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