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         if (card->shutdown)
 154                 return;
 155         read_lock(&card->ctl_files_rwlock);
 156 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 157         card->mixer_oss_change_count++;
 158 #endif
 159         list_for_each_entry(ctl, &card->ctl_files, list) {
 160                 if (!ctl->subscribed)
 161                         continue;
 162                 spin_lock_irqsave(&ctl->read_lock, flags);
 163                 list_for_each_entry(ev, &ctl->events, list) {
 164                         if (ev->id.numid == id->numid) {
 165                                 ev->mask |= mask;
 166                                 goto _found;
 167                         }
 168                 }
 169                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 170                 if (ev) {
 171                         ev->id = *id;
 172                         ev->mask = mask;
 173                         list_add_tail(&ev->list, &ctl->events);
 174                 } else {
 175                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 176                 }
 177         _found:
 178                 wake_up(&ctl->change_sleep);
 179                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 180                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 181         }
 182         read_unlock(&card->ctl_files_rwlock);
 183 }
 184
 185 EXPORT_SYMBOL(snd_ctl_notify);
 186
 187 /**
 188  * snd_ctl_new - create a control instance from the template
 189  * @control: the control template
 190  * @access: the default control access
 191  *
 192  * Allocates a new struct snd_kcontrol instance and copies the given template
 193  * to the new instance. It does not copy volatile data (access).
 194  *
 195  * Returns the pointer of the new instance, or NULL on failure.
 196  */
 197 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 198                                         unsigned int access)
 199 {
 200         struct snd_kcontrol *kctl;
 201         unsigned int idx;
 202
 203         if (snd_BUG_ON(!control || !control->count))
 204                 return NULL;
 205
 206         if (control->count > MAX_CONTROL_COUNT)
 207                 return NULL;
 208
 209         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 210         if (kctl == NULL) {
 211                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 212                 return NULL;
 213         }
 214         *kctl = *control;
 215         for (idx = 0; idx < kctl->count; idx++)
 216                 kctl->vd[idx].access = access;
 217         return kctl;
 218 }
 219
 220 /**
 221  * snd_ctl_new1 - create a control instance from the template
 222  * @ncontrol: the initialization record
 223  * @private_data: the private data to set
 224  *
 225  * Allocates a new struct snd_kcontrol instance and initialize from the given
 226  * template.  When the access field of ncontrol is 0, it's assumed as
 227  * READWRITE access. When the count field is 0, it's assumes as one.
 228  *
 229  * Returns the pointer of the newly generated instance, or NULL on failure.
 230  */
 231 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 232                                   void *private_data)
 233 {
 234         struct snd_kcontrol kctl;
 235         unsigned int access;
 236
 237         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 238                 return NULL;
 239         memset(&kctl, 0, sizeof(kctl));
 240         kctl.id.iface = ncontrol->iface;
 241         kctl.id.device = ncontrol->device;
 242         kctl.id.subdevice = ncontrol->subdevice;
 243         if (ncontrol->name) {
 244                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 245                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 246                         snd_printk(KERN_WARNING
 247                                    "Control name '%s' truncated to '%s'\n",
 248                                    ncontrol->name, kctl.id.name);
 249         }
 250         kctl.id.index = ncontrol->index;
 251         kctl.count = ncontrol->count ? ncontrol->count : 1;
 252         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 253                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 254                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 255                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 256                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 257                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 258         kctl.info = ncontrol->info;
 259         kctl.get = ncontrol->get;
 260         kctl.put = ncontrol->put;
 261         kctl.tlv.p = ncontrol->tlv.p;
 262         kctl.private_value = ncontrol->private_value;
 263         kctl.private_data = private_data;
 264         return snd_ctl_new(&kctl, access);
 265 }
 266
 267 EXPORT_SYMBOL(snd_ctl_new1);
 268
 269 /**
 270  * snd_ctl_free_one - release the control instance
 271  * @kcontrol: the control instance
 272  *
 273  * Releases the control instance created via snd_ctl_new()
 274  * or snd_ctl_new1().
 275  * Don't call this after the control was added to the card.
 276  */
 277 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 278 {
 279         if (kcontrol) {
 280                 if (kcontrol->private_free)
 281                         kcontrol->private_free(kcontrol);
 282                 kfree(kcontrol);
 283         }
 284 }
 285
 286 EXPORT_SYMBOL(snd_ctl_free_one);
 287
 288 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 289                                           unsigned int count)
 290 {
 291         struct snd_kcontrol *kctl;
 292
 293         /* Make sure that the ids assigned to the control do not wrap around */
 294         if (card->last_numid >= UINT_MAX - count)
 295                 card->last_numid = 0;
 296
 297         list_for_each_entry(kctl, &card->controls, list) {
 298                 if (kctl->id.numid < card->last_numid + 1 + count &&
 299                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 300                         card->last_numid = kctl->id.numid + kctl->count - 1;
 301                         return true;
 302                 }
 303         }
 304         return false;
 305 }
 306
 307 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 308 {
 309         unsigned int iter = 100000;
 310
 311         while (snd_ctl_remove_numid_conflict(card, count)) {
 312                 if (--iter == 0) {
 313                         /* this situation is very unlikely */
 314                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 315                         return -ENOMEM;
 316                 }
 317         }
 318         return 0;
 319 }
 320
 321 /**
 322  * snd_ctl_add - add the control instance to the card
 323  * @card: the card instance
 324  * @kcontrol: the control instance to add
 325  *
 326  * Adds the control instance created via snd_ctl_new() or
 327  * snd_ctl_new1() to the given card. Assigns also an unique
 328  * numid used for fast search.
 329  *
 330  * Returns zero if successful, or a negative error code on failure.
 331  *
 332  * It frees automatically the control which cannot be added.
 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         if (id.index > UINT_MAX - kcontrol->count)
 347                 goto error;
 348
 349         down_write(&card->controls_rwsem);
 350         if (snd_ctl_find_id(card, &id)) {
 351                 up_write(&card->controls_rwsem);
 352                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 353                                         id.iface,
 354                                         id.device,
 355                                         id.subdevice,
 356                                         id.name,
 357                                         id.index);
 358                 err = -EBUSY;
 359                 goto error;
 360         }
 361         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 362                 up_write(&card->controls_rwsem);
 363                 err = -ENOMEM;
 364                 goto error;
 365         }
 366         list_add_tail(&kcontrol->list, &card->controls);
 367         card->controls_count += kcontrol->count;
 368         kcontrol->id.numid = card->last_numid + 1;
 369         card->last_numid += kcontrol->count;
 370         count = kcontrol->count;
 371         up_write(&card->controls_rwsem);
 372         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 373                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 374         return 0;
 375
 376  error:
 377         snd_ctl_free_one(kcontrol);
 378         return err;
 379 }
 380
 381 EXPORT_SYMBOL(snd_ctl_add);
 382
 383 /**
 384  * snd_ctl_replace - replace the control instance of the card
 385  * @card: the card instance
 386  * @kcontrol: the control instance to replace
 387  * @add_on_replace: add the control if not already added
 388  *
 389  * Replaces the given control.  If the given control does not exist
 390  * and the add_on_replace flag is set, the control is added.  If the
 391  * control exists, it is destroyed first.
 392  *
 393  * Returns zero if successful, or a negative error code on failure.
 394  *
 395  * It frees automatically the control which cannot be added or replaced.
 396  */
 397 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 398                     bool add_on_replace)
 399 {
 400         struct snd_ctl_elem_id id;
 401         unsigned int count;
 402         unsigned int idx;
 403         struct snd_kcontrol *old;
 404         int ret;
 405
 406         if (!kcontrol)
 407                 return -EINVAL;
 408         if (snd_BUG_ON(!card || !kcontrol->info)) {
 409                 ret = -EINVAL;
 410                 goto error;
 411         }
 412         id = kcontrol->id;
 413         down_write(&card->controls_rwsem);
 414         old = snd_ctl_find_id(card, &id);
 415         if (!old) {
 416                 if (add_on_replace)
 417                         goto add;
 418                 up_write(&card->controls_rwsem);
 419                 ret = -EINVAL;
 420                 goto error;
 421         }
 422         ret = snd_ctl_remove(card, old);
 423         if (ret < 0) {
 424                 up_write(&card->controls_rwsem);
 425                 goto error;
 426         }
 427 add:
 428         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 429                 up_write(&card->controls_rwsem);
 430                 ret = -ENOMEM;
 431                 goto error;
 432         }
 433         list_add_tail(&kcontrol->list, &card->controls);
 434         card->controls_count += kcontrol->count;
 435         kcontrol->id.numid = card->last_numid + 1;
 436         card->last_numid += kcontrol->count;
 437         count = kcontrol->count;
 438         up_write(&card->controls_rwsem);
 439         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 440                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 441         return 0;
 442
 443 error:
 444         snd_ctl_free_one(kcontrol);
 445         return ret;
 446 }
 447 EXPORT_SYMBOL(snd_ctl_replace);
 448
 449 /**
 450  * snd_ctl_remove - remove the control from the card and release it
 451  * @card: the card instance
 452  * @kcontrol: the control instance to remove
 453  *
 454  * Removes the control from the card and then releases the instance.
 455  * You don't need to call snd_ctl_free_one(). You must be in
 456  * the write lock - down_write(&card->controls_rwsem).
 457  *
 458  * Returns 0 if successful, or a negative error code on failure.
 459  */
 460 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 461 {
 462         struct snd_ctl_elem_id id;
 463         unsigned int idx;
 464
 465         if (snd_BUG_ON(!card || !kcontrol))
 466                 return -EINVAL;
 467         list_del(&kcontrol->list);
 468         card->controls_count -= kcontrol->count;
 469         id = kcontrol->id;
 470         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 471                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 472         snd_ctl_free_one(kcontrol);
 473         return 0;
 474 }
 475
 476 EXPORT_SYMBOL(snd_ctl_remove);
 477
 478 /**
 479  * snd_ctl_remove_id - remove the control of the given id and release it
 480  * @card: the card instance
 481  * @id: the control id to remove
 482  *
 483  * Finds the control instance with the given id, removes it from the
 484  * card list and releases it.
 485  *
 486  * Returns 0 if successful, or a negative error code on failure.
 487  */
 488 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 489 {
 490         struct snd_kcontrol *kctl;
 491         int ret;
 492
 493         down_write(&card->controls_rwsem);
 494         kctl = snd_ctl_find_id(card, id);
 495         if (kctl == NULL) {
 496                 up_write(&card->controls_rwsem);
 497                 return -ENOENT;
 498         }
 499         ret = snd_ctl_remove(card, kctl);
 500         up_write(&card->controls_rwsem);
 501         return ret;
 502 }
 503
 504 EXPORT_SYMBOL(snd_ctl_remove_id);
 505
 506 /**
 507  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 508  * @file: active control handle
 509  * @id: the control id to remove
 510  *
 511  * Finds the control instance with the given id, removes it from the
 512  * card list and releases it.
 513  *
 514  * Returns 0 if successful, or a negative error code on failure.
 515  */
 516 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 517                                    struct snd_ctl_elem_id *id)
 518 {
 519         struct snd_card *card = file->card;
 520         struct snd_kcontrol *kctl;
 521         int idx, ret;
 522
 523         down_write(&card->controls_rwsem);
 524         kctl = snd_ctl_find_id(card, id);
 525         if (kctl == NULL) {
 526                 ret = -ENOENT;
 527                 goto error;
 528         }
 529         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 530                 ret = -EINVAL;
 531                 goto error;
 532         }
 533         for (idx = 0; idx < kctl->count; idx++)
 534                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 535                         ret = -EBUSY;
 536                         goto error;
 537                 }
 538         ret = snd_ctl_remove(card, kctl);
 539         if (ret < 0)
 540                 goto error;
 541         card->user_ctl_count--;
 542 error:
 543         up_write(&card->controls_rwsem);
 544         return ret;
 545 }
 546
 547 /**
 548  * snd_ctl_activate_id - activate/inactivate the control of the given id
 549  * @card: the card instance
 550  * @id: the control id to activate/inactivate
 551  * @active: non-zero to activate
 552  *
 553  * Finds the control instance with the given id, and activate or
 554  * inactivate the control together with notification, if changed.
 555  *
 556  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 557  */
 558 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 559                         int active)
 560 {
 561         struct snd_kcontrol *kctl;
 562         struct snd_kcontrol_volatile *vd;
 563         unsigned int index_offset;
 564         int ret;
 565
 566         down_write(&card->controls_rwsem);
 567         kctl = snd_ctl_find_id(card, id);
 568         if (kctl == NULL) {
 569                 ret = -ENOENT;
 570                 goto unlock;
 571         }
 572         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 573         vd = &kctl->vd[index_offset];
 574         ret = 0;
 575         if (active) {
 576                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 577                         goto unlock;
 578                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 579         } else {
 580                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 581                         goto unlock;
 582                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 583         }
 584         ret = 1;
 585  unlock:
 586         up_write(&card->controls_rwsem);
 587         if (ret > 0)
 588                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 589         return ret;
 590 }
 591 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 592
 593 /**
 594  * snd_ctl_rename_id - replace the id of a control on the card
 595  * @card: the card instance
 596  * @src_id: the old id
 597  * @dst_id: the new id
 598  *
 599  * Finds the control with the old id from the card, and replaces the
 600  * id with the new one.
 601  *
 602  * Returns zero if successful, or a negative error code on failure.
 603  */
 604 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 605                       struct snd_ctl_elem_id *dst_id)
 606 {
 607         struct snd_kcontrol *kctl;
 608
 609         down_write(&card->controls_rwsem);
 610         kctl = snd_ctl_find_id(card, src_id);
 611         if (kctl == NULL) {
 612                 up_write(&card->controls_rwsem);
 613                 return -ENOENT;
 614         }
 615         kctl->id = *dst_id;
 616         kctl->id.numid = card->last_numid + 1;
 617         card->last_numid += kctl->count;
 618         up_write(&card->controls_rwsem);
 619         return 0;
 620 }
 621
 622 EXPORT_SYMBOL(snd_ctl_rename_id);
 623
 624 /**
 625  * snd_ctl_find_numid - find the control instance with the given number-id
 626  * @card: the card instance
 627  * @numid: the number-id to search
 628  *
 629  * Finds the control instance with the given number-id from the card.
 630  *
 631  * Returns the pointer of the instance if found, or NULL if not.
 632  *
 633  * The caller must down card->controls_rwsem before calling this function
 634  * (if the race condition can happen).
 635  */
 636 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 637 {
 638         struct snd_kcontrol *kctl;
 639
 640         if (snd_BUG_ON(!card || !numid))
 641                 return NULL;
 642         list_for_each_entry(kctl, &card->controls, list) {
 643                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 644                         return kctl;
 645         }
 646         return NULL;
 647 }
 648
 649 EXPORT_SYMBOL(snd_ctl_find_numid);
 650
 651 /**
 652  * snd_ctl_find_id - find the control instance with the given id
 653  * @card: the card instance
 654  * @id: the id to search
 655  *
 656  * Finds the control instance with the given id from the card.
 657  *
 658  * Returns the pointer of the instance if found, or NULL if not.
 659  *
 660  * The caller must down card->controls_rwsem before calling this function
 661  * (if the race condition can happen).
 662  */
 663 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 664                                      struct snd_ctl_elem_id *id)
 665 {
 666         struct snd_kcontrol *kctl;
 667
 668         if (snd_BUG_ON(!card || !id))
 669                 return NULL;
 670         if (id->numid != 0)
 671                 return snd_ctl_find_numid(card, id->numid);
 672         list_for_each_entry(kctl, &card->controls, list) {
 673                 if (kctl->id.iface != id->iface)
 674                         continue;
 675                 if (kctl->id.device != id->device)
 676                         continue;
 677                 if (kctl->id.subdevice != id->subdevice)
 678                         continue;
 679                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 680                         continue;
 681                 if (kctl->id.index > id->index)
 682                         continue;
 683                 if (kctl->id.index + kctl->count <= id->index)
 684                         continue;
 685                 return kctl;
 686         }
 687         return NULL;
 688 }
 689
 690 EXPORT_SYMBOL(snd_ctl_find_id);
 691
 692 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 693                              unsigned int cmd, void __user *arg)
 694 {
 695         struct snd_ctl_card_info *info;
 696
 697         info = kzalloc(sizeof(*info), GFP_KERNEL);
 698         if (! info)
 699                 return -ENOMEM;
 700         down_read(&snd_ioctl_rwsem);
 701         info->card = card->number;
 702         strlcpy(info->id, card->id, sizeof(info->id));
 703         strlcpy(info->driver, card->driver, sizeof(info->driver));
 704         strlcpy(info->name, card->shortname, sizeof(info->name));
 705         strlcpy(info->longname, card->longname, sizeof(info->longname));
 706         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 707         strlcpy(info->components, card->components, sizeof(info->components));
 708         up_read(&snd_ioctl_rwsem);
 709         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 710                 kfree(info);
 711                 return -EFAULT;
 712         }
 713         kfree(info);
 714         return 0;
 715 }
 716
 717 static int snd_ctl_elem_list(struct snd_card *card,
 718                              struct snd_ctl_elem_list __user *_list)
 719 {
 720         struct list_head *plist;
 721         struct snd_ctl_elem_list list;
 722         struct snd_kcontrol *kctl;
 723         struct snd_ctl_elem_id *dst, *id;
 724         unsigned int offset, space, jidx;
 725
 726         if (copy_from_user(&list, _list, sizeof(list)))
 727                 return -EFAULT;
 728         offset = list.offset;
 729         space = list.space;
 730         /* try limit maximum space */
 731         if (space > 16384)
 732                 return -ENOMEM;
 733         if (space > 0) {
 734                 /* allocate temporary buffer for atomic operation */
 735                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 736                 if (dst == NULL)
 737                         return -ENOMEM;
 738                 down_read(&card->controls_rwsem);
 739                 list.count = card->controls_count;
 740                 plist = card->controls.next;
 741                 while (plist != &card->controls) {
 742                         if (offset == 0)
 743                                 break;
 744                         kctl = snd_kcontrol(plist);
 745                         if (offset < kctl->count)
 746                                 break;
 747                         offset -= kctl->count;
 748                         plist = plist->next;
 749                 }
 750                 list.used = 0;
 751                 id = dst;
 752                 while (space > 0 && plist != &card->controls) {
 753                         kctl = snd_kcontrol(plist);
 754                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 755                                 snd_ctl_build_ioff(id, kctl, jidx);
 756                                 id++;
 757                                 space--;
 758                                 list.used++;
 759                         }
 760                         plist = plist->next;
 761                         offset = 0;
 762                 }
 763                 up_read(&card->controls_rwsem);
 764                 if (list.used > 0 &&
 765                     copy_to_user(list.pids, dst,
 766                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 767                         vfree(dst);
 768                         return -EFAULT;
 769                 }
 770                 vfree(dst);
 771         } else {
 772                 down_read(&card->controls_rwsem);
 773                 list.count = card->controls_count;
 774                 up_read(&card->controls_rwsem);
 775         }
 776         if (copy_to_user(_list, &list, sizeof(list)))
 777                 return -EFAULT;
 778         return 0;
 779 }
 780
 781 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 782                              struct snd_ctl_elem_info *info)
 783 {
 784         struct snd_card *card = ctl->card;
 785         struct snd_kcontrol *kctl;
 786         struct snd_kcontrol_volatile *vd;
 787         unsigned int index_offset;
 788         int result;
 789
 790         down_read(&card->controls_rwsem);
 791         kctl = snd_ctl_find_id(card, &info->id);
 792         if (kctl == NULL) {
 793                 up_read(&card->controls_rwsem);
 794                 return -ENOENT;
 795         }
 796 #ifdef CONFIG_SND_DEBUG
 797         info->access = 0;
 798 #endif
 799         result = kctl->info(kctl, info);
 800         if (result >= 0) {
 801                 snd_BUG_ON(info->access);
 802                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 803                 vd = &kctl->vd[index_offset];
 804                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 805                 info->access = vd->access;
 806                 if (vd->owner) {
 807                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 808                         if (vd->owner == ctl)
 809                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 810                         info->owner = pid_vnr(vd->owner->pid);
 811                 } else {
 812                         info->owner = -1;
 813                 }
 814         }
 815         up_read(&card->controls_rwsem);
 816         return result;
 817 }
 818
 819 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 820                                   struct snd_ctl_elem_info __user *_info)
 821 {
 822         struct snd_ctl_elem_info info;
 823         int result;
 824
 825         if (copy_from_user(&info, _info, sizeof(info)))
 826                 return -EFAULT;
 827         snd_power_lock(ctl->card);
 828         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 829         if (result >= 0)
 830                 result = snd_ctl_elem_info(ctl, &info);
 831         snd_power_unlock(ctl->card);
 832         if (result >= 0)
 833                 if (copy_to_user(_info, &info, sizeof(info)))
 834                         return -EFAULT;
 835         return result;
 836 }
 837
 838 static int snd_ctl_elem_read(struct snd_card *card,
 839                              struct snd_ctl_elem_value *control)
 840 {
 841         struct snd_kcontrol *kctl;
 842         struct snd_kcontrol_volatile *vd;
 843         unsigned int index_offset;
 844         int result;
 845
 846         down_read(&card->controls_rwsem);
 847         kctl = snd_ctl_find_id(card, &control->id);
 848         if (kctl == NULL) {
 849                 result = -ENOENT;
 850         } else {
 851                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 852                 vd = &kctl->vd[index_offset];
 853                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 854                     kctl->get != NULL) {
 855                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 856                         result = kctl->get(kctl, control);
 857                 } else
 858                         result = -EPERM;
 859         }
 860         up_read(&card->controls_rwsem);
 861         return result;
 862 }
 863
 864 static int snd_ctl_elem_read_user(struct snd_card *card,
 865                                   struct snd_ctl_elem_value __user *_control)
 866 {
 867         struct snd_ctl_elem_value *control;
 868         int result;
 869
 870         control = memdup_user(_control, sizeof(*control));
 871         if (IS_ERR(control))
 872                 return PTR_ERR(control);
 873
 874         snd_power_lock(card);
 875         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 876         if (result >= 0)
 877                 result = snd_ctl_elem_read(card, control);
 878         snd_power_unlock(card);
 879         if (result >= 0)
 880                 if (copy_to_user(_control, control, sizeof(*control)))
 881                         result = -EFAULT;
 882         kfree(control);
 883         return result;
 884 }
 885
 886 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 887                               struct snd_ctl_elem_value *control)
 888 {
 889         struct snd_kcontrol *kctl;
 890         struct snd_kcontrol_volatile *vd;
 891         unsigned int index_offset;
 892         int result;
 893
 894         down_read(&card->controls_rwsem);
 895         kctl = snd_ctl_find_id(card, &control->id);
 896         if (kctl == NULL) {
 897                 result = -ENOENT;
 898         } else {
 899                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 900                 vd = &kctl->vd[index_offset];
 901                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 902                     kctl->put == NULL ||
 903                     (file && vd->owner && vd->owner != file)) {
 904                         result = -EPERM;
 905                 } else {
 906                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 907                         result = kctl->put(kctl, control);
 908                 }
 909                 if (result > 0) {
 910                         struct snd_ctl_elem_id id = control->id;
 911                         up_read(&card->controls_rwsem);
 912                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
 913                         return 0;
 914                 }
 915         }
 916         up_read(&card->controls_rwsem);
 917         return result;
 918 }
 919
 920 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 921                                    struct snd_ctl_elem_value __user *_control)
 922 {
 923         struct snd_ctl_elem_value *control;
 924         struct snd_card *card;
 925         int result;
 926
 927         control = memdup_user(_control, sizeof(*control));
 928         if (IS_ERR(control))
 929                 return PTR_ERR(control);
 930
 931         card = file->card;
 932         snd_power_lock(card);
 933         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 934         if (result >= 0)
 935                 result = snd_ctl_elem_write(card, file, control);
 936         snd_power_unlock(card);
 937         if (result >= 0)
 938                 if (copy_to_user(_control, control, sizeof(*control)))
 939                         result = -EFAULT;
 940         kfree(control);
 941         return result;
 942 }
 943
 944 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 945                              struct snd_ctl_elem_id __user *_id)
 946 {
 947         struct snd_card *card = file->card;
 948         struct snd_ctl_elem_id id;
 949         struct snd_kcontrol *kctl;
 950         struct snd_kcontrol_volatile *vd;
 951         int result;
 952
 953         if (copy_from_user(&id, _id, sizeof(id)))
 954                 return -EFAULT;
 955         down_write(&card->controls_rwsem);
 956         kctl = snd_ctl_find_id(card, &id);
 957         if (kctl == NULL) {
 958                 result = -ENOENT;
 959         } else {
 960                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 961                 if (vd->owner != NULL)
 962                         result = -EBUSY;
 963                 else {
 964                         vd->owner = file;
 965                         result = 0;
 966                 }
 967         }
 968         up_write(&card->controls_rwsem);
 969         return result;
 970 }
 971
 972 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 973                                struct snd_ctl_elem_id __user *_id)
 974 {
 975         struct snd_card *card = file->card;
 976         struct snd_ctl_elem_id id;
 977         struct snd_kcontrol *kctl;
 978         struct snd_kcontrol_volatile *vd;
 979         int result;
 980
 981         if (copy_from_user(&id, _id, sizeof(id)))
 982                 return -EFAULT;
 983         down_write(&card->controls_rwsem);
 984         kctl = snd_ctl_find_id(card, &id);
 985         if (kctl == NULL) {
 986                 result = -ENOENT;
 987         } else {
 988                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 989                 if (vd->owner == NULL)
 990                         result = -EINVAL;
 991                 else if (vd->owner != file)
 992                         result = -EPERM;
 993                 else {
 994                         vd->owner = NULL;
 995                         result = 0;
 996                 }
 997         }
 998         up_write(&card->controls_rwsem);
 999         return result;
1000 }
1001
1002 struct user_element {
1003         struct snd_ctl_elem_info info;
1004         struct snd_card *card;
1005         void *elem_data;                /* element data */
1006         unsigned long elem_data_size;   /* size of element data in bytes */
1007         void *tlv_data;                 /* TLV data */
1008         unsigned long tlv_data_size;    /* TLV data size */
1009         void *priv_data;                /* private data (like strings for enumerated type) */
1010 };
1011
1012 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1013                                   struct snd_ctl_elem_info *uinfo)
1014 {
1015         struct user_element *ue = kcontrol->private_data;
1016
1017         *uinfo = ue->info;
1018         return 0;
1019 }
1020
1021 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1022                                        struct snd_ctl_elem_info *uinfo)
1023 {
1024         struct user_element *ue = kcontrol->private_data;
1025         const char *names;
1026         unsigned int item;
1027
1028         item = uinfo->value.enumerated.item;
1029
1030         *uinfo = ue->info;
1031
1032         item = min(item, uinfo->value.enumerated.items - 1);
1033         uinfo->value.enumerated.item = item;
1034
1035         names = ue->priv_data;
1036         for (; item > 0; --item)
1037                 names += strlen(names) + 1;
1038         strcpy(uinfo->value.enumerated.name, names);
1039
1040         return 0;
1041 }
1042
1043 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1044                                  struct snd_ctl_elem_value *ucontrol)
1045 {
1046         struct user_element *ue = kcontrol->private_data;
1047
1048         mutex_lock(&ue->card->user_ctl_lock);
1049         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1050         mutex_unlock(&ue->card->user_ctl_lock);
1051         return 0;
1052 }
1053
1054 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1055                                  struct snd_ctl_elem_value *ucontrol)
1056 {
1057         int change;
1058         struct user_element *ue = kcontrol->private_data;
1059
1060         mutex_lock(&ue->card->user_ctl_lock);
1061         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1062         if (change)
1063                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1064         mutex_unlock(&ue->card->user_ctl_lock);
1065         return change;
1066 }
1067
1068 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1069                                  int op_flag,
1070                                  unsigned int size,
1071                                  unsigned int __user *tlv)
1072 {
1073         struct user_element *ue = kcontrol->private_data;
1074         int change = 0;
1075         void *new_data;
1076
1077         if (op_flag > 0) {
1078                 if (size > 1024 * 128)  /* sane value */
1079                         return -EINVAL;
1080
1081                 new_data = memdup_user(tlv, size);
1082                 if (IS_ERR(new_data))
1083                         return PTR_ERR(new_data);
1084                 mutex_lock(&ue->card->user_ctl_lock);
1085                 change = ue->tlv_data_size != size;
1086                 if (!change)
1087                         change = memcmp(ue->tlv_data, new_data, size) != 0;
1088                 kfree(ue->tlv_data);
1089                 ue->tlv_data = new_data;
1090                 ue->tlv_data_size = size;
1091                 mutex_unlock(&ue->card->user_ctl_lock);
1092         } else {
1093                 int ret = 0;
1094
1095                 mutex_lock(&ue->card->user_ctl_lock);
1096                 if (!ue->tlv_data_size || !ue->tlv_data) {
1097                         ret = -ENXIO;
1098                         goto err_unlock;
1099                 }
1100                 if (size < ue->tlv_data_size) {
1101                         ret = -ENOSPC;
1102                         goto err_unlock;
1103                 }
1104                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1105                         ret = -EFAULT;
1106 err_unlock:
1107                 mutex_unlock(&ue->card->user_ctl_lock);
1108                 if (ret)
1109                         return ret;
1110         }
1111         return change;
1112 }
1113
1114 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1115 {
1116         char *names, *p;
1117         size_t buf_len, name_len;
1118         unsigned int i;
1119         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1120
1121         if (ue->info.value.enumerated.names_length > 64 * 1024)
1122                 return -EINVAL;
1123
1124         names = memdup_user((const void __user *)user_ptrval,
1125                 ue->info.value.enumerated.names_length);
1126         if (IS_ERR(names))
1127                 return PTR_ERR(names);
1128
1129         /* check that there are enough valid names */
1130         buf_len = ue->info.value.enumerated.names_length;
1131         p = names;
1132         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1133                 name_len = strnlen(p, buf_len);
1134                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1135                         kfree(names);
1136                         return -EINVAL;
1137                 }
1138                 p += name_len + 1;
1139                 buf_len -= name_len + 1;
1140         }
1141
1142         ue->priv_data = names;
1143         ue->info.value.enumerated.names_ptr = 0;
1144
1145         return 0;
1146 }
1147
1148 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1149 {
1150         struct user_element *ue = kcontrol->private_data;
1151
1152         kfree(ue->tlv_data);
1153         kfree(ue->priv_data);
1154         kfree(ue);
1155 }
1156
1157 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1158                             struct snd_ctl_elem_info *info, int replace)
1159 {
1160         struct snd_card *card = file->card;
1161         struct snd_kcontrol kctl, *_kctl;
1162         unsigned int access;
1163         long private_size;
1164         struct user_element *ue;
1165         int idx, err;
1166
1167         if (info->count < 1)
1168                 return -EINVAL;
1169         if (!*info->id.name)
1170                 return -EINVAL;
1171         if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1172                 return -EINVAL;
1173         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1174                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1175                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1176                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1177         info->id.numid = 0;
1178         memset(&kctl, 0, sizeof(kctl));
1179
1180         if (replace) {
1181                 err = snd_ctl_remove_user_ctl(file, &info->id);
1182                 if (err)
1183                         return err;
1184         }
1185
1186         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1187                 return -ENOMEM;
1188
1189         memcpy(&kctl.id, &info->id, sizeof(info->id));
1190         kctl.count = info->owner ? info->owner : 1;
1191         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1192         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1193                 kctl.info = snd_ctl_elem_user_enum_info;
1194         else
1195                 kctl.info = snd_ctl_elem_user_info;
1196         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1197                 kctl.get = snd_ctl_elem_user_get;
1198         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1199                 kctl.put = snd_ctl_elem_user_put;
1200         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1201                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1202                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1203         }
1204         switch (info->type) {
1205         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1206         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1207                 private_size = sizeof(long);
1208                 if (info->count > 128)
1209                         return -EINVAL;
1210                 break;
1211         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1212                 private_size = sizeof(long long);
1213                 if (info->count > 64)
1214                         return -EINVAL;
1215                 break;
1216         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1217                 private_size = sizeof(unsigned int);
1218                 if (info->count > 128 || info->value.enumerated.items == 0)
1219                         return -EINVAL;
1220                 break;
1221         case SNDRV_CTL_ELEM_TYPE_BYTES:
1222                 private_size = sizeof(unsigned char);
1223                 if (info->count > 512)
1224                         return -EINVAL;
1225                 break;
1226         case SNDRV_CTL_ELEM_TYPE_IEC958:
1227                 private_size = sizeof(struct snd_aes_iec958);
1228                 if (info->count != 1)
1229                         return -EINVAL;
1230                 break;
1231         default:
1232                 return -EINVAL;
1233         }
1234         private_size *= info->count;
1235         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1236         if (ue == NULL)
1237                 return -ENOMEM;
1238         ue->card = card;
1239         ue->info = *info;
1240         ue->info.access = 0;
1241         ue->elem_data = (char *)ue + sizeof(*ue);
1242         ue->elem_data_size = private_size;
1243         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1244                 err = snd_ctl_elem_init_enum_names(ue);
1245                 if (err < 0) {
1246                         kfree(ue);
1247                         return err;
1248                 }
1249         }
1250         kctl.private_free = snd_ctl_elem_user_free;
1251         _kctl = snd_ctl_new(&kctl, access);
1252         if (_kctl == NULL) {
1253                 kfree(ue->priv_data);
1254                 kfree(ue);
1255                 return -ENOMEM;
1256         }
1257         _kctl->private_data = ue;
1258         for (idx = 0; idx < _kctl->count; idx++)
1259                 _kctl->vd[idx].owner = file;
1260         err = snd_ctl_add(card, _kctl);
1261         if (err < 0)
1262                 return err;
1263
1264         down_write(&card->controls_rwsem);
1265         card->user_ctl_count++;
1266         up_write(&card->controls_rwsem);
1267
1268         return 0;
1269 }
1270
1271 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1272                                  struct snd_ctl_elem_info __user *_info, int replace)
1273 {
1274         struct snd_ctl_elem_info info;
1275         if (copy_from_user(&info, _info, sizeof(info)))
1276                 return -EFAULT;
1277         return snd_ctl_elem_add(file, &info, replace);
1278 }
1279
1280 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1281                                struct snd_ctl_elem_id __user *_id)
1282 {
1283         struct snd_ctl_elem_id id;
1284
1285         if (copy_from_user(&id, _id, sizeof(id)))
1286                 return -EFAULT;
1287         return snd_ctl_remove_user_ctl(file, &id);
1288 }
1289
1290 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1291 {
1292         int subscribe;
1293         if (get_user(subscribe, ptr))
1294                 return -EFAULT;
1295         if (subscribe < 0) {
1296                 subscribe = file->subscribed;
1297                 if (put_user(subscribe, ptr))
1298                         return -EFAULT;
1299                 return 0;
1300         }
1301         if (subscribe) {
1302                 file->subscribed = 1;
1303                 return 0;
1304         } else if (file->subscribed) {
1305                 snd_ctl_empty_read_queue(file);
1306                 file->subscribed = 0;
1307         }
1308         return 0;
1309 }
1310
1311 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1312                              struct snd_ctl_tlv __user *_tlv,
1313                              int op_flag)
1314 {
1315         struct snd_card *card = file->card;
1316         struct snd_ctl_tlv tlv;
1317         struct snd_kcontrol *kctl;
1318         struct snd_kcontrol_volatile *vd;
1319         unsigned int len;
1320         int err = 0;
1321
1322         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1323                 return -EFAULT;
1324         if (tlv.length < sizeof(unsigned int) * 2)
1325                 return -EINVAL;
1326         if (!tlv.numid)
1327                 return -EINVAL;
1328         down_read(&card->controls_rwsem);
1329         kctl = snd_ctl_find_numid(card, tlv.numid);
1330         if (kctl == NULL) {
1331                 err = -ENOENT;
1332                 goto __kctl_end;
1333         }
1334         if (kctl->tlv.p == NULL) {
1335                 err = -ENXIO;
1336                 goto __kctl_end;
1337         }
1338         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1339         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1340             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1341             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1342                 err = -ENXIO;
1343                 goto __kctl_end;
1344         }
1345         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1346                 if (vd->owner != NULL && vd->owner != file) {
1347                         err = -EPERM;
1348                         goto __kctl_end;
1349                 }
1350                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1351                 if (err > 0) {
1352                         struct snd_ctl_elem_id id = kctl->id;
1353                         up_read(&card->controls_rwsem);
1354                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1355                         return 0;
1356                 }
1357         } else {
1358                 if (op_flag) {
1359                         err = -ENXIO;
1360                         goto __kctl_end;
1361                 }
1362                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1363                 if (tlv.length < len) {
1364                         err = -ENOMEM;
1365                         goto __kctl_end;
1366                 }
1367                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1368                         err = -EFAULT;
1369         }
1370       __kctl_end:
1371         up_read(&card->controls_rwsem);
1372         return err;
1373 }
1374
1375 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1376 {
1377         struct snd_ctl_file *ctl;
1378         struct snd_card *card;
1379         struct snd_kctl_ioctl *p;
1380         void __user *argp = (void __user *)arg;
1381         int __user *ip = argp;
1382         int err;
1383
1384         ctl = file->private_data;
1385         card = ctl->card;
1386         if (snd_BUG_ON(!card))
1387                 return -ENXIO;
1388         switch (cmd) {
1389         case SNDRV_CTL_IOCTL_PVERSION:
1390                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1391         case SNDRV_CTL_IOCTL_CARD_INFO:
1392                 return snd_ctl_card_info(card, ctl, cmd, argp);
1393         case SNDRV_CTL_IOCTL_ELEM_LIST:
1394                 return snd_ctl_elem_list(card, argp);
1395         case SNDRV_CTL_IOCTL_ELEM_INFO:
1396                 return snd_ctl_elem_info_user(ctl, argp);
1397         case SNDRV_CTL_IOCTL_ELEM_READ:
1398                 return snd_ctl_elem_read_user(card, argp);
1399         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1400                 return snd_ctl_elem_write_user(ctl, argp);
1401         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1402                 return snd_ctl_elem_lock(ctl, argp);
1403         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1404                 return snd_ctl_elem_unlock(ctl, argp);
1405         case SNDRV_CTL_IOCTL_ELEM_ADD:
1406                 return snd_ctl_elem_add_user(ctl, argp, 0);
1407         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1408                 return snd_ctl_elem_add_user(ctl, argp, 1);
1409         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1410                 return snd_ctl_elem_remove(ctl, argp);
1411         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1412                 return snd_ctl_subscribe_events(ctl, ip);
1413         case SNDRV_CTL_IOCTL_TLV_READ:
1414                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1415         case SNDRV_CTL_IOCTL_TLV_WRITE:
1416                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1417         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1418                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1419         case SNDRV_CTL_IOCTL_POWER:
1420                 return -ENOPROTOOPT;
1421         case SNDRV_CTL_IOCTL_POWER_STATE:
1422 #ifdef CONFIG_PM
1423                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1424 #else
1425                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1426 #endif
1427         }
1428         down_read(&snd_ioctl_rwsem);
1429         list_for_each_entry(p, &snd_control_ioctls, list) {
1430                 err = p->fioctl(card, ctl, cmd, arg);
1431                 if (err != -ENOIOCTLCMD) {
1432                         up_read(&snd_ioctl_rwsem);
1433                         return err;
1434                 }
1435         }
1436         up_read(&snd_ioctl_rwsem);
1437         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1438         return -ENOTTY;
1439 }
1440
1441 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1442                             size_t count, loff_t * offset)
1443 {
1444         struct snd_ctl_file *ctl;
1445         int err = 0;
1446         ssize_t result = 0;
1447
1448         ctl = file->private_data;
1449         if (snd_BUG_ON(!ctl || !ctl->card))
1450                 return -ENXIO;
1451         if (!ctl->subscribed)
1452                 return -EBADFD;
1453         if (count < sizeof(struct snd_ctl_event))
1454                 return -EINVAL;
1455         spin_lock_irq(&ctl->read_lock);
1456         while (count >= sizeof(struct snd_ctl_event)) {
1457                 struct snd_ctl_event ev;
1458                 struct snd_kctl_event *kev;
1459                 while (list_empty(&ctl->events)) {
1460                         wait_queue_t wait;
1461                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1462                                 err = -EAGAIN;
1463                                 goto __end_lock;
1464                         }
1465                         init_waitqueue_entry(&wait, current);
1466                         add_wait_queue(&ctl->change_sleep, &wait);
1467                         set_current_state(TASK_INTERRUPTIBLE);
1468                         spin_unlock_irq(&ctl->read_lock);
1469                         schedule();
1470                         remove_wait_queue(&ctl->change_sleep, &wait);
1471                         if (ctl->card->shutdown)
1472                                 return -ENODEV;
1473                         if (signal_pending(current))
1474                                 return -ERESTARTSYS;
1475                         spin_lock_irq(&ctl->read_lock);
1476                 }
1477                 kev = snd_kctl_event(ctl->events.next);
1478                 ev.type = SNDRV_CTL_EVENT_ELEM;
1479                 ev.data.elem.mask = kev->mask;
1480                 ev.data.elem.id = kev->id;
1481                 list_del(&kev->list);
1482                 spin_unlock_irq(&ctl->read_lock);
1483                 kfree(kev);
1484                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1485                         err = -EFAULT;
1486                         goto __end;
1487                 }
1488                 spin_lock_irq(&ctl->read_lock);
1489                 buffer += sizeof(struct snd_ctl_event);
1490                 count -= sizeof(struct snd_ctl_event);
1491                 result += sizeof(struct snd_ctl_event);
1492         }
1493       __end_lock:
1494         spin_unlock_irq(&ctl->read_lock);
1495       __end:
1496         return result > 0 ? result : err;
1497 }
1498
1499 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1500 {
1501         unsigned int mask;
1502         struct snd_ctl_file *ctl;
1503
1504         ctl = file->private_data;
1505         if (!ctl->subscribed)
1506                 return 0;
1507         poll_wait(file, &ctl->change_sleep, wait);
1508
1509         mask = 0;
1510         if (!list_empty(&ctl->events))
1511                 mask |= POLLIN | POLLRDNORM;
1512
1513         return mask;
1514 }
1515
1516 /*
1517  * register the device-specific control-ioctls.
1518  * called from each device manager like pcm.c, hwdep.c, etc.
1519  */
1520 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1521 {
1522         struct snd_kctl_ioctl *pn;
1523
1524         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1525         if (pn == NULL)
1526                 return -ENOMEM;
1527         pn->fioctl = fcn;
1528         down_write(&snd_ioctl_rwsem);
1529         list_add_tail(&pn->list, lists);
1530         up_write(&snd_ioctl_rwsem);
1531         return 0;
1532 }
1533
1534 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1535 {
1536         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1537 }
1538
1539 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1540
1541 #ifdef CONFIG_COMPAT
1542 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1543 {
1544         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1545 }
1546
1547 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1548 #endif
1549
1550 /*
1551  * de-register the device-specific control-ioctls.
1552  */
1553 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1554                                      struct list_head *lists)
1555 {
1556         struct snd_kctl_ioctl *p;
1557
1558         if (snd_BUG_ON(!fcn))
1559                 return -EINVAL;
1560         down_write(&snd_ioctl_rwsem);
1561         list_for_each_entry(p, lists, list) {
1562                 if (p->fioctl == fcn) {
1563                         list_del(&p->list);
1564                         up_write(&snd_ioctl_rwsem);
1565                         kfree(p);
1566                         return 0;
1567                 }
1568         }
1569         up_write(&snd_ioctl_rwsem);
1570         snd_BUG();
1571         return -EINVAL;
1572 }
1573
1574 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1575 {
1576         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1577 }
1578
1579 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1580
1581 #ifdef CONFIG_COMPAT
1582 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1583 {
1584         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1585 }
1586
1587 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1588 #endif
1589
1590 static int snd_ctl_fasync(int fd, struct file * file, int on)
1591 {
1592         struct snd_ctl_file *ctl;
1593
1594         ctl = file->private_data;
1595         return fasync_helper(fd, file, on, &ctl->fasync);
1596 }
1597
1598 /*
1599  * ioctl32 compat
1600  */
1601 #ifdef CONFIG_COMPAT
1602 #include "control_compat.c"
1603 #else
1604 #define snd_ctl_ioctl_compat    NULL
1605 #endif
1606
1607 /*
1608  *  INIT PART
1609  */
1610
1611 static const struct file_operations snd_ctl_f_ops =
1612 {
1613         .owner =        THIS_MODULE,
1614         .read =         snd_ctl_read,
1615         .open =         snd_ctl_open,
1616         .release =      snd_ctl_release,
1617         .llseek =       no_llseek,
1618         .poll =         snd_ctl_poll,
1619         .unlocked_ioctl =       snd_ctl_ioctl,
1620         .compat_ioctl = snd_ctl_ioctl_compat,
1621         .fasync =       snd_ctl_fasync,
1622 };
1623
1624 /*
1625  * registration of the control device
1626  */
1627 static int snd_ctl_dev_register(struct snd_device *device)
1628 {
1629         struct snd_card *card = device->device_data;
1630         int err, cardnum;
1631         char name[16];
1632
1633         if (snd_BUG_ON(!card))
1634                 return -ENXIO;
1635         cardnum = card->number;
1636         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1637                 return -ENXIO;
1638         sprintf(name, "controlC%i", cardnum);
1639         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1640                                        &snd_ctl_f_ops, card, name)) < 0)
1641                 return err;
1642         return 0;
1643 }
1644
1645 /*
1646  * disconnection of the control device
1647  */
1648 static int snd_ctl_dev_disconnect(struct snd_device *device)
1649 {
1650         struct snd_card *card = device->device_data;
1651         struct snd_ctl_file *ctl;
1652         int err, cardnum;
1653
1654         if (snd_BUG_ON(!card))
1655                 return -ENXIO;
1656         cardnum = card->number;
1657         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1658                 return -ENXIO;
1659
1660         read_lock(&card->ctl_files_rwlock);
1661         list_for_each_entry(ctl, &card->ctl_files, list) {
1662                 wake_up(&ctl->change_sleep);
1663                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1664         }
1665         read_unlock(&card->ctl_files_rwlock);
1666
1667         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1668                                          card, -1)) < 0)
1669                 return err;
1670         return 0;
1671 }
1672
1673 /*
1674  * free all controls
1675  */
1676 static int snd_ctl_dev_free(struct snd_device *device)
1677 {
1678         struct snd_card *card = device->device_data;
1679         struct snd_kcontrol *control;
1680
1681         down_write(&card->controls_rwsem);
1682         while (!list_empty(&card->controls)) {
1683                 control = snd_kcontrol(card->controls.next);
1684                 snd_ctl_remove(card, control);
1685         }
1686         up_write(&card->controls_rwsem);
1687         return 0;
1688 }
1689
1690 /*
1691  * create control core:
1692  * called from init.c
1693  */
1694 int snd_ctl_create(struct snd_card *card)
1695 {
1696         static struct snd_device_ops ops = {
1697                 .dev_free = snd_ctl_dev_free,
1698                 .dev_register = snd_ctl_dev_register,
1699                 .dev_disconnect = snd_ctl_dev_disconnect,
1700         };
1701
1702         if (snd_BUG_ON(!card))
1703                 return -ENXIO;
1704         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1705 }
1706
1707 /*
1708  * Frequently used control callbacks/helpers
1709  */
1710 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1711                               struct snd_ctl_elem_info *uinfo)
1712 {
1713         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1714         uinfo->count = 1;
1715         uinfo->value.integer.min = 0;
1716         uinfo->value.integer.max = 1;
1717         return 0;
1718 }
1719
1720 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1721
1722 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1723                                 struct snd_ctl_elem_info *uinfo)
1724 {
1725         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1726         uinfo->count = 2;
1727         uinfo->value.integer.min = 0;
1728         uinfo->value.integer.max = 1;
1729         return 0;
1730 }
1731
1732 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1733
1734 /**
1735  * snd_ctl_enum_info - fills the info structure for an enumerated control
1736  * @info: the structure to be filled
1737  * @channels: the number of the control's channels; often one
1738  * @items: the number of control values; also the size of @names
1739  * @names: an array containing the names of all control values
1740  *
1741  * Sets all required fields in @info to their appropriate values.
1742  * If the control's accessibility is not the default (readable and writable),
1743  * the caller has to fill @info->access.
1744  */
1745 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1746                       unsigned int items, const char *const names[])
1747 {
1748         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1749         info->count = channels;
1750         info->value.enumerated.items = items;
1751         if (info->value.enumerated.item >= items)
1752                 info->value.enumerated.item = items - 1;
1753         strlcpy(info->value.enumerated.name,
1754                 names[info->value.enumerated.item],
1755                 sizeof(info->value.enumerated.name));
1756         return 0;
1757 }
1758 EXPORT_SYMBOL(snd_ctl_enum_info);