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/module.h>
  25 #include <linux/slab.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/time.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/info.h>
  31 #include <sound/control.h>
  32
  33 /* max number of user-defined controls */
  34 #define MAX_USER_CONTROLS       32
  35 #define MAX_CONTROL_COUNT       1028
  36
  37 struct snd_kctl_ioctl {
  38         struct list_head list;          /* list of all ioctls */
  39         snd_kctl_ioctl_func_t fioctl;
  40 };
  41
  42 static DECLARE_RWSEM(snd_ioctl_rwsem);
  43 static LIST_HEAD(snd_control_ioctls);
  44 #ifdef CONFIG_COMPAT
  45 static LIST_HEAD(snd_control_compat_ioctls);
  46 #endif
  47
  48 static int snd_ctl_open(struct inode *inode, struct file *file)
  49 {
  50         unsigned long flags;
  51         struct snd_card *card;
  52         struct snd_ctl_file *ctl;
  53         int err;
  54
  55         err = nonseekable_open(inode, file);
  56         if (err < 0)
  57                 return err;
  58
  59         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  60         if (!card) {
  61                 err = -ENODEV;
  62                 goto __error1;
  63         }
  64         err = snd_card_file_add(card, file);
  65         if (err < 0) {
  66                 err = -ENODEV;
  67                 goto __error1;
  68         }
  69         if (!try_module_get(card->module)) {
  70                 err = -EFAULT;
  71                 goto __error2;
  72         }
  73         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  74         if (ctl == NULL) {
  75                 err = -ENOMEM;
  76                 goto __error;
  77         }
  78         INIT_LIST_HEAD(&ctl->events);
  79         init_waitqueue_head(&ctl->change_sleep);
  80         spin_lock_init(&ctl->read_lock);
  81         ctl->card = card;
  82         ctl->prefer_pcm_subdevice = -1;
  83         ctl->prefer_rawmidi_subdevice = -1;
  84         ctl->pid = get_pid(task_pid(current));
  85         file->private_data = ctl;
  86         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  87         list_add_tail(&ctl->list, &card->ctl_files);
  88         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  89         return 0;
  90
  91       __error:
  92         module_put(card->module);
  93       __error2:
  94         snd_card_file_remove(card, file);
  95       __error1:
  96         return err;
  97 }
  98
  99 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
 100 {
 101         unsigned long flags;
 102         struct snd_kctl_event *cread;
 103
 104         spin_lock_irqsave(&ctl->read_lock, flags);
 105         while (!list_empty(&ctl->events)) {
 106                 cread = snd_kctl_event(ctl->events.next);
 107                 list_del(&cread->list);
 108                 kfree(cread);
 109         }
 110         spin_unlock_irqrestore(&ctl->read_lock, flags);
 111 }
 112
 113 static int snd_ctl_release(struct inode *inode, struct file *file)
 114 {
 115         unsigned long flags;
 116         struct snd_card *card;
 117         struct snd_ctl_file *ctl;
 118         struct snd_kcontrol *control;
 119         unsigned int idx;
 120
 121         ctl = file->private_data;
 122         file->private_data = NULL;
 123         card = ctl->card;
 124         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 125         list_del(&ctl->list);
 126         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 127         down_write(&card->controls_rwsem);
 128         list_for_each_entry(control, &card->controls, list)
 129                 for (idx = 0; idx < control->count; idx++)
 130                         if (control->vd[idx].owner == ctl)
 131                                 control->vd[idx].owner = NULL;
 132         up_write(&card->controls_rwsem);
 133         snd_ctl_empty_read_queue(ctl);
 134         put_pid(ctl->pid);
 135         kfree(ctl);
 136         module_put(card->module);
 137         snd_card_file_remove(card, file);
 138         return 0;
 139 }
 140
 141 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 142                     struct snd_ctl_elem_id *id)
 143 {
 144         unsigned long flags;
 145         struct snd_ctl_file *ctl;
 146         struct snd_kctl_event *ev;
 147
 148         if (snd_BUG_ON(!card || !id))
 149                 return;
 150         read_lock(&card->ctl_files_rwlock);
 151 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 152         card->mixer_oss_change_count++;
 153 #endif
 154         list_for_each_entry(ctl, &card->ctl_files, list) {
 155                 if (!ctl->subscribed)
 156                         continue;
 157                 spin_lock_irqsave(&ctl->read_lock, flags);
 158                 list_for_each_entry(ev, &ctl->events, list) {
 159                         if (ev->id.numid == id->numid) {
 160                                 ev->mask |= mask;
 161                                 goto _found;
 162                         }
 163                 }
 164                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 165                 if (ev) {
 166                         ev->id = *id;
 167                         ev->mask = mask;
 168                         list_add_tail(&ev->list, &ctl->events);
 169                 } else {
 170                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 171                 }
 172         _found:
 173                 wake_up(&ctl->change_sleep);
 174                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 175                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 176         }
 177         read_unlock(&card->ctl_files_rwlock);
 178 }
 179
 180 EXPORT_SYMBOL(snd_ctl_notify);
 181
 182 /**
 183  * snd_ctl_new - create a control instance from the template
 184  * @control: the control template
 185  * @access: the default control access
 186  *
 187  * Allocates a new struct snd_kcontrol instance and copies the given template
 188  * to the new instance. It does not copy volatile data (access).
 189  *
 190  * Returns the pointer of the new instance, or NULL on failure.
 191  */
 192 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 193                                         unsigned int access)
 194 {
 195         struct snd_kcontrol *kctl;
 196         unsigned int idx;
 197
 198         if (snd_BUG_ON(!control || !control->count))
 199                 return NULL;
 200
 201         if (control->count > MAX_CONTROL_COUNT)
 202                 return NULL;
 203
 204         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 205         if (kctl == NULL) {
 206                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 207                 return NULL;
 208         }
 209         *kctl = *control;
 210         for (idx = 0; idx < kctl->count; idx++)
 211                 kctl->vd[idx].access = access;
 212         return kctl;
 213 }
 214
 215 /**
 216  * snd_ctl_new1 - create a control instance from the template
 217  * @ncontrol: the initialization record
 218  * @private_data: the private data to set
 219  *
 220  * Allocates a new struct snd_kcontrol instance and initialize from the given
 221  * template.  When the access field of ncontrol is 0, it's assumed as
 222  * READWRITE access. When the count field is 0, it's assumes as one.
 223  *
 224  * Returns the pointer of the newly generated instance, or NULL on failure.
 225  */
 226 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 227                                   void *private_data)
 228 {
 229         struct snd_kcontrol kctl;
 230         unsigned int access;
 231
 232         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 233                 return NULL;
 234         memset(&kctl, 0, sizeof(kctl));
 235         kctl.id.iface = ncontrol->iface;
 236         kctl.id.device = ncontrol->device;
 237         kctl.id.subdevice = ncontrol->subdevice;
 238         if (ncontrol->name) {
 239                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 240                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 241                         snd_printk(KERN_WARNING
 242                                    "Control name '%s' truncated to '%s'\n",
 243                                    ncontrol->name, kctl.id.name);
 244         }
 245         kctl.id.index = ncontrol->index;
 246         kctl.count = ncontrol->count ? ncontrol->count : 1;
 247         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 248                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 249                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 250                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 251                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 252                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 253         kctl.info = ncontrol->info;
 254         kctl.get = ncontrol->get;
 255         kctl.put = ncontrol->put;
 256         kctl.tlv.p = ncontrol->tlv.p;
 257         kctl.private_value = ncontrol->private_value;
 258         kctl.private_data = private_data;
 259         return snd_ctl_new(&kctl, access);
 260 }
 261
 262 EXPORT_SYMBOL(snd_ctl_new1);
 263
 264 /**
 265  * snd_ctl_free_one - release the control instance
 266  * @kcontrol: the control instance
 267  *
 268  * Releases the control instance created via snd_ctl_new()
 269  * or snd_ctl_new1().
 270  * Don't call this after the control was added to the card.
 271  */
 272 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 273 {
 274         if (kcontrol) {
 275                 if (kcontrol->private_free)
 276                         kcontrol->private_free(kcontrol);
 277                 kfree(kcontrol);
 278         }
 279 }
 280
 281 EXPORT_SYMBOL(snd_ctl_free_one);
 282
 283 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 284                                           unsigned int count)
 285 {
 286         struct snd_kcontrol *kctl;
 287
 288         list_for_each_entry(kctl, &card->controls, list) {
 289                 if (kctl->id.numid < card->last_numid + 1 + count &&
 290                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 291                         card->last_numid = kctl->id.numid + kctl->count - 1;
 292                         return true;
 293                 }
 294         }
 295         return false;
 296 }
 297
 298 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 299 {
 300         unsigned int iter = 100000;
 301
 302         while (snd_ctl_remove_numid_conflict(card, count)) {
 303                 if (--iter == 0) {
 304                         /* this situation is very unlikely */
 305                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 306                         return -ENOMEM;
 307                 }
 308         }
 309         return 0;
 310 }
 311
 312 /**
 313  * snd_ctl_add - add the control instance to the card
 314  * @card: the card instance
 315  * @kcontrol: the control instance to add
 316  *
 317  * Adds the control instance created via snd_ctl_new() or
 318  * snd_ctl_new1() to the given card. Assigns also an unique
 319  * numid used for fast search.
 320  *
 321  * Returns zero if successful, or a negative error code on failure.
 322  *
 323  * It frees automatically the control which cannot be added.
 324  */
 325 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 326 {
 327         struct snd_ctl_elem_id id;
 328         unsigned int idx;
 329         int err = -EINVAL;
 330
 331         if (! kcontrol)
 332                 return err;
 333         if (snd_BUG_ON(!card || !kcontrol->info))
 334                 goto error;
 335         id = kcontrol->id;
 336         down_write(&card->controls_rwsem);
 337         if (snd_ctl_find_id(card, &id)) {
 338                 up_write(&card->controls_rwsem);
 339                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 340                                         id.iface,
 341                                         id.device,
 342                                         id.subdevice,
 343                                         id.name,
 344                                         id.index);
 345                 err = -EBUSY;
 346                 goto error;
 347         }
 348         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 349                 up_write(&card->controls_rwsem);
 350                 err = -ENOMEM;
 351                 goto error;
 352         }
 353         list_add_tail(&kcontrol->list, &card->controls);
 354         card->controls_count += kcontrol->count;
 355         kcontrol->id.numid = card->last_numid + 1;
 356         card->last_numid += kcontrol->count;
 357         up_write(&card->controls_rwsem);
 358         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 359                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 360         return 0;
 361
 362  error:
 363         snd_ctl_free_one(kcontrol);
 364         return err;
 365 }
 366
 367 EXPORT_SYMBOL(snd_ctl_add);
 368
 369 /**
 370  * snd_ctl_replace - replace the control instance of the card
 371  * @card: the card instance
 372  * @kcontrol: the control instance to replace
 373  * @add_on_replace: add the control if not already added
 374  *
 375  * Replaces the given control.  If the given control does not exist
 376  * and the add_on_replace flag is set, the control is added.  If the
 377  * control exists, it is destroyed first.
 378  *
 379  * Returns zero if successful, or a negative error code on failure.
 380  *
 381  * It frees automatically the control which cannot be added or replaced.
 382  */
 383 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 384                     bool add_on_replace)
 385 {
 386         struct snd_ctl_elem_id id;
 387         unsigned int idx;
 388         struct snd_kcontrol *old;
 389         int ret;
 390
 391         if (!kcontrol)
 392                 return -EINVAL;
 393         if (snd_BUG_ON(!card || !kcontrol->info)) {
 394                 ret = -EINVAL;
 395                 goto error;
 396         }
 397         id = kcontrol->id;
 398         down_write(&card->controls_rwsem);
 399         old = snd_ctl_find_id(card, &id);
 400         if (!old) {
 401                 if (add_on_replace)
 402                         goto add;
 403                 up_write(&card->controls_rwsem);
 404                 ret = -EINVAL;
 405                 goto error;
 406         }
 407         ret = snd_ctl_remove(card, old);
 408         if (ret < 0) {
 409                 up_write(&card->controls_rwsem);
 410                 goto error;
 411         }
 412 add:
 413         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 414                 up_write(&card->controls_rwsem);
 415                 ret = -ENOMEM;
 416                 goto error;
 417         }
 418         list_add_tail(&kcontrol->list, &card->controls);
 419         card->controls_count += kcontrol->count;
 420         kcontrol->id.numid = card->last_numid + 1;
 421         card->last_numid += kcontrol->count;
 422         up_write(&card->controls_rwsem);
 423         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 424                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 425         return 0;
 426
 427 error:
 428         snd_ctl_free_one(kcontrol);
 429         return ret;
 430 }
 431 EXPORT_SYMBOL(snd_ctl_replace);
 432
 433 /**
 434  * snd_ctl_remove - remove the control from the card and release it
 435  * @card: the card instance
 436  * @kcontrol: the control instance to remove
 437  *
 438  * Removes the control from the card and then releases the instance.
 439  * You don't need to call snd_ctl_free_one(). You must be in
 440  * the write lock - down_write(&card->controls_rwsem).
 441  *
 442  * Returns 0 if successful, or a negative error code on failure.
 443  */
 444 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 445 {
 446         struct snd_ctl_elem_id id;
 447         unsigned int idx;
 448
 449         if (snd_BUG_ON(!card || !kcontrol))
 450                 return -EINVAL;
 451         list_del(&kcontrol->list);
 452         card->controls_count -= kcontrol->count;
 453         id = kcontrol->id;
 454         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 455                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 456         snd_ctl_free_one(kcontrol);
 457         return 0;
 458 }
 459
 460 EXPORT_SYMBOL(snd_ctl_remove);
 461
 462 /**
 463  * snd_ctl_remove_id - remove the control of the given id and release it
 464  * @card: the card instance
 465  * @id: the control id to remove
 466  *
 467  * Finds the control instance with the given id, removes it from the
 468  * card list and releases it.
 469  *
 470  * Returns 0 if successful, or a negative error code on failure.
 471  */
 472 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 473 {
 474         struct snd_kcontrol *kctl;
 475         int ret;
 476
 477         down_write(&card->controls_rwsem);
 478         kctl = snd_ctl_find_id(card, id);
 479         if (kctl == NULL) {
 480                 up_write(&card->controls_rwsem);
 481                 return -ENOENT;
 482         }
 483         ret = snd_ctl_remove(card, kctl);
 484         up_write(&card->controls_rwsem);
 485         return ret;
 486 }
 487
 488 EXPORT_SYMBOL(snd_ctl_remove_id);
 489
 490 /**
 491  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 492  * @file: active control handle
 493  * @id: the control id to remove
 494  *
 495  * Finds the control instance with the given id, removes it from the
 496  * card list and releases it.
 497  *
 498  * Returns 0 if successful, or a negative error code on failure.
 499  */
 500 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 501                                    struct snd_ctl_elem_id *id)
 502 {
 503         struct snd_card *card = file->card;
 504         struct snd_kcontrol *kctl;
 505         int idx, ret;
 506
 507         down_write(&card->controls_rwsem);
 508         kctl = snd_ctl_find_id(card, id);
 509         if (kctl == NULL) {
 510                 ret = -ENOENT;
 511                 goto error;
 512         }
 513         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 514                 ret = -EINVAL;
 515                 goto error;
 516         }
 517         for (idx = 0; idx < kctl->count; idx++)
 518                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 519                         ret = -EBUSY;
 520                         goto error;
 521                 }
 522         ret = snd_ctl_remove(card, kctl);
 523         if (ret < 0)
 524                 goto error;
 525         card->user_ctl_count--;
 526 error:
 527         up_write(&card->controls_rwsem);
 528         return ret;
 529 }
 530
 531 /**
 532  * snd_ctl_activate_id - activate/inactivate the control of the given id
 533  * @card: the card instance
 534  * @id: the control id to activate/inactivate
 535  * @active: non-zero to activate
 536  *
 537  * Finds the control instance with the given id, and activate or
 538  * inactivate the control together with notification, if changed.
 539  *
 540  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 541  */
 542 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 543                         int active)
 544 {
 545         struct snd_kcontrol *kctl;
 546         struct snd_kcontrol_volatile *vd;
 547         unsigned int index_offset;
 548         int ret;
 549
 550         down_write(&card->controls_rwsem);
 551         kctl = snd_ctl_find_id(card, id);
 552         if (kctl == NULL) {
 553                 ret = -ENOENT;
 554                 goto unlock;
 555         }
 556         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 557         vd = &kctl->vd[index_offset];
 558         ret = 0;
 559         if (active) {
 560                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 561                         goto unlock;
 562                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 563         } else {
 564                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 565                         goto unlock;
 566                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 567         }
 568         ret = 1;
 569  unlock:
 570         up_write(&card->controls_rwsem);
 571         if (ret > 0)
 572                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 573         return ret;
 574 }
 575 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 576
 577 /**
 578  * snd_ctl_rename_id - replace the id of a control on the card
 579  * @card: the card instance
 580  * @src_id: the old id
 581  * @dst_id: the new id
 582  *
 583  * Finds the control with the old id from the card, and replaces the
 584  * id with the new one.
 585  *
 586  * Returns zero if successful, or a negative error code on failure.
 587  */
 588 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 589                       struct snd_ctl_elem_id *dst_id)
 590 {
 591         struct snd_kcontrol *kctl;
 592
 593         down_write(&card->controls_rwsem);
 594         kctl = snd_ctl_find_id(card, src_id);
 595         if (kctl == NULL) {
 596                 up_write(&card->controls_rwsem);
 597                 return -ENOENT;
 598         }
 599         kctl->id = *dst_id;
 600         kctl->id.numid = card->last_numid + 1;
 601         card->last_numid += kctl->count;
 602         up_write(&card->controls_rwsem);
 603         return 0;
 604 }
 605
 606 EXPORT_SYMBOL(snd_ctl_rename_id);
 607
 608 /**
 609  * snd_ctl_find_numid - find the control instance with the given number-id
 610  * @card: the card instance
 611  * @numid: the number-id to search
 612  *
 613  * Finds the control instance with the given number-id from the card.
 614  *
 615  * Returns the pointer of the instance if found, or NULL if not.
 616  *
 617  * The caller must down card->controls_rwsem before calling this function
 618  * (if the race condition can happen).
 619  */
 620 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 621 {
 622         struct snd_kcontrol *kctl;
 623
 624         if (snd_BUG_ON(!card || !numid))
 625                 return NULL;
 626         list_for_each_entry(kctl, &card->controls, list) {
 627                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 628                         return kctl;
 629         }
 630         return NULL;
 631 }
 632
 633 EXPORT_SYMBOL(snd_ctl_find_numid);
 634
 635 /**
 636  * snd_ctl_find_id - find the control instance with the given id
 637  * @card: the card instance
 638  * @id: the id to search
 639  *
 640  * Finds the control instance with the given id from the card.
 641  *
 642  * Returns the pointer of the instance if found, or NULL if not.
 643  *
 644  * The caller must down card->controls_rwsem before calling this function
 645  * (if the race condition can happen).
 646  */
 647 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 648                                      struct snd_ctl_elem_id *id)
 649 {
 650         struct snd_kcontrol *kctl;
 651
 652         if (snd_BUG_ON(!card || !id))
 653                 return NULL;
 654         if (id->numid != 0)
 655                 return snd_ctl_find_numid(card, id->numid);
 656         list_for_each_entry(kctl, &card->controls, list) {
 657                 if (kctl->id.iface != id->iface)
 658                         continue;
 659                 if (kctl->id.device != id->device)
 660                         continue;
 661                 if (kctl->id.subdevice != id->subdevice)
 662                         continue;
 663                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 664                         continue;
 665                 if (kctl->id.index > id->index)
 666                         continue;
 667                 if (kctl->id.index + kctl->count <= id->index)
 668                         continue;
 669                 return kctl;
 670         }
 671         return NULL;
 672 }
 673
 674 EXPORT_SYMBOL(snd_ctl_find_id);
 675
 676 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 677                              unsigned int cmd, void __user *arg)
 678 {
 679         struct snd_ctl_card_info *info;
 680
 681         info = kzalloc(sizeof(*info), GFP_KERNEL);
 682         if (! info)
 683                 return -ENOMEM;
 684         down_read(&snd_ioctl_rwsem);
 685         info->card = card->number;
 686         strlcpy(info->id, card->id, sizeof(info->id));
 687         strlcpy(info->driver, card->driver, sizeof(info->driver));
 688         strlcpy(info->name, card->shortname, sizeof(info->name));
 689         strlcpy(info->longname, card->longname, sizeof(info->longname));
 690         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 691         strlcpy(info->components, card->components, sizeof(info->components));
 692         up_read(&snd_ioctl_rwsem);
 693         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 694                 kfree(info);
 695                 return -EFAULT;
 696         }
 697         kfree(info);
 698         return 0;
 699 }
 700
 701 static int snd_ctl_elem_list(struct snd_card *card,
 702                              struct snd_ctl_elem_list __user *_list)
 703 {
 704         struct list_head *plist;
 705         struct snd_ctl_elem_list list;
 706         struct snd_kcontrol *kctl;
 707         struct snd_ctl_elem_id *dst, *id;
 708         unsigned int offset, space, jidx;
 709
 710         if (copy_from_user(&list, _list, sizeof(list)))
 711                 return -EFAULT;
 712         offset = list.offset;
 713         space = list.space;
 714         /* try limit maximum space */
 715         if (space > 16384)
 716                 return -ENOMEM;
 717         if (space > 0) {
 718                 /* allocate temporary buffer for atomic operation */
 719                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 720                 if (dst == NULL)
 721                         return -ENOMEM;
 722                 down_read(&card->controls_rwsem);
 723                 list.count = card->controls_count;
 724                 plist = card->controls.next;
 725                 while (plist != &card->controls) {
 726                         if (offset == 0)
 727                                 break;
 728                         kctl = snd_kcontrol(plist);
 729                         if (offset < kctl->count)
 730                                 break;
 731                         offset -= kctl->count;
 732                         plist = plist->next;
 733                 }
 734                 list.used = 0;
 735                 id = dst;
 736                 while (space > 0 && plist != &card->controls) {
 737                         kctl = snd_kcontrol(plist);
 738                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 739                                 snd_ctl_build_ioff(id, kctl, jidx);
 740                                 id++;
 741                                 space--;
 742                                 list.used++;
 743                         }
 744                         plist = plist->next;
 745                         offset = 0;
 746                 }
 747                 up_read(&card->controls_rwsem);
 748                 if (list.used > 0 &&
 749                     copy_to_user(list.pids, dst,
 750                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 751                         vfree(dst);
 752                         return -EFAULT;
 753                 }
 754                 vfree(dst);
 755         } else {
 756                 down_read(&card->controls_rwsem);
 757                 list.count = card->controls_count;
 758                 up_read(&card->controls_rwsem);
 759         }
 760         if (copy_to_user(_list, &list, sizeof(list)))
 761                 return -EFAULT;
 762         return 0;
 763 }
 764
 765 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 766                              struct snd_ctl_elem_info *info)
 767 {
 768         struct snd_card *card = ctl->card;
 769         struct snd_kcontrol *kctl;
 770         struct snd_kcontrol_volatile *vd;
 771         unsigned int index_offset;
 772         int result;
 773
 774         down_read(&card->controls_rwsem);
 775         kctl = snd_ctl_find_id(card, &info->id);
 776         if (kctl == NULL) {
 777                 up_read(&card->controls_rwsem);
 778                 return -ENOENT;
 779         }
 780 #ifdef CONFIG_SND_DEBUG
 781         info->access = 0;
 782 #endif
 783         result = kctl->info(kctl, info);
 784         if (result >= 0) {
 785                 snd_BUG_ON(info->access);
 786                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 787                 vd = &kctl->vd[index_offset];
 788                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 789                 info->access = vd->access;
 790                 if (vd->owner) {
 791                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 792                         if (vd->owner == ctl)
 793                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 794                         info->owner = pid_vnr(vd->owner->pid);
 795                 } else {
 796                         info->owner = -1;
 797                 }
 798         }
 799         up_read(&card->controls_rwsem);
 800         return result;
 801 }
 802
 803 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 804                                   struct snd_ctl_elem_info __user *_info)
 805 {
 806         struct snd_ctl_elem_info info;
 807         int result;
 808
 809         if (copy_from_user(&info, _info, sizeof(info)))
 810                 return -EFAULT;
 811         snd_power_lock(ctl->card);
 812         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 813         if (result >= 0)
 814                 result = snd_ctl_elem_info(ctl, &info);
 815         snd_power_unlock(ctl->card);
 816         if (result >= 0)
 817                 if (copy_to_user(_info, &info, sizeof(info)))
 818                         return -EFAULT;
 819         return result;
 820 }
 821
 822 static int snd_ctl_elem_read(struct snd_card *card,
 823                              struct snd_ctl_elem_value *control)
 824 {
 825         struct snd_kcontrol *kctl;
 826         struct snd_kcontrol_volatile *vd;
 827         unsigned int index_offset;
 828         int result;
 829
 830         down_read(&card->controls_rwsem);
 831         kctl = snd_ctl_find_id(card, &control->id);
 832         if (kctl == NULL) {
 833                 result = -ENOENT;
 834         } else {
 835                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 836                 vd = &kctl->vd[index_offset];
 837                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 838                     kctl->get != NULL) {
 839                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 840                         result = kctl->get(kctl, control);
 841                 } else
 842                         result = -EPERM;
 843         }
 844         up_read(&card->controls_rwsem);
 845         return result;
 846 }
 847
 848 static int snd_ctl_elem_read_user(struct snd_card *card,
 849                                   struct snd_ctl_elem_value __user *_control)
 850 {
 851         struct snd_ctl_elem_value *control;
 852         int result;
 853
 854         control = memdup_user(_control, sizeof(*control));
 855         if (IS_ERR(control))
 856                 return PTR_ERR(control);
 857
 858         snd_power_lock(card);
 859         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 860         if (result >= 0)
 861                 result = snd_ctl_elem_read(card, control);
 862         snd_power_unlock(card);
 863         if (result >= 0)
 864                 if (copy_to_user(_control, control, sizeof(*control)))
 865                         result = -EFAULT;
 866         kfree(control);
 867         return result;
 868 }
 869
 870 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 871                               struct snd_ctl_elem_value *control)
 872 {
 873         struct snd_kcontrol *kctl;
 874         struct snd_kcontrol_volatile *vd;
 875         unsigned int index_offset;
 876         int result;
 877
 878         down_read(&card->controls_rwsem);
 879         kctl = snd_ctl_find_id(card, &control->id);
 880         if (kctl == NULL) {
 881                 result = -ENOENT;
 882         } else {
 883                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 884                 vd = &kctl->vd[index_offset];
 885                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 886                     kctl->put == NULL ||
 887                     (file && vd->owner && vd->owner != file)) {
 888                         result = -EPERM;
 889                 } else {
 890                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 891                         result = kctl->put(kctl, control);
 892                 }
 893                 if (result > 0) {
 894                         up_read(&card->controls_rwsem);
 895                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 896                                        &control->id);
 897                         return 0;
 898                 }
 899         }
 900         up_read(&card->controls_rwsem);
 901         return result;
 902 }
 903
 904 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 905                                    struct snd_ctl_elem_value __user *_control)
 906 {
 907         struct snd_ctl_elem_value *control;
 908         struct snd_card *card;
 909         int result;
 910
 911         control = memdup_user(_control, sizeof(*control));
 912         if (IS_ERR(control))
 913                 return PTR_ERR(control);
 914
 915         card = file->card;
 916         snd_power_lock(card);
 917         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 918         if (result >= 0)
 919                 result = snd_ctl_elem_write(card, file, control);
 920         snd_power_unlock(card);
 921         if (result >= 0)
 922                 if (copy_to_user(_control, control, sizeof(*control)))
 923                         result = -EFAULT;
 924         kfree(control);
 925         return result;
 926 }
 927
 928 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 929                              struct snd_ctl_elem_id __user *_id)
 930 {
 931         struct snd_card *card = file->card;
 932         struct snd_ctl_elem_id id;
 933         struct snd_kcontrol *kctl;
 934         struct snd_kcontrol_volatile *vd;
 935         int result;
 936
 937         if (copy_from_user(&id, _id, sizeof(id)))
 938                 return -EFAULT;
 939         down_write(&card->controls_rwsem);
 940         kctl = snd_ctl_find_id(card, &id);
 941         if (kctl == NULL) {
 942                 result = -ENOENT;
 943         } else {
 944                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 945                 if (vd->owner != NULL)
 946                         result = -EBUSY;
 947                 else {
 948                         vd->owner = file;
 949                         result = 0;
 950                 }
 951         }
 952         up_write(&card->controls_rwsem);
 953         return result;
 954 }
 955
 956 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 957                                struct snd_ctl_elem_id __user *_id)
 958 {
 959         struct snd_card *card = file->card;
 960         struct snd_ctl_elem_id id;
 961         struct snd_kcontrol *kctl;
 962         struct snd_kcontrol_volatile *vd;
 963         int result;
 964
 965         if (copy_from_user(&id, _id, sizeof(id)))
 966                 return -EFAULT;
 967         down_write(&card->controls_rwsem);
 968         kctl = snd_ctl_find_id(card, &id);
 969         if (kctl == NULL) {
 970                 result = -ENOENT;
 971         } else {
 972                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 973                 if (vd->owner == NULL)
 974                         result = -EINVAL;
 975                 else if (vd->owner != file)
 976                         result = -EPERM;
 977                 else {
 978                         vd->owner = NULL;
 979                         result = 0;
 980                 }
 981         }
 982         up_write(&card->controls_rwsem);
 983         return result;
 984 }
 985
 986 struct user_element {
 987         struct snd_ctl_elem_info info;
 988         void *elem_data;                /* element data */
 989         unsigned long elem_data_size;   /* size of element data in bytes */
 990         void *tlv_data;                 /* TLV data */
 991         unsigned long tlv_data_size;    /* TLV data size */
 992         void *priv_data;                /* private data (like strings for enumerated type) */
 993 };
 994
 995 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 996                                   struct snd_ctl_elem_info *uinfo)
 997 {
 998         struct user_element *ue = kcontrol->private_data;
 999
1000         *uinfo = ue->info;
1001         return 0;
1002 }
1003
1004 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1005                                        struct snd_ctl_elem_info *uinfo)
1006 {
1007         struct user_element *ue = kcontrol->private_data;
1008         const char *names;
1009         unsigned int item;
1010
1011         item = uinfo->value.enumerated.item;
1012
1013         *uinfo = ue->info;
1014
1015         item = min(item, uinfo->value.enumerated.items - 1);
1016         uinfo->value.enumerated.item = item;
1017
1018         names = ue->priv_data;
1019         for (; item > 0; --item)
1020                 names += strlen(names) + 1;
1021         strcpy(uinfo->value.enumerated.name, names);
1022
1023         return 0;
1024 }
1025
1026 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1027                                  struct snd_ctl_elem_value *ucontrol)
1028 {
1029         struct user_element *ue = kcontrol->private_data;
1030
1031         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1032         return 0;
1033 }
1034
1035 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1036                                  struct snd_ctl_elem_value *ucontrol)
1037 {
1038         int change;
1039         struct user_element *ue = kcontrol->private_data;
1040
1041         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1042         if (change)
1043                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1044         return change;
1045 }
1046
1047 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1048                                  int op_flag,
1049                                  unsigned int size,
1050                                  unsigned int __user *tlv)
1051 {
1052         struct user_element *ue = kcontrol->private_data;
1053         int change = 0;
1054         void *new_data;
1055
1056         if (op_flag > 0) {
1057                 if (size > 1024 * 128)  /* sane value */
1058                         return -EINVAL;
1059
1060                 new_data = memdup_user(tlv, size);
1061                 if (IS_ERR(new_data))
1062                         return PTR_ERR(new_data);
1063                 change = ue->tlv_data_size != size;
1064                 if (!change)
1065                         change = memcmp(ue->tlv_data, new_data, size);
1066                 kfree(ue->tlv_data);
1067                 ue->tlv_data = new_data;
1068                 ue->tlv_data_size = size;
1069         } else {
1070                 if (! ue->tlv_data_size || ! ue->tlv_data)
1071                         return -ENXIO;
1072                 if (size < ue->tlv_data_size)
1073                         return -ENOSPC;
1074                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1075                         return -EFAULT;
1076         }
1077         return change;
1078 }
1079
1080 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1081 {
1082         char *names, *p;
1083         size_t buf_len, name_len;
1084         unsigned int i;
1085         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1086
1087         if (ue->info.value.enumerated.names_length > 64 * 1024)
1088                 return -EINVAL;
1089
1090         names = memdup_user((const void __user *)user_ptrval,
1091                 ue->info.value.enumerated.names_length);
1092         if (IS_ERR(names))
1093                 return PTR_ERR(names);
1094
1095         /* check that there are enough valid names */
1096         buf_len = ue->info.value.enumerated.names_length;
1097         p = names;
1098         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1099                 name_len = strnlen(p, buf_len);
1100                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1101                         kfree(names);
1102                         return -EINVAL;
1103                 }
1104                 p += name_len + 1;
1105                 buf_len -= name_len + 1;
1106         }
1107
1108         ue->priv_data = names;
1109         ue->info.value.enumerated.names_ptr = 0;
1110
1111         return 0;
1112 }
1113
1114 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1115 {
1116         struct user_element *ue = kcontrol->private_data;
1117
1118         kfree(ue->tlv_data);
1119         kfree(ue->priv_data);
1120         kfree(ue);
1121 }
1122
1123 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1124                             struct snd_ctl_elem_info *info, int replace)
1125 {
1126         struct snd_card *card = file->card;
1127         struct snd_kcontrol kctl, *_kctl;
1128         unsigned int access;
1129         long private_size;
1130         struct user_element *ue;
1131         int idx, err;
1132
1133         if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1134                 return -ENOMEM;
1135         if (info->count < 1)
1136                 return -EINVAL;
1137         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1138                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1139                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1140                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1141         info->id.numid = 0;
1142         memset(&kctl, 0, sizeof(kctl));
1143         down_write(&card->controls_rwsem);
1144         _kctl = snd_ctl_find_id(card, &info->id);
1145         err = 0;
1146         if (_kctl) {
1147                 if (replace)
1148                         err = snd_ctl_remove(card, _kctl);
1149                 else
1150                         err = -EBUSY;
1151         } else {
1152                 if (replace)
1153                         err = -ENOENT;
1154         }
1155         up_write(&card->controls_rwsem);
1156         if (err < 0)
1157                 return err;
1158         memcpy(&kctl.id, &info->id, sizeof(info->id));
1159         kctl.count = info->owner ? info->owner : 1;
1160         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1161         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1162                 kctl.info = snd_ctl_elem_user_enum_info;
1163         else
1164                 kctl.info = snd_ctl_elem_user_info;
1165         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1166                 kctl.get = snd_ctl_elem_user_get;
1167         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1168                 kctl.put = snd_ctl_elem_user_put;
1169         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1170                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1171                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1172         }
1173         switch (info->type) {
1174         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1175         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1176                 private_size = sizeof(long);
1177                 if (info->count > 128)
1178                         return -EINVAL;
1179                 break;
1180         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1181                 private_size = sizeof(long long);
1182                 if (info->count > 64)
1183                         return -EINVAL;
1184                 break;
1185         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1186                 private_size = sizeof(unsigned int);
1187                 if (info->count > 128 || info->value.enumerated.items == 0)
1188                         return -EINVAL;
1189                 break;
1190         case SNDRV_CTL_ELEM_TYPE_BYTES:
1191                 private_size = sizeof(unsigned char);
1192                 if (info->count > 512)
1193                         return -EINVAL;
1194                 break;
1195         case SNDRV_CTL_ELEM_TYPE_IEC958:
1196                 private_size = sizeof(struct snd_aes_iec958);
1197                 if (info->count != 1)
1198                         return -EINVAL;
1199                 break;
1200         default:
1201                 return -EINVAL;
1202         }
1203         private_size *= info->count;
1204         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1205         if (ue == NULL)
1206                 return -ENOMEM;
1207         ue->info = *info;
1208         ue->info.access = 0;
1209         ue->elem_data = (char *)ue + sizeof(*ue);
1210         ue->elem_data_size = private_size;
1211         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1212                 err = snd_ctl_elem_init_enum_names(ue);
1213                 if (err < 0) {
1214                         kfree(ue);
1215                         return err;
1216                 }
1217         }
1218         kctl.private_free = snd_ctl_elem_user_free;
1219         _kctl = snd_ctl_new(&kctl, access);
1220         if (_kctl == NULL) {
1221                 kfree(ue->priv_data);
1222                 kfree(ue);
1223                 return -ENOMEM;
1224         }
1225         _kctl->private_data = ue;
1226         for (idx = 0; idx < _kctl->count; idx++)
1227                 _kctl->vd[idx].owner = file;
1228         err = snd_ctl_add(card, _kctl);
1229         if (err < 0)
1230                 return err;
1231
1232         down_write(&card->controls_rwsem);
1233         card->user_ctl_count++;
1234         up_write(&card->controls_rwsem);
1235
1236         return 0;
1237 }
1238
1239 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1240                                  struct snd_ctl_elem_info __user *_info, int replace)
1241 {
1242         struct snd_ctl_elem_info info;
1243         if (copy_from_user(&info, _info, sizeof(info)))
1244                 return -EFAULT;
1245         return snd_ctl_elem_add(file, &info, replace);
1246 }
1247
1248 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1249                                struct snd_ctl_elem_id __user *_id)
1250 {
1251         struct snd_ctl_elem_id id;
1252
1253         if (copy_from_user(&id, _id, sizeof(id)))
1254                 return -EFAULT;
1255         return snd_ctl_remove_user_ctl(file, &id);
1256 }
1257
1258 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1259 {
1260         int subscribe;
1261         if (get_user(subscribe, ptr))
1262                 return -EFAULT;
1263         if (subscribe < 0) {
1264                 subscribe = file->subscribed;
1265                 if (put_user(subscribe, ptr))
1266                         return -EFAULT;
1267                 return 0;
1268         }
1269         if (subscribe) {
1270                 file->subscribed = 1;
1271                 return 0;
1272         } else if (file->subscribed) {
1273                 snd_ctl_empty_read_queue(file);
1274                 file->subscribed = 0;
1275         }
1276         return 0;
1277 }
1278
1279 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1280                              struct snd_ctl_tlv __user *_tlv,
1281                              int op_flag)
1282 {
1283         struct snd_card *card = file->card;
1284         struct snd_ctl_tlv tlv;
1285         struct snd_kcontrol *kctl;
1286         struct snd_kcontrol_volatile *vd;
1287         unsigned int len;
1288         int err = 0;
1289
1290         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1291                 return -EFAULT;
1292         if (tlv.length < sizeof(unsigned int) * 2)
1293                 return -EINVAL;
1294         down_read(&card->controls_rwsem);
1295         kctl = snd_ctl_find_numid(card, tlv.numid);
1296         if (kctl == NULL) {
1297                 err = -ENOENT;
1298                 goto __kctl_end;
1299         }
1300         if (kctl->tlv.p == NULL) {
1301                 err = -ENXIO;
1302                 goto __kctl_end;
1303         }
1304         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1305         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1306             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1307             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1308                 err = -ENXIO;
1309                 goto __kctl_end;
1310         }
1311         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1312                 if (vd->owner != NULL && vd->owner != file) {
1313                         err = -EPERM;
1314                         goto __kctl_end;
1315                 }
1316                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1317                 if (err > 0) {
1318                         up_read(&card->controls_rwsem);
1319                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1320                         return 0;
1321                 }
1322         } else {
1323                 if (op_flag) {
1324                         err = -ENXIO;
1325                         goto __kctl_end;
1326                 }
1327                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1328                 if (tlv.length < len) {
1329                         err = -ENOMEM;
1330                         goto __kctl_end;
1331                 }
1332                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1333                         err = -EFAULT;
1334         }
1335       __kctl_end:
1336         up_read(&card->controls_rwsem);
1337         return err;
1338 }
1339
1340 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1341 {
1342         struct snd_ctl_file *ctl;
1343         struct snd_card *card;
1344         struct snd_kctl_ioctl *p;
1345         void __user *argp = (void __user *)arg;
1346         int __user *ip = argp;
1347         int err;
1348
1349         ctl = file->private_data;
1350         card = ctl->card;
1351         if (snd_BUG_ON(!card))
1352                 return -ENXIO;
1353         switch (cmd) {
1354         case SNDRV_CTL_IOCTL_PVERSION:
1355                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1356         case SNDRV_CTL_IOCTL_CARD_INFO:
1357                 return snd_ctl_card_info(card, ctl, cmd, argp);
1358         case SNDRV_CTL_IOCTL_ELEM_LIST:
1359                 return snd_ctl_elem_list(card, argp);
1360         case SNDRV_CTL_IOCTL_ELEM_INFO:
1361                 return snd_ctl_elem_info_user(ctl, argp);
1362         case SNDRV_CTL_IOCTL_ELEM_READ:
1363                 return snd_ctl_elem_read_user(card, argp);
1364         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1365                 return snd_ctl_elem_write_user(ctl, argp);
1366         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1367                 return snd_ctl_elem_lock(ctl, argp);
1368         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1369                 return snd_ctl_elem_unlock(ctl, argp);
1370         case SNDRV_CTL_IOCTL_ELEM_ADD:
1371                 return snd_ctl_elem_add_user(ctl, argp, 0);
1372         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1373                 return snd_ctl_elem_add_user(ctl, argp, 1);
1374         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1375                 return snd_ctl_elem_remove(ctl, argp);
1376         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1377                 return snd_ctl_subscribe_events(ctl, ip);
1378         case SNDRV_CTL_IOCTL_TLV_READ:
1379                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1380         case SNDRV_CTL_IOCTL_TLV_WRITE:
1381                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1382         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1383                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1384         case SNDRV_CTL_IOCTL_POWER:
1385                 return -ENOPROTOOPT;
1386         case SNDRV_CTL_IOCTL_POWER_STATE:
1387 #ifdef CONFIG_PM
1388                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1389 #else
1390                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1391 #endif
1392         }
1393         down_read(&snd_ioctl_rwsem);
1394         list_for_each_entry(p, &snd_control_ioctls, list) {
1395                 err = p->fioctl(card, ctl, cmd, arg);
1396                 if (err != -ENOIOCTLCMD) {
1397                         up_read(&snd_ioctl_rwsem);
1398                         return err;
1399                 }
1400         }
1401         up_read(&snd_ioctl_rwsem);
1402         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1403         return -ENOTTY;
1404 }
1405
1406 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1407                             size_t count, loff_t * offset)
1408 {
1409         struct snd_ctl_file *ctl;
1410         int err = 0;
1411         ssize_t result = 0;
1412
1413         ctl = file->private_data;
1414         if (snd_BUG_ON(!ctl || !ctl->card))
1415                 return -ENXIO;
1416         if (!ctl->subscribed)
1417                 return -EBADFD;
1418         if (count < sizeof(struct snd_ctl_event))
1419                 return -EINVAL;
1420         spin_lock_irq(&ctl->read_lock);
1421         while (count >= sizeof(struct snd_ctl_event)) {
1422                 struct snd_ctl_event ev;
1423                 struct snd_kctl_event *kev;
1424                 while (list_empty(&ctl->events)) {
1425                         wait_queue_t wait;
1426                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1427                                 err = -EAGAIN;
1428                                 goto __end_lock;
1429                         }
1430                         init_waitqueue_entry(&wait, current);
1431                         add_wait_queue(&ctl->change_sleep, &wait);
1432                         set_current_state(TASK_INTERRUPTIBLE);
1433                         spin_unlock_irq(&ctl->read_lock);
1434                         schedule();
1435                         remove_wait_queue(&ctl->change_sleep, &wait);
1436                         if (signal_pending(current))
1437                                 return -ERESTARTSYS;
1438                         spin_lock_irq(&ctl->read_lock);
1439                 }
1440                 kev = snd_kctl_event(ctl->events.next);
1441                 ev.type = SNDRV_CTL_EVENT_ELEM;
1442                 ev.data.elem.mask = kev->mask;
1443                 ev.data.elem.id = kev->id;
1444                 list_del(&kev->list);
1445                 spin_unlock_irq(&ctl->read_lock);
1446                 kfree(kev);
1447                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1448                         err = -EFAULT;
1449                         goto __end;
1450                 }
1451                 spin_lock_irq(&ctl->read_lock);
1452                 buffer += sizeof(struct snd_ctl_event);
1453                 count -= sizeof(struct snd_ctl_event);
1454                 result += sizeof(struct snd_ctl_event);
1455         }
1456       __end_lock:
1457         spin_unlock_irq(&ctl->read_lock);
1458       __end:
1459         return result > 0 ? result : err;
1460 }
1461
1462 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1463 {
1464         unsigned int mask;
1465         struct snd_ctl_file *ctl;
1466
1467         ctl = file->private_data;
1468         if (!ctl->subscribed)
1469                 return 0;
1470         poll_wait(file, &ctl->change_sleep, wait);
1471
1472         mask = 0;
1473         if (!list_empty(&ctl->events))
1474                 mask |= POLLIN | POLLRDNORM;
1475
1476         return mask;
1477 }
1478
1479 /*
1480  * register the device-specific control-ioctls.
1481  * called from each device manager like pcm.c, hwdep.c, etc.
1482  */
1483 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1484 {
1485         struct snd_kctl_ioctl *pn;
1486
1487         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1488         if (pn == NULL)
1489                 return -ENOMEM;
1490         pn->fioctl = fcn;
1491         down_write(&snd_ioctl_rwsem);
1492         list_add_tail(&pn->list, lists);
1493         up_write(&snd_ioctl_rwsem);
1494         return 0;
1495 }
1496
1497 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1498 {
1499         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1500 }
1501
1502 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1503
1504 #ifdef CONFIG_COMPAT
1505 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1506 {
1507         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1508 }
1509
1510 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1511 #endif
1512
1513 /*
1514  * de-register the device-specific control-ioctls.
1515  */
1516 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1517                                      struct list_head *lists)
1518 {
1519         struct snd_kctl_ioctl *p;
1520
1521         if (snd_BUG_ON(!fcn))
1522                 return -EINVAL;
1523         down_write(&snd_ioctl_rwsem);
1524         list_for_each_entry(p, lists, list) {
1525                 if (p->fioctl == fcn) {
1526                         list_del(&p->list);
1527                         up_write(&snd_ioctl_rwsem);
1528                         kfree(p);
1529                         return 0;
1530                 }
1531         }
1532         up_write(&snd_ioctl_rwsem);
1533         snd_BUG();
1534         return -EINVAL;
1535 }
1536
1537 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1538 {
1539         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1540 }
1541
1542 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1543
1544 #ifdef CONFIG_COMPAT
1545 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1546 {
1547         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1548 }
1549
1550 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1551 #endif
1552
1553 static int snd_ctl_fasync(int fd, struct file * file, int on)
1554 {
1555         struct snd_ctl_file *ctl;
1556
1557         ctl = file->private_data;
1558         return fasync_helper(fd, file, on, &ctl->fasync);
1559 }
1560
1561 /*
1562  * ioctl32 compat
1563  */
1564 #ifdef CONFIG_COMPAT
1565 #include "control_compat.c"
1566 #else
1567 #define snd_ctl_ioctl_compat    NULL
1568 #endif
1569
1570 /*
1571  *  INIT PART
1572  */
1573
1574 static const struct file_operations snd_ctl_f_ops =
1575 {
1576         .owner =        THIS_MODULE,
1577         .read =         snd_ctl_read,
1578         .open =         snd_ctl_open,
1579         .release =      snd_ctl_release,
1580         .llseek =       no_llseek,
1581         .poll =         snd_ctl_poll,
1582         .unlocked_ioctl =       snd_ctl_ioctl,
1583         .compat_ioctl = snd_ctl_ioctl_compat,
1584         .fasync =       snd_ctl_fasync,
1585 };
1586
1587 /*
1588  * registration of the control device
1589  */
1590 static int snd_ctl_dev_register(struct snd_device *device)
1591 {
1592         struct snd_card *card = device->device_data;
1593         int err, cardnum;
1594         char name[16];
1595
1596         if (snd_BUG_ON(!card))
1597                 return -ENXIO;
1598         cardnum = card->number;
1599         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1600                 return -ENXIO;
1601         sprintf(name, "controlC%i", cardnum);
1602         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1603                                        &snd_ctl_f_ops, card, name)) < 0)
1604                 return err;
1605         return 0;
1606 }
1607
1608 /*
1609  * disconnection of the control device
1610  */
1611 static int snd_ctl_dev_disconnect(struct snd_device *device)
1612 {
1613         struct snd_card *card = device->device_data;
1614         struct snd_ctl_file *ctl;
1615         int err, cardnum;
1616
1617         if (snd_BUG_ON(!card))
1618                 return -ENXIO;
1619         cardnum = card->number;
1620         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1621                 return -ENXIO;
1622
1623         read_lock(&card->ctl_files_rwlock);
1624         list_for_each_entry(ctl, &card->ctl_files, list) {
1625                 wake_up(&ctl->change_sleep);
1626                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1627         }
1628         read_unlock(&card->ctl_files_rwlock);
1629
1630         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1631                                          card, -1)) < 0)
1632                 return err;
1633         return 0;
1634 }
1635
1636 /*
1637  * free all controls
1638  */
1639 static int snd_ctl_dev_free(struct snd_device *device)
1640 {
1641         struct snd_card *card = device->device_data;
1642         struct snd_kcontrol *control;
1643
1644         down_write(&card->controls_rwsem);
1645         while (!list_empty(&card->controls)) {
1646                 control = snd_kcontrol(card->controls.next);
1647                 snd_ctl_remove(card, control);
1648         }
1649         up_write(&card->controls_rwsem);
1650         return 0;
1651 }
1652
1653 /*
1654  * create control core:
1655  * called from init.c
1656  */
1657 int snd_ctl_create(struct snd_card *card)
1658 {
1659         static struct snd_device_ops ops = {
1660                 .dev_free = snd_ctl_dev_free,
1661                 .dev_register = snd_ctl_dev_register,
1662                 .dev_disconnect = snd_ctl_dev_disconnect,
1663         };
1664
1665         if (snd_BUG_ON(!card))
1666                 return -ENXIO;
1667         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1668 }
1669
1670 /*
1671  * Frequently used control callbacks/helpers
1672  */
1673 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1674                               struct snd_ctl_elem_info *uinfo)
1675 {
1676         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1677         uinfo->count = 1;
1678         uinfo->value.integer.min = 0;
1679         uinfo->value.integer.max = 1;
1680         return 0;
1681 }
1682
1683 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1684
1685 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1686                                 struct snd_ctl_elem_info *uinfo)
1687 {
1688         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1689         uinfo->count = 2;
1690         uinfo->value.integer.min = 0;
1691         uinfo->value.integer.max = 1;
1692         return 0;
1693 }
1694
1695 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1696
1697 /**
1698  * snd_ctl_enum_info - fills the info structure for an enumerated control
1699  * @info: the structure to be filled
1700  * @channels: the number of the control's channels; often one
1701  * @items: the number of control values; also the size of @names
1702  * @names: an array containing the names of all control values
1703  *
1704  * Sets all required fields in @info to their appropriate values.
1705  * If the control's accessibility is not the default (readable and writable),
1706  * the caller has to fill @info->access.
1707  */
1708 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1709                       unsigned int items, const char *const names[])
1710 {
1711         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1712         info->count = channels;
1713         info->value.enumerated.items = items;
1714         if (info->value.enumerated.item >= items)
1715                 info->value.enumerated.item = items - 1;
1716         strlcpy(info->value.enumerated.name,
1717                 names[info->value.enumerated.item],
1718                 sizeof(info->value.enumerated.name));
1719         return 0;
1720 }
1721 EXPORT_SYMBOL(snd_ctl_enum_info);