sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/threads.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/slab.h>
  25 #include <linux/vmalloc.h>
  26 #include <linux/time.h>
  27 #include <sound/core.h>
  28 #include <sound/minors.h>
  29 #include <sound/info.h>
  30 #include <sound/control.h>
  31
  32 /* max number of user-defined controls */
  33 #define MAX_USER_CONTROLS       32
  34
  35 struct snd_kctl_ioctl {
  36         struct list_head list;          /* list of all ioctls */
  37         snd_kctl_ioctl_func_t fioctl;
  38 };
  39
  40 static DECLARE_RWSEM(snd_ioctl_rwsem);
  41 static LIST_HEAD(snd_control_ioctls);
  42 #ifdef CONFIG_COMPAT
  43 static LIST_HEAD(snd_control_compat_ioctls);
  44 #endif
  45
  46 static int snd_ctl_open(struct inode *inode, struct file *file)
  47 {
  48         unsigned long flags;
  49         struct snd_card *card;
  50         struct snd_ctl_file *ctl;
  51         int err;
  52
  53         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  54         if (!card) {
  55                 err = -ENODEV;
  56                 goto __error1;
  57         }
  58         err = snd_card_file_add(card, file);
  59         if (err < 0) {
  60                 err = -ENODEV;
  61                 goto __error1;
  62         }
  63         if (!try_module_get(card->module)) {
  64                 err = -EFAULT;
  65                 goto __error2;
  66         }
  67         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  68         if (ctl == NULL) {
  69                 err = -ENOMEM;
  70                 goto __error;
  71         }
  72         INIT_LIST_HEAD(&ctl->events);
  73         init_waitqueue_head(&ctl->change_sleep);
  74         spin_lock_init(&ctl->read_lock);
  75         ctl->card = card;
  76         ctl->prefer_pcm_subdevice = -1;
  77         ctl->prefer_rawmidi_subdevice = -1;
  78         ctl->pid = current->pid;
  79         file->private_data = ctl;
  80         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  81         list_add_tail(&ctl->list, &card->ctl_files);
  82         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  83         return 0;
  84
  85       __error:
  86         module_put(card->module);
  87       __error2:
  88         snd_card_file_remove(card, file);
  89       __error1:
  90         return err;
  91 }
  92
  93 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  94 {
  95         unsigned long flags;
  96         struct snd_kctl_event *cread;
  97
  98         spin_lock_irqsave(&ctl->read_lock, flags);
  99         while (!list_empty(&ctl->events)) {
 100                 cread = snd_kctl_event(ctl->events.next);
 101                 list_del(&cread->list);
 102                 kfree(cread);
 103         }
 104         spin_unlock_irqrestore(&ctl->read_lock, flags);
 105 }
 106
 107 static int snd_ctl_release(struct inode *inode, struct file *file)
 108 {
 109         unsigned long flags;
 110         struct snd_card *card;
 111         struct snd_ctl_file *ctl;
 112         struct snd_kcontrol *control;
 113         unsigned int idx;
 114
 115         ctl = file->private_data;
 116         file->private_data = NULL;
 117         card = ctl->card;
 118         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 119         list_del(&ctl->list);
 120         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 121         down_write(&card->controls_rwsem);
 122         list_for_each_entry(control, &card->controls, list)
 123                 for (idx = 0; idx < control->count; idx++)
 124                         if (control->vd[idx].owner == ctl)
 125                                 control->vd[idx].owner = NULL;
 126         up_write(&card->controls_rwsem);
 127         snd_ctl_empty_read_queue(ctl);
 128         kfree(ctl);
 129         module_put(card->module);
 130         snd_card_file_remove(card, file);
 131         return 0;
 132 }
 133
 134 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 135                     struct snd_ctl_elem_id *id)
 136 {
 137         unsigned long flags;
 138         struct snd_ctl_file *ctl;
 139         struct snd_kctl_event *ev;
 140
 141         if (snd_BUG_ON(!card || !id))
 142                 return;
 143         read_lock(&card->ctl_files_rwlock);
 144 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 145         card->mixer_oss_change_count++;
 146 #endif
 147         list_for_each_entry(ctl, &card->ctl_files, list) {
 148                 if (!ctl->subscribed)
 149                         continue;
 150                 spin_lock_irqsave(&ctl->read_lock, flags);
 151                 list_for_each_entry(ev, &ctl->events, list) {
 152                         if (ev->id.numid == id->numid) {
 153                                 ev->mask |= mask;
 154                                 goto _found;
 155                         }
 156                 }
 157                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 158                 if (ev) {
 159                         ev->id = *id;
 160                         ev->mask = mask;
 161                         list_add_tail(&ev->list, &ctl->events);
 162                 } else {
 163                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 164                 }
 165         _found:
 166                 wake_up(&ctl->change_sleep);
 167                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 168                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 169         }
 170         read_unlock(&card->ctl_files_rwlock);
 171 }
 172
 173 EXPORT_SYMBOL(snd_ctl_notify);
 174
 175 /**
 176  * snd_ctl_new - create a control instance from the template
 177  * @control: the control template
 178  * @access: the default control access
 179  *
 180  * Allocates a new struct snd_kcontrol instance and copies the given template
 181  * to the new instance. It does not copy volatile data (access).
 182  *
 183  * Returns the pointer of the new instance, or NULL on failure.
 184  */
 185 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 186                                         unsigned int access)
 187 {
 188         struct snd_kcontrol *kctl;
 189         unsigned int idx;
 190
 191         if (snd_BUG_ON(!control || !control->count))
 192                 return NULL;
 193         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 194         if (kctl == NULL) {
 195                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 196                 return NULL;
 197         }
 198         *kctl = *control;
 199         for (idx = 0; idx < kctl->count; idx++)
 200                 kctl->vd[idx].access = access;
 201         return kctl;
 202 }
 203
 204 /**
 205  * snd_ctl_new1 - create a control instance from the template
 206  * @ncontrol: the initialization record
 207  * @private_data: the private data to set
 208  *
 209  * Allocates a new struct snd_kcontrol instance and initialize from the given
 210  * template.  When the access field of ncontrol is 0, it's assumed as
 211  * READWRITE access. When the count field is 0, it's assumes as one.
 212  *
 213  * Returns the pointer of the newly generated instance, or NULL on failure.
 214  */
 215 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 216                                   void *private_data)
 217 {
 218         struct snd_kcontrol kctl;
 219         unsigned int access;
 220
 221         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 222                 return NULL;
 223         memset(&kctl, 0, sizeof(kctl));
 224         kctl.id.iface = ncontrol->iface;
 225         kctl.id.device = ncontrol->device;
 226         kctl.id.subdevice = ncontrol->subdevice;
 227         if (ncontrol->name) {
 228                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 229                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 230                         snd_printk(KERN_WARNING
 231                                    "Control name '%s' truncated to '%s'\n",
 232                                    ncontrol->name, kctl.id.name);
 233         }
 234         kctl.id.index = ncontrol->index;
 235         kctl.count = ncontrol->count ? ncontrol->count : 1;
 236         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 237                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 238                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 239                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 240                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 241         kctl.info = ncontrol->info;
 242         kctl.get = ncontrol->get;
 243         kctl.put = ncontrol->put;
 244         kctl.tlv.p = ncontrol->tlv.p;
 245         kctl.private_value = ncontrol->private_value;
 246         kctl.private_data = private_data;
 247         return snd_ctl_new(&kctl, access);
 248 }
 249
 250 EXPORT_SYMBOL(snd_ctl_new1);
 251
 252 /**
 253  * snd_ctl_free_one - release the control instance
 254  * @kcontrol: the control instance
 255  *
 256  * Releases the control instance created via snd_ctl_new()
 257  * or snd_ctl_new1().
 258  * Don't call this after the control was added to the card.
 259  */
 260 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 261 {
 262         if (kcontrol) {
 263                 if (kcontrol->private_free)
 264                         kcontrol->private_free(kcontrol);
 265                 kfree(kcontrol);
 266         }
 267 }
 268
 269 EXPORT_SYMBOL(snd_ctl_free_one);
 270
 271 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 272                                        unsigned int count)
 273 {
 274         struct snd_kcontrol *kctl;
 275
 276         list_for_each_entry(kctl, &card->controls, list) {
 277                 if ((kctl->id.numid <= card->last_numid &&
 278                      kctl->id.numid + kctl->count > card->last_numid) ||
 279                     (kctl->id.numid <= card->last_numid + count - 1 &&
 280                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 281                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 282         }
 283         return card->last_numid;
 284 }
 285
 286 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 287 {
 288         unsigned int last_numid, iter = 100000;
 289
 290         last_numid = card->last_numid;
 291         while (last_numid != snd_ctl_hole_check(card, count)) {
 292                 if (--iter == 0) {
 293                         /* this situation is very unlikely */
 294                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 295                         return -ENOMEM;
 296                 }
 297                 last_numid = card->last_numid;
 298         }
 299         return 0;
 300 }
 301
 302 /**
 303  * snd_ctl_add - add the control instance to the card
 304  * @card: the card instance
 305  * @kcontrol: the control instance to add
 306  *
 307  * Adds the control instance created via snd_ctl_new() or
 308  * snd_ctl_new1() to the given card. Assigns also an unique
 309  * numid used for fast search.
 310  *
 311  * Returns zero if successful, or a negative error code on failure.
 312  *
 313  * It frees automatically the control which cannot be added.
 314  */
 315 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 316 {
 317         struct snd_ctl_elem_id id;
 318         unsigned int idx;
 319         int err = -EINVAL;
 320
 321         if (! kcontrol)
 322                 return err;
 323         if (snd_BUG_ON(!card || !kcontrol->info))
 324                 goto error;
 325         id = kcontrol->id;
 326         down_write(&card->controls_rwsem);
 327         if (snd_ctl_find_id(card, &id)) {
 328                 up_write(&card->controls_rwsem);
 329                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 330                                         id.iface,
 331                                         id.device,
 332                                         id.subdevice,
 333                                         id.name,
 334                                         id.index);
 335                 err = -EBUSY;
 336                 goto error;
 337         }
 338         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 339                 up_write(&card->controls_rwsem);
 340                 err = -ENOMEM;
 341                 goto error;
 342         }
 343         list_add_tail(&kcontrol->list, &card->controls);
 344         card->controls_count += kcontrol->count;
 345         kcontrol->id.numid = card->last_numid + 1;
 346         card->last_numid += kcontrol->count;
 347         up_write(&card->controls_rwsem);
 348         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 349                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 350         return 0;
 351
 352  error:
 353         snd_ctl_free_one(kcontrol);
 354         return err;
 355 }
 356
 357 EXPORT_SYMBOL(snd_ctl_add);
 358
 359 /**
 360  * snd_ctl_remove - remove the control from the card and release it
 361  * @card: the card instance
 362  * @kcontrol: the control instance to remove
 363  *
 364  * Removes the control from the card and then releases the instance.
 365  * You don't need to call snd_ctl_free_one(). You must be in
 366  * the write lock - down_write(&card->controls_rwsem).
 367  *
 368  * Returns 0 if successful, or a negative error code on failure.
 369  */
 370 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 371 {
 372         struct snd_ctl_elem_id id;
 373         unsigned int idx;
 374
 375         if (snd_BUG_ON(!card || !kcontrol))
 376                 return -EINVAL;
 377         list_del(&kcontrol->list);
 378         card->controls_count -= kcontrol->count;
 379         id = kcontrol->id;
 380         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 381                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 382         snd_ctl_free_one(kcontrol);
 383         return 0;
 384 }
 385
 386 EXPORT_SYMBOL(snd_ctl_remove);
 387
 388 /**
 389  * snd_ctl_remove_id - remove the control of the given id and release it
 390  * @card: the card instance
 391  * @id: the control id to remove
 392  *
 393  * Finds the control instance with the given id, removes it from the
 394  * card list and releases it.
 395  *
 396  * Returns 0 if successful, or a negative error code on failure.
 397  */
 398 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 399 {
 400         struct snd_kcontrol *kctl;
 401         int ret;
 402
 403         down_write(&card->controls_rwsem);
 404         kctl = snd_ctl_find_id(card, id);
 405         if (kctl == NULL) {
 406                 up_write(&card->controls_rwsem);
 407                 return -ENOENT;
 408         }
 409         ret = snd_ctl_remove(card, kctl);
 410         up_write(&card->controls_rwsem);
 411         return ret;
 412 }
 413
 414 EXPORT_SYMBOL(snd_ctl_remove_id);
 415
 416 /**
 417  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 418  * @file: active control handle
 419  * @id: the control id to remove
 420  *
 421  * Finds the control instance with the given id, removes it from the
 422  * card list and releases it.
 423  *
 424  * Returns 0 if successful, or a negative error code on failure.
 425  */
 426 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 427                                       struct snd_ctl_elem_id *id)
 428 {
 429         struct snd_card *card = file->card;
 430         struct snd_kcontrol *kctl;
 431         int idx, ret;
 432
 433         down_write(&card->controls_rwsem);
 434         kctl = snd_ctl_find_id(card, id);
 435         if (kctl == NULL) {
 436                 up_write(&card->controls_rwsem);
 437                 return -ENOENT;
 438         }
 439         for (idx = 0; idx < kctl->count; idx++)
 440                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 441                         up_write(&card->controls_rwsem);
 442                         return -EBUSY;
 443                 }
 444         ret = snd_ctl_remove(card, kctl);
 445         up_write(&card->controls_rwsem);
 446         return ret;
 447 }
 448
 449 /**
 450  * snd_ctl_rename_id - replace the id of a control on the card
 451  * @card: the card instance
 452  * @src_id: the old id
 453  * @dst_id: the new id
 454  *
 455  * Finds the control with the old id from the card, and replaces the
 456  * id with the new one.
 457  *
 458  * Returns zero if successful, or a negative error code on failure.
 459  */
 460 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 461                       struct snd_ctl_elem_id *dst_id)
 462 {
 463         struct snd_kcontrol *kctl;
 464
 465         down_write(&card->controls_rwsem);
 466         kctl = snd_ctl_find_id(card, src_id);
 467         if (kctl == NULL) {
 468                 up_write(&card->controls_rwsem);
 469                 return -ENOENT;
 470         }
 471         kctl->id = *dst_id;
 472         kctl->id.numid = card->last_numid + 1;
 473         card->last_numid += kctl->count;
 474         up_write(&card->controls_rwsem);
 475         return 0;
 476 }
 477
 478 EXPORT_SYMBOL(snd_ctl_rename_id);
 479
 480 /**
 481  * snd_ctl_find_numid - find the control instance with the given number-id
 482  * @card: the card instance
 483  * @numid: the number-id to search
 484  *
 485  * Finds the control instance with the given number-id from the card.
 486  *
 487  * Returns the pointer of the instance if found, or NULL if not.
 488  *
 489  * The caller must down card->controls_rwsem before calling this function
 490  * (if the race condition can happen).
 491  */
 492 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 493 {
 494         struct snd_kcontrol *kctl;
 495
 496         if (snd_BUG_ON(!card || !numid))
 497                 return NULL;
 498         list_for_each_entry(kctl, &card->controls, list) {
 499                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 500                         return kctl;
 501         }
 502         return NULL;
 503 }
 504
 505 EXPORT_SYMBOL(snd_ctl_find_numid);
 506
 507 /**
 508  * snd_ctl_find_id - find the control instance with the given id
 509  * @card: the card instance
 510  * @id: the id to search
 511  *
 512  * Finds the control instance with the given id from the card.
 513  *
 514  * Returns the pointer of the instance if found, or NULL if not.
 515  *
 516  * The caller must down card->controls_rwsem before calling this function
 517  * (if the race condition can happen).
 518  */
 519 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 520                                      struct snd_ctl_elem_id *id)
 521 {
 522         struct snd_kcontrol *kctl;
 523
 524         if (snd_BUG_ON(!card || !id))
 525                 return NULL;
 526         if (id->numid != 0)
 527                 return snd_ctl_find_numid(card, id->numid);
 528         list_for_each_entry(kctl, &card->controls, list) {
 529                 if (kctl->id.iface != id->iface)
 530                         continue;
 531                 if (kctl->id.device != id->device)
 532                         continue;
 533                 if (kctl->id.subdevice != id->subdevice)
 534                         continue;
 535                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 536                         continue;
 537                 if (kctl->id.index > id->index)
 538                         continue;
 539                 if (kctl->id.index + kctl->count <= id->index)
 540                         continue;
 541                 return kctl;
 542         }
 543         return NULL;
 544 }
 545
 546 EXPORT_SYMBOL(snd_ctl_find_id);
 547
 548 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 549                              unsigned int cmd, void __user *arg)
 550 {
 551         struct snd_ctl_card_info *info;
 552
 553         info = kzalloc(sizeof(*info), GFP_KERNEL);
 554         if (! info)
 555                 return -ENOMEM;
 556         down_read(&snd_ioctl_rwsem);
 557         info->card = card->number;
 558         strlcpy(info->id, card->id, sizeof(info->id));
 559         strlcpy(info->driver, card->driver, sizeof(info->driver));
 560         strlcpy(info->name, card->shortname, sizeof(info->name));
 561         strlcpy(info->longname, card->longname, sizeof(info->longname));
 562         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 563         strlcpy(info->components, card->components, sizeof(info->components));
 564         up_read(&snd_ioctl_rwsem);
 565         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 566                 kfree(info);
 567                 return -EFAULT;
 568         }
 569         kfree(info);
 570         return 0;
 571 }
 572
 573 static int snd_ctl_elem_list(struct snd_card *card,
 574                              struct snd_ctl_elem_list __user *_list)
 575 {
 576         struct list_head *plist;
 577         struct snd_ctl_elem_list list;
 578         struct snd_kcontrol *kctl;
 579         struct snd_ctl_elem_id *dst, *id;
 580         unsigned int offset, space, first, jidx;
 581
 582         if (copy_from_user(&list, _list, sizeof(list)))
 583                 return -EFAULT;
 584         offset = list.offset;
 585         space = list.space;
 586         first = 0;
 587         /* try limit maximum space */
 588         if (space > 16384)
 589                 return -ENOMEM;
 590         if (space > 0) {
 591                 /* allocate temporary buffer for atomic operation */
 592                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 593                 if (dst == NULL)
 594                         return -ENOMEM;
 595                 down_read(&card->controls_rwsem);
 596                 list.count = card->controls_count;
 597                 plist = card->controls.next;
 598                 while (plist != &card->controls) {
 599                         if (offset == 0)
 600                                 break;
 601                         kctl = snd_kcontrol(plist);
 602                         if (offset < kctl->count)
 603                                 break;
 604                         offset -= kctl->count;
 605                         plist = plist->next;
 606                 }
 607                 list.used = 0;
 608                 id = dst;
 609                 while (space > 0 && plist != &card->controls) {
 610                         kctl = snd_kcontrol(plist);
 611                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 612                                 snd_ctl_build_ioff(id, kctl, jidx);
 613                                 id++;
 614                                 space--;
 615                                 list.used++;
 616                         }
 617                         plist = plist->next;
 618                         offset = 0;
 619                 }
 620                 up_read(&card->controls_rwsem);
 621                 if (list.used > 0 &&
 622                     copy_to_user(list.pids, dst,
 623                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 624                         vfree(dst);
 625                         return -EFAULT;
 626                 }
 627                 vfree(dst);
 628         } else {
 629                 down_read(&card->controls_rwsem);
 630                 list.count = card->controls_count;
 631                 up_read(&card->controls_rwsem);
 632         }
 633         if (copy_to_user(_list, &list, sizeof(list)))
 634                 return -EFAULT;
 635         return 0;
 636 }
 637
 638 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 639                              struct snd_ctl_elem_info *info)
 640 {
 641         struct snd_card *card = ctl->card;
 642         struct snd_kcontrol *kctl;
 643         struct snd_kcontrol_volatile *vd;
 644         unsigned int index_offset;
 645         int result;
 646
 647         down_read(&card->controls_rwsem);
 648         kctl = snd_ctl_find_id(card, &info->id);
 649         if (kctl == NULL) {
 650                 up_read(&card->controls_rwsem);
 651                 return -ENOENT;
 652         }
 653 #ifdef CONFIG_SND_DEBUG
 654         info->access = 0;
 655 #endif
 656         result = kctl->info(kctl, info);
 657         if (result >= 0) {
 658                 snd_BUG_ON(info->access);
 659                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 660                 vd = &kctl->vd[index_offset];
 661                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 662                 info->access = vd->access;
 663                 if (vd->owner) {
 664                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 665                         if (vd->owner == ctl)
 666                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 667                         info->owner = vd->owner_pid;
 668                 } else {
 669                         info->owner = -1;
 670                 }
 671         }
 672         up_read(&card->controls_rwsem);
 673         return result;
 674 }
 675
 676 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 677                                   struct snd_ctl_elem_info __user *_info)
 678 {
 679         struct snd_ctl_elem_info info;
 680         int result;
 681
 682         if (copy_from_user(&info, _info, sizeof(info)))
 683                 return -EFAULT;
 684         snd_power_lock(ctl->card);
 685         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 686         if (result >= 0)
 687                 result = snd_ctl_elem_info(ctl, &info);
 688         snd_power_unlock(ctl->card);
 689         if (result >= 0)
 690                 if (copy_to_user(_info, &info, sizeof(info)))
 691                         return -EFAULT;
 692         return result;
 693 }
 694
 695 static int snd_ctl_elem_read(struct snd_card *card,
 696                              struct snd_ctl_elem_value *control)
 697 {
 698         struct snd_kcontrol *kctl;
 699         struct snd_kcontrol_volatile *vd;
 700         unsigned int index_offset;
 701         int result;
 702
 703         down_read(&card->controls_rwsem);
 704         kctl = snd_ctl_find_id(card, &control->id);
 705         if (kctl == NULL) {
 706                 result = -ENOENT;
 707         } else {
 708                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 709                 vd = &kctl->vd[index_offset];
 710                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 711                     kctl->get != NULL) {
 712                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 713                         result = kctl->get(kctl, control);
 714                 } else
 715                         result = -EPERM;
 716         }
 717         up_read(&card->controls_rwsem);
 718         return result;
 719 }
 720
 721 static int snd_ctl_elem_read_user(struct snd_card *card,
 722                                   struct snd_ctl_elem_value __user *_control)
 723 {
 724         struct snd_ctl_elem_value *control;
 725         int result;
 726
 727         control = memdup_user(_control, sizeof(*control));
 728         if (IS_ERR(control))
 729                 return PTR_ERR(control);
 730
 731         snd_power_lock(card);
 732         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 733         if (result >= 0)
 734                 result = snd_ctl_elem_read(card, control);
 735         snd_power_unlock(card);
 736         if (result >= 0)
 737                 if (copy_to_user(_control, control, sizeof(*control)))
 738                         result = -EFAULT;
 739         kfree(control);
 740         return result;
 741 }
 742
 743 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 744                               struct snd_ctl_elem_value *control)
 745 {
 746         struct snd_kcontrol *kctl;
 747         struct snd_kcontrol_volatile *vd;
 748         unsigned int index_offset;
 749         int result;
 750
 751         down_read(&card->controls_rwsem);
 752         kctl = snd_ctl_find_id(card, &control->id);
 753         if (kctl == NULL) {
 754                 result = -ENOENT;
 755         } else {
 756                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 757                 vd = &kctl->vd[index_offset];
 758                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 759                     kctl->put == NULL ||
 760                     (file && vd->owner && vd->owner != file)) {
 761                         result = -EPERM;
 762                 } else {
 763                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 764                         result = kctl->put(kctl, control);
 765                 }
 766                 if (result > 0) {
 767                         up_read(&card->controls_rwsem);
 768                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 769                                        &control->id);
 770                         return 0;
 771                 }
 772         }
 773         up_read(&card->controls_rwsem);
 774         return result;
 775 }
 776
 777 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 778                                    struct snd_ctl_elem_value __user *_control)
 779 {
 780         struct snd_ctl_elem_value *control;
 781         struct snd_card *card;
 782         int result;
 783
 784         control = memdup_user(_control, sizeof(*control));
 785         if (IS_ERR(control))
 786                 return PTR_ERR(control);
 787
 788         card = file->card;
 789         snd_power_lock(card);
 790         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 791         if (result >= 0)
 792                 result = snd_ctl_elem_write(card, file, control);
 793         snd_power_unlock(card);
 794         if (result >= 0)
 795                 if (copy_to_user(_control, control, sizeof(*control)))
 796                         result = -EFAULT;
 797         kfree(control);
 798         return result;
 799 }
 800
 801 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 802                              struct snd_ctl_elem_id __user *_id)
 803 {
 804         struct snd_card *card = file->card;
 805         struct snd_ctl_elem_id id;
 806         struct snd_kcontrol *kctl;
 807         struct snd_kcontrol_volatile *vd;
 808         int result;
 809
 810         if (copy_from_user(&id, _id, sizeof(id)))
 811                 return -EFAULT;
 812         down_write(&card->controls_rwsem);
 813         kctl = snd_ctl_find_id(card, &id);
 814         if (kctl == NULL) {
 815                 result = -ENOENT;
 816         } else {
 817                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 818                 if (vd->owner != NULL)
 819                         result = -EBUSY;
 820                 else {
 821                         vd->owner = file;
 822                         vd->owner_pid = current->pid;
 823                         result = 0;
 824                 }
 825         }
 826         up_write(&card->controls_rwsem);
 827         return result;
 828 }
 829
 830 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 831                                struct snd_ctl_elem_id __user *_id)
 832 {
 833         struct snd_card *card = file->card;
 834         struct snd_ctl_elem_id id;
 835         struct snd_kcontrol *kctl;
 836         struct snd_kcontrol_volatile *vd;
 837         int result;
 838
 839         if (copy_from_user(&id, _id, sizeof(id)))
 840                 return -EFAULT;
 841         down_write(&card->controls_rwsem);
 842         kctl = snd_ctl_find_id(card, &id);
 843         if (kctl == NULL) {
 844                 result = -ENOENT;
 845         } else {
 846                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 847                 if (vd->owner == NULL)
 848                         result = -EINVAL;
 849                 else if (vd->owner != file)
 850                         result = -EPERM;
 851                 else {
 852                         vd->owner = NULL;
 853                         vd->owner_pid = 0;
 854                         result = 0;
 855                 }
 856         }
 857         up_write(&card->controls_rwsem);
 858         return result;
 859 }
 860
 861 struct user_element {
 862         struct snd_ctl_elem_info info;
 863         void *elem_data;                /* element data */
 864         unsigned long elem_data_size;   /* size of element data in bytes */
 865         void *tlv_data;                 /* TLV data */
 866         unsigned long tlv_data_size;    /* TLV data size */
 867         void *priv_data;                /* private data (like strings for enumerated type) */
 868         unsigned long priv_data_size;   /* size of private data in bytes */
 869 };
 870
 871 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 872                                   struct snd_ctl_elem_info *uinfo)
 873 {
 874         struct user_element *ue = kcontrol->private_data;
 875
 876         *uinfo = ue->info;
 877         return 0;
 878 }
 879
 880 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 881                                  struct snd_ctl_elem_value *ucontrol)
 882 {
 883         struct user_element *ue = kcontrol->private_data;
 884
 885         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 886         return 0;
 887 }
 888
 889 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 890                                  struct snd_ctl_elem_value *ucontrol)
 891 {
 892         int change;
 893         struct user_element *ue = kcontrol->private_data;
 894
 895         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 896         if (change)
 897                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 898         return change;
 899 }
 900
 901 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 902                                  int op_flag,
 903                                  unsigned int size,
 904                                  unsigned int __user *tlv)
 905 {
 906         struct user_element *ue = kcontrol->private_data;
 907         int change = 0;
 908         void *new_data;
 909
 910         if (op_flag > 0) {
 911                 if (size > 1024 * 128)  /* sane value */
 912                         return -EINVAL;
 913
 914                 new_data = memdup_user(tlv, size);
 915                 if (IS_ERR(new_data))
 916                         return PTR_ERR(new_data);
 917                 change = ue->tlv_data_size != size;
 918                 if (!change)
 919                         change = memcmp(ue->tlv_data, new_data, size);
 920                 kfree(ue->tlv_data);
 921                 ue->tlv_data = new_data;
 922                 ue->tlv_data_size = size;
 923         } else {
 924                 if (! ue->tlv_data_size || ! ue->tlv_data)
 925                         return -ENXIO;
 926                 if (size < ue->tlv_data_size)
 927                         return -ENOSPC;
 928                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 929                         return -EFAULT;
 930         }
 931         return change;
 932 }
 933
 934 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 935 {
 936         struct user_element *ue = kcontrol->private_data;
 937         if (ue->tlv_data)
 938                 kfree(ue->tlv_data);
 939         kfree(ue);
 940 }
 941
 942 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 943                             struct snd_ctl_elem_info *info, int replace)
 944 {
 945         struct snd_card *card = file->card;
 946         struct snd_kcontrol kctl, *_kctl;
 947         unsigned int access;
 948         long private_size;
 949         struct user_element *ue;
 950         int idx, err;
 951
 952         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 953                 return -ENOMEM;
 954         if (info->count > 1024)
 955                 return -EINVAL;
 956         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 957                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 958                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 959                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 960         info->id.numid = 0;
 961         memset(&kctl, 0, sizeof(kctl));
 962         down_write(&card->controls_rwsem);
 963         _kctl = snd_ctl_find_id(card, &info->id);
 964         err = 0;
 965         if (_kctl) {
 966                 if (replace)
 967                         err = snd_ctl_remove(card, _kctl);
 968                 else
 969                         err = -EBUSY;
 970         } else {
 971                 if (replace)
 972                         err = -ENOENT;
 973         }
 974         up_write(&card->controls_rwsem);
 975         if (err < 0)
 976                 return err;
 977         memcpy(&kctl.id, &info->id, sizeof(info->id));
 978         kctl.count = info->owner ? info->owner : 1;
 979         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 980         kctl.info = snd_ctl_elem_user_info;
 981         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 982                 kctl.get = snd_ctl_elem_user_get;
 983         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 984                 kctl.put = snd_ctl_elem_user_put;
 985         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 986                 kctl.tlv.c = snd_ctl_elem_user_tlv;
 987                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 988         }
 989         switch (info->type) {
 990         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 991         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 992                 private_size = sizeof(long);
 993                 if (info->count > 128)
 994                         return -EINVAL;
 995                 break;
 996         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 997                 private_size = sizeof(long long);
 998                 if (info->count > 64)
 999                         return -EINVAL;
1000                 break;
1001         case SNDRV_CTL_ELEM_TYPE_BYTES:
1002                 private_size = sizeof(unsigned char);
1003                 if (info->count > 512)
1004                         return -EINVAL;
1005                 break;
1006         case SNDRV_CTL_ELEM_TYPE_IEC958:
1007                 private_size = sizeof(struct snd_aes_iec958);
1008                 if (info->count != 1)
1009                         return -EINVAL;
1010                 break;
1011         default:
1012                 return -EINVAL;
1013         }
1014         private_size *= info->count;
1015         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1016         if (ue == NULL)
1017                 return -ENOMEM;
1018         ue->info = *info;
1019         ue->info.access = 0;
1020         ue->elem_data = (char *)ue + sizeof(*ue);
1021         ue->elem_data_size = private_size;
1022         kctl.private_free = snd_ctl_elem_user_free;
1023         _kctl = snd_ctl_new(&kctl, access);
1024         if (_kctl == NULL) {
1025                 kfree(ue);
1026                 return -ENOMEM;
1027         }
1028         _kctl->private_data = ue;
1029         for (idx = 0; idx < _kctl->count; idx++)
1030                 _kctl->vd[idx].owner = file;
1031         err = snd_ctl_add(card, _kctl);
1032         if (err < 0)
1033                 return err;
1034
1035         down_write(&card->controls_rwsem);
1036         card->user_ctl_count++;
1037         up_write(&card->controls_rwsem);
1038
1039         return 0;
1040 }
1041
1042 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1043                                  struct snd_ctl_elem_info __user *_info, int replace)
1044 {
1045         struct snd_ctl_elem_info info;
1046         if (copy_from_user(&info, _info, sizeof(info)))
1047                 return -EFAULT;
1048         return snd_ctl_elem_add(file, &info, replace);
1049 }
1050
1051 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1052                                struct snd_ctl_elem_id __user *_id)
1053 {
1054         struct snd_ctl_elem_id id;
1055         int err;
1056
1057         if (copy_from_user(&id, _id, sizeof(id)))
1058                 return -EFAULT;
1059         err = snd_ctl_remove_unlocked_id(file, &id);
1060         if (! err) {
1061                 struct snd_card *card = file->card;
1062                 down_write(&card->controls_rwsem);
1063                 card->user_ctl_count--;
1064                 up_write(&card->controls_rwsem);
1065         }
1066         return err;
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) * 3)
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 (file && 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);