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