SAFE public projects git trees. - safe/jmp/linux-2.6/blob - sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
  23 #include <linux/threads.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/slab.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/time.h>
  29 #include <sound/core.h>
  30 #include <sound/minors.h>
  31 #include <sound/info.h>
  32 #include <sound/control.h>
  33
  34 /* max number of user-defined controls */
  35 #define MAX_USER_CONTROLS       32
  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         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  56         if (!card) {
  57                 err = -ENODEV;
  58                 goto __error1;
  59         }
  60         err = snd_card_file_add(card, file);
  61         if (err < 0) {
  62                 err = -ENODEV;
  63                 goto __error1;
  64         }
  65         if (!try_module_get(card->module)) {
  66                 err = -EFAULT;
  67                 goto __error2;
  68         }
  69         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  70         if (ctl == NULL) {
  71                 err = -ENOMEM;
  72                 goto __error;
  73         }
  74         INIT_LIST_HEAD(&ctl->events);
  75         init_waitqueue_head(&ctl->change_sleep);
  76         spin_lock_init(&ctl->read_lock);
  77         ctl->card = card;
  78         ctl->pid = current->pid;
  79         file->private_data = ctl;
  80         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  81         list_add_tail(&ctl->list, &card->ctl_files);
  82         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  83         return 0;
  84
  85       __error:
  86         module_put(card->module);
  87       __error2:
  88         snd_card_file_remove(card, file);
  89       __error1:
  90         return err;
  91 }
  92
  93 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  94 {
  95         struct snd_kctl_event *cread;
  96
  97         spin_lock(&ctl->read_lock);
  98         while (!list_empty(&ctl->events)) {
  99                 cread = snd_kctl_event(ctl->events.next);
 100                 list_del(&cread->list);
 101                 kfree(cread);
 102         }
 103         spin_unlock(&ctl->read_lock);
 104 }
 105
 106 static int snd_ctl_release(struct inode *inode, struct file *file)
 107 {
 108         unsigned long flags;
 109         struct list_head *list;
 110         struct snd_card *card;
 111         struct snd_ctl_file *ctl;
 112         struct snd_kcontrol *control;
 113         unsigned int idx;
 114
 115         ctl = file->private_data;
 116         fasync_helper(-1, file, 0, &ctl->fasync);
 117         file->private_data = NULL;
 118         card = ctl->card;
 119         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 120         list_del(&ctl->list);
 121         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 122         down_write(&card->controls_rwsem);
 123         list_for_each(list, &card->controls) {
 124                 control = snd_kcontrol(list);
 125                 for (idx = 0; idx < control->count; idx++)
 126                         if (control->vd[idx].owner == ctl)
 127                                 control->vd[idx].owner = NULL;
 128         }
 129         up_write(&card->controls_rwsem);
 130         snd_ctl_empty_read_queue(ctl);
 131         kfree(ctl);
 132         module_put(card->module);
 133         snd_card_file_remove(card, file);
 134         return 0;
 135 }
 136
 137 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 138                     struct snd_ctl_elem_id *id)
 139 {
 140         unsigned long flags;
 141         struct list_head *flist;
 142         struct snd_ctl_file *ctl;
 143         struct snd_kctl_event *ev;
 144
 145         snd_assert(card != NULL && id != NULL, return);
 146         read_lock(&card->ctl_files_rwlock);
 147 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 148         card->mixer_oss_change_count++;
 149 #endif
 150         list_for_each(flist, &card->ctl_files) {
 151                 struct list_head *elist;
 152                 ctl = snd_ctl_file(flist);
 153                 if (!ctl->subscribed)
 154                         continue;
 155                 spin_lock_irqsave(&ctl->read_lock, flags);
 156                 list_for_each(elist, &ctl->events) {
 157                         ev = snd_kctl_event(elist);
 158                         if (ev->id.numid == id->numid) {
 159                                 ev->mask |= mask;
 160                                 goto _found;
 161                         }
 162                 }
 163                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 164                 if (ev) {
 165                         ev->id = *id;
 166                         ev->mask = mask;
 167                         list_add_tail(&ev->list, &ctl->events);
 168                 } else {
 169                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 170                 }
 171         _found:
 172                 wake_up(&ctl->change_sleep);
 173                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 174                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 175         }
 176         read_unlock(&card->ctl_files_rwlock);
 177 }
 178
 179 EXPORT_SYMBOL(snd_ctl_notify);
 180
 181 /**
 182  * snd_ctl_new - create a control instance from the template
 183  * @control: the control template
 184  * @access: the default control access
 185  *
 186  * Allocates a new struct snd_kcontrol instance and copies the given template
 187  * to the new instance. It does not copy volatile data (access).
 188  *
 189  * Returns the pointer of the new instance, or NULL on failure.
 190  */
 191 struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control, unsigned int access)
 192 {
 193         struct snd_kcontrol *kctl;
 194         unsigned int idx;
 195
 196         snd_assert(control != NULL, return NULL);
 197         snd_assert(control->count > 0, return NULL);
 198         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 199         if (kctl == NULL) {
 200                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 201                 return NULL;
 202         }
 203         *kctl = *control;
 204         for (idx = 0; idx < kctl->count; idx++)
 205                 kctl->vd[idx].access = access;
 206         return kctl;
 207 }
 208
 209 EXPORT_SYMBOL(snd_ctl_new);
 210
 211 /**
 212  * snd_ctl_new1 - create a control instance from the template
 213  * @ncontrol: the initialization record
 214  * @private_data: the private data to set
 215  *
 216  * Allocates a new struct snd_kcontrol instance and initialize from the given
 217  * template.  When the access field of ncontrol is 0, it's assumed as
 218  * READWRITE access. When the count field is 0, it's assumes as one.
 219  *
 220  * Returns the pointer of the newly generated instance, or NULL on failure.
 221  */
 222 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 223                                   void *private_data)
 224 {
 225         struct snd_kcontrol kctl;
 226         unsigned int access;
 227
 228         snd_assert(ncontrol != NULL, return NULL);
 229         snd_assert(ncontrol->info != NULL, return NULL);
 230         memset(&kctl, 0, sizeof(kctl));
 231         kctl.id.iface = ncontrol->iface;
 232         kctl.id.device = ncontrol->device;
 233         kctl.id.subdevice = ncontrol->subdevice;
 234         if (ncontrol->name)
 235                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 236         kctl.id.index = ncontrol->index;
 237         kctl.count = ncontrol->count ? ncontrol->count : 1;
 238         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 239                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 240                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
 241         kctl.info = ncontrol->info;
 242         kctl.get = ncontrol->get;
 243         kctl.put = ncontrol->put;
 244         kctl.tlv = ncontrol->tlv;
 245         kctl.private_value = ncontrol->private_value;
 246         kctl.private_data = private_data;
 247         return snd_ctl_new(&kctl, access);
 248 }
 249
 250 EXPORT_SYMBOL(snd_ctl_new1);
 251
 252 /**
 253  * snd_ctl_free_one - release the control instance
 254  * @kcontrol: the control instance
 255  *
 256  * Releases the control instance created via snd_ctl_new()
 257  * or snd_ctl_new1().
 258  * Don't call this after the control was added to the card.
 259  */
 260 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 261 {
 262         if (kcontrol) {
 263                 if (kcontrol->private_free)
 264                         kcontrol->private_free(kcontrol);
 265                 kfree(kcontrol);
 266         }
 267 }
 268
 269 EXPORT_SYMBOL(snd_ctl_free_one);
 270
 271 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 272                                        unsigned int count)
 273 {
 274         struct list_head *list;
 275         struct snd_kcontrol *kctl;
 276
 277         list_for_each(list, &card->controls) {
 278                 kctl = snd_kcontrol(list);
 279                 if ((kctl->id.numid <= card->last_numid &&
 280                      kctl->id.numid + kctl->count > card->last_numid) ||
 281                     (kctl->id.numid <= card->last_numid + count - 1 &&
 282                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 283                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 284         }
 285         return card->last_numid;
 286 }
 287
 288 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 289 {
 290         unsigned int last_numid, iter = 100000;
 291
 292         last_numid = card->last_numid;
 293         while (last_numid != snd_ctl_hole_check(card, count)) {
 294                 if (--iter == 0) {
 295                         /* this situation is very unlikely */
 296                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 297                         return -ENOMEM;
 298                 }
 299                 last_numid = card->last_numid;
 300         }
 301         return 0;
 302 }
 303
 304 /**
 305  * snd_ctl_add - add the control instance to the card
 306  * @card: the card instance
 307  * @kcontrol: the control instance to add
 308  *
 309  * Adds the control instance created via snd_ctl_new() or
 310  * snd_ctl_new1() to the given card. Assigns also an unique
 311  * numid used for fast search.
 312  *
 313  * Returns zero if successful, or a negative error code on failure.
 314  *
 315  * It frees automatically the control which cannot be added.
 316  */
 317 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 318 {
 319         struct snd_ctl_elem_id id;
 320         unsigned int idx;
 321         int err = -EINVAL;
 322
 323         if (! kcontrol)
 324                 return err;
 325         snd_assert(card != NULL, goto error);
 326         snd_assert(kcontrol->info != NULL, goto error);
 327         id = kcontrol->id;
 328         down_write(&card->controls_rwsem);
 329         if (snd_ctl_find_id(card, &id)) {
 330                 up_write(&card->controls_rwsem);
 331                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 332                                         id.iface,
 333                                         id.device,
 334                                         id.subdevice,
 335                                         id.name,
 336                                         id.index);
 337                 err = -EBUSY;
 338                 goto error;
 339         }
 340         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 341                 up_write(&card->controls_rwsem);
 342                 err = -ENOMEM;
 343                 goto error;
 344         }
 345         list_add_tail(&kcontrol->list, &card->controls);
 346         card->controls_count += kcontrol->count;
 347         kcontrol->id.numid = card->last_numid + 1;
 348         card->last_numid += kcontrol->count;
 349         up_write(&card->controls_rwsem);
 350         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 351                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 352         return 0;
 353
 354  error:
 355         snd_ctl_free_one(kcontrol);
 356         return err;
 357 }
 358
 359 EXPORT_SYMBOL(snd_ctl_add);
 360
 361 /**
 362  * snd_ctl_remove - remove the control from the card and release it
 363  * @card: the card instance
 364  * @kcontrol: the control instance to remove
 365  *
 366  * Removes the control from the card and then releases the instance.
 367  * You don't need to call snd_ctl_free_one(). You must be in
 368  * the write lock - down_write(&card->controls_rwsem).
 369  *
 370  * Returns 0 if successful, or a negative error code on failure.
 371  */
 372 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 373 {
 374         struct snd_ctl_elem_id id;
 375         unsigned int idx;
 376
 377         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 378         list_del(&kcontrol->list);
 379         card->controls_count -= kcontrol->count;
 380         id = kcontrol->id;
 381         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 382                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 383         snd_ctl_free_one(kcontrol);
 384         return 0;
 385 }
 386
 387 EXPORT_SYMBOL(snd_ctl_remove);
 388
 389 /**
 390  * snd_ctl_remove_id - remove the control of the given id and release it
 391  * @card: the card instance
 392  * @id: the control id to remove
 393  *
 394  * Finds the control instance with the given id, removes it from the
 395  * card list and releases it.
 396  *
 397  * Returns 0 if successful, or a negative error code on failure.
 398  */
 399 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 400 {
 401         struct snd_kcontrol *kctl;
 402         int ret;
 403
 404         down_write(&card->controls_rwsem);
 405         kctl = snd_ctl_find_id(card, id);
 406         if (kctl == NULL) {
 407                 up_write(&card->controls_rwsem);
 408                 return -ENOENT;
 409         }
 410         ret = snd_ctl_remove(card, kctl);
 411         up_write(&card->controls_rwsem);
 412         return ret;
 413 }
 414
 415 EXPORT_SYMBOL(snd_ctl_remove_id);
 416
 417 /**
 418  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 419  * @file: active control handle
 420  * @id: the control id to remove
 421  *
 422  * Finds the control instance with the given id, removes it from the
 423  * card list and releases it.
 424  *
 425  * Returns 0 if successful, or a negative error code on failure.
 426  */
 427 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 428                                       struct snd_ctl_elem_id *id)
 429 {
 430         struct snd_card *card = file->card;
 431         struct snd_kcontrol *kctl;
 432         int idx, ret;
 433
 434         down_write(&card->controls_rwsem);
 435         kctl = snd_ctl_find_id(card, id);
 436         if (kctl == NULL) {
 437                 up_write(&card->controls_rwsem);
 438                 return -ENOENT;
 439         }
 440         for (idx = 0; idx < kctl->count; idx++)
 441                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 442                         up_write(&card->controls_rwsem);
 443                         return -EBUSY;
 444                 }
 445         ret = snd_ctl_remove(card, kctl);
 446         up_write(&card->controls_rwsem);
 447         return ret;
 448 }
 449
 450 /**
 451  * snd_ctl_rename_id - replace the id of a control on the card
 452  * @card: the card instance
 453  * @src_id: the old id
 454  * @dst_id: the new id
 455  *
 456  * Finds the control with the old id from the card, and replaces the
 457  * id with the new one.
 458  *
 459  * Returns zero if successful, or a negative error code on failure.
 460  */
 461 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 462                       struct snd_ctl_elem_id *dst_id)
 463 {
 464         struct snd_kcontrol *kctl;
 465
 466         down_write(&card->controls_rwsem);
 467         kctl = snd_ctl_find_id(card, src_id);
 468         if (kctl == NULL) {
 469                 up_write(&card->controls_rwsem);
 470                 return -ENOENT;
 471         }
 472         kctl->id = *dst_id;
 473         kctl->id.numid = card->last_numid + 1;
 474         card->last_numid += kctl->count;
 475         up_write(&card->controls_rwsem);
 476         return 0;
 477 }
 478
 479 EXPORT_SYMBOL(snd_ctl_rename_id);
 480
 481 /**
 482  * snd_ctl_find_numid - find the control instance with the given number-id
 483  * @card: the card instance
 484  * @numid: the number-id to search
 485  *
 486  * Finds the control instance with the given number-id from the card.
 487  *
 488  * Returns the pointer of the instance if found, or NULL if not.
 489  *
 490  * The caller must down card->controls_rwsem before calling this function
 491  * (if the race condition can happen).
 492  */
 493 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 494 {
 495         struct list_head *list;
 496         struct snd_kcontrol *kctl;
 497
 498         snd_assert(card != NULL && numid != 0, return NULL);
 499         list_for_each(list, &card->controls) {
 500                 kctl = snd_kcontrol(list);
 501                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 502                         return kctl;
 503         }
 504         return NULL;
 505 }
 506
 507 EXPORT_SYMBOL(snd_ctl_find_numid);
 508
 509 /**
 510  * snd_ctl_find_id - find the control instance with the given id
 511  * @card: the card instance
 512  * @id: the id to search
 513  *
 514  * Finds the control instance with the given id from the card.
 515  *
 516  * Returns the pointer of the instance if found, or NULL if not.
 517  *
 518  * The caller must down card->controls_rwsem before calling this function
 519  * (if the race condition can happen).
 520  */
 521 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 522                                      struct snd_ctl_elem_id *id)
 523 {
 524         struct list_head *list;
 525         struct snd_kcontrol *kctl;
 526
 527         snd_assert(card != NULL && id != NULL, return NULL);
 528         if (id->numid != 0)
 529                 return snd_ctl_find_numid(card, id->numid);
 530         list_for_each(list, &card->controls) {
 531                 kctl = snd_kcontrol(list);
 532                 if (kctl->id.iface != id->iface)
 533                         continue;
 534                 if (kctl->id.device != id->device)
 535                         continue;
 536                 if (kctl->id.subdevice != id->subdevice)
 537                         continue;
 538                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 539                         continue;
 540                 if (kctl->id.index > id->index)
 541                         continue;
 542                 if (kctl->id.index + kctl->count <= id->index)
 543                         continue;
 544                 return kctl;
 545         }
 546         return NULL;
 547 }
 548
 549 EXPORT_SYMBOL(snd_ctl_find_id);
 550
 551 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 552                              unsigned int cmd, void __user *arg)
 553 {
 554         struct snd_ctl_card_info *info;
 555
 556         info = kzalloc(sizeof(*info), GFP_KERNEL);
 557         if (! info)
 558                 return -ENOMEM;
 559         down_read(&snd_ioctl_rwsem);
 560         info->card = card->number;
 561         strlcpy(info->id, card->id, sizeof(info->id));
 562         strlcpy(info->driver, card->driver, sizeof(info->driver));
 563         strlcpy(info->name, card->shortname, sizeof(info->name));
 564         strlcpy(info->longname, card->longname, sizeof(info->longname));
 565         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 566         strlcpy(info->components, card->components, sizeof(info->components));
 567         up_read(&snd_ioctl_rwsem);
 568         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 569                 kfree(info);
 570                 return -EFAULT;
 571         }
 572         kfree(info);
 573         return 0;
 574 }
 575
 576 static int snd_ctl_elem_list(struct snd_card *card,
 577                              struct snd_ctl_elem_list __user *_list)
 578 {
 579         struct list_head *plist;
 580         struct snd_ctl_elem_list list;
 581         struct snd_kcontrol *kctl;
 582         struct snd_ctl_elem_id *dst, *id;
 583         unsigned int offset, space, first, jidx;
 584
 585         if (copy_from_user(&list, _list, sizeof(list)))
 586                 return -EFAULT;
 587         offset = list.offset;
 588         space = list.space;
 589         first = 0;
 590         /* try limit maximum space */
 591         if (space > 16384)
 592                 return -ENOMEM;
 593         if (space > 0) {
 594                 /* allocate temporary buffer for atomic operation */
 595                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 596                 if (dst == NULL)
 597                         return -ENOMEM;
 598                 down_read(&card->controls_rwsem);
 599                 list.count = card->controls_count;
 600                 plist = card->controls.next;
 601                 while (plist != &card->controls) {
 602                         if (offset == 0)
 603                                 break;
 604                         kctl = snd_kcontrol(plist);
 605                         if (offset < kctl->count)
 606                                 break;
 607                         offset -= kctl->count;
 608                         plist = plist->next;
 609                 }
 610                 list.used = 0;
 611                 id = dst;
 612                 while (space > 0 && plist != &card->controls) {
 613                         kctl = snd_kcontrol(plist);
 614                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 615                                 snd_ctl_build_ioff(id, kctl, jidx);
 616                                 id++;
 617                                 space--;
 618                                 list.used++;
 619                         }
 620                         plist = plist->next;
 621                         offset = 0;
 622                 }
 623                 up_read(&card->controls_rwsem);
 624                 if (list.used > 0 &&
 625                     copy_to_user(list.pids, dst,
 626                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 627                         vfree(dst);
 628                         return -EFAULT;
 629                 }
 630                 vfree(dst);
 631         } else {
 632                 down_read(&card->controls_rwsem);
 633                 list.count = card->controls_count;
 634                 up_read(&card->controls_rwsem);
 635         }
 636         if (copy_to_user(_list, &list, sizeof(list)))
 637                 return -EFAULT;
 638         return 0;
 639 }
 640
 641 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 642                              struct snd_ctl_elem_info *info)
 643 {
 644         struct snd_card *card = ctl->card;
 645         struct snd_kcontrol *kctl;
 646         struct snd_kcontrol_volatile *vd;
 647         unsigned int index_offset;
 648         int result;
 649
 650         down_read(&card->controls_rwsem);
 651         kctl = snd_ctl_find_id(card, &info->id);
 652         if (kctl == NULL) {
 653                 up_read(&card->controls_rwsem);
 654                 return -ENOENT;
 655         }
 656 #ifdef CONFIG_SND_DEBUG
 657         info->access = 0;
 658 #endif
 659         result = kctl->info(kctl, info);
 660         if (result >= 0) {
 661                 snd_assert(info->access == 0, );
 662                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 663                 vd = &kctl->vd[index_offset];
 664                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 665                 info->access = vd->access;
 666                 if (vd->owner) {
 667                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 668                         if (vd->owner == ctl)
 669                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 670                         info->owner = vd->owner_pid;
 671                 } else {
 672                         info->owner = -1;
 673                 }
 674         }
 675         up_read(&card->controls_rwsem);
 676         return result;
 677 }
 678
 679 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 680                                   struct snd_ctl_elem_info __user *_info)
 681 {
 682         struct snd_ctl_elem_info info;
 683         int result;
 684
 685         if (copy_from_user(&info, _info, sizeof(info)))
 686                 return -EFAULT;
 687         snd_power_lock(ctl->card);
 688         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 689         if (result >= 0)
 690                 result = snd_ctl_elem_info(ctl, &info);
 691         snd_power_unlock(ctl->card);
 692         if (result >= 0)
 693                 if (copy_to_user(_info, &info, sizeof(info)))
 694                         return -EFAULT;
 695         return result;
 696 }
 697
 698 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
 699 {
 700         struct snd_kcontrol *kctl;
 701         struct snd_kcontrol_volatile *vd;
 702         unsigned int index_offset;
 703         int result, indirect;
 704
 705         down_read(&card->controls_rwsem);
 706         kctl = snd_ctl_find_id(card, &control->id);
 707         if (kctl == NULL) {
 708                 result = -ENOENT;
 709         } else {
 710                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 711                 vd = &kctl->vd[index_offset];
 712                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 713                 if (control->indirect != indirect) {
 714                         result = -EACCES;
 715                 } else {
 716                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 717                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 718                                 result = kctl->get(kctl, control);
 719                         } else {
 720                                 result = -EPERM;
 721                         }
 722                 }
 723         }
 724         up_read(&card->controls_rwsem);
 725         return result;
 726 }
 727
 728 EXPORT_SYMBOL(snd_ctl_elem_read);
 729
 730 static int snd_ctl_elem_read_user(struct snd_card *card,
 731                                   struct snd_ctl_elem_value __user *_control)
 732 {
 733         struct snd_ctl_elem_value *control;
 734         int result;
 735
 736         control = kmalloc(sizeof(*control), GFP_KERNEL);
 737         if (control == NULL)
 738                 return -ENOMEM;
 739         if (copy_from_user(control, _control, sizeof(*control))) {
 740                 kfree(control);
 741                 return -EFAULT;
 742         }
 743         snd_power_lock(card);
 744         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 745         if (result >= 0)
 746                 result = snd_ctl_elem_read(card, control);
 747         snd_power_unlock(card);
 748         if (result >= 0)
 749                 if (copy_to_user(_control, control, sizeof(*control)))
 750                         result = -EFAULT;
 751         kfree(control);
 752         return result;
 753 }
 754
 755 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 756                        struct snd_ctl_elem_value *control)
 757 {
 758         struct snd_kcontrol *kctl;
 759         struct snd_kcontrol_volatile *vd;
 760         unsigned int index_offset;
 761         int result, indirect;
 762
 763         down_read(&card->controls_rwsem);
 764         kctl = snd_ctl_find_id(card, &control->id);
 765         if (kctl == NULL) {
 766                 result = -ENOENT;
 767         } else {
 768                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 769                 vd = &kctl->vd[index_offset];
 770                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 771                 if (control->indirect != indirect) {
 772                         result = -EACCES;
 773                 } else {
 774                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 775                             kctl->put == NULL ||
 776                             (file && vd->owner != NULL && vd->owner != file)) {
 777                                 result = -EPERM;
 778                         } else {
 779                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 780                                 result = kctl->put(kctl, control);
 781                         }
 782                         if (result > 0) {
 783                                 up_read(&card->controls_rwsem);
 784                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 785                                 return 0;
 786                         }
 787                 }
 788         }
 789         up_read(&card->controls_rwsem);
 790         return result;
 791 }
 792
 793 EXPORT_SYMBOL(snd_ctl_elem_write);
 794
 795 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 796                                    struct snd_ctl_elem_value __user *_control)
 797 {
 798         struct snd_ctl_elem_value *control;
 799         struct snd_card *card;
 800         int result;
 801
 802         control = kmalloc(sizeof(*control), GFP_KERNEL);
 803         if (control == NULL)
 804                 return -ENOMEM;
 805         if (copy_from_user(control, _control, sizeof(*control))) {
 806                 kfree(control);
 807                 return -EFAULT;
 808         }
 809         card = file->card;
 810         snd_power_lock(card);
 811         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 812         if (result >= 0)
 813                 result = snd_ctl_elem_write(card, file, control);
 814         snd_power_unlock(card);
 815         if (result >= 0)
 816                 if (copy_to_user(_control, control, sizeof(*control)))
 817                         result = -EFAULT;
 818         kfree(control);
 819         return result;
 820 }
 821
 822 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 823                              struct snd_ctl_elem_id __user *_id)
 824 {
 825         struct snd_card *card = file->card;
 826         struct snd_ctl_elem_id id;
 827         struct snd_kcontrol *kctl;
 828         struct snd_kcontrol_volatile *vd;
 829         int result;
 830
 831         if (copy_from_user(&id, _id, sizeof(id)))
 832                 return -EFAULT;
 833         down_write(&card->controls_rwsem);
 834         kctl = snd_ctl_find_id(card, &id);
 835         if (kctl == NULL) {
 836                 result = -ENOENT;
 837         } else {
 838                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 839                 if (vd->owner != NULL)
 840                         result = -EBUSY;
 841                 else {
 842                         vd->owner = file;
 843                         vd->owner_pid = current->pid;
 844                         result = 0;
 845                 }
 846         }
 847         up_write(&card->controls_rwsem);
 848         return result;
 849 }
 850
 851 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 852                                struct snd_ctl_elem_id __user *_id)
 853 {
 854         struct snd_card *card = file->card;
 855         struct snd_ctl_elem_id id;
 856         struct snd_kcontrol *kctl;
 857         struct snd_kcontrol_volatile *vd;
 858         int result;
 859
 860         if (copy_from_user(&id, _id, sizeof(id)))
 861                 return -EFAULT;
 862         down_write(&card->controls_rwsem);
 863         kctl = snd_ctl_find_id(card, &id);
 864         if (kctl == NULL) {
 865                 result = -ENOENT;
 866         } else {
 867                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 868                 if (vd->owner == NULL)
 869                         result = -EINVAL;
 870                 else if (vd->owner != file)
 871                         result = -EPERM;
 872                 else {
 873                         vd->owner = NULL;
 874                         vd->owner_pid = 0;
 875                         result = 0;
 876                 }
 877         }
 878         up_write(&card->controls_rwsem);
 879         return result;
 880 }
 881
 882 struct user_element {
 883         struct snd_ctl_elem_info info;
 884         void *elem_data;                /* element data */
 885         unsigned long elem_data_size;   /* size of element data in bytes */
 886         void *priv_data;                /* private data (like strings for enumerated type) */
 887         unsigned long priv_data_size;   /* size of private data in bytes */
 888 };
 889
 890 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 891                                   struct snd_ctl_elem_info *uinfo)
 892 {
 893         struct user_element *ue = kcontrol->private_data;
 894
 895         *uinfo = ue->info;
 896         return 0;
 897 }
 898
 899 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 900                                  struct snd_ctl_elem_value *ucontrol)
 901 {
 902         struct user_element *ue = kcontrol->private_data;
 903
 904         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 905         return 0;
 906 }
 907
 908 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 909                                  struct snd_ctl_elem_value *ucontrol)
 910 {
 911         int change;
 912         struct user_element *ue = kcontrol->private_data;
 913
 914         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 915         if (change)
 916                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 917         return change;
 918 }
 919
 920 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 921 {
 922         kfree(kcontrol->private_data);
 923 }
 924
 925 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 926                             struct snd_ctl_elem_info *info, int replace)
 927 {
 928         struct snd_card *card = file->card;
 929         struct snd_kcontrol kctl, *_kctl;
 930         unsigned int access;
 931         long private_size;
 932         struct user_element *ue;
 933         int idx, err;
 934
 935         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 936                 return -ENOMEM;
 937         if (info->count > 1024)
 938                 return -EINVAL;
 939         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 940                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 941                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE));
 942         info->id.numid = 0;
 943         memset(&kctl, 0, sizeof(kctl));
 944         down_write(&card->controls_rwsem);
 945         _kctl = snd_ctl_find_id(card, &info->id);
 946         err = 0;
 947         if (_kctl) {
 948                 if (replace)
 949                         err = snd_ctl_remove(card, _kctl);
 950                 else
 951                         err = -EBUSY;
 952         } else {
 953                 if (replace)
 954                         err = -ENOENT;
 955         }
 956         up_write(&card->controls_rwsem);
 957         if (err < 0)
 958                 return err;
 959         memcpy(&kctl.id, &info->id, sizeof(info->id));
 960         kctl.count = info->owner ? info->owner : 1;
 961         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 962         kctl.info = snd_ctl_elem_user_info;
 963         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 964                 kctl.get = snd_ctl_elem_user_get;
 965         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 966                 kctl.put = snd_ctl_elem_user_put;
 967         switch (info->type) {
 968         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 969                 private_size = sizeof(char);
 970                 if (info->count > 128)
 971                         return -EINVAL;
 972                 break;
 973         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 974                 private_size = sizeof(long);
 975                 if (info->count > 128)
 976                         return -EINVAL;
 977                 break;
 978         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 979                 private_size = sizeof(long long);
 980                 if (info->count > 64)
 981                         return -EINVAL;
 982                 break;
 983         case SNDRV_CTL_ELEM_TYPE_BYTES:
 984                 private_size = sizeof(unsigned char);
 985                 if (info->count > 512)
 986                         return -EINVAL;
 987                 break;
 988         case SNDRV_CTL_ELEM_TYPE_IEC958:
 989                 private_size = sizeof(struct snd_aes_iec958);
 990                 if (info->count != 1)
 991                         return -EINVAL;
 992                 break;
 993         default:
 994                 return -EINVAL;
 995         }
 996         private_size *= info->count;
 997         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
 998         if (ue == NULL)
 999                 return -ENOMEM;
1000         ue->info = *info;
1001         ue->elem_data = (char *)ue + sizeof(*ue);
1002         ue->elem_data_size = private_size;
1003         kctl.private_free = snd_ctl_elem_user_free;
1004         _kctl = snd_ctl_new(&kctl, access);
1005         if (_kctl == NULL) {
1006                 kfree(ue);
1007                 return -ENOMEM;
1008         }
1009         _kctl->private_data = ue;
1010         for (idx = 0; idx < _kctl->count; idx++)
1011                 _kctl->vd[idx].owner = file;
1012         err = snd_ctl_add(card, _kctl);
1013         if (err < 0)
1014                 return err;
1015
1016         down_write(&card->controls_rwsem);
1017         card->user_ctl_count++;
1018         up_write(&card->controls_rwsem);
1019
1020         return 0;
1021 }
1022
1023 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1024                                  struct snd_ctl_elem_info __user *_info, int replace)
1025 {
1026         struct snd_ctl_elem_info info;
1027         if (copy_from_user(&info, _info, sizeof(info)))
1028                 return -EFAULT;
1029         return snd_ctl_elem_add(file, &info, replace);
1030 }
1031
1032 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1033                                struct snd_ctl_elem_id __user *_id)
1034 {
1035         struct snd_ctl_elem_id id;
1036         int err;
1037
1038         if (copy_from_user(&id, _id, sizeof(id)))
1039                 return -EFAULT;
1040         err = snd_ctl_remove_unlocked_id(file, &id);
1041         if (! err) {
1042                 struct snd_card *card = file->card;
1043                 down_write(&card->controls_rwsem);
1044                 card->user_ctl_count--;
1045                 up_write(&card->controls_rwsem);
1046         }
1047         return err;
1048 }
1049
1050 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1051 {
1052         int subscribe;
1053         if (get_user(subscribe, ptr))
1054                 return -EFAULT;
1055         if (subscribe < 0) {
1056                 subscribe = file->subscribed;
1057                 if (put_user(subscribe, ptr))
1058                         return -EFAULT;
1059                 return 0;
1060         }
1061         if (subscribe) {
1062                 file->subscribed = 1;
1063                 return 0;
1064         } else if (file->subscribed) {
1065                 snd_ctl_empty_read_queue(file);
1066                 file->subscribed = 0;
1067         }
1068         return 0;
1069 }
1070
1071 static int snd_ctl_tlv_read(struct snd_card *card,
1072                             struct snd_ctl_tlv __user *_tlv)
1073 {
1074         struct snd_ctl_tlv tlv;
1075         struct snd_kcontrol *kctl;
1076         unsigned int len;
1077         int err = 0;
1078
1079         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1080                 return -EFAULT;
1081         if (tlv.length < sizeof(unsigned int) * 3)
1082                 return -EINVAL;
1083         down_read(&card->controls_rwsem);
1084         kctl = snd_ctl_find_numid(card, tlv.numid);
1085         if (kctl == NULL) {
1086                 err = -ENOENT;
1087                 goto __kctl_end;
1088         }
1089         if (kctl->tlv == NULL) {
1090                 err = -ENXIO;
1091                 goto __kctl_end;
1092         }
1093         len = kctl->tlv[1] + 2 * sizeof(unsigned int);
1094         if (tlv.length < len) {
1095                 err = -ENOMEM;
1096                 goto __kctl_end;
1097         }
1098         if (copy_to_user(_tlv->tlv, kctl->tlv, len))
1099                 err = -EFAULT;
1100       __kctl_end:
1101         up_read(&card->controls_rwsem);
1102         return err;
1103 }
1104
1105 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1106 {
1107         struct snd_ctl_file *ctl;
1108         struct snd_card *card;
1109         struct list_head *list;
1110         struct snd_kctl_ioctl *p;
1111         void __user *argp = (void __user *)arg;
1112         int __user *ip = argp;
1113         int err;
1114
1115         ctl = file->private_data;
1116         card = ctl->card;
1117         snd_assert(card != NULL, return -ENXIO);
1118         switch (cmd) {
1119         case SNDRV_CTL_IOCTL_PVERSION:
1120                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1121         case SNDRV_CTL_IOCTL_CARD_INFO:
1122                 return snd_ctl_card_info(card, ctl, cmd, argp);
1123         case SNDRV_CTL_IOCTL_ELEM_LIST:
1124                 return snd_ctl_elem_list(card, argp);
1125         case SNDRV_CTL_IOCTL_ELEM_INFO:
1126                 return snd_ctl_elem_info_user(ctl, argp);
1127         case SNDRV_CTL_IOCTL_ELEM_READ:
1128                 return snd_ctl_elem_read_user(card, argp);
1129         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1130                 return snd_ctl_elem_write_user(ctl, argp);
1131         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1132                 return snd_ctl_elem_lock(ctl, argp);
1133         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1134                 return snd_ctl_elem_unlock(ctl, argp);
1135         case SNDRV_CTL_IOCTL_ELEM_ADD:
1136                 return snd_ctl_elem_add_user(ctl, argp, 0);
1137         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1138                 return snd_ctl_elem_add_user(ctl, argp, 1);
1139         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1140                 return snd_ctl_elem_remove(ctl, argp);
1141         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1142                 return snd_ctl_subscribe_events(ctl, ip);
1143         case SNDRV_CTL_IOCTL_TLV_READ:
1144                 return snd_ctl_tlv_read(card, argp);
1145         case SNDRV_CTL_IOCTL_POWER:
1146                 return -ENOPROTOOPT;
1147         case SNDRV_CTL_IOCTL_POWER_STATE:
1148 #ifdef CONFIG_PM
1149                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1150 #else
1151                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1152 #endif
1153         }
1154         down_read(&snd_ioctl_rwsem);
1155         list_for_each(list, &snd_control_ioctls) {
1156                 p = list_entry(list, struct snd_kctl_ioctl, list);
1157                 err = p->fioctl(card, ctl, cmd, arg);
1158                 if (err != -ENOIOCTLCMD) {
1159                         up_read(&snd_ioctl_rwsem);
1160                         return err;
1161                 }
1162         }
1163         up_read(&snd_ioctl_rwsem);
1164         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1165         return -ENOTTY;
1166 }
1167
1168 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1169                             size_t count, loff_t * offset)
1170 {
1171         struct snd_ctl_file *ctl;
1172         int err = 0;
1173         ssize_t result = 0;
1174
1175         ctl = file->private_data;
1176         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1177         if (!ctl->subscribed)
1178                 return -EBADFD;
1179         if (count < sizeof(struct snd_ctl_event))
1180                 return -EINVAL;
1181         spin_lock_irq(&ctl->read_lock);
1182         while (count >= sizeof(struct snd_ctl_event)) {
1183                 struct snd_ctl_event ev;
1184                 struct snd_kctl_event *kev;
1185                 while (list_empty(&ctl->events)) {
1186                         wait_queue_t wait;
1187                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1188                                 err = -EAGAIN;
1189                                 goto __end_lock;
1190                         }
1191                         init_waitqueue_entry(&wait, current);
1192                         add_wait_queue(&ctl->change_sleep, &wait);
1193                         set_current_state(TASK_INTERRUPTIBLE);
1194                         spin_unlock_irq(&ctl->read_lock);
1195                         schedule();
1196                         remove_wait_queue(&ctl->change_sleep, &wait);
1197                         if (signal_pending(current))
1198                                 return result > 0 ? result : -ERESTARTSYS;
1199                         spin_lock_irq(&ctl->read_lock);
1200                 }
1201                 kev = snd_kctl_event(ctl->events.next);
1202                 ev.type = SNDRV_CTL_EVENT_ELEM;
1203                 ev.data.elem.mask = kev->mask;
1204                 ev.data.elem.id = kev->id;
1205                 list_del(&kev->list);
1206                 spin_unlock_irq(&ctl->read_lock);
1207                 kfree(kev);
1208                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1209                         err = -EFAULT;
1210                         goto __end;
1211                 }
1212                 spin_lock_irq(&ctl->read_lock);
1213                 buffer += sizeof(struct snd_ctl_event);
1214                 count -= sizeof(struct snd_ctl_event);
1215                 result += sizeof(struct snd_ctl_event);
1216         }
1217       __end_lock:
1218         spin_unlock_irq(&ctl->read_lock);
1219       __end:
1220         return result > 0 ? result : err;
1221 }
1222
1223 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1224 {
1225         unsigned int mask;
1226         struct snd_ctl_file *ctl;
1227
1228         ctl = file->private_data;
1229         if (!ctl->subscribed)
1230                 return 0;
1231         poll_wait(file, &ctl->change_sleep, wait);
1232
1233         mask = 0;
1234         if (!list_empty(&ctl->events))
1235                 mask |= POLLIN | POLLRDNORM;
1236
1237         return mask;
1238 }
1239
1240 /*
1241  * register the device-specific control-ioctls.
1242  * called from each device manager like pcm.c, hwdep.c, etc.
1243  */
1244 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1245 {
1246         struct snd_kctl_ioctl *pn;
1247
1248         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1249         if (pn == NULL)
1250                 return -ENOMEM;
1251         pn->fioctl = fcn;
1252         down_write(&snd_ioctl_rwsem);
1253         list_add_tail(&pn->list, lists);
1254         up_write(&snd_ioctl_rwsem);
1255         return 0;
1256 }
1257
1258 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1259 {
1260         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1261 }
1262
1263 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1264
1265 #ifdef CONFIG_COMPAT
1266 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1267 {
1268         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1269 }
1270
1271 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1272 #endif
1273
1274 /*
1275  * de-register the device-specific control-ioctls.
1276  */
1277 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1278                                      struct list_head *lists)
1279 {
1280         struct list_head *list;
1281         struct snd_kctl_ioctl *p;
1282
1283         snd_assert(fcn != NULL, return -EINVAL);
1284         down_write(&snd_ioctl_rwsem);
1285         list_for_each(list, lists) {
1286                 p = list_entry(list, struct snd_kctl_ioctl, list);
1287                 if (p->fioctl == fcn) {
1288                         list_del(&p->list);
1289                         up_write(&snd_ioctl_rwsem);
1290                         kfree(p);
1291                         return 0;
1292                 }
1293         }
1294         up_write(&snd_ioctl_rwsem);
1295         snd_BUG();
1296         return -EINVAL;
1297 }
1298
1299 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1300 {
1301         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1302 }
1303
1304 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1305
1306 #ifdef CONFIG_COMPAT
1307 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1308 {
1309         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1310 }
1311
1312 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1313 #endif
1314
1315 static int snd_ctl_fasync(int fd, struct file * file, int on)
1316 {
1317         struct snd_ctl_file *ctl;
1318         int err;
1319         ctl = file->private_data;
1320         err = fasync_helper(fd, file, on, &ctl->fasync);
1321         if (err < 0)
1322                 return err;
1323         return 0;
1324 }
1325
1326 /*
1327  * ioctl32 compat
1328  */
1329 #ifdef CONFIG_COMPAT
1330 #include "control_compat.c"
1331 #else
1332 #define snd_ctl_ioctl_compat    NULL
1333 #endif
1334
1335 /*
1336  *  INIT PART
1337  */
1338
1339 static struct file_operations snd_ctl_f_ops =
1340 {
1341         .owner =        THIS_MODULE,
1342         .read =         snd_ctl_read,
1343         .open =         snd_ctl_open,
1344         .release =      snd_ctl_release,
1345         .poll =         snd_ctl_poll,
1346         .unlocked_ioctl =       snd_ctl_ioctl,
1347         .compat_ioctl = snd_ctl_ioctl_compat,
1348         .fasync =       snd_ctl_fasync,
1349 };
1350
1351 /*
1352  * registration of the control device
1353  */
1354 static int snd_ctl_dev_register(struct snd_device *device)
1355 {
1356         struct snd_card *card = device->device_data;
1357         int err, cardnum;
1358         char name[16];
1359
1360         snd_assert(card != NULL, return -ENXIO);
1361         cardnum = card->number;
1362         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1363         sprintf(name, "controlC%i", cardnum);
1364         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1365                                        &snd_ctl_f_ops, card, name)) < 0)
1366                 return err;
1367         return 0;
1368 }
1369
1370 /*
1371  * disconnection of the control device
1372  */
1373 static int snd_ctl_dev_disconnect(struct snd_device *device)
1374 {
1375         struct snd_card *card = device->device_data;
1376         struct list_head *flist;
1377         struct snd_ctl_file *ctl;
1378
1379         down_read(&card->controls_rwsem);
1380         list_for_each(flist, &card->ctl_files) {
1381                 ctl = snd_ctl_file(flist);
1382                 wake_up(&ctl->change_sleep);
1383                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1384         }
1385         up_read(&card->controls_rwsem);
1386         return 0;
1387 }
1388
1389 /*
1390  * free all controls
1391  */
1392 static int snd_ctl_dev_free(struct snd_device *device)
1393 {
1394         struct snd_card *card = device->device_data;
1395         struct snd_kcontrol *control;
1396
1397         down_write(&card->controls_rwsem);
1398         while (!list_empty(&card->controls)) {
1399                 control = snd_kcontrol(card->controls.next);
1400                 snd_ctl_remove(card, control);
1401         }
1402         up_write(&card->controls_rwsem);
1403         return 0;
1404 }
1405
1406 /*
1407  * de-registration of the control device
1408  */
1409 static int snd_ctl_dev_unregister(struct snd_device *device)
1410 {
1411         struct snd_card *card = device->device_data;
1412         int err, cardnum;
1413
1414         snd_assert(card != NULL, return -ENXIO);
1415         cardnum = card->number;
1416         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1417         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1418                                          card, -1)) < 0)
1419                 return err;
1420         return snd_ctl_dev_free(device);
1421 }
1422
1423 /*
1424  * create control core:
1425  * called from init.c
1426  */
1427 int snd_ctl_create(struct snd_card *card)
1428 {
1429         static struct snd_device_ops ops = {
1430                 .dev_free = snd_ctl_dev_free,
1431                 .dev_register = snd_ctl_dev_register,
1432                 .dev_disconnect = snd_ctl_dev_disconnect,
1433                 .dev_unregister = snd_ctl_dev_unregister
1434         };
1435
1436         snd_assert(card != NULL, return -ENXIO);
1437         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1438 }