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