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