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         snd_card_unref(card);
  90         return 0;
  91
  92       __error:
  93         module_put(card->module);
  94       __error2:
  95         snd_card_file_remove(card, file);
  96       __error1:
  97         if (card)
  98                 snd_card_unref(card);
  99         return err;
 100 }
 101
 102 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
 103 {
 104         unsigned long flags;
 105         struct snd_kctl_event *cread;
 106
 107         spin_lock_irqsave(&ctl->read_lock, flags);
 108         while (!list_empty(&ctl->events)) {
 109                 cread = snd_kctl_event(ctl->events.next);
 110                 list_del(&cread->list);
 111                 kfree(cread);
 112         }
 113         spin_unlock_irqrestore(&ctl->read_lock, flags);
 114 }
 115
 116 static int snd_ctl_release(struct inode *inode, struct file *file)
 117 {
 118         unsigned long flags;
 119         struct snd_card *card;
 120         struct snd_ctl_file *ctl;
 121         struct snd_kcontrol *control;
 122         unsigned int idx;
 123
 124         ctl = file->private_data;
 125         file->private_data = NULL;
 126         card = ctl->card;
 127         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 128         list_del(&ctl->list);
 129         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 130         down_write(&card->controls_rwsem);
 131         list_for_each_entry(control, &card->controls, list)
 132                 for (idx = 0; idx < control->count; idx++)
 133                         if (control->vd[idx].owner == ctl)
 134                                 control->vd[idx].owner = NULL;
 135         up_write(&card->controls_rwsem);
 136         snd_ctl_empty_read_queue(ctl);
 137         put_pid(ctl->pid);
 138         kfree(ctl);
 139         module_put(card->module);
 140         snd_card_file_remove(card, file);
 141         return 0;
 142 }
 143
 144 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 145                     struct snd_ctl_elem_id *id)
 146 {
 147         unsigned long flags;
 148         struct snd_ctl_file *ctl;
 149         struct snd_kctl_event *ev;
 150
 151         if (snd_BUG_ON(!card || !id))
 152                 return;
 153         read_lock(&card->ctl_files_rwlock);
 154 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 155         card->mixer_oss_change_count++;
 156 #endif
 157         list_for_each_entry(ctl, &card->ctl_files, list) {
 158                 if (!ctl->subscribed)
 159                         continue;
 160                 spin_lock_irqsave(&ctl->read_lock, flags);
 161                 list_for_each_entry(ev, &ctl->events, list) {
 162                         if (ev->id.numid == id->numid) {
 163                                 ev->mask |= mask;
 164                                 goto _found;
 165                         }
 166                 }
 167                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 168                 if (ev) {
 169                         ev->id = *id;
 170                         ev->mask = mask;
 171                         list_add_tail(&ev->list, &ctl->events);
 172                 } else {
 173                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 174                 }
 175         _found:
 176                 wake_up(&ctl->change_sleep);
 177                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 178                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 179         }
 180         read_unlock(&card->ctl_files_rwlock);
 181 }
 182
 183 EXPORT_SYMBOL(snd_ctl_notify);
 184
 185 /**
 186  * snd_ctl_new - create a control instance from the template
 187  * @control: the control template
 188  * @access: the default control access
 189  *
 190  * Allocates a new struct snd_kcontrol instance and copies the given template
 191  * to the new instance. It does not copy volatile data (access).
 192  *
 193  * Return: The pointer of the new instance, or %NULL on failure.
 194  */
 195 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 196                                         unsigned int access)
 197 {
 198         struct snd_kcontrol *kctl;
 199         unsigned int idx;
 200
 201         if (snd_BUG_ON(!control || !control->count))
 202                 return NULL;
 203
 204         if (control->count > MAX_CONTROL_COUNT)
 205                 return NULL;
 206
 207         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 208         if (kctl == NULL) {
 209                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 210                 return NULL;
 211         }
 212         *kctl = *control;
 213         for (idx = 0; idx < kctl->count; idx++)
 214                 kctl->vd[idx].access = access;
 215         return kctl;
 216 }
 217
 218 /**
 219  * snd_ctl_new1 - create a control instance from the template
 220  * @ncontrol: the initialization record
 221  * @private_data: the private data to set
 222  *
 223  * Allocates a new struct snd_kcontrol instance and initialize from the given
 224  * template.  When the access field of ncontrol is 0, it's assumed as
 225  * READWRITE access. When the count field is 0, it's assumes as one.
 226  *
 227  * Return: The pointer of the newly generated instance, or %NULL on failure.
 228  */
 229 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 230                                   void *private_data)
 231 {
 232         struct snd_kcontrol kctl;
 233         unsigned int access;
 234
 235         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 236                 return NULL;
 237         memset(&kctl, 0, sizeof(kctl));
 238         kctl.id.iface = ncontrol->iface;
 239         kctl.id.device = ncontrol->device;
 240         kctl.id.subdevice = ncontrol->subdevice;
 241         if (ncontrol->name) {
 242                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 243                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 244                         snd_printk(KERN_WARNING
 245                                    "Control name '%s' truncated to '%s'\n",
 246                                    ncontrol->name, kctl.id.name);
 247         }
 248         kctl.id.index = ncontrol->index;
 249         kctl.count = ncontrol->count ? ncontrol->count : 1;
 250         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 251                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 252                                       SNDRV_CTL_ELEM_ACCESS_VOLATILE|
 253                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 254                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 255                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 256                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 257         kctl.info = ncontrol->info;
 258         kctl.get = ncontrol->get;
 259         kctl.put = ncontrol->put;
 260         kctl.tlv.p = ncontrol->tlv.p;
 261         kctl.private_value = ncontrol->private_value;
 262         kctl.private_data = private_data;
 263         return snd_ctl_new(&kctl, access);
 264 }
 265
 266 EXPORT_SYMBOL(snd_ctl_new1);
 267
 268 /**
 269  * snd_ctl_free_one - release the control instance
 270  * @kcontrol: the control instance
 271  *
 272  * Releases the control instance created via snd_ctl_new()
 273  * or snd_ctl_new1().
 274  * Don't call this after the control was added to the card.
 275  */
 276 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 277 {
 278         if (kcontrol) {
 279                 if (kcontrol->private_free)
 280                         kcontrol->private_free(kcontrol);
 281                 kfree(kcontrol);
 282         }
 283 }
 284
 285 EXPORT_SYMBOL(snd_ctl_free_one);
 286
 287 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 288                                           unsigned int count)
 289 {
 290         struct snd_kcontrol *kctl;
 291
 292         /* Make sure that the ids assigned to the control do not wrap around */
 293         if (card->last_numid >= UINT_MAX - count)
 294                 card->last_numid = 0;
 295
 296         list_for_each_entry(kctl, &card->controls, list) {
 297                 if (kctl->id.numid < card->last_numid + 1 + count &&
 298                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 299                         card->last_numid = kctl->id.numid + kctl->count - 1;
 300                         return true;
 301                 }
 302         }
 303         return false;
 304 }
 305
 306 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 307 {
 308         unsigned int iter = 100000;
 309
 310         while (snd_ctl_remove_numid_conflict(card, count)) {
 311                 if (--iter == 0) {
 312                         /* this situation is very unlikely */
 313                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 314                         return -ENOMEM;
 315                 }
 316         }
 317         return 0;
 318 }
 319
 320 /**
 321  * snd_ctl_add - add the control instance to the card
 322  * @card: the card instance
 323  * @kcontrol: the control instance to add
 324  *
 325  * Adds the control instance created via snd_ctl_new() or
 326  * snd_ctl_new1() to the given card. Assigns also an unique
 327  * numid used for fast search.
 328  *
 329  * It frees automatically the control which cannot be added.
 330  *
 331  * Return: Zero if successful, or a negative error code on failure.
 332  *
 333  */
 334 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 335 {
 336         struct snd_ctl_elem_id id;
 337         unsigned int idx;
 338         unsigned int count;
 339         int err = -EINVAL;
 340
 341         if (! kcontrol)
 342                 return err;
 343         if (snd_BUG_ON(!card || !kcontrol->info))
 344                 goto error;
 345         id = kcontrol->id;
 346         down_write(&card->controls_rwsem);
 347         if (snd_ctl_find_id(card, &id)) {
 348                 up_write(&card->controls_rwsem);
 349                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 350                                         id.iface,
 351                                         id.device,
 352                                         id.subdevice,
 353                                         id.name,
 354                                         id.index);
 355                 err = -EBUSY;
 356                 goto error;
 357         }
 358         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 359                 up_write(&card->controls_rwsem);
 360                 err = -ENOMEM;
 361                 goto error;
 362         }
 363         list_add_tail(&kcontrol->list, &card->controls);
 364         card->controls_count += kcontrol->count;
 365         kcontrol->id.numid = card->last_numid + 1;
 366         card->last_numid += kcontrol->count;
 367         count = kcontrol->count;
 368         up_write(&card->controls_rwsem);
 369         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 370                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 371         return 0;
 372
 373  error:
 374         snd_ctl_free_one(kcontrol);
 375         return err;
 376 }
 377
 378 EXPORT_SYMBOL(snd_ctl_add);
 379
 380 /**
 381  * snd_ctl_replace - replace the control instance of the card
 382  * @card: the card instance
 383  * @kcontrol: the control instance to replace
 384  * @add_on_replace: add the control if not already added
 385  *
 386  * Replaces the given control.  If the given control does not exist
 387  * and the add_on_replace flag is set, the control is added.  If the
 388  * control exists, it is destroyed first.
 389  *
 390  * It frees automatically the control which cannot be added or replaced.
 391  *
 392  * Return: Zero if successful, or a negative error code on failure.
 393  */
 394 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 395                     bool add_on_replace)
 396 {
 397         struct snd_ctl_elem_id id;
 398         unsigned int count;
 399         unsigned int idx;
 400         struct snd_kcontrol *old;
 401         int ret;
 402
 403         if (!kcontrol)
 404                 return -EINVAL;
 405         if (snd_BUG_ON(!card || !kcontrol->info)) {
 406                 ret = -EINVAL;
 407                 goto error;
 408         }
 409         id = kcontrol->id;
 410         down_write(&card->controls_rwsem);
 411         old = snd_ctl_find_id(card, &id);
 412         if (!old) {
 413                 if (add_on_replace)
 414                         goto add;
 415                 up_write(&card->controls_rwsem);
 416                 ret = -EINVAL;
 417                 goto error;
 418         }
 419         ret = snd_ctl_remove(card, old);
 420         if (ret < 0) {
 421                 up_write(&card->controls_rwsem);
 422                 goto error;
 423         }
 424 add:
 425         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 426                 up_write(&card->controls_rwsem);
 427                 ret = -ENOMEM;
 428                 goto error;
 429         }
 430         list_add_tail(&kcontrol->list, &card->controls);
 431         card->controls_count += kcontrol->count;
 432         kcontrol->id.numid = card->last_numid + 1;
 433         card->last_numid += kcontrol->count;
 434         count = kcontrol->count;
 435         up_write(&card->controls_rwsem);
 436         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 437                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 438         return 0;
 439
 440 error:
 441         snd_ctl_free_one(kcontrol);
 442         return ret;
 443 }
 444 EXPORT_SYMBOL(snd_ctl_replace);
 445
 446 /**
 447  * snd_ctl_remove - remove the control from the card and release it
 448  * @card: the card instance
 449  * @kcontrol: the control instance to remove
 450  *
 451  * Removes the control from the card and then releases the instance.
 452  * You don't need to call snd_ctl_free_one(). You must be in
 453  * the write lock - down_write(&card->controls_rwsem).
 454  *
 455  * Return: 0 if successful, or a negative error code on failure.
 456  */
 457 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 458 {
 459         struct snd_ctl_elem_id id;
 460         unsigned int idx;
 461
 462         if (snd_BUG_ON(!card || !kcontrol))
 463                 return -EINVAL;
 464         list_del(&kcontrol->list);
 465         card->controls_count -= kcontrol->count;
 466         id = kcontrol->id;
 467         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 468                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 469         snd_ctl_free_one(kcontrol);
 470         return 0;
 471 }
 472
 473 EXPORT_SYMBOL(snd_ctl_remove);
 474
 475 /**
 476  * snd_ctl_remove_id - remove the control of the given id and release it
 477  * @card: the card instance
 478  * @id: the control id to remove
 479  *
 480  * Finds the control instance with the given id, removes it from the
 481  * card list and releases it.
 482  *
 483  * Return: 0 if successful, or a negative error code on failure.
 484  */
 485 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 486 {
 487         struct snd_kcontrol *kctl;
 488         int ret;
 489
 490         down_write(&card->controls_rwsem);
 491         kctl = snd_ctl_find_id(card, id);
 492         if (kctl == NULL) {
 493                 up_write(&card->controls_rwsem);
 494                 return -ENOENT;
 495         }
 496         ret = snd_ctl_remove(card, kctl);
 497         up_write(&card->controls_rwsem);
 498         return ret;
 499 }
 500
 501 EXPORT_SYMBOL(snd_ctl_remove_id);
 502
 503 /**
 504  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 505  * @file: active control handle
 506  * @id: the control id to remove
 507  *
 508  * Finds the control instance with the given id, removes it from the
 509  * card list and releases it.
 510  *
 511  * Return: 0 if successful, or a negative error code on failure.
 512  */
 513 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 514                                    struct snd_ctl_elem_id *id)
 515 {
 516         struct snd_card *card = file->card;
 517         struct snd_kcontrol *kctl;
 518         int idx, ret;
 519
 520         down_write(&card->controls_rwsem);
 521         kctl = snd_ctl_find_id(card, id);
 522         if (kctl == NULL) {
 523                 ret = -ENOENT;
 524                 goto error;
 525         }
 526         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 527                 ret = -EINVAL;
 528                 goto error;
 529         }
 530         for (idx = 0; idx < kctl->count; idx++)
 531                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 532                         ret = -EBUSY;
 533                         goto error;
 534                 }
 535         ret = snd_ctl_remove(card, kctl);
 536         if (ret < 0)
 537                 goto error;
 538         card->user_ctl_count--;
 539 error:
 540         up_write(&card->controls_rwsem);
 541         return ret;
 542 }
 543
 544 /**
 545  * snd_ctl_activate_id - activate/inactivate the control of the given id
 546  * @card: the card instance
 547  * @id: the control id to activate/inactivate
 548  * @active: non-zero to activate
 549  *
 550  * Finds the control instance with the given id, and activate or
 551  * inactivate the control together with notification, if changed.
 552  *
 553  * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
 554  */
 555 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 556                         int active)
 557 {
 558         struct snd_kcontrol *kctl;
 559         struct snd_kcontrol_volatile *vd;
 560         unsigned int index_offset;
 561         int ret;
 562
 563         down_write(&card->controls_rwsem);
 564         kctl = snd_ctl_find_id(card, id);
 565         if (kctl == NULL) {
 566                 ret = -ENOENT;
 567                 goto unlock;
 568         }
 569         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 570         vd = &kctl->vd[index_offset];
 571         ret = 0;
 572         if (active) {
 573                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 574                         goto unlock;
 575                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 576         } else {
 577                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 578                         goto unlock;
 579                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 580         }
 581         ret = 1;
 582  unlock:
 583         up_write(&card->controls_rwsem);
 584         if (ret > 0)
 585                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 586         return ret;
 587 }
 588 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 589
 590 /**
 591  * snd_ctl_rename_id - replace the id of a control on the card
 592  * @card: the card instance
 593  * @src_id: the old id
 594  * @dst_id: the new id
 595  *
 596  * Finds the control with the old id from the card, and replaces the
 597  * id with the new one.
 598  *
 599  * Return: Zero if successful, or a negative error code on failure.
 600  */
 601 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 602                       struct snd_ctl_elem_id *dst_id)
 603 {
 604         struct snd_kcontrol *kctl;
 605
 606         down_write(&card->controls_rwsem);
 607         kctl = snd_ctl_find_id(card, src_id);
 608         if (kctl == NULL) {
 609                 up_write(&card->controls_rwsem);
 610                 return -ENOENT;
 611         }
 612         kctl->id = *dst_id;
 613         kctl->id.numid = card->last_numid + 1;
 614         card->last_numid += kctl->count;
 615         up_write(&card->controls_rwsem);
 616         return 0;
 617 }
 618
 619 EXPORT_SYMBOL(snd_ctl_rename_id);
 620
 621 /**
 622  * snd_ctl_find_numid - find the control instance with the given number-id
 623  * @card: the card instance
 624  * @numid: the number-id to search
 625  *
 626  * Finds the control instance with the given number-id from the card.
 627  *
 628  * The caller must down card->controls_rwsem before calling this function
 629  * (if the race condition can happen).
 630  *
 631  * Return: The pointer of the instance if found, or %NULL if not.
 632  *
 633  */
 634 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 635 {
 636         struct snd_kcontrol *kctl;
 637
 638         if (snd_BUG_ON(!card || !numid))
 639                 return NULL;
 640         list_for_each_entry(kctl, &card->controls, list) {
 641                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 642                         return kctl;
 643         }
 644         return NULL;
 645 }
 646
 647 EXPORT_SYMBOL(snd_ctl_find_numid);
 648
 649 /**
 650  * snd_ctl_find_id - find the control instance with the given id
 651  * @card: the card instance
 652  * @id: the id to search
 653  *
 654  * Finds the control instance with the given id from the card.
 655  *
 656  * The caller must down card->controls_rwsem before calling this function
 657  * (if the race condition can happen).
 658  *
 659  * Return: The pointer of the instance if found, or %NULL if not.
 660  *
 661  */
 662 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 663                                      struct snd_ctl_elem_id *id)
 664 {
 665         struct snd_kcontrol *kctl;
 666
 667         if (snd_BUG_ON(!card || !id))
 668                 return NULL;
 669         if (id->numid != 0)
 670                 return snd_ctl_find_numid(card, id->numid);
 671         list_for_each_entry(kctl, &card->controls, list) {
 672                 if (kctl->id.iface != id->iface)
 673                         continue;
 674                 if (kctl->id.device != id->device)
 675                         continue;
 676                 if (kctl->id.subdevice != id->subdevice)
 677                         continue;
 678                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 679                         continue;
 680                 if (kctl->id.index > id->index)
 681                         continue;
 682                 if (kctl->id.index + kctl->count <= id->index)
 683                         continue;
 684                 return kctl;
 685         }
 686         return NULL;
 687 }
 688
 689 EXPORT_SYMBOL(snd_ctl_find_id);
 690
 691 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 692                              unsigned int cmd, void __user *arg)
 693 {
 694         struct snd_ctl_card_info *info;
 695
 696         info = kzalloc(sizeof(*info), GFP_KERNEL);
 697         if (! info)
 698                 return -ENOMEM;
 699         down_read(&snd_ioctl_rwsem);
 700         info->card = card->number;
 701         strlcpy(info->id, card->id, sizeof(info->id));
 702         strlcpy(info->driver, card->driver, sizeof(info->driver));
 703         strlcpy(info->name, card->shortname, sizeof(info->name));
 704         strlcpy(info->longname, card->longname, sizeof(info->longname));
 705         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 706         strlcpy(info->components, card->components, sizeof(info->components));
 707         up_read(&snd_ioctl_rwsem);
 708         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 709                 kfree(info);
 710                 return -EFAULT;
 711         }
 712         kfree(info);
 713         return 0;
 714 }
 715
 716 static int snd_ctl_elem_list(struct snd_card *card,
 717                              struct snd_ctl_elem_list __user *_list)
 718 {
 719         struct list_head *plist;
 720         struct snd_ctl_elem_list list;
 721         struct snd_kcontrol *kctl;
 722         struct snd_ctl_elem_id *dst, *id;
 723         unsigned int offset, space, jidx;
 724
 725         if (copy_from_user(&list, _list, sizeof(list)))
 726                 return -EFAULT;
 727         offset = list.offset;
 728         space = list.space;
 729         /* try limit maximum space */
 730         if (space > 16384)
 731                 return -ENOMEM;
 732         if (space > 0) {
 733                 /* allocate temporary buffer for atomic operation */
 734                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 735                 if (dst == NULL)
 736                         return -ENOMEM;
 737                 down_read(&card->controls_rwsem);
 738                 list.count = card->controls_count;
 739                 plist = card->controls.next;
 740                 while (plist != &card->controls) {
 741                         if (offset == 0)
 742                                 break;
 743                         kctl = snd_kcontrol(plist);
 744                         if (offset < kctl->count)
 745                                 break;
 746                         offset -= kctl->count;
 747                         plist = plist->next;
 748                 }
 749                 list.used = 0;
 750                 id = dst;
 751                 while (space > 0 && plist != &card->controls) {
 752                         kctl = snd_kcontrol(plist);
 753                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 754                                 snd_ctl_build_ioff(id, kctl, jidx);
 755                                 id++;
 756                                 space--;
 757                                 list.used++;
 758                         }
 759                         plist = plist->next;
 760                         offset = 0;
 761                 }
 762                 up_read(&card->controls_rwsem);
 763                 if (list.used > 0 &&
 764                     copy_to_user(list.pids, dst,
 765                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 766                         vfree(dst);
 767                         return -EFAULT;
 768                 }
 769                 vfree(dst);
 770         } else {
 771                 down_read(&card->controls_rwsem);
 772                 list.count = card->controls_count;
 773                 up_read(&card->controls_rwsem);
 774         }
 775         if (copy_to_user(_list, &list, sizeof(list)))
 776                 return -EFAULT;
 777         return 0;
 778 }
 779
 780 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 781                              struct snd_ctl_elem_info *info)
 782 {
 783         struct snd_card *card = ctl->card;
 784         struct snd_kcontrol *kctl;
 785         struct snd_kcontrol_volatile *vd;
 786         unsigned int index_offset;
 787         int result;
 788
 789         down_read(&card->controls_rwsem);
 790         kctl = snd_ctl_find_id(card, &info->id);
 791         if (kctl == NULL) {
 792                 up_read(&card->controls_rwsem);
 793                 return -ENOENT;
 794         }
 795 #ifdef CONFIG_SND_DEBUG
 796         info->access = 0;
 797 #endif
 798         result = kctl->info(kctl, info);
 799         if (result >= 0) {
 800                 snd_BUG_ON(info->access);
 801                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 802                 vd = &kctl->vd[index_offset];
 803                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 804                 info->access = vd->access;
 805                 if (vd->owner) {
 806                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 807                         if (vd->owner == ctl)
 808                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 809                         info->owner = pid_vnr(vd->owner->pid);
 810                 } else {
 811                         info->owner = -1;
 812                 }
 813         }
 814         up_read(&card->controls_rwsem);
 815         return result;
 816 }
 817
 818 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 819                                   struct snd_ctl_elem_info __user *_info)
 820 {
 821         struct snd_ctl_elem_info info;
 822         int result;
 823
 824         if (copy_from_user(&info, _info, sizeof(info)))
 825                 return -EFAULT;
 826         snd_power_lock(ctl->card);
 827         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 828         if (result >= 0)
 829                 result = snd_ctl_elem_info(ctl, &info);
 830         snd_power_unlock(ctl->card);
 831         if (result >= 0)
 832                 if (copy_to_user(_info, &info, sizeof(info)))
 833                         return -EFAULT;
 834         return result;
 835 }
 836
 837 static int snd_ctl_elem_read(struct snd_card *card,
 838                              struct snd_ctl_elem_value *control)
 839 {
 840         struct snd_kcontrol *kctl;
 841         struct snd_kcontrol_volatile *vd;
 842         unsigned int index_offset;
 843         int result;
 844
 845         down_read(&card->controls_rwsem);
 846         kctl = snd_ctl_find_id(card, &control->id);
 847         if (kctl == NULL) {
 848                 result = -ENOENT;
 849         } else {
 850                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 851                 vd = &kctl->vd[index_offset];
 852                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 853                     kctl->get != NULL) {
 854                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 855                         result = kctl->get(kctl, control);
 856                 } else
 857                         result = -EPERM;
 858         }
 859         up_read(&card->controls_rwsem);
 860         return result;
 861 }
 862
 863 static int snd_ctl_elem_read_user(struct snd_card *card,
 864                                   struct snd_ctl_elem_value __user *_control)
 865 {
 866         struct snd_ctl_elem_value *control;
 867         int result;
 868
 869         control = memdup_user(_control, sizeof(*control));
 870         if (IS_ERR(control))
 871                 return PTR_ERR(control);
 872
 873         snd_power_lock(card);
 874         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 875         if (result >= 0)
 876                 result = snd_ctl_elem_read(card, control);
 877         snd_power_unlock(card);
 878         if (result >= 0)
 879                 if (copy_to_user(_control, control, sizeof(*control)))
 880                         result = -EFAULT;
 881         kfree(control);
 882         return result;
 883 }
 884
 885 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 886                               struct snd_ctl_elem_value *control)
 887 {
 888         struct snd_kcontrol *kctl;
 889         struct snd_kcontrol_volatile *vd;
 890         unsigned int index_offset;
 891         int result;
 892
 893         down_read(&card->controls_rwsem);
 894         kctl = snd_ctl_find_id(card, &control->id);
 895         if (kctl == NULL) {
 896                 result = -ENOENT;
 897         } else {
 898                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 899                 vd = &kctl->vd[index_offset];
 900                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 901                     kctl->put == NULL ||
 902                     (file && vd->owner && vd->owner != file)) {
 903                         result = -EPERM;
 904                 } else {
 905                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 906                         result = kctl->put(kctl, control);
 907                 }
 908                 if (result > 0) {
 909                         struct snd_ctl_elem_id id = control->id;
 910                         up_read(&card->controls_rwsem);
 911                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
 912                         return 0;
 913                 }
 914         }
 915         up_read(&card->controls_rwsem);
 916         return result;
 917 }
 918
 919 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 920                                    struct snd_ctl_elem_value __user *_control)
 921 {
 922         struct snd_ctl_elem_value *control;
 923         struct snd_card *card;
 924         int result;
 925
 926         control = memdup_user(_control, sizeof(*control));
 927         if (IS_ERR(control))
 928                 return PTR_ERR(control);
 929
 930         card = file->card;
 931         snd_power_lock(card);
 932         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 933         if (result >= 0)
 934                 result = snd_ctl_elem_write(card, file, control);
 935         snd_power_unlock(card);
 936         if (result >= 0)
 937                 if (copy_to_user(_control, control, sizeof(*control)))
 938                         result = -EFAULT;
 939         kfree(control);
 940         return result;
 941 }
 942
 943 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 944                              struct snd_ctl_elem_id __user *_id)
 945 {
 946         struct snd_card *card = file->card;
 947         struct snd_ctl_elem_id id;
 948         struct snd_kcontrol *kctl;
 949         struct snd_kcontrol_volatile *vd;
 950         int result;
 951
 952         if (copy_from_user(&id, _id, sizeof(id)))
 953                 return -EFAULT;
 954         down_write(&card->controls_rwsem);
 955         kctl = snd_ctl_find_id(card, &id);
 956         if (kctl == NULL) {
 957                 result = -ENOENT;
 958         } else {
 959                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 960                 if (vd->owner != NULL)
 961                         result = -EBUSY;
 962                 else {
 963                         vd->owner = file;
 964                         result = 0;
 965                 }
 966         }
 967         up_write(&card->controls_rwsem);
 968         return result;
 969 }
 970
 971 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 972                                struct snd_ctl_elem_id __user *_id)
 973 {
 974         struct snd_card *card = file->card;
 975         struct snd_ctl_elem_id id;
 976         struct snd_kcontrol *kctl;
 977         struct snd_kcontrol_volatile *vd;
 978         int result;
 979
 980         if (copy_from_user(&id, _id, sizeof(id)))
 981                 return -EFAULT;
 982         down_write(&card->controls_rwsem);
 983         kctl = snd_ctl_find_id(card, &id);
 984         if (kctl == NULL) {
 985                 result = -ENOENT;
 986         } else {
 987                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 988                 if (vd->owner == NULL)
 989                         result = -EINVAL;
 990                 else if (vd->owner != file)
 991                         result = -EPERM;
 992                 else {
 993                         vd->owner = NULL;
 994                         result = 0;
 995                 }
 996         }
 997         up_write(&card->controls_rwsem);
 998         return result;
 999 }
1000
1001 struct user_element {
1002         struct snd_ctl_elem_info info;
1003         struct snd_card *card;
1004         void *elem_data;                /* element data */
1005         unsigned long elem_data_size;   /* size of element data in bytes */
1006         void *tlv_data;                 /* TLV data */
1007         unsigned long tlv_data_size;    /* TLV data size */
1008         void *priv_data;                /* private data (like strings for enumerated type) */
1009 };
1010
1011 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1012                                   struct snd_ctl_elem_info *uinfo)
1013 {
1014         struct user_element *ue = kcontrol->private_data;
1015
1016         *uinfo = ue->info;
1017         return 0;
1018 }
1019
1020 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1021                                        struct snd_ctl_elem_info *uinfo)
1022 {
1023         struct user_element *ue = kcontrol->private_data;
1024         const char *names;
1025         unsigned int item;
1026
1027         item = uinfo->value.enumerated.item;
1028
1029         *uinfo = ue->info;
1030
1031         item = min(item, uinfo->value.enumerated.items - 1);
1032         uinfo->value.enumerated.item = item;
1033
1034         names = ue->priv_data;
1035         for (; item > 0; --item)
1036                 names += strlen(names) + 1;
1037         strcpy(uinfo->value.enumerated.name, names);
1038
1039         return 0;
1040 }
1041
1042 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1043                                  struct snd_ctl_elem_value *ucontrol)
1044 {
1045         struct user_element *ue = kcontrol->private_data;
1046
1047         mutex_lock(&ue->card->user_ctl_lock);
1048         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1049         mutex_unlock(&ue->card->user_ctl_lock);
1050         return 0;
1051 }
1052
1053 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1054                                  struct snd_ctl_elem_value *ucontrol)
1055 {
1056         int change;
1057         struct user_element *ue = kcontrol->private_data;
1058
1059         mutex_lock(&ue->card->user_ctl_lock);
1060         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1061         if (change)
1062                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1063         mutex_unlock(&ue->card->user_ctl_lock);
1064         return change;
1065 }
1066
1067 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1068                                  int op_flag,
1069                                  unsigned int size,
1070                                  unsigned int __user *tlv)
1071 {
1072         struct user_element *ue = kcontrol->private_data;
1073         int change = 0;
1074         void *new_data;
1075
1076         if (op_flag > 0) {
1077                 if (size > 1024 * 128)  /* sane value */
1078                         return -EINVAL;
1079
1080                 new_data = memdup_user(tlv, size);
1081                 if (IS_ERR(new_data))
1082                         return PTR_ERR(new_data);
1083                 mutex_lock(&ue->card->user_ctl_lock);
1084                 change = ue->tlv_data_size != size;
1085                 if (!change)
1086                         change = memcmp(ue->tlv_data, new_data, size);
1087                 kfree(ue->tlv_data);
1088                 ue->tlv_data = new_data;
1089                 ue->tlv_data_size = size;
1090                 mutex_unlock(&ue->card->user_ctl_lock);
1091         } else {
1092                 int ret = 0;
1093
1094                 mutex_lock(&ue->card->user_ctl_lock);
1095                 if (!ue->tlv_data_size || !ue->tlv_data) {
1096                         ret = -ENXIO;
1097                         goto err_unlock;
1098                 }
1099                 if (size < ue->tlv_data_size) {
1100                         ret = -ENOSPC;
1101                         goto err_unlock;
1102                 }
1103                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1104                         ret = -EFAULT;
1105 err_unlock:
1106                 mutex_unlock(&ue->card->user_ctl_lock);
1107                 if (ret)
1108                         return ret;
1109         }
1110         return change;
1111 }
1112
1113 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1114 {
1115         char *names, *p;
1116         size_t buf_len, name_len;
1117         unsigned int i;
1118         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1119
1120         if (ue->info.value.enumerated.names_length > 64 * 1024)
1121                 return -EINVAL;
1122
1123         names = memdup_user((const void __user *)user_ptrval,
1124                 ue->info.value.enumerated.names_length);
1125         if (IS_ERR(names))
1126                 return PTR_ERR(names);
1127
1128         /* check that there are enough valid names */
1129         buf_len = ue->info.value.enumerated.names_length;
1130         p = names;
1131         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1132                 name_len = strnlen(p, buf_len);
1133                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1134                         kfree(names);
1135                         return -EINVAL;
1136                 }
1137                 p += name_len + 1;
1138                 buf_len -= name_len + 1;
1139         }
1140
1141         ue->priv_data = names;
1142         ue->info.value.enumerated.names_ptr = 0;
1143
1144         return 0;
1145 }
1146
1147 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1148 {
1149         struct user_element *ue = kcontrol->private_data;
1150
1151         kfree(ue->tlv_data);
1152         kfree(ue->priv_data);
1153         kfree(ue);
1154 }
1155
1156 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1157                             struct snd_ctl_elem_info *info, int replace)
1158 {
1159         struct snd_card *card = file->card;
1160         struct snd_kcontrol kctl, *_kctl;
1161         unsigned int access;
1162         long private_size;
1163         struct user_element *ue;
1164         int idx, err;
1165
1166         if (info->count < 1)
1167                 return -EINVAL;
1168         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1169                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1170                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1171                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1172         info->id.numid = 0;
1173         memset(&kctl, 0, sizeof(kctl));
1174
1175         if (replace) {
1176                 err = snd_ctl_remove_user_ctl(file, &info->id);
1177                 if (err)
1178                         return err;
1179         }
1180
1181         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1182                 return -ENOMEM;
1183
1184         memcpy(&kctl.id, &info->id, sizeof(info->id));
1185         kctl.count = info->owner ? info->owner : 1;
1186         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1187         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1188                 kctl.info = snd_ctl_elem_user_enum_info;
1189         else
1190                 kctl.info = snd_ctl_elem_user_info;
1191         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1192                 kctl.get = snd_ctl_elem_user_get;
1193         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1194                 kctl.put = snd_ctl_elem_user_put;
1195         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1196                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1197                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1198         }
1199         switch (info->type) {
1200         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1201         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1202                 private_size = sizeof(long);
1203                 if (info->count > 128)
1204                         return -EINVAL;
1205                 break;
1206         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1207                 private_size = sizeof(long long);
1208                 if (info->count > 64)
1209                         return -EINVAL;
1210                 break;
1211         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1212                 private_size = sizeof(unsigned int);
1213                 if (info->count > 128 || info->value.enumerated.items == 0)
1214                         return -EINVAL;
1215                 break;
1216         case SNDRV_CTL_ELEM_TYPE_BYTES:
1217                 private_size = sizeof(unsigned char);
1218                 if (info->count > 512)
1219                         return -EINVAL;
1220                 break;
1221         case SNDRV_CTL_ELEM_TYPE_IEC958:
1222                 private_size = sizeof(struct snd_aes_iec958);
1223                 if (info->count != 1)
1224                         return -EINVAL;
1225                 break;
1226         default:
1227                 return -EINVAL;
1228         }
1229         private_size *= info->count;
1230         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1231         if (ue == NULL)
1232                 return -ENOMEM;
1233         ue->card = card;
1234         ue->info = *info;
1235         ue->info.access = 0;
1236         ue->elem_data = (char *)ue + sizeof(*ue);
1237         ue->elem_data_size = private_size;
1238         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1239                 err = snd_ctl_elem_init_enum_names(ue);
1240                 if (err < 0) {
1241                         kfree(ue);
1242                         return err;
1243                 }
1244         }
1245         kctl.private_free = snd_ctl_elem_user_free;
1246         _kctl = snd_ctl_new(&kctl, access);
1247         if (_kctl == NULL) {
1248                 kfree(ue->priv_data);
1249                 kfree(ue);
1250                 return -ENOMEM;
1251         }
1252         _kctl->private_data = ue;
1253         for (idx = 0; idx < _kctl->count; idx++)
1254                 _kctl->vd[idx].owner = file;
1255         err = snd_ctl_add(card, _kctl);
1256         if (err < 0)
1257                 return err;
1258
1259         down_write(&card->controls_rwsem);
1260         card->user_ctl_count++;
1261         up_write(&card->controls_rwsem);
1262
1263         return 0;
1264 }
1265
1266 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1267                                  struct snd_ctl_elem_info __user *_info, int replace)
1268 {
1269         struct snd_ctl_elem_info info;
1270         if (copy_from_user(&info, _info, sizeof(info)))
1271                 return -EFAULT;
1272         return snd_ctl_elem_add(file, &info, replace);
1273 }
1274
1275 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1276                                struct snd_ctl_elem_id __user *_id)
1277 {
1278         struct snd_ctl_elem_id id;
1279
1280         if (copy_from_user(&id, _id, sizeof(id)))
1281                 return -EFAULT;
1282         return snd_ctl_remove_user_ctl(file, &id);
1283 }
1284
1285 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1286 {
1287         int subscribe;
1288         if (get_user(subscribe, ptr))
1289                 return -EFAULT;
1290         if (subscribe < 0) {
1291                 subscribe = file->subscribed;
1292                 if (put_user(subscribe, ptr))
1293                         return -EFAULT;
1294                 return 0;
1295         }
1296         if (subscribe) {
1297                 file->subscribed = 1;
1298                 return 0;
1299         } else if (file->subscribed) {
1300                 snd_ctl_empty_read_queue(file);
1301                 file->subscribed = 0;
1302         }
1303         return 0;
1304 }
1305
1306 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1307                              struct snd_ctl_tlv __user *_tlv,
1308                              int op_flag)
1309 {
1310         struct snd_card *card = file->card;
1311         struct snd_ctl_tlv tlv;
1312         struct snd_kcontrol *kctl;
1313         struct snd_kcontrol_volatile *vd;
1314         unsigned int len;
1315         int err = 0;
1316
1317         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1318                 return -EFAULT;
1319         if (tlv.length < sizeof(unsigned int) * 2)
1320                 return -EINVAL;
1321         down_read(&card->controls_rwsem);
1322         kctl = snd_ctl_find_numid(card, tlv.numid);
1323         if (kctl == NULL) {
1324                 err = -ENOENT;
1325                 goto __kctl_end;
1326         }
1327         if (kctl->tlv.p == NULL) {
1328                 err = -ENXIO;
1329                 goto __kctl_end;
1330         }
1331         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1332         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1333             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1334             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1335                 err = -ENXIO;
1336                 goto __kctl_end;
1337         }
1338         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1339                 if (vd->owner != NULL && vd->owner != file) {
1340                         err = -EPERM;
1341                         goto __kctl_end;
1342                 }
1343                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1344                 if (err > 0) {
1345                         struct snd_ctl_elem_id id = kctl->id;
1346                         up_read(&card->controls_rwsem);
1347                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1348                         return 0;
1349                 }
1350         } else {
1351                 if (op_flag) {
1352                         err = -ENXIO;
1353                         goto __kctl_end;
1354                 }
1355                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1356                 if (tlv.length < len) {
1357                         err = -ENOMEM;
1358                         goto __kctl_end;
1359                 }
1360                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1361                         err = -EFAULT;
1362         }
1363       __kctl_end:
1364         up_read(&card->controls_rwsem);
1365         return err;
1366 }
1367
1368 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1369 {
1370         struct snd_ctl_file *ctl;
1371         struct snd_card *card;
1372         struct snd_kctl_ioctl *p;
1373         void __user *argp = (void __user *)arg;
1374         int __user *ip = argp;
1375         int err;
1376
1377         ctl = file->private_data;
1378         card = ctl->card;
1379         if (snd_BUG_ON(!card))
1380                 return -ENXIO;
1381         switch (cmd) {
1382         case SNDRV_CTL_IOCTL_PVERSION:
1383                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1384         case SNDRV_CTL_IOCTL_CARD_INFO:
1385                 return snd_ctl_card_info(card, ctl, cmd, argp);
1386         case SNDRV_CTL_IOCTL_ELEM_LIST:
1387                 return snd_ctl_elem_list(card, argp);
1388         case SNDRV_CTL_IOCTL_ELEM_INFO:
1389                 return snd_ctl_elem_info_user(ctl, argp);
1390         case SNDRV_CTL_IOCTL_ELEM_READ:
1391                 return snd_ctl_elem_read_user(card, argp);
1392         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1393                 return snd_ctl_elem_write_user(ctl, argp);
1394         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1395                 return snd_ctl_elem_lock(ctl, argp);
1396         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1397                 return snd_ctl_elem_unlock(ctl, argp);
1398         case SNDRV_CTL_IOCTL_ELEM_ADD:
1399                 return snd_ctl_elem_add_user(ctl, argp, 0);
1400         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1401                 return snd_ctl_elem_add_user(ctl, argp, 1);
1402         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1403                 return snd_ctl_elem_remove(ctl, argp);
1404         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1405                 return snd_ctl_subscribe_events(ctl, ip);
1406         case SNDRV_CTL_IOCTL_TLV_READ:
1407                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1408         case SNDRV_CTL_IOCTL_TLV_WRITE:
1409                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1410         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1411                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1412         case SNDRV_CTL_IOCTL_POWER:
1413                 return -ENOPROTOOPT;
1414         case SNDRV_CTL_IOCTL_POWER_STATE:
1415 #ifdef CONFIG_PM
1416                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1417 #else
1418                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1419 #endif
1420         }
1421         down_read(&snd_ioctl_rwsem);
1422         list_for_each_entry(p, &snd_control_ioctls, list) {
1423                 err = p->fioctl(card, ctl, cmd, arg);
1424                 if (err != -ENOIOCTLCMD) {
1425                         up_read(&snd_ioctl_rwsem);
1426                         return err;
1427                 }
1428         }
1429         up_read(&snd_ioctl_rwsem);
1430         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1431         return -ENOTTY;
1432 }
1433
1434 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1435                             size_t count, loff_t * offset)
1436 {
1437         struct snd_ctl_file *ctl;
1438         int err = 0;
1439         ssize_t result = 0;
1440
1441         ctl = file->private_data;
1442         if (snd_BUG_ON(!ctl || !ctl->card))
1443                 return -ENXIO;
1444         if (!ctl->subscribed)
1445                 return -EBADFD;
1446         if (count < sizeof(struct snd_ctl_event))
1447                 return -EINVAL;
1448         spin_lock_irq(&ctl->read_lock);
1449         while (count >= sizeof(struct snd_ctl_event)) {
1450                 struct snd_ctl_event ev;
1451                 struct snd_kctl_event *kev;
1452                 while (list_empty(&ctl->events)) {
1453                         wait_queue_t wait;
1454                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1455                                 err = -EAGAIN;
1456                                 goto __end_lock;
1457                         }
1458                         init_waitqueue_entry(&wait, current);
1459                         add_wait_queue(&ctl->change_sleep, &wait);
1460                         set_current_state(TASK_INTERRUPTIBLE);
1461                         spin_unlock_irq(&ctl->read_lock);
1462                         schedule();
1463                         remove_wait_queue(&ctl->change_sleep, &wait);
1464                         if (ctl->card->shutdown)
1465                                 return -ENODEV;
1466                         if (signal_pending(current))
1467                                 return -ERESTARTSYS;
1468                         spin_lock_irq(&ctl->read_lock);
1469                 }
1470                 kev = snd_kctl_event(ctl->events.next);
1471                 ev.type = SNDRV_CTL_EVENT_ELEM;
1472                 ev.data.elem.mask = kev->mask;
1473                 ev.data.elem.id = kev->id;
1474                 list_del(&kev->list);
1475                 spin_unlock_irq(&ctl->read_lock);
1476                 kfree(kev);
1477                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1478                         err = -EFAULT;
1479                         goto __end;
1480                 }
1481                 spin_lock_irq(&ctl->read_lock);
1482                 buffer += sizeof(struct snd_ctl_event);
1483                 count -= sizeof(struct snd_ctl_event);
1484                 result += sizeof(struct snd_ctl_event);
1485         }
1486       __end_lock:
1487         spin_unlock_irq(&ctl->read_lock);
1488       __end:
1489         return result > 0 ? result : err;
1490 }
1491
1492 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1493 {
1494         unsigned int mask;
1495         struct snd_ctl_file *ctl;
1496
1497         ctl = file->private_data;
1498         if (!ctl->subscribed)
1499                 return 0;
1500         poll_wait(file, &ctl->change_sleep, wait);
1501
1502         mask = 0;
1503         if (!list_empty(&ctl->events))
1504                 mask |= POLLIN | POLLRDNORM;
1505
1506         return mask;
1507 }
1508
1509 /*
1510  * register the device-specific control-ioctls.
1511  * called from each device manager like pcm.c, hwdep.c, etc.
1512  */
1513 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1514 {
1515         struct snd_kctl_ioctl *pn;
1516
1517         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1518         if (pn == NULL)
1519                 return -ENOMEM;
1520         pn->fioctl = fcn;
1521         down_write(&snd_ioctl_rwsem);
1522         list_add_tail(&pn->list, lists);
1523         up_write(&snd_ioctl_rwsem);
1524         return 0;
1525 }
1526
1527 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1528 {
1529         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1530 }
1531
1532 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1533
1534 #ifdef CONFIG_COMPAT
1535 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1536 {
1537         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1538 }
1539
1540 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1541 #endif
1542
1543 /*
1544  * de-register the device-specific control-ioctls.
1545  */
1546 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1547                                      struct list_head *lists)
1548 {
1549         struct snd_kctl_ioctl *p;
1550
1551         if (snd_BUG_ON(!fcn))
1552                 return -EINVAL;
1553         down_write(&snd_ioctl_rwsem);
1554         list_for_each_entry(p, lists, list) {
1555                 if (p->fioctl == fcn) {
1556                         list_del(&p->list);
1557                         up_write(&snd_ioctl_rwsem);
1558                         kfree(p);
1559                         return 0;
1560                 }
1561         }
1562         up_write(&snd_ioctl_rwsem);
1563         snd_BUG();
1564         return -EINVAL;
1565 }
1566
1567 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1568 {
1569         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1570 }
1571
1572 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1573
1574 #ifdef CONFIG_COMPAT
1575 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1576 {
1577         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1578 }
1579
1580 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1581 #endif
1582
1583 static int snd_ctl_fasync(int fd, struct file * file, int on)
1584 {
1585         struct snd_ctl_file *ctl;
1586
1587         ctl = file->private_data;
1588         return fasync_helper(fd, file, on, &ctl->fasync);
1589 }
1590
1591 /*
1592  * ioctl32 compat
1593  */
1594 #ifdef CONFIG_COMPAT
1595 #include "control_compat.c"
1596 #else
1597 #define snd_ctl_ioctl_compat    NULL
1598 #endif
1599
1600 /*
1601  *  INIT PART
1602  */
1603
1604 static const struct file_operations snd_ctl_f_ops =
1605 {
1606         .owner =        THIS_MODULE,
1607         .read =         snd_ctl_read,
1608         .open =         snd_ctl_open,
1609         .release =      snd_ctl_release,
1610         .llseek =       no_llseek,
1611         .poll =         snd_ctl_poll,
1612         .unlocked_ioctl =       snd_ctl_ioctl,
1613         .compat_ioctl = snd_ctl_ioctl_compat,
1614         .fasync =       snd_ctl_fasync,
1615 };
1616
1617 /*
1618  * registration of the control device
1619  */
1620 static int snd_ctl_dev_register(struct snd_device *device)
1621 {
1622         struct snd_card *card = device->device_data;
1623         int err, cardnum;
1624         char name[16];
1625
1626         if (snd_BUG_ON(!card))
1627                 return -ENXIO;
1628         cardnum = card->number;
1629         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1630                 return -ENXIO;
1631         sprintf(name, "controlC%i", cardnum);
1632         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1633                                        &snd_ctl_f_ops, card, name)) < 0)
1634                 return err;
1635         return 0;
1636 }
1637
1638 /*
1639  * disconnection of the control device
1640  */
1641 static int snd_ctl_dev_disconnect(struct snd_device *device)
1642 {
1643         struct snd_card *card = device->device_data;
1644         struct snd_ctl_file *ctl;
1645         int err, cardnum;
1646
1647         if (snd_BUG_ON(!card))
1648                 return -ENXIO;
1649         cardnum = card->number;
1650         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1651                 return -ENXIO;
1652
1653         read_lock(&card->ctl_files_rwlock);
1654         list_for_each_entry(ctl, &card->ctl_files, list) {
1655                 wake_up(&ctl->change_sleep);
1656                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1657         }
1658         read_unlock(&card->ctl_files_rwlock);
1659
1660         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1661                                          card, -1)) < 0)
1662                 return err;
1663         return 0;
1664 }
1665
1666 /*
1667  * free all controls
1668  */
1669 static int snd_ctl_dev_free(struct snd_device *device)
1670 {
1671         struct snd_card *card = device->device_data;
1672         struct snd_kcontrol *control;
1673
1674         down_write(&card->controls_rwsem);
1675         while (!list_empty(&card->controls)) {
1676                 control = snd_kcontrol(card->controls.next);
1677                 snd_ctl_remove(card, control);
1678         }
1679         up_write(&card->controls_rwsem);
1680         return 0;
1681 }
1682
1683 /*
1684  * create control core:
1685  * called from init.c
1686  */
1687 int snd_ctl_create(struct snd_card *card)
1688 {
1689         static struct snd_device_ops ops = {
1690                 .dev_free = snd_ctl_dev_free,
1691                 .dev_register = snd_ctl_dev_register,
1692                 .dev_disconnect = snd_ctl_dev_disconnect,
1693         };
1694
1695         if (snd_BUG_ON(!card))
1696                 return -ENXIO;
1697         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1698 }
1699
1700 /*
1701  * Frequently used control callbacks/helpers
1702  */
1703 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1704                               struct snd_ctl_elem_info *uinfo)
1705 {
1706         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1707         uinfo->count = 1;
1708         uinfo->value.integer.min = 0;
1709         uinfo->value.integer.max = 1;
1710         return 0;
1711 }
1712
1713 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1714
1715 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1716                                 struct snd_ctl_elem_info *uinfo)
1717 {
1718         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1719         uinfo->count = 2;
1720         uinfo->value.integer.min = 0;
1721         uinfo->value.integer.max = 1;
1722         return 0;
1723 }
1724
1725 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1726
1727 /**
1728  * snd_ctl_enum_info - fills the info structure for an enumerated control
1729  * @info: the structure to be filled
1730  * @channels: the number of the control's channels; often one
1731  * @items: the number of control values; also the size of @names
1732  * @names: an array containing the names of all control values
1733  *
1734  * Sets all required fields in @info to their appropriate values.
1735  * If the control's accessibility is not the default (readable and writable),
1736  * the caller has to fill @info->access.
1737  *
1738  * Return: Zero.
1739  */
1740 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1741                       unsigned int items, const char *const names[])
1742 {
1743         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1744         info->count = channels;
1745         info->value.enumerated.items = items;
1746         if (info->value.enumerated.item >= items)
1747                 info->value.enumerated.item = items - 1;
1748         strlcpy(info->value.enumerated.name,
1749                 names[info->value.enumerated.item],
1750                 sizeof(info->value.enumerated.name));
1751         return 0;
1752 }
1753 EXPORT_SYMBOL(snd_ctl_enum_info);