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 #define MAX_CONTROL_COUNT       1028
  35
  36 struct snd_kctl_ioctl {
  37         struct list_head list;          /* list of all ioctls */
  38         snd_kctl_ioctl_func_t fioctl;
  39 };
  40
  41 static DECLARE_RWSEM(snd_ioctl_rwsem);
  42 static LIST_HEAD(snd_control_ioctls);
  43 #ifdef CONFIG_COMPAT
  44 static LIST_HEAD(snd_control_compat_ioctls);
  45 #endif
  46
  47 static int snd_ctl_open(struct inode *inode, struct file *file)
  48 {
  49         unsigned long flags;
  50         struct snd_card *card;
  51         struct snd_ctl_file *ctl;
  52         int err;
  53
  54         err = nonseekable_open(inode, file);
  55         if (err < 0)
  56                 return err;
  57
  58         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  59         if (!card) {
  60                 err = -ENODEV;
  61                 goto __error1;
  62         }
  63         err = snd_card_file_add(card, file);
  64         if (err < 0) {
  65                 err = -ENODEV;
  66                 goto __error1;
  67         }
  68         if (!try_module_get(card->module)) {
  69                 err = -EFAULT;
  70                 goto __error2;
  71         }
  72         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  73         if (ctl == NULL) {
  74                 err = -ENOMEM;
  75                 goto __error;
  76         }
  77         INIT_LIST_HEAD(&ctl->events);
  78         init_waitqueue_head(&ctl->change_sleep);
  79         spin_lock_init(&ctl->read_lock);
  80         ctl->card = card;
  81         ctl->prefer_pcm_subdevice = -1;
  82         ctl->prefer_rawmidi_subdevice = -1;
  83         ctl->pid = get_pid(task_pid(current));
  84         file->private_data = ctl;
  85         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  86         list_add_tail(&ctl->list, &card->ctl_files);
  87         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  88         return 0;
  89
  90       __error:
  91         module_put(card->module);
  92       __error2:
  93         snd_card_file_remove(card, file);
  94       __error1:
  95         return err;
  96 }
  97
  98 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  99 {
 100         unsigned long flags;
 101         struct snd_kctl_event *cread;
 102
 103         spin_lock_irqsave(&ctl->read_lock, flags);
 104         while (!list_empty(&ctl->events)) {
 105                 cread = snd_kctl_event(ctl->events.next);
 106                 list_del(&cread->list);
 107                 kfree(cread);
 108         }
 109         spin_unlock_irqrestore(&ctl->read_lock, flags);
 110 }
 111
 112 static int snd_ctl_release(struct inode *inode, struct file *file)
 113 {
 114         unsigned long flags;
 115         struct snd_card *card;
 116         struct snd_ctl_file *ctl;
 117         struct snd_kcontrol *control;
 118         unsigned int idx;
 119
 120         ctl = file->private_data;
 121         file->private_data = NULL;
 122         card = ctl->card;
 123         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 124         list_del(&ctl->list);
 125         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 126         down_write(&card->controls_rwsem);
 127         list_for_each_entry(control, &card->controls, list)
 128                 for (idx = 0; idx < control->count; idx++)
 129                         if (control->vd[idx].owner == ctl)
 130                                 control->vd[idx].owner = NULL;
 131         up_write(&card->controls_rwsem);
 132         snd_ctl_empty_read_queue(ctl);
 133         put_pid(ctl->pid);
 134         kfree(ctl);
 135         module_put(card->module);
 136         snd_card_file_remove(card, file);
 137         return 0;
 138 }
 139
 140 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 141                     struct snd_ctl_elem_id *id)
 142 {
 143         unsigned long flags;
 144         struct snd_ctl_file *ctl;
 145         struct snd_kctl_event *ev;
 146
 147         if (snd_BUG_ON(!card || !id))
 148                 return;
 149         read_lock(&card->ctl_files_rwlock);
 150 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 151         card->mixer_oss_change_count++;
 152 #endif
 153         list_for_each_entry(ctl, &card->ctl_files, list) {
 154                 if (!ctl->subscribed)
 155                         continue;
 156                 spin_lock_irqsave(&ctl->read_lock, flags);
 157                 list_for_each_entry(ev, &ctl->events, list) {
 158                         if (ev->id.numid == id->numid) {
 159                                 ev->mask |= mask;
 160                                 goto _found;
 161                         }
 162                 }
 163                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 164                 if (ev) {
 165                         ev->id = *id;
 166                         ev->mask = mask;
 167                         list_add_tail(&ev->list, &ctl->events);
 168                 } else {
 169                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 170                 }
 171         _found:
 172                 wake_up(&ctl->change_sleep);
 173                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 174                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 175         }
 176         read_unlock(&card->ctl_files_rwlock);
 177 }
 178
 179 EXPORT_SYMBOL(snd_ctl_notify);
 180
 181 /**
 182  * snd_ctl_new - create a control instance from the template
 183  * @control: the control template
 184  * @access: the default control access
 185  *
 186  * Allocates a new struct snd_kcontrol instance and copies the given template
 187  * to the new instance. It does not copy volatile data (access).
 188  *
 189  * Returns the pointer of the new instance, or NULL on failure.
 190  */
 191 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 192                                         unsigned int access)
 193 {
 194         struct snd_kcontrol *kctl;
 195         unsigned int idx;
 196
 197         if (snd_BUG_ON(!control || !control->count))
 198                 return NULL;
 199
 200         if (control->count > MAX_CONTROL_COUNT)
 201                 return NULL;
 202
 203         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 204         if (kctl == NULL) {
 205                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 206                 return NULL;
 207         }
 208         *kctl = *control;
 209         for (idx = 0; idx < kctl->count; idx++)
 210                 kctl->vd[idx].access = access;
 211         return kctl;
 212 }
 213
 214 /**
 215  * snd_ctl_new1 - create a control instance from the template
 216  * @ncontrol: the initialization record
 217  * @private_data: the private data to set
 218  *
 219  * Allocates a new struct snd_kcontrol instance and initialize from the given
 220  * template.  When the access field of ncontrol is 0, it's assumed as
 221  * READWRITE access. When the count field is 0, it's assumes as one.
 222  *
 223  * Returns the pointer of the newly generated instance, or NULL on failure.
 224  */
 225 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 226                                   void *private_data)
 227 {
 228         struct snd_kcontrol kctl;
 229         unsigned int access;
 230
 231         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 232                 return NULL;
 233         memset(&kctl, 0, sizeof(kctl));
 234         kctl.id.iface = ncontrol->iface;
 235         kctl.id.device = ncontrol->device;
 236         kctl.id.subdevice = ncontrol->subdevice;
 237         if (ncontrol->name) {
 238                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 239                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 240                         snd_printk(KERN_WARNING
 241                                    "Control name '%s' truncated to '%s'\n",
 242                                    ncontrol->name, kctl.id.name);
 243         }
 244         kctl.id.index = ncontrol->index;
 245         kctl.count = ncontrol->count ? ncontrol->count : 1;
 246         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 247                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 248                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 249                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 250                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 251                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 252         kctl.info = ncontrol->info;
 253         kctl.get = ncontrol->get;
 254         kctl.put = ncontrol->put;
 255         kctl.tlv.p = ncontrol->tlv.p;
 256         kctl.private_value = ncontrol->private_value;
 257         kctl.private_data = private_data;
 258         return snd_ctl_new(&kctl, access);
 259 }
 260
 261 EXPORT_SYMBOL(snd_ctl_new1);
 262
 263 /**
 264  * snd_ctl_free_one - release the control instance
 265  * @kcontrol: the control instance
 266  *
 267  * Releases the control instance created via snd_ctl_new()
 268  * or snd_ctl_new1().
 269  * Don't call this after the control was added to the card.
 270  */
 271 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 272 {
 273         if (kcontrol) {
 274                 if (kcontrol->private_free)
 275                         kcontrol->private_free(kcontrol);
 276                 kfree(kcontrol);
 277         }
 278 }
 279
 280 EXPORT_SYMBOL(snd_ctl_free_one);
 281
 282 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 283                                           unsigned int count)
 284 {
 285         struct snd_kcontrol *kctl;
 286
 287         list_for_each_entry(kctl, &card->controls, list) {
 288                 if (kctl->id.numid < card->last_numid + 1 + count &&
 289                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 290                         card->last_numid = kctl->id.numid + kctl->count - 1;
 291                         return true;
 292                 }
 293         }
 294         return false;
 295 }
 296
 297 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 298 {
 299         unsigned int iter = 100000;
 300
 301         while (snd_ctl_remove_numid_conflict(card, count)) {
 302                 if (--iter == 0) {
 303                         /* this situation is very unlikely */
 304                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 305                         return -ENOMEM;
 306                 }
 307         }
 308         return 0;
 309 }
 310
 311 /**
 312  * snd_ctl_add - add the control instance to the card
 313  * @card: the card instance
 314  * @kcontrol: the control instance to add
 315  *
 316  * Adds the control instance created via snd_ctl_new() or
 317  * snd_ctl_new1() to the given card. Assigns also an unique
 318  * numid used for fast search.
 319  *
 320  * Returns zero if successful, or a negative error code on failure.
 321  *
 322  * It frees automatically the control which cannot be added.
 323  */
 324 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 325 {
 326         struct snd_ctl_elem_id id;
 327         unsigned int idx;
 328         int err = -EINVAL;
 329
 330         if (! kcontrol)
 331                 return err;
 332         if (snd_BUG_ON(!card || !kcontrol->info))
 333                 goto error;
 334         id = kcontrol->id;
 335         down_write(&card->controls_rwsem);
 336         if (snd_ctl_find_id(card, &id)) {
 337                 up_write(&card->controls_rwsem);
 338                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 339                                         id.iface,
 340                                         id.device,
 341                                         id.subdevice,
 342                                         id.name,
 343                                         id.index);
 344                 err = -EBUSY;
 345                 goto error;
 346         }
 347         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 348                 up_write(&card->controls_rwsem);
 349                 err = -ENOMEM;
 350                 goto error;
 351         }
 352         list_add_tail(&kcontrol->list, &card->controls);
 353         card->controls_count += kcontrol->count;
 354         kcontrol->id.numid = card->last_numid + 1;
 355         card->last_numid += kcontrol->count;
 356         up_write(&card->controls_rwsem);
 357         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 358                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 359         return 0;
 360
 361  error:
 362         snd_ctl_free_one(kcontrol);
 363         return err;
 364 }
 365
 366 EXPORT_SYMBOL(snd_ctl_add);
 367
 368 /**
 369  * snd_ctl_replace - replace the control instance of the card
 370  * @card: the card instance
 371  * @kcontrol: the control instance to replace
 372  * @add_on_replace: add the control if not already added
 373  *
 374  * Replaces the given control.  If the given control does not exist
 375  * and the add_on_replace flag is set, the control is added.  If the
 376  * control exists, it is destroyed first.
 377  *
 378  * Returns zero if successful, or a negative error code on failure.
 379  *
 380  * It frees automatically the control which cannot be added or replaced.
 381  */
 382 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 383                     bool add_on_replace)
 384 {
 385         struct snd_ctl_elem_id id;
 386         unsigned int idx;
 387         struct snd_kcontrol *old;
 388         int ret;
 389
 390         if (!kcontrol)
 391                 return -EINVAL;
 392         if (snd_BUG_ON(!card || !kcontrol->info)) {
 393                 ret = -EINVAL;
 394                 goto error;
 395         }
 396         id = kcontrol->id;
 397         down_write(&card->controls_rwsem);
 398         old = snd_ctl_find_id(card, &id);
 399         if (!old) {
 400                 if (add_on_replace)
 401                         goto add;
 402                 up_write(&card->controls_rwsem);
 403                 ret = -EINVAL;
 404                 goto error;
 405         }
 406         ret = snd_ctl_remove(card, old);
 407         if (ret < 0) {
 408                 up_write(&card->controls_rwsem);
 409                 goto error;
 410         }
 411 add:
 412         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 413                 up_write(&card->controls_rwsem);
 414                 ret = -ENOMEM;
 415                 goto error;
 416         }
 417         list_add_tail(&kcontrol->list, &card->controls);
 418         card->controls_count += kcontrol->count;
 419         kcontrol->id.numid = card->last_numid + 1;
 420         card->last_numid += kcontrol->count;
 421         up_write(&card->controls_rwsem);
 422         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 423                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 424         return 0;
 425
 426 error:
 427         snd_ctl_free_one(kcontrol);
 428         return ret;
 429 }
 430 EXPORT_SYMBOL(snd_ctl_replace);
 431
 432 /**
 433  * snd_ctl_remove - remove the control from the card and release it
 434  * @card: the card instance
 435  * @kcontrol: the control instance to remove
 436  *
 437  * Removes the control from the card and then releases the instance.
 438  * You don't need to call snd_ctl_free_one(). You must be in
 439  * the write lock - down_write(&card->controls_rwsem).
 440  *
 441  * Returns 0 if successful, or a negative error code on failure.
 442  */
 443 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 444 {
 445         struct snd_ctl_elem_id id;
 446         unsigned int idx;
 447
 448         if (snd_BUG_ON(!card || !kcontrol))
 449                 return -EINVAL;
 450         list_del(&kcontrol->list);
 451         card->controls_count -= kcontrol->count;
 452         id = kcontrol->id;
 453         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 454                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 455         snd_ctl_free_one(kcontrol);
 456         return 0;
 457 }
 458
 459 EXPORT_SYMBOL(snd_ctl_remove);
 460
 461 /**
 462  * snd_ctl_remove_id - remove the control of the given id and release it
 463  * @card: the card instance
 464  * @id: the control id to remove
 465  *
 466  * Finds the control instance with the given id, removes it from the
 467  * card list and releases it.
 468  *
 469  * Returns 0 if successful, or a negative error code on failure.
 470  */
 471 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 472 {
 473         struct snd_kcontrol *kctl;
 474         int ret;
 475
 476         down_write(&card->controls_rwsem);
 477         kctl = snd_ctl_find_id(card, id);
 478         if (kctl == NULL) {
 479                 up_write(&card->controls_rwsem);
 480                 return -ENOENT;
 481         }
 482         ret = snd_ctl_remove(card, kctl);
 483         up_write(&card->controls_rwsem);
 484         return ret;
 485 }
 486
 487 EXPORT_SYMBOL(snd_ctl_remove_id);
 488
 489 /**
 490  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 491  * @file: active control handle
 492  * @id: the control id to remove
 493  *
 494  * Finds the control instance with the given id, removes it from the
 495  * card list and releases it.
 496  *
 497  * Returns 0 if successful, or a negative error code on failure.
 498  */
 499 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 500                                    struct snd_ctl_elem_id *id)
 501 {
 502         struct snd_card *card = file->card;
 503         struct snd_kcontrol *kctl;
 504         int idx, ret;
 505
 506         down_write(&card->controls_rwsem);
 507         kctl = snd_ctl_find_id(card, id);
 508         if (kctl == NULL) {
 509                 ret = -ENOENT;
 510                 goto error;
 511         }
 512         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 513                 ret = -EINVAL;
 514                 goto error;
 515         }
 516         for (idx = 0; idx < kctl->count; idx++)
 517                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 518                         ret = -EBUSY;
 519                         goto error;
 520                 }
 521         ret = snd_ctl_remove(card, kctl);
 522         if (ret < 0)
 523                 goto error;
 524         card->user_ctl_count--;
 525 error:
 526         up_write(&card->controls_rwsem);
 527         return ret;
 528 }
 529
 530 /**
 531  * snd_ctl_activate_id - activate/inactivate the control of the given id
 532  * @card: the card instance
 533  * @id: the control id to activate/inactivate
 534  * @active: non-zero to activate
 535  *
 536  * Finds the control instance with the given id, and activate or
 537  * inactivate the control together with notification, if changed.
 538  *
 539  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 540  */
 541 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 542                         int active)
 543 {
 544         struct snd_kcontrol *kctl;
 545         struct snd_kcontrol_volatile *vd;
 546         unsigned int index_offset;
 547         int ret;
 548
 549         down_write(&card->controls_rwsem);
 550         kctl = snd_ctl_find_id(card, id);
 551         if (kctl == NULL) {
 552                 ret = -ENOENT;
 553                 goto unlock;
 554         }
 555         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 556         vd = &kctl->vd[index_offset];
 557         ret = 0;
 558         if (active) {
 559                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 560                         goto unlock;
 561                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 562         } else {
 563                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 564                         goto unlock;
 565                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 566         }
 567         ret = 1;
 568  unlock:
 569         up_write(&card->controls_rwsem);
 570         if (ret > 0)
 571                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 572         return ret;
 573 }
 574 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 575
 576 /**
 577  * snd_ctl_rename_id - replace the id of a control on the card
 578  * @card: the card instance
 579  * @src_id: the old id
 580  * @dst_id: the new id
 581  *
 582  * Finds the control with the old id from the card, and replaces the
 583  * id with the new one.
 584  *
 585  * Returns zero if successful, or a negative error code on failure.
 586  */
 587 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 588                       struct snd_ctl_elem_id *dst_id)
 589 {
 590         struct snd_kcontrol *kctl;
 591
 592         down_write(&card->controls_rwsem);
 593         kctl = snd_ctl_find_id(card, src_id);
 594         if (kctl == NULL) {
 595                 up_write(&card->controls_rwsem);
 596                 return -ENOENT;
 597         }
 598         kctl->id = *dst_id;
 599         kctl->id.numid = card->last_numid + 1;
 600         card->last_numid += kctl->count;
 601         up_write(&card->controls_rwsem);
 602         return 0;
 603 }
 604
 605 EXPORT_SYMBOL(snd_ctl_rename_id);
 606
 607 /**
 608  * snd_ctl_find_numid - find the control instance with the given number-id
 609  * @card: the card instance
 610  * @numid: the number-id to search
 611  *
 612  * Finds the control instance with the given number-id from the card.
 613  *
 614  * Returns the pointer of the instance if found, or NULL if not.
 615  *
 616  * The caller must down card->controls_rwsem before calling this function
 617  * (if the race condition can happen).
 618  */
 619 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 620 {
 621         struct snd_kcontrol *kctl;
 622
 623         if (snd_BUG_ON(!card || !numid))
 624                 return NULL;
 625         list_for_each_entry(kctl, &card->controls, list) {
 626                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 627                         return kctl;
 628         }
 629         return NULL;
 630 }
 631
 632 EXPORT_SYMBOL(snd_ctl_find_numid);
 633
 634 /**
 635  * snd_ctl_find_id - find the control instance with the given id
 636  * @card: the card instance
 637  * @id: the id to search
 638  *
 639  * Finds the control instance with the given id from the card.
 640  *
 641  * Returns the pointer of the instance if found, or NULL if not.
 642  *
 643  * The caller must down card->controls_rwsem before calling this function
 644  * (if the race condition can happen).
 645  */
 646 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 647                                      struct snd_ctl_elem_id *id)
 648 {
 649         struct snd_kcontrol *kctl;
 650
 651         if (snd_BUG_ON(!card || !id))
 652                 return NULL;
 653         if (id->numid != 0)
 654                 return snd_ctl_find_numid(card, id->numid);
 655         list_for_each_entry(kctl, &card->controls, list) {
 656                 if (kctl->id.iface != id->iface)
 657                         continue;
 658                 if (kctl->id.device != id->device)
 659                         continue;
 660                 if (kctl->id.subdevice != id->subdevice)
 661                         continue;
 662                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 663                         continue;
 664                 if (kctl->id.index > id->index)
 665                         continue;
 666                 if (kctl->id.index + kctl->count <= id->index)
 667                         continue;
 668                 return kctl;
 669         }
 670         return NULL;
 671 }
 672
 673 EXPORT_SYMBOL(snd_ctl_find_id);
 674
 675 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 676                              unsigned int cmd, void __user *arg)
 677 {
 678         struct snd_ctl_card_info *info;
 679
 680         info = kzalloc(sizeof(*info), GFP_KERNEL);
 681         if (! info)
 682                 return -ENOMEM;
 683         down_read(&snd_ioctl_rwsem);
 684         info->card = card->number;
 685         strlcpy(info->id, card->id, sizeof(info->id));
 686         strlcpy(info->driver, card->driver, sizeof(info->driver));
 687         strlcpy(info->name, card->shortname, sizeof(info->name));
 688         strlcpy(info->longname, card->longname, sizeof(info->longname));
 689         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 690         strlcpy(info->components, card->components, sizeof(info->components));
 691         up_read(&snd_ioctl_rwsem);
 692         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 693                 kfree(info);
 694                 return -EFAULT;
 695         }
 696         kfree(info);
 697         return 0;
 698 }
 699
 700 static int snd_ctl_elem_list(struct snd_card *card,
 701                              struct snd_ctl_elem_list __user *_list)
 702 {
 703         struct list_head *plist;
 704         struct snd_ctl_elem_list list;
 705         struct snd_kcontrol *kctl;
 706         struct snd_ctl_elem_id *dst, *id;
 707         unsigned int offset, space, jidx;
 708
 709         if (copy_from_user(&list, _list, sizeof(list)))
 710                 return -EFAULT;
 711         offset = list.offset;
 712         space = list.space;
 713         /* try limit maximum space */
 714         if (space > 16384)
 715                 return -ENOMEM;
 716         if (space > 0) {
 717                 /* allocate temporary buffer for atomic operation */
 718                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 719                 if (dst == NULL)
 720                         return -ENOMEM;
 721                 down_read(&card->controls_rwsem);
 722                 list.count = card->controls_count;
 723                 plist = card->controls.next;
 724                 while (plist != &card->controls) {
 725                         if (offset == 0)
 726                                 break;
 727                         kctl = snd_kcontrol(plist);
 728                         if (offset < kctl->count)
 729                                 break;
 730                         offset -= kctl->count;
 731                         plist = plist->next;
 732                 }
 733                 list.used = 0;
 734                 id = dst;
 735                 while (space > 0 && plist != &card->controls) {
 736                         kctl = snd_kcontrol(plist);
 737                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 738                                 snd_ctl_build_ioff(id, kctl, jidx);
 739                                 id++;
 740                                 space--;
 741                                 list.used++;
 742                         }
 743                         plist = plist->next;
 744                         offset = 0;
 745                 }
 746                 up_read(&card->controls_rwsem);
 747                 if (list.used > 0 &&
 748                     copy_to_user(list.pids, dst,
 749                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 750                         vfree(dst);
 751                         return -EFAULT;
 752                 }
 753                 vfree(dst);
 754         } else {
 755                 down_read(&card->controls_rwsem);
 756                 list.count = card->controls_count;
 757                 up_read(&card->controls_rwsem);
 758         }
 759         if (copy_to_user(_list, &list, sizeof(list)))
 760                 return -EFAULT;
 761         return 0;
 762 }
 763
 764 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 765                              struct snd_ctl_elem_info *info)
 766 {
 767         struct snd_card *card = ctl->card;
 768         struct snd_kcontrol *kctl;
 769         struct snd_kcontrol_volatile *vd;
 770         unsigned int index_offset;
 771         int result;
 772
 773         down_read(&card->controls_rwsem);
 774         kctl = snd_ctl_find_id(card, &info->id);
 775         if (kctl == NULL) {
 776                 up_read(&card->controls_rwsem);
 777                 return -ENOENT;
 778         }
 779 #ifdef CONFIG_SND_DEBUG
 780         info->access = 0;
 781 #endif
 782         result = kctl->info(kctl, info);
 783         if (result >= 0) {
 784                 snd_BUG_ON(info->access);
 785                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 786                 vd = &kctl->vd[index_offset];
 787                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 788                 info->access = vd->access;
 789                 if (vd->owner) {
 790                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 791                         if (vd->owner == ctl)
 792                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 793                         info->owner = pid_vnr(vd->owner->pid);
 794                 } else {
 795                         info->owner = -1;
 796                 }
 797         }
 798         up_read(&card->controls_rwsem);
 799         return result;
 800 }
 801
 802 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 803                                   struct snd_ctl_elem_info __user *_info)
 804 {
 805         struct snd_ctl_elem_info info;
 806         int result;
 807
 808         if (copy_from_user(&info, _info, sizeof(info)))
 809                 return -EFAULT;
 810         snd_power_lock(ctl->card);
 811         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 812         if (result >= 0)
 813                 result = snd_ctl_elem_info(ctl, &info);
 814         snd_power_unlock(ctl->card);
 815         if (result >= 0)
 816                 if (copy_to_user(_info, &info, sizeof(info)))
 817                         return -EFAULT;
 818         return result;
 819 }
 820
 821 static int snd_ctl_elem_read(struct snd_card *card,
 822                              struct snd_ctl_elem_value *control)
 823 {
 824         struct snd_kcontrol *kctl;
 825         struct snd_kcontrol_volatile *vd;
 826         unsigned int index_offset;
 827         int result;
 828
 829         down_read(&card->controls_rwsem);
 830         kctl = snd_ctl_find_id(card, &control->id);
 831         if (kctl == NULL) {
 832                 result = -ENOENT;
 833         } else {
 834                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 835                 vd = &kctl->vd[index_offset];
 836                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 837                     kctl->get != NULL) {
 838                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 839                         result = kctl->get(kctl, control);
 840                 } else
 841                         result = -EPERM;
 842         }
 843         up_read(&card->controls_rwsem);
 844         return result;
 845 }
 846
 847 static int snd_ctl_elem_read_user(struct snd_card *card,
 848                                   struct snd_ctl_elem_value __user *_control)
 849 {
 850         struct snd_ctl_elem_value *control;
 851         int result;
 852
 853         control = memdup_user(_control, sizeof(*control));
 854         if (IS_ERR(control))
 855                 return PTR_ERR(control);
 856
 857         snd_power_lock(card);
 858         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 859         if (result >= 0)
 860                 result = snd_ctl_elem_read(card, control);
 861         snd_power_unlock(card);
 862         if (result >= 0)
 863                 if (copy_to_user(_control, control, sizeof(*control)))
 864                         result = -EFAULT;
 865         kfree(control);
 866         return result;
 867 }
 868
 869 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 870                               struct snd_ctl_elem_value *control)
 871 {
 872         struct snd_kcontrol *kctl;
 873         struct snd_kcontrol_volatile *vd;
 874         unsigned int index_offset;
 875         int result;
 876
 877         down_read(&card->controls_rwsem);
 878         kctl = snd_ctl_find_id(card, &control->id);
 879         if (kctl == NULL) {
 880                 result = -ENOENT;
 881         } else {
 882                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 883                 vd = &kctl->vd[index_offset];
 884                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 885                     kctl->put == NULL ||
 886                     (file && vd->owner && vd->owner != file)) {
 887                         result = -EPERM;
 888                 } else {
 889                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 890                         result = kctl->put(kctl, control);
 891                 }
 892                 if (result > 0) {
 893                         up_read(&card->controls_rwsem);
 894                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 895                                        &control->id);
 896                         return 0;
 897                 }
 898         }
 899         up_read(&card->controls_rwsem);
 900         return result;
 901 }
 902
 903 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 904                                    struct snd_ctl_elem_value __user *_control)
 905 {
 906         struct snd_ctl_elem_value *control;
 907         struct snd_card *card;
 908         int result;
 909
 910         control = memdup_user(_control, sizeof(*control));
 911         if (IS_ERR(control))
 912                 return PTR_ERR(control);
 913
 914         card = file->card;
 915         snd_power_lock(card);
 916         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 917         if (result >= 0)
 918                 result = snd_ctl_elem_write(card, file, control);
 919         snd_power_unlock(card);
 920         if (result >= 0)
 921                 if (copy_to_user(_control, control, sizeof(*control)))
 922                         result = -EFAULT;
 923         kfree(control);
 924         return result;
 925 }
 926
 927 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 928                              struct snd_ctl_elem_id __user *_id)
 929 {
 930         struct snd_card *card = file->card;
 931         struct snd_ctl_elem_id id;
 932         struct snd_kcontrol *kctl;
 933         struct snd_kcontrol_volatile *vd;
 934         int result;
 935
 936         if (copy_from_user(&id, _id, sizeof(id)))
 937                 return -EFAULT;
 938         down_write(&card->controls_rwsem);
 939         kctl = snd_ctl_find_id(card, &id);
 940         if (kctl == NULL) {
 941                 result = -ENOENT;
 942         } else {
 943                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 944                 if (vd->owner != NULL)
 945                         result = -EBUSY;
 946                 else {
 947                         vd->owner = file;
 948                         result = 0;
 949                 }
 950         }
 951         up_write(&card->controls_rwsem);
 952         return result;
 953 }
 954
 955 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 956                                struct snd_ctl_elem_id __user *_id)
 957 {
 958         struct snd_card *card = file->card;
 959         struct snd_ctl_elem_id id;
 960         struct snd_kcontrol *kctl;
 961         struct snd_kcontrol_volatile *vd;
 962         int result;
 963
 964         if (copy_from_user(&id, _id, sizeof(id)))
 965                 return -EFAULT;
 966         down_write(&card->controls_rwsem);
 967         kctl = snd_ctl_find_id(card, &id);
 968         if (kctl == NULL) {
 969                 result = -ENOENT;
 970         } else {
 971                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 972                 if (vd->owner == NULL)
 973                         result = -EINVAL;
 974                 else if (vd->owner != file)
 975                         result = -EPERM;
 976                 else {
 977                         vd->owner = NULL;
 978                         result = 0;
 979                 }
 980         }
 981         up_write(&card->controls_rwsem);
 982         return result;
 983 }
 984
 985 struct user_element {
 986         struct snd_ctl_elem_info info;
 987         void *elem_data;                /* element data */
 988         unsigned long elem_data_size;   /* size of element data in bytes */
 989         void *tlv_data;                 /* TLV data */
 990         unsigned long tlv_data_size;    /* TLV data size */
 991         void *priv_data;                /* private data (like strings for enumerated type) */
 992 };
 993
 994 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 995                                   struct snd_ctl_elem_info *uinfo)
 996 {
 997         struct user_element *ue = kcontrol->private_data;
 998
 999         *uinfo = ue->info;
1000         return 0;
1001 }
1002
1003 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1004                                        struct snd_ctl_elem_info *uinfo)
1005 {
1006         struct user_element *ue = kcontrol->private_data;
1007         const char *names;
1008         unsigned int item;
1009
1010         item = uinfo->value.enumerated.item;
1011
1012         *uinfo = ue->info;
1013
1014         item = min(item, uinfo->value.enumerated.items - 1);
1015         uinfo->value.enumerated.item = item;
1016
1017         names = ue->priv_data;
1018         for (; item > 0; --item)
1019                 names += strlen(names) + 1;
1020         strcpy(uinfo->value.enumerated.name, names);
1021
1022         return 0;
1023 }
1024
1025 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1026                                  struct snd_ctl_elem_value *ucontrol)
1027 {
1028         struct user_element *ue = kcontrol->private_data;
1029
1030         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1031         return 0;
1032 }
1033
1034 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1035                                  struct snd_ctl_elem_value *ucontrol)
1036 {
1037         int change;
1038         struct user_element *ue = kcontrol->private_data;
1039
1040         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1041         if (change)
1042                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1043         return change;
1044 }
1045
1046 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1047                                  int op_flag,
1048                                  unsigned int size,
1049                                  unsigned int __user *tlv)
1050 {
1051         struct user_element *ue = kcontrol->private_data;
1052         int change = 0;
1053         void *new_data;
1054
1055         if (op_flag > 0) {
1056                 if (size > 1024 * 128)  /* sane value */
1057                         return -EINVAL;
1058
1059                 new_data = memdup_user(tlv, size);
1060                 if (IS_ERR(new_data))
1061                         return PTR_ERR(new_data);
1062                 change = ue->tlv_data_size != size;
1063                 if (!change)
1064                         change = memcmp(ue->tlv_data, new_data, size);
1065                 kfree(ue->tlv_data);
1066                 ue->tlv_data = new_data;
1067                 ue->tlv_data_size = size;
1068         } else {
1069                 if (! ue->tlv_data_size || ! ue->tlv_data)
1070                         return -ENXIO;
1071                 if (size < ue->tlv_data_size)
1072                         return -ENOSPC;
1073                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1074                         return -EFAULT;
1075         }
1076         return change;
1077 }
1078
1079 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1080 {
1081         char *names, *p;
1082         size_t buf_len, name_len;
1083         unsigned int i;
1084         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1085
1086         if (ue->info.value.enumerated.names_length > 64 * 1024)
1087                 return -EINVAL;
1088
1089         names = memdup_user((const void __user *)user_ptrval,
1090                 ue->info.value.enumerated.names_length);
1091         if (IS_ERR(names))
1092                 return PTR_ERR(names);
1093
1094         /* check that there are enough valid names */
1095         buf_len = ue->info.value.enumerated.names_length;
1096         p = names;
1097         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1098                 name_len = strnlen(p, buf_len);
1099                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1100                         kfree(names);
1101                         return -EINVAL;
1102                 }
1103                 p += name_len + 1;
1104                 buf_len -= name_len + 1;
1105         }
1106
1107         ue->priv_data = names;
1108         ue->info.value.enumerated.names_ptr = 0;
1109
1110         return 0;
1111 }
1112
1113 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1114 {
1115         struct user_element *ue = kcontrol->private_data;
1116
1117         kfree(ue->tlv_data);
1118         kfree(ue->priv_data);
1119         kfree(ue);
1120 }
1121
1122 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1123                             struct snd_ctl_elem_info *info, int replace)
1124 {
1125         struct snd_card *card = file->card;
1126         struct snd_kcontrol kctl, *_kctl;
1127         unsigned int access;
1128         long private_size;
1129         struct user_element *ue;
1130         int idx, err;
1131
1132         if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1133                 return -ENOMEM;
1134         if (info->count < 1)
1135                 return -EINVAL;
1136         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1137                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1138                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1139                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1140         info->id.numid = 0;
1141         memset(&kctl, 0, sizeof(kctl));
1142         down_write(&card->controls_rwsem);
1143         _kctl = snd_ctl_find_id(card, &info->id);
1144         err = 0;
1145         if (_kctl) {
1146                 if (replace)
1147                         err = snd_ctl_remove(card, _kctl);
1148                 else
1149                         err = -EBUSY;
1150         } else {
1151                 if (replace)
1152                         err = -ENOENT;
1153         }
1154         up_write(&card->controls_rwsem);
1155         if (err < 0)
1156                 return err;
1157         memcpy(&kctl.id, &info->id, sizeof(info->id));
1158         kctl.count = info->owner ? info->owner : 1;
1159         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1160         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1161                 kctl.info = snd_ctl_elem_user_enum_info;
1162         else
1163                 kctl.info = snd_ctl_elem_user_info;
1164         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1165                 kctl.get = snd_ctl_elem_user_get;
1166         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1167                 kctl.put = snd_ctl_elem_user_put;
1168         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1169                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1170                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1171         }
1172         switch (info->type) {
1173         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1174         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1175                 private_size = sizeof(long);
1176                 if (info->count > 128)
1177                         return -EINVAL;
1178                 break;
1179         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1180                 private_size = sizeof(long long);
1181                 if (info->count > 64)
1182                         return -EINVAL;
1183                 break;
1184         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1185                 private_size = sizeof(unsigned int);
1186                 if (info->count > 128 || info->value.enumerated.items == 0)
1187                         return -EINVAL;
1188                 break;
1189         case SNDRV_CTL_ELEM_TYPE_BYTES:
1190                 private_size = sizeof(unsigned char);
1191                 if (info->count > 512)
1192                         return -EINVAL;
1193                 break;
1194         case SNDRV_CTL_ELEM_TYPE_IEC958:
1195                 private_size = sizeof(struct snd_aes_iec958);
1196                 if (info->count != 1)
1197                         return -EINVAL;
1198                 break;
1199         default:
1200                 return -EINVAL;
1201         }
1202         private_size *= info->count;
1203         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1204         if (ue == NULL)
1205                 return -ENOMEM;
1206         ue->info = *info;
1207         ue->info.access = 0;
1208         ue->elem_data = (char *)ue + sizeof(*ue);
1209         ue->elem_data_size = private_size;
1210         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1211                 err = snd_ctl_elem_init_enum_names(ue);
1212                 if (err < 0) {
1213                         kfree(ue);
1214                         return err;
1215                 }
1216         }
1217         kctl.private_free = snd_ctl_elem_user_free;
1218         _kctl = snd_ctl_new(&kctl, access);
1219         if (_kctl == NULL) {
1220                 kfree(ue->priv_data);
1221                 kfree(ue);
1222                 return -ENOMEM;
1223         }
1224         _kctl->private_data = ue;
1225         for (idx = 0; idx < _kctl->count; idx++)
1226                 _kctl->vd[idx].owner = file;
1227         err = snd_ctl_add(card, _kctl);
1228         if (err < 0)
1229                 return err;
1230
1231         down_write(&card->controls_rwsem);
1232         card->user_ctl_count++;
1233         up_write(&card->controls_rwsem);
1234
1235         return 0;
1236 }
1237
1238 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1239                                  struct snd_ctl_elem_info __user *_info, int replace)
1240 {
1241         struct snd_ctl_elem_info info;
1242         if (copy_from_user(&info, _info, sizeof(info)))
1243                 return -EFAULT;
1244         return snd_ctl_elem_add(file, &info, replace);
1245 }
1246
1247 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1248                                struct snd_ctl_elem_id __user *_id)
1249 {
1250         struct snd_ctl_elem_id id;
1251
1252         if (copy_from_user(&id, _id, sizeof(id)))
1253                 return -EFAULT;
1254         return snd_ctl_remove_user_ctl(file, &id);
1255 }
1256
1257 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1258 {
1259         int subscribe;
1260         if (get_user(subscribe, ptr))
1261                 return -EFAULT;
1262         if (subscribe < 0) {
1263                 subscribe = file->subscribed;
1264                 if (put_user(subscribe, ptr))
1265                         return -EFAULT;
1266                 return 0;
1267         }
1268         if (subscribe) {
1269                 file->subscribed = 1;
1270                 return 0;
1271         } else if (file->subscribed) {
1272                 snd_ctl_empty_read_queue(file);
1273                 file->subscribed = 0;
1274         }
1275         return 0;
1276 }
1277
1278 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1279                              struct snd_ctl_tlv __user *_tlv,
1280                              int op_flag)
1281 {
1282         struct snd_card *card = file->card;
1283         struct snd_ctl_tlv tlv;
1284         struct snd_kcontrol *kctl;
1285         struct snd_kcontrol_volatile *vd;
1286         unsigned int len;
1287         int err = 0;
1288
1289         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1290                 return -EFAULT;
1291         if (tlv.length < sizeof(unsigned int) * 2)
1292                 return -EINVAL;
1293         down_read(&card->controls_rwsem);
1294         kctl = snd_ctl_find_numid(card, tlv.numid);
1295         if (kctl == NULL) {
1296                 err = -ENOENT;
1297                 goto __kctl_end;
1298         }
1299         if (kctl->tlv.p == NULL) {
1300                 err = -ENXIO;
1301                 goto __kctl_end;
1302         }
1303         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1304         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1305             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1306             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1307                 err = -ENXIO;
1308                 goto __kctl_end;
1309         }
1310         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1311                 if (vd->owner != NULL && vd->owner != file) {
1312                         err = -EPERM;
1313                         goto __kctl_end;
1314                 }
1315                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1316                 if (err > 0) {
1317                         up_read(&card->controls_rwsem);
1318                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1319                         return 0;
1320                 }
1321         } else {
1322                 if (op_flag) {
1323                         err = -ENXIO;
1324                         goto __kctl_end;
1325                 }
1326                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1327                 if (tlv.length < len) {
1328                         err = -ENOMEM;
1329                         goto __kctl_end;
1330                 }
1331                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1332                         err = -EFAULT;
1333         }
1334       __kctl_end:
1335         up_read(&card->controls_rwsem);
1336         return err;
1337 }
1338
1339 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1340 {
1341         struct snd_ctl_file *ctl;
1342         struct snd_card *card;
1343         struct snd_kctl_ioctl *p;
1344         void __user *argp = (void __user *)arg;
1345         int __user *ip = argp;
1346         int err;
1347
1348         ctl = file->private_data;
1349         card = ctl->card;
1350         if (snd_BUG_ON(!card))
1351                 return -ENXIO;
1352         switch (cmd) {
1353         case SNDRV_CTL_IOCTL_PVERSION:
1354                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1355         case SNDRV_CTL_IOCTL_CARD_INFO:
1356                 return snd_ctl_card_info(card, ctl, cmd, argp);
1357         case SNDRV_CTL_IOCTL_ELEM_LIST:
1358                 return snd_ctl_elem_list(card, argp);
1359         case SNDRV_CTL_IOCTL_ELEM_INFO:
1360                 return snd_ctl_elem_info_user(ctl, argp);
1361         case SNDRV_CTL_IOCTL_ELEM_READ:
1362                 return snd_ctl_elem_read_user(card, argp);
1363         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1364                 return snd_ctl_elem_write_user(ctl, argp);
1365         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1366                 return snd_ctl_elem_lock(ctl, argp);
1367         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1368                 return snd_ctl_elem_unlock(ctl, argp);
1369         case SNDRV_CTL_IOCTL_ELEM_ADD:
1370                 return snd_ctl_elem_add_user(ctl, argp, 0);
1371         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1372                 return snd_ctl_elem_add_user(ctl, argp, 1);
1373         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1374                 return snd_ctl_elem_remove(ctl, argp);
1375         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1376                 return snd_ctl_subscribe_events(ctl, ip);
1377         case SNDRV_CTL_IOCTL_TLV_READ:
1378                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1379         case SNDRV_CTL_IOCTL_TLV_WRITE:
1380                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1381         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1382                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1383         case SNDRV_CTL_IOCTL_POWER:
1384                 return -ENOPROTOOPT;
1385         case SNDRV_CTL_IOCTL_POWER_STATE:
1386 #ifdef CONFIG_PM
1387                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1388 #else
1389                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1390 #endif
1391         }
1392         down_read(&snd_ioctl_rwsem);
1393         list_for_each_entry(p, &snd_control_ioctls, list) {
1394                 err = p->fioctl(card, ctl, cmd, arg);
1395                 if (err != -ENOIOCTLCMD) {
1396                         up_read(&snd_ioctl_rwsem);
1397                         return err;
1398                 }
1399         }
1400         up_read(&snd_ioctl_rwsem);
1401         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1402         return -ENOTTY;
1403 }
1404
1405 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1406                             size_t count, loff_t * offset)
1407 {
1408         struct snd_ctl_file *ctl;
1409         int err = 0;
1410         ssize_t result = 0;
1411
1412         ctl = file->private_data;
1413         if (snd_BUG_ON(!ctl || !ctl->card))
1414                 return -ENXIO;
1415         if (!ctl->subscribed)
1416                 return -EBADFD;
1417         if (count < sizeof(struct snd_ctl_event))
1418                 return -EINVAL;
1419         spin_lock_irq(&ctl->read_lock);
1420         while (count >= sizeof(struct snd_ctl_event)) {
1421                 struct snd_ctl_event ev;
1422                 struct snd_kctl_event *kev;
1423                 while (list_empty(&ctl->events)) {
1424                         wait_queue_t wait;
1425                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1426                                 err = -EAGAIN;
1427                                 goto __end_lock;
1428                         }
1429                         init_waitqueue_entry(&wait, current);
1430                         add_wait_queue(&ctl->change_sleep, &wait);
1431                         set_current_state(TASK_INTERRUPTIBLE);
1432                         spin_unlock_irq(&ctl->read_lock);
1433                         schedule();
1434                         remove_wait_queue(&ctl->change_sleep, &wait);
1435                         if (signal_pending(current))
1436                                 return -ERESTARTSYS;
1437                         spin_lock_irq(&ctl->read_lock);
1438                 }
1439                 kev = snd_kctl_event(ctl->events.next);
1440                 ev.type = SNDRV_CTL_EVENT_ELEM;
1441                 ev.data.elem.mask = kev->mask;
1442                 ev.data.elem.id = kev->id;
1443                 list_del(&kev->list);
1444                 spin_unlock_irq(&ctl->read_lock);
1445                 kfree(kev);
1446                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1447                         err = -EFAULT;
1448                         goto __end;
1449                 }
1450                 spin_lock_irq(&ctl->read_lock);
1451                 buffer += sizeof(struct snd_ctl_event);
1452                 count -= sizeof(struct snd_ctl_event);
1453                 result += sizeof(struct snd_ctl_event);
1454         }
1455       __end_lock:
1456         spin_unlock_irq(&ctl->read_lock);
1457       __end:
1458         return result > 0 ? result : err;
1459 }
1460
1461 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1462 {
1463         unsigned int mask;
1464         struct snd_ctl_file *ctl;
1465
1466         ctl = file->private_data;
1467         if (!ctl->subscribed)
1468                 return 0;
1469         poll_wait(file, &ctl->change_sleep, wait);
1470
1471         mask = 0;
1472         if (!list_empty(&ctl->events))
1473                 mask |= POLLIN | POLLRDNORM;
1474
1475         return mask;
1476 }
1477
1478 /*
1479  * register the device-specific control-ioctls.
1480  * called from each device manager like pcm.c, hwdep.c, etc.
1481  */
1482 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1483 {
1484         struct snd_kctl_ioctl *pn;
1485
1486         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1487         if (pn == NULL)
1488                 return -ENOMEM;
1489         pn->fioctl = fcn;
1490         down_write(&snd_ioctl_rwsem);
1491         list_add_tail(&pn->list, lists);
1492         up_write(&snd_ioctl_rwsem);
1493         return 0;
1494 }
1495
1496 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1497 {
1498         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1499 }
1500
1501 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1502
1503 #ifdef CONFIG_COMPAT
1504 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1505 {
1506         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1507 }
1508
1509 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1510 #endif
1511
1512 /*
1513  * de-register the device-specific control-ioctls.
1514  */
1515 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1516                                      struct list_head *lists)
1517 {
1518         struct snd_kctl_ioctl *p;
1519
1520         if (snd_BUG_ON(!fcn))
1521                 return -EINVAL;
1522         down_write(&snd_ioctl_rwsem);
1523         list_for_each_entry(p, lists, list) {
1524                 if (p->fioctl == fcn) {
1525                         list_del(&p->list);
1526                         up_write(&snd_ioctl_rwsem);
1527                         kfree(p);
1528                         return 0;
1529                 }
1530         }
1531         up_write(&snd_ioctl_rwsem);
1532         snd_BUG();
1533         return -EINVAL;
1534 }
1535
1536 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1537 {
1538         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1539 }
1540
1541 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1542
1543 #ifdef CONFIG_COMPAT
1544 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1545 {
1546         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1547 }
1548
1549 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1550 #endif
1551
1552 static int snd_ctl_fasync(int fd, struct file * file, int on)
1553 {
1554         struct snd_ctl_file *ctl;
1555
1556         ctl = file->private_data;
1557         return fasync_helper(fd, file, on, &ctl->fasync);
1558 }
1559
1560 /*
1561  * ioctl32 compat
1562  */
1563 #ifdef CONFIG_COMPAT
1564 #include "control_compat.c"
1565 #else
1566 #define snd_ctl_ioctl_compat    NULL
1567 #endif
1568
1569 /*
1570  *  INIT PART
1571  */
1572
1573 static const struct file_operations snd_ctl_f_ops =
1574 {
1575         .owner =        THIS_MODULE,
1576         .read =         snd_ctl_read,
1577         .open =         snd_ctl_open,
1578         .release =      snd_ctl_release,
1579         .llseek =       no_llseek,
1580         .poll =         snd_ctl_poll,
1581         .unlocked_ioctl =       snd_ctl_ioctl,
1582         .compat_ioctl = snd_ctl_ioctl_compat,
1583         .fasync =       snd_ctl_fasync,
1584 };
1585
1586 /*
1587  * registration of the control device
1588  */
1589 static int snd_ctl_dev_register(struct snd_device *device)
1590 {
1591         struct snd_card *card = device->device_data;
1592         int err, cardnum;
1593         char name[16];
1594
1595         if (snd_BUG_ON(!card))
1596                 return -ENXIO;
1597         cardnum = card->number;
1598         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1599                 return -ENXIO;
1600         sprintf(name, "controlC%i", cardnum);
1601         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1602                                        &snd_ctl_f_ops, card, name)) < 0)
1603                 return err;
1604         return 0;
1605 }
1606
1607 /*
1608  * disconnection of the control device
1609  */
1610 static int snd_ctl_dev_disconnect(struct snd_device *device)
1611 {
1612         struct snd_card *card = device->device_data;
1613         struct snd_ctl_file *ctl;
1614         int err, cardnum;
1615
1616         if (snd_BUG_ON(!card))
1617                 return -ENXIO;
1618         cardnum = card->number;
1619         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1620                 return -ENXIO;
1621
1622         read_lock(&card->ctl_files_rwlock);
1623         list_for_each_entry(ctl, &card->ctl_files, list) {
1624                 wake_up(&ctl->change_sleep);
1625                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1626         }
1627         read_unlock(&card->ctl_files_rwlock);
1628
1629         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1630                                          card, -1)) < 0)
1631                 return err;
1632         return 0;
1633 }
1634
1635 /*
1636  * free all controls
1637  */
1638 static int snd_ctl_dev_free(struct snd_device *device)
1639 {
1640         struct snd_card *card = device->device_data;
1641         struct snd_kcontrol *control;
1642
1643         down_write(&card->controls_rwsem);
1644         while (!list_empty(&card->controls)) {
1645                 control = snd_kcontrol(card->controls.next);
1646                 snd_ctl_remove(card, control);
1647         }
1648         up_write(&card->controls_rwsem);
1649         return 0;
1650 }
1651
1652 /*
1653  * create control core:
1654  * called from init.c
1655  */
1656 int snd_ctl_create(struct snd_card *card)
1657 {
1658         static struct snd_device_ops ops = {
1659                 .dev_free = snd_ctl_dev_free,
1660                 .dev_register = snd_ctl_dev_register,
1661                 .dev_disconnect = snd_ctl_dev_disconnect,
1662         };
1663
1664         if (snd_BUG_ON(!card))
1665                 return -ENXIO;
1666         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1667 }
1668
1669 /*
1670  * Frequently used control callbacks/helpers
1671  */
1672 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1673                               struct snd_ctl_elem_info *uinfo)
1674 {
1675         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1676         uinfo->count = 1;
1677         uinfo->value.integer.min = 0;
1678         uinfo->value.integer.max = 1;
1679         return 0;
1680 }
1681
1682 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1683
1684 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1685                                 struct snd_ctl_elem_info *uinfo)
1686 {
1687         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1688         uinfo->count = 2;
1689         uinfo->value.integer.min = 0;
1690         uinfo->value.integer.max = 1;
1691         return 0;
1692 }
1693
1694 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1695
1696 /**
1697  * snd_ctl_enum_info - fills the info structure for an enumerated control
1698  * @info: the structure to be filled
1699  * @channels: the number of the control's channels; often one
1700  * @items: the number of control values; also the size of @names
1701  * @names: an array containing the names of all control values
1702  *
1703  * Sets all required fields in @info to their appropriate values.
1704  * If the control's accessibility is not the default (readable and writable),
1705  * the caller has to fill @info->access.
1706  */
1707 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1708                       unsigned int items, const char *const names[])
1709 {
1710         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1711         info->count = channels;
1712         info->value.enumerated.items = items;
1713         if (info->value.enumerated.item >= items)
1714                 info->value.enumerated.item = items - 1;
1715         strlcpy(info->value.enumerated.name,
1716                 names[info->value.enumerated.item],
1717                 sizeof(info->value.enumerated.name));
1718         return 0;
1719 }
1720 EXPORT_SYMBOL(snd_ctl_enum_info);