         }
1125         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1126         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1127             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1128             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1129                 err = -ENXIO;
1130                 goto __kctl_end;
1131         }
1132         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1133                 if (file && vd->owner != NULL && vd->owner != file) {
1134                         err = -EPERM;
1135                         goto __kctl_end;
1136                 }
1137                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1138                 if (err > 0) {
1139                         up_read(&card->controls_rwsem);
1140                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1141                         return 0;
1142                 }
1143         } else {
1144                 if (op_flag) {
1145                         err = -ENXIO;
1146                         goto __kctl_end;
1147                 }
1148                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1149                 if (tlv.length < len) {
1150                         err = -ENOMEM;
1151                         goto __kctl_end;
1152                 }
1153                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1154                         err = -EFAULT;
1155         }
1156       __kctl_end:
1157         up_read(&card->controls_rwsem);
1158         return err;
1159 }
1160
1161 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1162 {
1163         struct snd_ctl_file *ctl;
1164         struct snd_card *card;
1165         struct snd_kctl_ioctl *p;
1166         void __user *argp = (void __user *)arg;
1167         int __user *ip = argp;
1168         int err;
1169
1170         ctl = file->private_data;
1171         card = ctl->card;
1172         if (snd_BUG_ON(!card))
1173                 return -ENXIO;
1174         switch (cmd) {
1175         case SNDRV_CTL_IOCTL_PVERSION:
1176                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1177         case SNDRV_CTL_IOCTL_CARD_INFO:
1178                 return snd_ctl_card_info(card, ctl, cmd, argp);
1179         case SNDRV_CTL_IOCTL_ELEM_LIST:
1180                 return snd_ctl_elem_list(card, argp);
1181         case SNDRV_CTL_IOCTL_ELEM_INFO:
1182                 return snd_ctl_elem_info_user(ctl, argp);
1183         case SNDRV_CTL_IOCTL_ELEM_READ:
1184                 return snd_ctl_elem_read_user(card, argp);
1185         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1186                 return snd_ctl_elem_write_user(ctl, argp);
1187         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1188                 return snd_ctl_elem_lock(ctl, argp);
1189         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1190                 return snd_ctl_elem_unlock(ctl, argp);
1191         case SNDRV_CTL_IOCTL_ELEM_ADD:
1192                 return snd_ctl_elem_add_user(ctl, argp, 0);
1193         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1194                 return snd_ctl_elem_add_user(ctl, argp, 1);
1195         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1196                 return snd_ctl_elem_remove(ctl, argp);
1197         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1198                 return snd_ctl_subscribe_events(ctl, ip);
1199         case SNDRV_CTL_IOCTL_TLV_READ:
1200                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1201         case SNDRV_CTL_IOCTL_TLV_WRITE:
1202                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1203         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1204                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1205         case SNDRV_CTL_IOCTL_POWER:
1206                 return -ENOPROTOOPT;
1207         case SNDRV_CTL_IOCTL_POWER_STATE:
1208 #ifdef CONFIG_PM
1209                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1210 #else
1211                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1212 #endif
1213         }
1214         down_read(&snd_ioctl_rwsem);
1215         list_for_each_entry(p, &snd_control_ioctls, list) {
1216                 err = p->fioctl(card, ctl, cmd, arg);
1217                 if (err != -ENOIOCTLCMD) {
1218                         up_read(&snd_ioctl_rwsem);
1219                         return err;
1220                 }
1221         }
1222         up_read(&snd_ioctl_rwsem);
1223         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1224         return -ENOTTY;
1225 }
1226
1227 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1228                             size_t count, loff_t * offset)
1229 {
1230         struct snd_ctl_file *ctl;
1231         int err = 0;
1232         ssize_t result = 0;
1233
1234         ctl = file->private_data;
1235         if (snd_BUG_ON(!ctl || !ctl->card))
1236                 return -ENXIO;
1237         if (!ctl->subscribed)
1238                 return -EBADFD;
1239         if (count < sizeof(struct snd_ctl_event))
1240                 return -EINVAL;
1241         spin_lock_irq(&ctl->read_lock);
1242         while (count >= sizeof(struct snd_ctl_event)) {
1243                 struct snd_ctl_event ev;
1244                 struct snd_kctl_event *kev;
1245                 while (list_empty(&ctl->events)) {
1246                         wait_queue_t wait;
1247                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1248                                 err = -EAGAIN;
1249                                 goto __end_lock;
1250                         }
1251                         init_waitqueue_entry(&wait, current);
1252                         add_wait_queue(&ctl->change_sleep, &wait);
1253                         set_current_state(TASK_INTERRUPTIBLE);
1254                         spin_unlock_irq(&ctl->read_lock);
1255                         schedule();
1256                         remove_wait_queue(&ctl->change_sleep, &wait);
1257                         if (signal_pending(current))
1258                                 return -ERESTARTSYS;
1259                         spin_lock_irq(&ctl->read_lock);
1260                 }
1261                 kev = snd_kctl_event(ctl->events.next);
1262                 ev.type = SNDRV_CTL_EVENT_ELEM;
1263                 ev.data.elem.mask = kev->mask;
1264                 ev.data.elem.id = kev->id;
1265                 list_del(&kev->list);
1266                 spin_unlock_irq(&ctl->read_lock);
1267                 kfree(kev);
1268                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1269                         err = -EFAULT;
1270                         goto __end;
1271                 }
1272                 spin_lock_irq(&ctl->read_lock);
1273                 buffer += sizeof(struct snd_ctl_event);
1274                 count -= sizeof(struct snd_ctl_event);
1275                 result += sizeof(struct snd_ctl_event);
1276         }
1277       __end_lock:
1278         spin_unlock_irq(&ctl->read_lock);
1279       __end:
1280         return result > 0 ? result : err;
1281 }
1282
1283 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1284 {
1285         unsigned int mask;
1286         struct snd_ctl_file *ctl;
1287
1288         ctl = file->private_data;
1289         if (!ctl->subscribed)
1290                 return 0;
1291         poll_wait(file, &ctl->change_sleep, wait);
1292
1293         mask = 0;
1294         if (!list_empty(&ctl->events))
1295                 mask |= POLLIN | POLLRDNORM;
1296
1297         return mask;
1298 }
1299
1300 /*
1301  * register the device-specific control-ioctls.
1302  * called from each device manager like pcm.c, hwdep.c, etc.
1303  */
1304 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1305 {
1306         struct snd_kctl_ioctl *pn;
1307
1308         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1309         if (pn == NULL)
1310                 return -ENOMEM;
1311         pn->fioctl = fcn;
1312         down_write(&snd_ioctl_rwsem);
1313         list_add_tail(&pn->list, lists);
1314         up_write(&snd_ioctl_rwsem);
1315         return 0;
1316 }
1317
1318 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1319 {
1320         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1321 }
1322
1323 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1324
1325 #ifdef CONFIG_COMPAT
1326 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1327 {
1328         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1329 }
1330
1331 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1332 #endif
1333
1334 /*
1335  * de-register the device-specific control-ioctls.
1336  */
1337 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1338                                      struct list_head *lists)
1339 {
1340         struct snd_kctl_ioctl *p;
1341
1342         if (snd_BUG_ON(!fcn))
1343                 return -EINVAL;
1344         down_write(&snd_ioctl_rwsem);
1345         list_for_each_entry(p, lists, list) {
1346                 if (p->fioctl == fcn) {
1347                         list_del(&p->list);
1348                         up_write(&snd_ioctl_rwsem);
1349                         kfree(p);
1350                         return 0;
1351                 }
1352         }
1353         up_write(&snd_ioctl_rwsem);
1354         snd_BUG();
1355         return -EINVAL;
1356 }
1357
1358 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1359 {
1360         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1361 }
1362
1363 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1364
1365 #ifdef CONFIG_COMPAT
1366 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1367 {
1368         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1369 }
1370
1371 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1372 #endif
1373
1374 static int snd_ctl_fasync(int fd, struct file * file, int on)
1375 {
1376         struct snd_ctl_file *ctl;
1377         int err;
1378         ctl = file->private_data;
1379         err = fasync_helper(fd, file, on, &ctl->fasync);
1380         if (err < 0)
1381                 return err;
1382         return 0;
1383 }
1384
1385 /*
1386  * ioctl32 compat
1387  */
1388 #ifdef CONFIG_COMPAT
1389 #include "control_compat.c"
1390 #else
1391 #define snd_ctl_ioctl_compat    NULL
1392 #endif
1393
1394 /*
1395  *  INIT PART
1396  */
1397
1398 static const struct file_operations snd_ctl_f_ops =
1399 {
1400         .owner =        THIS_MODULE,
1401         .read =         snd_ctl_read,
1402         .open =         snd_ctl_open,
1403         .release =      snd_ctl_release,
1404         .poll =         snd_ctl_poll,
1405         .unlocked_ioctl =       snd_ctl_ioctl,
1406         .compat_ioctl = snd_ctl_ioctl_compat,
1407         .fasync =       snd_ctl_fasync,
1408 };
1409
1410 /*
1411  * registration of the control device
1412  */
1413 static int snd_ctl_dev_register(struct snd_device *device)
1414 {
1415         struct snd_card *card = device->device_data;
1416         int err, cardnum;
1417         char name[16];
1418
1419         if (snd_BUG_ON(!card))
1420                 return -ENXIO;
1421         cardnum = card->number;
1422         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1423                 return -ENXIO;
1424         sprintf(name, "controlC%i", cardnum);
1425         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1426                                        &snd_ctl_f_ops, card, name)) < 0)
1427                 return err;
1428         return 0;
1429 }
1430
1431 /*
1432  * disconnection of the control device
1433  */
1434 static int snd_ctl_dev_disconnect(struct snd_device *device)
1435 {
1436         struct snd_card *card = device->device_data;
1437         struct snd_ctl_file *ctl;
1438         int err, cardnum;
1439
1440         if (snd_BUG_ON(!card))
1441                 return -ENXIO;
1442         cardnum = card->number;
1443         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1444                 return -ENXIO;
1445
1446         read_lock(&card->ctl_files_rwlock);
1447         list_for_each_entry(ctl, &card->ctl_files, list) {
1448                 wake_up(&ctl->change_sleep);
1449                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1450         }
1451         read_unlock(&card->ctl_files_rwlock);
1452
1453         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1454                                          card, -1)) < 0)
1455                 return err;
1456         return 0;
1457 }
1458
1459 /*
1460  * free all controls
1461  */
1462 static int snd_ctl_dev_free(struct snd_device *device)
1463 {
1464         struct snd_card *card = device->device_data;
1465         struct snd_kcontrol *control;
1466
1467         down_write(&card->controls_rwsem);
1468         while (!list_empty(&card->controls)) {
1469                 control = snd_kcontrol(card->controls.next);
1470                 snd_ctl_remove(card, control);
1471         }
1472         up_write(&card->controls_rwsem);
1473         return 0;
1474 }
1475
1476 /*
1477  * create control core:
1478  * called from init.c
1479  */
1480 int snd_ctl_create(struct snd_card *card)
1481 {
1482         static struct snd_device_ops ops = {
1483                 .dev_free = snd_ctl_dev_free,
1484                 .dev_register = snd_ctl_dev_register,
1485                 .dev_disconnect = snd_ctl_dev_disconnect,
1486         };
1487
1488         if (snd_BUG_ON(!card))
1489                 return -ENXIO;
1490         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1491 }
1492
1493 /*
1494  * Frequently used control callbacks
1495  */
1496 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1497                               struct snd_ctl_elem_info *uinfo)
1498 {
1499         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1500         uinfo->count = 1;
1501         uinfo->value.integer.min = 0;
1502         uinfo->value.integer.max = 1;
1503         return 0;
1504 }
1505
1506 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1507
1508 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1509                                 struct snd_ctl_elem_info *uinfo)
1510 {
1511         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1512         uinfo->count = 2;
1513         uinfo->value.integer.min = 0;
1514         uinfo->value.integer.max = 1;
1515         return 0;
1516 }
1517
1518 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);