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 typedef struct _snd_kctl_ioctl {
  38         struct list_head list;          /* list of all ioctls */
  39         snd_kctl_ioctl_func_t fioctl;
  40 } snd_kctl_ioctl_t;
  41
  42 #define snd_kctl_ioctl(n) list_entry(n, snd_kctl_ioctl_t, list)
  43
  44 static DECLARE_RWSEM(snd_ioctl_rwsem);
  45 static LIST_HEAD(snd_control_ioctls);
  46 #ifdef CONFIG_COMPAT
  47 static LIST_HEAD(snd_control_compat_ioctls);
  48 #endif
  49
  50 static int snd_ctl_open(struct inode *inode, struct file *file)
  51 {
  52         int cardnum = SNDRV_MINOR_CARD(iminor(inode));
  53         unsigned long flags;
  54         snd_card_t *card;
  55         snd_ctl_file_t *ctl;
  56         int err;
  57
  58         card = snd_cards[cardnum];
  59         if (!card) {
  60                 err = -ENODEV;
  61                 goto __error1;
  62         }
  63         err = snd_card_file_add(card, file);
  64         if (err < 0) {
  65                 err = -ENODEV;
  66                 goto __error1;
  67         }
  68         if (!try_module_get(card->module)) {
  69                 err = -EFAULT;
  70                 goto __error2;
  71         }
  72         ctl = kcalloc(1, sizeof(*ctl), GFP_KERNEL);
  73         if (ctl == NULL) {
  74                 err = -ENOMEM;
  75                 goto __error;
  76         }
  77         INIT_LIST_HEAD(&ctl->events);
  78         init_waitqueue_head(&ctl->change_sleep);
  79         spin_lock_init(&ctl->read_lock);
  80         ctl->card = card;
  81         ctl->pid = current->pid;
  82         file->private_data = ctl;
  83         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  84         list_add_tail(&ctl->list, &card->ctl_files);
  85         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  86         return 0;
  87
  88       __error:
  89         module_put(card->module);
  90       __error2:
  91         snd_card_file_remove(card, file);
  92       __error1:
  93         return err;
  94 }
  95
  96 static void snd_ctl_empty_read_queue(snd_ctl_file_t * ctl)
  97 {
  98         snd_kctl_event_t *cread;
  99
 100         spin_lock(&ctl->read_lock);
 101         while (!list_empty(&ctl->events)) {
 102                 cread = snd_kctl_event(ctl->events.next);
 103                 list_del(&cread->list);
 104                 kfree(cread);
 105         }
 106         spin_unlock(&ctl->read_lock);
 107 }
 108
 109 static int snd_ctl_release(struct inode *inode, struct file *file)
 110 {
 111         unsigned long flags;
 112         struct list_head *list;
 113         snd_card_t *card;
 114         snd_ctl_file_t *ctl;
 115         snd_kcontrol_t *control;
 116         unsigned int idx;
 117
 118         ctl = file->private_data;
 119         fasync_helper(-1, file, 0, &ctl->fasync);
 120         file->private_data = NULL;
 121         card = ctl->card;
 122         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 123         list_del(&ctl->list);
 124         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 125         down_write(&card->controls_rwsem);
 126         list_for_each(list, &card->controls) {
 127                 control = snd_kcontrol(list);
 128                 for (idx = 0; idx < control->count; idx++)
 129                         if (control->vd[idx].owner == ctl)
 130                                 control->vd[idx].owner = NULL;
 131         }
 132         up_write(&card->controls_rwsem);
 133         snd_ctl_empty_read_queue(ctl);
 134         kfree(ctl);
 135         module_put(card->module);
 136         snd_card_file_remove(card, file);
 137         return 0;
 138 }
 139
 140 void snd_ctl_notify(snd_card_t *card, unsigned int mask, snd_ctl_elem_id_t *id)
 141 {
 142         unsigned long flags;
 143         struct list_head *flist;
 144         snd_ctl_file_t *ctl;
 145         snd_kctl_event_t *ev;
 146
 147         snd_runtime_check(card != NULL && id != NULL, return);
 148         read_lock(&card->ctl_files_rwlock);
 149 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 150         card->mixer_oss_change_count++;
 151 #endif
 152         list_for_each(flist, &card->ctl_files) {
 153                 struct list_head *elist;
 154                 ctl = snd_ctl_file(flist);
 155                 if (!ctl->subscribed)
 156                         continue;
 157                 spin_lock_irqsave(&ctl->read_lock, flags);
 158                 list_for_each(elist, &ctl->events) {
 159                         ev = snd_kctl_event(elist);
 160                         if (ev->id.numid == id->numid) {
 161                                 ev->mask |= mask;
 162                                 goto _found;
 163                         }
 164                 }
 165                 ev = kcalloc(1, sizeof(*ev), GFP_ATOMIC);
 166                 if (ev) {
 167                         ev->id = *id;
 168                         ev->mask = mask;
 169                         list_add_tail(&ev->list, &ctl->events);
 170                 } else {
 171                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 172                 }
 173         _found:
 174                 wake_up(&ctl->change_sleep);
 175                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 176                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 177         }
 178         read_unlock(&card->ctl_files_rwlock);
 179 }
 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 snd_kcontrol_t 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 snd_kcontrol_t *snd_ctl_new(snd_kcontrol_t * control, unsigned int access)
 192 {
 193         snd_kcontrol_t *kctl;
 194         unsigned int idx;
 195
 196         snd_runtime_check(control != NULL, return NULL);
 197         snd_runtime_check(control->count > 0, return NULL);
 198         kctl = kcalloc(1, sizeof(*kctl) + sizeof(snd_kcontrol_volatile_t) * control->count, GFP_KERNEL);
 199         if (kctl == NULL)
 200                 return NULL;
 201         *kctl = *control;
 202         for (idx = 0; idx < kctl->count; idx++)
 203                 kctl->vd[idx].access = access;
 204         return kctl;
 205 }
 206
 207 /**
 208  * snd_ctl_new1 - create a control instance from the template
 209  * @ncontrol: the initialization record
 210  * @private_data: the private data to set
 211  *
 212  * Allocates a new snd_kcontrol_t instance and initialize from the given
 213  * template.  When the access field of ncontrol is 0, it's assumed as
 214  * READWRITE access. When the count field is 0, it's assumes as one.
 215  *
 216  * Returns the pointer of the newly generated instance, or NULL on failure.
 217  */
 218 snd_kcontrol_t *snd_ctl_new1(snd_kcontrol_new_t * ncontrol, void *private_data)
 219 {
 220         snd_kcontrol_t kctl;
 221         unsigned int access;
 222
 223         snd_runtime_check(ncontrol != NULL, return NULL);
 224         snd_assert(ncontrol->info != NULL, return NULL);
 225         memset(&kctl, 0, sizeof(kctl));
 226         kctl.id.iface = ncontrol->iface;
 227         kctl.id.device = ncontrol->device;
 228         kctl.id.subdevice = ncontrol->subdevice;
 229         if (ncontrol->name)
 230                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 231         kctl.id.index = ncontrol->index;
 232         kctl.count = ncontrol->count ? ncontrol->count : 1;
 233         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 234                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 235                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
 236         kctl.info = ncontrol->info;
 237         kctl.get = ncontrol->get;
 238         kctl.put = ncontrol->put;
 239         kctl.private_value = ncontrol->private_value;
 240         kctl.private_data = private_data;
 241         return snd_ctl_new(&kctl, access);
 242 }
 243
 244 /**
 245  * snd_ctl_free_one - release the control instance
 246  * @kcontrol: the control instance
 247  *
 248  * Releases the control instance created via snd_ctl_new()
 249  * or snd_ctl_new1().
 250  * Don't call this after the control was added to the card.
 251  */
 252 void snd_ctl_free_one(snd_kcontrol_t * kcontrol)
 253 {
 254         if (kcontrol) {
 255                 if (kcontrol->private_free)
 256                         kcontrol->private_free(kcontrol);
 257                 kfree(kcontrol);
 258         }
 259 }
 260
 261 static unsigned int snd_ctl_hole_check(snd_card_t * card,
 262                                        unsigned int count)
 263 {
 264         struct list_head *list;
 265         snd_kcontrol_t *kctl;
 266
 267         list_for_each(list, &card->controls) {
 268                 kctl = snd_kcontrol(list);
 269                 if ((kctl->id.numid <= card->last_numid &&
 270                      kctl->id.numid + kctl->count > card->last_numid) ||
 271                     (kctl->id.numid <= card->last_numid + count - 1 &&
 272                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 273                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 274         }
 275         return card->last_numid;
 276 }
 277
 278 static int snd_ctl_find_hole(snd_card_t * card, unsigned int count)
 279 {
 280         unsigned int last_numid, iter = 100000;
 281
 282         last_numid = card->last_numid;
 283         while (last_numid != snd_ctl_hole_check(card, count)) {
 284                 if (--iter == 0) {
 285                         /* this situation is very unlikely */
 286                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 287                         return -ENOMEM;
 288                 }
 289                 last_numid = card->last_numid;
 290         }
 291         return 0;
 292 }
 293
 294 /**
 295  * snd_ctl_add - add the control instance to the card
 296  * @card: the card instance
 297  * @kcontrol: the control instance to add
 298  *
 299  * Adds the control instance created via snd_ctl_new() or
 300  * snd_ctl_new1() to the given card. Assigns also an unique
 301  * numid used for fast search.
 302  *
 303  * Returns zero if successful, or a negative error code on failure.
 304  *
 305  * It frees automatically the control which cannot be added.
 306  */
 307 int snd_ctl_add(snd_card_t * card, snd_kcontrol_t * kcontrol)
 308 {
 309         snd_ctl_elem_id_t id;
 310         unsigned int idx;
 311
 312         snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
 313         snd_assert(kcontrol->info != NULL, return -EINVAL);
 314         id = kcontrol->id;
 315         down_write(&card->controls_rwsem);
 316         if (snd_ctl_find_id(card, &id)) {
 317                 up_write(&card->controls_rwsem);
 318                 snd_ctl_free_one(kcontrol);
 319                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 320                                         id.iface,
 321                                         id.device,
 322                                         id.subdevice,
 323                                         id.name,
 324                                         id.index);
 325                 return -EBUSY;
 326         }
 327         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 328                 up_write(&card->controls_rwsem);
 329                 snd_ctl_free_one(kcontrol);
 330                 return -ENOMEM;
 331         }
 332         list_add_tail(&kcontrol->list, &card->controls);
 333         card->controls_count += kcontrol->count;
 334         kcontrol->id.numid = card->last_numid + 1;
 335         card->last_numid += kcontrol->count;
 336         up_write(&card->controls_rwsem);
 337         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 338                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 339         return 0;
 340 }
 341
 342 /**
 343  * snd_ctl_remove - remove the control from the card and release it
 344  * @card: the card instance
 345  * @kcontrol: the control instance to remove
 346  *
 347  * Removes the control from the card and then releases the instance.
 348  * You don't need to call snd_ctl_free_one(). You must be in
 349  * the write lock - down_write(&card->controls_rwsem).
 350  *
 351  * Returns 0 if successful, or a negative error code on failure.
 352  */
 353 int snd_ctl_remove(snd_card_t * card, snd_kcontrol_t * kcontrol)
 354 {
 355         snd_ctl_elem_id_t id;
 356         unsigned int idx;
 357
 358         snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
 359         list_del(&kcontrol->list);
 360         card->controls_count -= kcontrol->count;
 361         id = kcontrol->id;
 362         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 363                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 364         snd_ctl_free_one(kcontrol);
 365         return 0;
 366 }
 367
 368 /**
 369  * snd_ctl_remove_id - remove the control of the given id and release it
 370  * @card: the card instance
 371  * @id: the control id to remove
 372  *
 373  * Finds the control instance with the given id, removes it from the
 374  * card list and releases it.
 375  *
 376  * Returns 0 if successful, or a negative error code on failure.
 377  */
 378 int snd_ctl_remove_id(snd_card_t * card, snd_ctl_elem_id_t *id)
 379 {
 380         snd_kcontrol_t *kctl;
 381         int ret;
 382
 383         down_write(&card->controls_rwsem);
 384         kctl = snd_ctl_find_id(card, id);
 385         if (kctl == NULL) {
 386                 up_write(&card->controls_rwsem);
 387                 return -ENOENT;
 388         }
 389         ret = snd_ctl_remove(card, kctl);
 390         up_write(&card->controls_rwsem);
 391         return ret;
 392 }
 393
 394 /**
 395  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 396  * @file: active control handle
 397  * @id: the control id to remove
 398  *
 399  * Finds the control instance with the given id, removes it from the
 400  * card list and releases it.
 401  *
 402  * Returns 0 if successful, or a negative error code on failure.
 403  */
 404 static int snd_ctl_remove_unlocked_id(snd_ctl_file_t * file, snd_ctl_elem_id_t *id)
 405 {
 406         snd_card_t *card = file->card;
 407         snd_kcontrol_t *kctl;
 408         int idx, ret;
 409
 410         down_write(&card->controls_rwsem);
 411         kctl = snd_ctl_find_id(card, id);
 412         if (kctl == NULL) {
 413                 up_write(&card->controls_rwsem);
 414                 return -ENOENT;
 415         }
 416         for (idx = 0; idx < kctl->count; idx++)
 417                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 418                         up_write(&card->controls_rwsem);
 419                         return -EBUSY;
 420                 }
 421         ret = snd_ctl_remove(card, kctl);
 422         up_write(&card->controls_rwsem);
 423         return ret;
 424 }
 425
 426 /**
 427  * snd_ctl_rename_id - replace the id of a control on the card
 428  * @card: the card instance
 429  * @src_id: the old id
 430  * @dst_id: the new id
 431  *
 432  * Finds the control with the old id from the card, and replaces the
 433  * id with the new one.
 434  *
 435  * Returns zero if successful, or a negative error code on failure.
 436  */
 437 int snd_ctl_rename_id(snd_card_t * card, snd_ctl_elem_id_t *src_id, snd_ctl_elem_id_t *dst_id)
 438 {
 439         snd_kcontrol_t *kctl;
 440
 441         down_write(&card->controls_rwsem);
 442         kctl = snd_ctl_find_id(card, src_id);
 443         if (kctl == NULL) {
 444                 up_write(&card->controls_rwsem);
 445                 return -ENOENT;
 446         }
 447         kctl->id = *dst_id;
 448         kctl->id.numid = card->last_numid + 1;
 449         card->last_numid += kctl->count;
 450         up_write(&card->controls_rwsem);
 451         return 0;
 452 }
 453
 454 /**
 455  * snd_ctl_find_numid - find the control instance with the given number-id
 456  * @card: the card instance
 457  * @numid: the number-id to search
 458  *
 459  * Finds the control instance with the given number-id from the card.
 460  *
 461  * Returns the pointer of the instance if found, or NULL if not.
 462  *
 463  * The caller must down card->controls_rwsem before calling this function
 464  * (if the race condition can happen).
 465  */
 466 snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid)
 467 {
 468         struct list_head *list;
 469         snd_kcontrol_t *kctl;
 470
 471         snd_runtime_check(card != NULL && numid != 0, return NULL);
 472         list_for_each(list, &card->controls) {
 473                 kctl = snd_kcontrol(list);
 474                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 475                         return kctl;
 476         }
 477         return NULL;
 478 }
 479
 480 /**
 481  * snd_ctl_find_id - find the control instance with the given id
 482  * @card: the card instance
 483  * @id: the id to search
 484  *
 485  * Finds the control instance with the given id from the card.
 486  *
 487  * Returns the pointer of the instance if found, or NULL if not.
 488  *
 489  * The caller must down card->controls_rwsem before calling this function
 490  * (if the race condition can happen).
 491  */
 492 snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
 493 {
 494         struct list_head *list;
 495         snd_kcontrol_t *kctl;
 496
 497         snd_runtime_check(card != NULL && id != NULL, return NULL);
 498         if (id->numid != 0)
 499                 return snd_ctl_find_numid(card, id->numid);
 500         list_for_each(list, &card->controls) {
 501                 kctl = snd_kcontrol(list);
 502                 if (kctl->id.iface != id->iface)
 503                         continue;
 504                 if (kctl->id.device != id->device)
 505                         continue;
 506                 if (kctl->id.subdevice != id->subdevice)
 507                         continue;
 508                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 509                         continue;
 510                 if (kctl->id.index > id->index)
 511                         continue;
 512                 if (kctl->id.index + kctl->count <= id->index)
 513                         continue;
 514                 return kctl;
 515         }
 516         return NULL;
 517 }
 518
 519 static int snd_ctl_card_info(snd_card_t * card, snd_ctl_file_t * ctl,
 520                              unsigned int cmd, void __user *arg)
 521 {
 522         snd_ctl_card_info_t *info;
 523
 524         info = kcalloc(1, sizeof(*info), GFP_KERNEL);
 525         if (! info)
 526                 return -ENOMEM;
 527         down_read(&snd_ioctl_rwsem);
 528         info->card = card->number;
 529         strlcpy(info->id, card->id, sizeof(info->id));
 530         strlcpy(info->driver, card->driver, sizeof(info->driver));
 531         strlcpy(info->name, card->shortname, sizeof(info->name));
 532         strlcpy(info->longname, card->longname, sizeof(info->longname));
 533         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 534         strlcpy(info->components, card->components, sizeof(info->components));
 535         up_read(&snd_ioctl_rwsem);
 536         if (copy_to_user(arg, info, sizeof(snd_ctl_card_info_t))) {
 537                 kfree(info);
 538                 return -EFAULT;
 539         }
 540         kfree(info);
 541         return 0;
 542 }
 543
 544 static int snd_ctl_elem_list(snd_card_t *card, snd_ctl_elem_list_t __user *_list)
 545 {
 546         struct list_head *plist;
 547         snd_ctl_elem_list_t list;
 548         snd_kcontrol_t *kctl;
 549         snd_ctl_elem_id_t *dst, *id;
 550         unsigned int offset, space, first, jidx;
 551
 552         if (copy_from_user(&list, _list, sizeof(list)))
 553                 return -EFAULT;
 554         offset = list.offset;
 555         space = list.space;
 556         first = 0;
 557         /* try limit maximum space */
 558         if (space > 16384)
 559                 return -ENOMEM;
 560         if (space > 0) {
 561                 /* allocate temporary buffer for atomic operation */
 562                 dst = vmalloc(space * sizeof(snd_ctl_elem_id_t));
 563                 if (dst == NULL)
 564                         return -ENOMEM;
 565                 down_read(&card->controls_rwsem);
 566                 list.count = card->controls_count;
 567                 plist = card->controls.next;
 568                 while (plist != &card->controls) {
 569                         if (offset == 0)
 570                                 break;
 571                         kctl = snd_kcontrol(plist);
 572                         if (offset < kctl->count)
 573                                 break;
 574                         offset -= kctl->count;
 575                         plist = plist->next;
 576                 }
 577                 list.used = 0;
 578                 id = dst;
 579                 while (space > 0 && plist != &card->controls) {
 580                         kctl = snd_kcontrol(plist);
 581                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 582                                 snd_ctl_build_ioff(id, kctl, jidx);
 583                                 id++;
 584                                 space--;
 585                                 list.used++;
 586                         }
 587                         plist = plist->next;
 588                         offset = 0;
 589                 }
 590                 up_read(&card->controls_rwsem);
 591                 if (list.used > 0 && copy_to_user(list.pids, dst, list.used * sizeof(snd_ctl_elem_id_t))) {
 592                         vfree(dst);
 593                         return -EFAULT;
 594                 }
 595                 vfree(dst);
 596         } else {
 597                 down_read(&card->controls_rwsem);
 598                 list.count = card->controls_count;
 599                 up_read(&card->controls_rwsem);
 600         }
 601         if (copy_to_user(_list, &list, sizeof(list)))
 602                 return -EFAULT;
 603         return 0;
 604 }
 605
 606 static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t *info)
 607 {
 608         snd_card_t *card = ctl->card;
 609         snd_kcontrol_t *kctl;
 610         snd_kcontrol_volatile_t *vd;
 611         unsigned int index_offset;
 612         int result;
 613
 614         down_read(&card->controls_rwsem);
 615         kctl = snd_ctl_find_id(card, &info->id);
 616         if (kctl == NULL) {
 617                 up_read(&card->controls_rwsem);
 618                 return -ENOENT;
 619         }
 620 #ifdef CONFIG_SND_DEBUG
 621         info->access = 0;
 622 #endif
 623         result = kctl->info(kctl, info);
 624         if (result >= 0) {
 625                 snd_assert(info->access == 0, );
 626                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 627                 vd = &kctl->vd[index_offset];
 628                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 629                 info->access = vd->access;
 630                 if (vd->owner) {
 631                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 632                         if (vd->owner == ctl)
 633                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 634                         info->owner = vd->owner_pid;
 635                 } else {
 636                         info->owner = -1;
 637                 }
 638         }
 639         up_read(&card->controls_rwsem);
 640         return result;
 641 }
 642
 643 static int snd_ctl_elem_info_user(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_info)
 644 {
 645         snd_ctl_elem_info_t info;
 646         int result;
 647
 648         if (copy_from_user(&info, _info, sizeof(info)))
 649                 return -EFAULT;
 650         result = snd_ctl_elem_info(ctl, &info);
 651         if (result >= 0)
 652                 if (copy_to_user(_info, &info, sizeof(info)))
 653                         return -EFAULT;
 654         return result;
 655 }
 656
 657 int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t *control)
 658 {
 659         snd_kcontrol_t *kctl;
 660         snd_kcontrol_volatile_t *vd;
 661         unsigned int index_offset;
 662         int result, indirect;
 663
 664         down_read(&card->controls_rwsem);
 665         kctl = snd_ctl_find_id(card, &control->id);
 666         if (kctl == NULL) {
 667                 result = -ENOENT;
 668         } else {
 669                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 670                 vd = &kctl->vd[index_offset];
 671                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 672                 if (control->indirect != indirect) {
 673                         result = -EACCES;
 674                 } else {
 675                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 676                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 677                                 result = kctl->get(kctl, control);
 678                         } else {
 679                                 result = -EPERM;
 680                         }
 681                 }
 682         }
 683         up_read(&card->controls_rwsem);
 684         return result;
 685 }
 686
 687 static int snd_ctl_elem_read_user(snd_card_t *card, snd_ctl_elem_value_t __user *_control)
 688 {
 689         snd_ctl_elem_value_t *control;
 690         int result;
 691
 692         control = kmalloc(sizeof(*control), GFP_KERNEL);
 693         if (control == NULL)
 694                 return -ENOMEM;
 695         if (copy_from_user(control, _control, sizeof(*control))) {
 696                 kfree(control);
 697                 return -EFAULT;
 698         }
 699         result = snd_ctl_elem_read(card, control);
 700         if (result >= 0)
 701                 if (copy_to_user(_control, control, sizeof(*control)))
 702                         result = -EFAULT;
 703         kfree(control);
 704         return result;
 705 }
 706
 707 int snd_ctl_elem_write(snd_card_t *card, snd_ctl_file_t *file, snd_ctl_elem_value_t *control)
 708 {
 709         snd_kcontrol_t *kctl;
 710         snd_kcontrol_volatile_t *vd;
 711         unsigned int index_offset;
 712         int result, indirect;
 713
 714         down_read(&card->controls_rwsem);
 715         kctl = snd_ctl_find_id(card, &control->id);
 716         if (kctl == NULL) {
 717                 result = -ENOENT;
 718         } else {
 719                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 720                 vd = &kctl->vd[index_offset];
 721                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 722                 if (control->indirect != indirect) {
 723                         result = -EACCES;
 724                 } else {
 725                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 726                             kctl->put == NULL ||
 727                             (file && vd->owner != NULL && vd->owner != file)) {
 728                                 result = -EPERM;
 729                         } else {
 730                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 731                                 result = kctl->put(kctl, control);
 732                         }
 733                         if (result > 0) {
 734                                 up_read(&card->controls_rwsem);
 735                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 736                                 return 0;
 737                         }
 738                 }
 739         }
 740         up_read(&card->controls_rwsem);
 741         return result;
 742 }
 743
 744 static int snd_ctl_elem_write_user(snd_ctl_file_t *file, snd_ctl_elem_value_t __user *_control)
 745 {
 746         snd_ctl_elem_value_t *control;
 747         int result;
 748
 749         control = kmalloc(sizeof(*control), GFP_KERNEL);
 750         if (control == NULL)
 751                 return -ENOMEM;
 752         if (copy_from_user(control, _control, sizeof(*control))) {
 753                 kfree(control);
 754                 return -EFAULT;
 755         }
 756         result = snd_ctl_elem_write(file->card, file, control);
 757         if (result >= 0)
 758                 if (copy_to_user(_control, control, sizeof(*control)))
 759                         result = -EFAULT;
 760         kfree(control);
 761         return result;
 762 }
 763
 764 static int snd_ctl_elem_lock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
 765 {
 766         snd_card_t *card = file->card;
 767         snd_ctl_elem_id_t id;
 768         snd_kcontrol_t *kctl;
 769         snd_kcontrol_volatile_t *vd;
 770         int result;
 771
 772         if (copy_from_user(&id, _id, sizeof(id)))
 773                 return -EFAULT;
 774         down_write(&card->controls_rwsem);
 775         kctl = snd_ctl_find_id(card, &id);
 776         if (kctl == NULL) {
 777                 result = -ENOENT;
 778         } else {
 779                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 780                 if (vd->owner != NULL)
 781                         result = -EBUSY;
 782                 else {
 783                         vd->owner = file;
 784                         vd->owner_pid = current->pid;
 785                         result = 0;
 786                 }
 787         }
 788         up_write(&card->controls_rwsem);
 789         return result;
 790 }
 791
 792 static int snd_ctl_elem_unlock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
 793 {
 794         snd_card_t *card = file->card;
 795         snd_ctl_elem_id_t id;
 796         snd_kcontrol_t *kctl;
 797         snd_kcontrol_volatile_t *vd;
 798         int result;
 799
 800         if (copy_from_user(&id, _id, sizeof(id)))
 801                 return -EFAULT;
 802         down_write(&card->controls_rwsem);
 803         kctl = snd_ctl_find_id(card, &id);
 804         if (kctl == NULL) {
 805                 result = -ENOENT;
 806         } else {
 807                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 808                 if (vd->owner == NULL)
 809                         result = -EINVAL;
 810                 else if (vd->owner != file)
 811                         result = -EPERM;
 812                 else {
 813                         vd->owner = NULL;
 814                         vd->owner_pid = 0;
 815                         result = 0;
 816                 }
 817         }
 818         up_write(&card->controls_rwsem);
 819         return result;
 820 }
 821
 822 struct user_element {
 823         snd_ctl_elem_info_t info;
 824         void *elem_data;                /* element data */
 825         unsigned long elem_data_size;   /* size of element data in bytes */
 826         void *priv_data;                /* private data (like strings for enumerated type) */
 827         unsigned long priv_data_size;   /* size of private data in bytes */
 828 };
 829
 830 static int snd_ctl_elem_user_info(snd_kcontrol_t *kcontrol, snd_ctl_elem_info_t *uinfo)
 831 {
 832         struct user_element *ue = kcontrol->private_data;
 833
 834         *uinfo = ue->info;
 835         return 0;
 836 }
 837
 838 static int snd_ctl_elem_user_get(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
 839 {
 840         struct user_element *ue = kcontrol->private_data;
 841
 842         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 843         return 0;
 844 }
 845
 846 static int snd_ctl_elem_user_put(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
 847 {
 848         int change;
 849         struct user_element *ue = kcontrol->private_data;
 850
 851         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 852         if (change)
 853                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 854         return change;
 855 }
 856
 857 static void snd_ctl_elem_user_free(snd_kcontrol_t * kcontrol)
 858 {
 859         kfree(kcontrol->private_data);
 860 }
 861
 862 static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t *info, int replace)
 863 {
 864         snd_card_t *card = file->card;
 865         snd_kcontrol_t kctl, *_kctl;
 866         unsigned int access;
 867         long private_size;
 868         struct user_element *ue;
 869         int idx, err;
 870
 871         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 872                 return -ENOMEM;
 873         if (info->count > 1024)
 874                 return -EINVAL;
 875         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 876                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE));
 877         info->id.numid = 0;
 878         memset(&kctl, 0, sizeof(kctl));
 879         down_write(&card->controls_rwsem);
 880         _kctl = snd_ctl_find_id(card, &info->id);
 881         err = 0;
 882         if (_kctl) {
 883                 if (replace)
 884                         err = snd_ctl_remove(card, _kctl);
 885                 else
 886                         err = -EBUSY;
 887         } else {
 888                 if (replace)
 889                         err = -ENOENT;
 890         }
 891         up_write(&card->controls_rwsem);
 892         if (err < 0)
 893                 return err;
 894         memcpy(&kctl.id, &info->id, sizeof(info->id));
 895         kctl.count = info->owner ? info->owner : 1;
 896         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 897         kctl.info = snd_ctl_elem_user_info;
 898         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 899                 kctl.get = snd_ctl_elem_user_get;
 900         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 901                 kctl.put = snd_ctl_elem_user_put;
 902         switch (info->type) {
 903         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 904                 private_size = sizeof(char);
 905                 if (info->count > 128)
 906                         return -EINVAL;
 907                 break;
 908         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 909                 private_size = sizeof(long);
 910                 if (info->count > 128)
 911                         return -EINVAL;
 912                 break;
 913         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 914                 private_size = sizeof(long long);
 915                 if (info->count > 64)
 916                         return -EINVAL;
 917                 break;
 918         case SNDRV_CTL_ELEM_TYPE_BYTES:
 919                 private_size = sizeof(unsigned char);
 920                 if (info->count > 512)
 921                         return -EINVAL;
 922                 break;
 923         case SNDRV_CTL_ELEM_TYPE_IEC958:
 924                 private_size = sizeof(struct sndrv_aes_iec958);
 925                 if (info->count != 1)
 926                         return -EINVAL;
 927                 break;
 928         default:
 929                 return -EINVAL;
 930         }
 931         private_size *= info->count;
 932         ue = kcalloc(1, sizeof(struct user_element) + private_size, GFP_KERNEL);
 933         if (ue == NULL)
 934                 return -ENOMEM;
 935         ue->info = *info;
 936         ue->elem_data = (char *)ue + sizeof(*ue);
 937         ue->elem_data_size = private_size;
 938         kctl.private_free = snd_ctl_elem_user_free;
 939         _kctl = snd_ctl_new(&kctl, access);
 940         if (_kctl == NULL) {
 941                 kfree(_kctl->private_data);
 942                 return -ENOMEM;
 943         }
 944         _kctl->private_data = ue;
 945         for (idx = 0; idx < _kctl->count; idx++)
 946                 _kctl->vd[idx].owner = file;
 947         err = snd_ctl_add(card, _kctl);
 948         if (err < 0) {
 949                 snd_ctl_free_one(_kctl);
 950                 return err;
 951         }
 952
 953         down_write(&card->controls_rwsem);
 954         card->user_ctl_count++;
 955         up_write(&card->controls_rwsem);
 956
 957         return 0;
 958 }
 959
 960 static int snd_ctl_elem_add_user(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_info, int replace)
 961 {
 962         snd_ctl_elem_info_t info;
 963         if (copy_from_user(&info, _info, sizeof(info)))
 964                 return -EFAULT;
 965         return snd_ctl_elem_add(file, &info, replace);
 966 }
 967
 968 static int snd_ctl_elem_remove(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
 969 {
 970         snd_ctl_elem_id_t id;
 971         int err;
 972
 973         if (copy_from_user(&id, _id, sizeof(id)))
 974                 return -EFAULT;
 975         err = snd_ctl_remove_unlocked_id(file, &id);
 976         if (! err) {
 977                 snd_card_t *card = file->card;
 978                 down_write(&card->controls_rwsem);
 979                 card->user_ctl_count--;
 980                 up_write(&card->controls_rwsem);
 981         }
 982         return err;
 983 }
 984
 985 static int snd_ctl_subscribe_events(snd_ctl_file_t *file, int __user *ptr)
 986 {
 987         int subscribe;
 988         if (get_user(subscribe, ptr))
 989                 return -EFAULT;
 990         if (subscribe < 0) {
 991                 subscribe = file->subscribed;
 992                 if (put_user(subscribe, ptr))
 993                         return -EFAULT;
 994                 return 0;
 995         }
 996         if (subscribe) {
 997                 file->subscribed = 1;
 998                 return 0;
 999         } else if (file->subscribed) {
1000                 snd_ctl_empty_read_queue(file);
1001                 file->subscribed = 0;
1002         }
1003         return 0;
1004 }
1005
1006 #ifdef CONFIG_PM
1007 /*
1008  * change the power state
1009  */
1010 static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
1011 {
1012         switch (power_state) {
1013         case SNDRV_CTL_POWER_D0:
1014                 if (card->power_state != power_state) {
1015                         card->pm_resume(card);
1016                         snd_power_change_state(card, power_state);
1017                 }
1018                 break;
1019         case SNDRV_CTL_POWER_D3hot:
1020                 if (card->power_state != power_state) {
1021                         card->pm_suspend(card, PMSG_SUSPEND);
1022                         snd_power_change_state(card, power_state);
1023                 }
1024                 break;
1025         case SNDRV_CTL_POWER_D1:
1026         case SNDRV_CTL_POWER_D2:
1027         case SNDRV_CTL_POWER_D3cold:
1028                 /* not supported yet */
1029         default:
1030                 return -EINVAL;
1031         }
1032         return 0;
1033 }
1034 #endif
1035
1036 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1037 {
1038         snd_ctl_file_t *ctl;
1039         snd_card_t *card;
1040         struct list_head *list;
1041         snd_kctl_ioctl_t *p;
1042         void __user *argp = (void __user *)arg;
1043         int __user *ip = argp;
1044         int err;
1045
1046         ctl = file->private_data;
1047         card = ctl->card;
1048         snd_assert(card != NULL, return -ENXIO);
1049         switch (cmd) {
1050         case SNDRV_CTL_IOCTL_PVERSION:
1051                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1052         case SNDRV_CTL_IOCTL_CARD_INFO:
1053                 return snd_ctl_card_info(card, ctl, cmd, argp);
1054         case SNDRV_CTL_IOCTL_ELEM_LIST:
1055                 return snd_ctl_elem_list(ctl->card, argp);
1056         case SNDRV_CTL_IOCTL_ELEM_INFO:
1057                 return snd_ctl_elem_info_user(ctl, argp);
1058         case SNDRV_CTL_IOCTL_ELEM_READ:
1059                 return snd_ctl_elem_read_user(ctl->card, argp);
1060         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1061                 return snd_ctl_elem_write_user(ctl, argp);
1062         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1063                 return snd_ctl_elem_lock(ctl, argp);
1064         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1065                 return snd_ctl_elem_unlock(ctl, argp);
1066         case SNDRV_CTL_IOCTL_ELEM_ADD:
1067                 return snd_ctl_elem_add_user(ctl, argp, 0);
1068         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1069                 return snd_ctl_elem_add_user(ctl, argp, 1);
1070         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1071                 return snd_ctl_elem_remove(ctl, argp);
1072         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1073                 return snd_ctl_subscribe_events(ctl, ip);
1074         case SNDRV_CTL_IOCTL_POWER:
1075                 if (get_user(err, ip))
1076                         return -EFAULT;
1077                 if (!capable(CAP_SYS_ADMIN))
1078                         return -EPERM;
1079 #ifdef CONFIG_PM
1080                 if (card->pm_suspend && card->pm_resume) {
1081                         snd_power_lock(card);
1082                         err = snd_ctl_set_power_state(card, err);
1083                         snd_power_unlock(card);
1084                 } else
1085 #endif
1086                         err = -ENOPROTOOPT;
1087                 return err;
1088         case SNDRV_CTL_IOCTL_POWER_STATE:
1089 #ifdef CONFIG_PM
1090                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1091 #else
1092                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1093 #endif
1094         }
1095         down_read(&snd_ioctl_rwsem);
1096         list_for_each(list, &snd_control_ioctls) {
1097                 p = list_entry(list, snd_kctl_ioctl_t, list);
1098                 err = p->fioctl(card, ctl, cmd, arg);
1099                 if (err != -ENOIOCTLCMD) {
1100                         up_read(&snd_ioctl_rwsem);
1101                         return err;
1102                 }
1103         }
1104         up_read(&snd_ioctl_rwsem);
1105         snd_printd("unknown ioctl = 0x%x\n", cmd);
1106         return -ENOTTY;
1107 }
1108
1109 static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count, loff_t * offset)
1110 {
1111         snd_ctl_file_t *ctl;
1112         int err = 0;
1113         ssize_t result = 0;
1114
1115         ctl = file->private_data;
1116         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1117         if (!ctl->subscribed)
1118                 return -EBADFD;
1119         if (count < sizeof(snd_ctl_event_t))
1120                 return -EINVAL;
1121         spin_lock_irq(&ctl->read_lock);
1122         while (count >= sizeof(snd_ctl_event_t)) {
1123                 snd_ctl_event_t ev;
1124                 snd_kctl_event_t *kev;
1125                 while (list_empty(&ctl->events)) {
1126                         wait_queue_t wait;
1127                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1128                                 err = -EAGAIN;
1129                                 goto __end_lock;
1130                         }
1131                         init_waitqueue_entry(&wait, current);
1132                         add_wait_queue(&ctl->change_sleep, &wait);
1133                         set_current_state(TASK_INTERRUPTIBLE);
1134                         spin_unlock_irq(&ctl->read_lock);
1135                         schedule();
1136                         remove_wait_queue(&ctl->change_sleep, &wait);
1137                         if (signal_pending(current))
1138                                 return result > 0 ? result : -ERESTARTSYS;
1139                         spin_lock_irq(&ctl->read_lock);
1140                 }
1141                 kev = snd_kctl_event(ctl->events.next);
1142                 ev.type = SNDRV_CTL_EVENT_ELEM;
1143                 ev.data.elem.mask = kev->mask;
1144                 ev.data.elem.id = kev->id;
1145                 list_del(&kev->list);
1146                 spin_unlock_irq(&ctl->read_lock);
1147                 kfree(kev);
1148                 if (copy_to_user(buffer, &ev, sizeof(snd_ctl_event_t))) {
1149                         err = -EFAULT;
1150                         goto __end;
1151                 }
1152                 spin_lock_irq(&ctl->read_lock);
1153                 buffer += sizeof(snd_ctl_event_t);
1154                 count -= sizeof(snd_ctl_event_t);
1155                 result += sizeof(snd_ctl_event_t);
1156         }
1157       __end_lock:
1158         spin_unlock_irq(&ctl->read_lock);
1159       __end:
1160         return result > 0 ? result : err;
1161 }
1162
1163 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1164 {
1165         unsigned int mask;
1166         snd_ctl_file_t *ctl;
1167
1168         ctl = file->private_data;
1169         if (!ctl->subscribed)
1170                 return 0;
1171         poll_wait(file, &ctl->change_sleep, wait);
1172
1173         mask = 0;
1174         if (!list_empty(&ctl->events))
1175                 mask |= POLLIN | POLLRDNORM;
1176
1177         return mask;
1178 }
1179
1180 /*
1181  * register the device-specific control-ioctls.
1182  * called from each device manager like pcm.c, hwdep.c, etc.
1183  */
1184 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1185 {
1186         snd_kctl_ioctl_t *pn;
1187
1188         pn = kcalloc(1, sizeof(snd_kctl_ioctl_t), GFP_KERNEL);
1189         if (pn == NULL)
1190                 return -ENOMEM;
1191         pn->fioctl = fcn;
1192         down_write(&snd_ioctl_rwsem);
1193         list_add_tail(&pn->list, lists);
1194         up_write(&snd_ioctl_rwsem);
1195         return 0;
1196 }
1197
1198 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1199 {
1200         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1201 }
1202
1203 #ifdef CONFIG_COMPAT
1204 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1205 {
1206         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1207 }
1208 #endif
1209
1210 /*
1211  * de-register the device-specific control-ioctls.
1212  */
1213 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1214 {
1215         struct list_head *list;
1216         snd_kctl_ioctl_t *p;
1217
1218         snd_runtime_check(fcn != NULL, return -EINVAL);
1219         down_write(&snd_ioctl_rwsem);
1220         list_for_each(list, lists) {
1221                 p = list_entry(list, snd_kctl_ioctl_t, list);
1222                 if (p->fioctl == fcn) {
1223                         list_del(&p->list);
1224                         up_write(&snd_ioctl_rwsem);
1225                         kfree(p);
1226                         return 0;
1227                 }
1228         }
1229         up_write(&snd_ioctl_rwsem);
1230         snd_BUG();
1231         return -EINVAL;
1232 }
1233
1234 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1235 {
1236         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1237 }
1238
1239 #ifdef CONFIG_COMPAT
1240 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1241 {
1242         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1243 }
1244
1245 #endif
1246
1247 static int snd_ctl_fasync(int fd, struct file * file, int on)
1248 {
1249         snd_ctl_file_t *ctl;
1250         int err;
1251         ctl = file->private_data;
1252         err = fasync_helper(fd, file, on, &ctl->fasync);
1253         if (err < 0)
1254                 return err;
1255         return 0;
1256 }
1257
1258 /*
1259  * ioctl32 compat
1260  */
1261 #ifdef CONFIG_COMPAT
1262 #include "control_compat.c"
1263 #else
1264 #define snd_ctl_ioctl_compat    NULL
1265 #endif
1266
1267 /*
1268  *  INIT PART
1269  */
1270
1271 static struct file_operations snd_ctl_f_ops =
1272 {
1273         .owner =        THIS_MODULE,
1274         .read =         snd_ctl_read,
1275         .open =         snd_ctl_open,
1276         .release =      snd_ctl_release,
1277         .poll =         snd_ctl_poll,
1278         .unlocked_ioctl =       snd_ctl_ioctl,
1279         .compat_ioctl = snd_ctl_ioctl_compat,
1280         .fasync =       snd_ctl_fasync,
1281 };
1282
1283 static snd_minor_t snd_ctl_reg =
1284 {
1285         .comment =      "ctl",
1286         .f_ops =        &snd_ctl_f_ops,
1287 };
1288
1289 /*
1290  * registration of the control device
1291  */
1292 static int snd_ctl_dev_register(snd_device_t *device)
1293 {
1294         snd_card_t *card = device->device_data;
1295         int err, cardnum;
1296         char name[16];
1297
1298         snd_assert(card != NULL, return -ENXIO);
1299         cardnum = card->number;
1300         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1301         sprintf(name, "controlC%i", cardnum);
1302         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL,
1303                                         card, 0, &snd_ctl_reg, name)) < 0)
1304                 return err;
1305         return 0;
1306 }
1307
1308 /*
1309  * disconnection of the control device
1310  */
1311 static int snd_ctl_dev_disconnect(snd_device_t *device)
1312 {
1313         snd_card_t *card = device->device_data;
1314         struct list_head *flist;
1315         snd_ctl_file_t *ctl;
1316
1317         down_read(&card->controls_rwsem);
1318         list_for_each(flist, &card->ctl_files) {
1319                 ctl = snd_ctl_file(flist);
1320                 wake_up(&ctl->change_sleep);
1321                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1322         }
1323         up_read(&card->controls_rwsem);
1324         return 0;
1325 }
1326
1327 /*
1328  * free all controls
1329  */
1330 static int snd_ctl_dev_free(snd_device_t *device)
1331 {
1332         snd_card_t *card = device->device_data;
1333         snd_kcontrol_t *control;
1334
1335         down_write(&card->controls_rwsem);
1336         while (!list_empty(&card->controls)) {
1337                 control = snd_kcontrol(card->controls.next);
1338                 snd_ctl_remove(card, control);
1339         }
1340         up_write(&card->controls_rwsem);
1341         return 0;
1342 }
1343
1344 /*
1345  * de-registration of the control device
1346  */
1347 static int snd_ctl_dev_unregister(snd_device_t *device)
1348 {
1349         snd_card_t *card = device->device_data;
1350         int err, cardnum;
1351
1352         snd_assert(card != NULL, return -ENXIO);
1353         cardnum = card->number;
1354         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1355         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL, card, 0)) < 0)
1356                 return err;
1357         return snd_ctl_dev_free(device);
1358 }
1359
1360 /*
1361  * create control core:
1362  * called from init.c
1363  */
1364 int snd_ctl_create(snd_card_t *card)
1365 {
1366         static snd_device_ops_t ops = {
1367                 .dev_free = snd_ctl_dev_free,
1368                 .dev_register = snd_ctl_dev_register,
1369                 .dev_disconnect = snd_ctl_dev_disconnect,
1370                 .dev_unregister = snd_ctl_dev_unregister
1371         };
1372
1373         snd_assert(card != NULL, return -ENXIO);
1374         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1375 }