git.oblomov.eu Git - 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->prefer_pcm_subdevice = -1;
  79         ctl->prefer_rawmidi_subdevice = -1;
  80         ctl->pid = current->pid;
  81         file->private_data = ctl;
  82         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  83         list_add_tail(&ctl->list, &card->ctl_files);
  84         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  85         return 0;
  86
  87       __error:
  88         module_put(card->module);
  89       __error2:
  90         snd_card_file_remove(card, file);
  91       __error1:
  92         return err;
  93 }
  94
  95 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  96 {
  97         struct snd_kctl_event *cread;
  98
  99         spin_lock(&ctl->read_lock);
 100         while (!list_empty(&ctl->events)) {
 101                 cread = snd_kctl_event(ctl->events.next);
 102                 list_del(&cread->list);
 103                 kfree(cread);
 104         }
 105         spin_unlock(&ctl->read_lock);
 106 }
 107
 108 static int snd_ctl_release(struct inode *inode, struct file *file)
 109 {
 110         unsigned long flags;
 111         struct list_head *list;
 112         struct snd_card *card;
 113         struct snd_ctl_file *ctl;
 114         struct snd_kcontrol *control;
 115         unsigned int idx;
 116
 117         ctl = file->private_data;
 118         fasync_helper(-1, file, 0, &ctl->fasync);
 119         file->private_data = NULL;
 120         card = ctl->card;
 121         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 122         list_del(&ctl->list);
 123         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 124         down_write(&card->controls_rwsem);
 125         list_for_each(list, &card->controls) {
 126                 control = snd_kcontrol(list);
 127                 for (idx = 0; idx < control->count; idx++)
 128                         if (control->vd[idx].owner == ctl)
 129                                 control->vd[idx].owner = NULL;
 130         }
 131         up_write(&card->controls_rwsem);
 132         snd_ctl_empty_read_queue(ctl);
 133         kfree(ctl);
 134         module_put(card->module);
 135         snd_card_file_remove(card, file);
 136         return 0;
 137 }
 138
 139 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 140                     struct snd_ctl_elem_id *id)
 141 {
 142         unsigned long flags;
 143         struct list_head *flist;
 144         struct snd_ctl_file *ctl;
 145         struct snd_kctl_event *ev;
 146
 147         snd_assert(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 = kzalloc(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 EXPORT_SYMBOL(snd_ctl_notify);
 182
 183 /**
 184  * snd_ctl_new - create a control instance from the template
 185  * @control: the control template
 186  * @access: the default control access
 187  *
 188  * Allocates a new struct snd_kcontrol instance and copies the given template
 189  * to the new instance. It does not copy volatile data (access).
 190  *
 191  * Returns the pointer of the new instance, or NULL on failure.
 192  */
 193 struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control, unsigned int access)
 194 {
 195         struct snd_kcontrol *kctl;
 196         unsigned int idx;
 197
 198         snd_assert(control != NULL, return NULL);
 199         snd_assert(control->count > 0, return NULL);
 200         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 201         if (kctl == NULL) {
 202                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 203                 return NULL;
 204         }
 205         *kctl = *control;
 206         for (idx = 0; idx < kctl->count; idx++)
 207                 kctl->vd[idx].access = access;
 208         return kctl;
 209 }
 210
 211 EXPORT_SYMBOL(snd_ctl_new);
 212
 213 /**
 214  * snd_ctl_new1 - create a control instance from the template
 215  * @ncontrol: the initialization record
 216  * @private_data: the private data to set
 217  *
 218  * Allocates a new struct snd_kcontrol instance and initialize from the given
 219  * template.  When the access field of ncontrol is 0, it's assumed as
 220  * READWRITE access. When the count field is 0, it's assumes as one.
 221  *
 222  * Returns the pointer of the newly generated instance, or NULL on failure.
 223  */
 224 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 225                                   void *private_data)
 226 {
 227         struct snd_kcontrol kctl;
 228         unsigned int access;
 229
 230         snd_assert(ncontrol != NULL, return NULL);
 231         snd_assert(ncontrol->info != NULL, return NULL);
 232         memset(&kctl, 0, sizeof(kctl));
 233         kctl.id.iface = ncontrol->iface;
 234         kctl.id.device = ncontrol->device;
 235         kctl.id.subdevice = ncontrol->subdevice;
 236         if (ncontrol->name)
 237                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 238         kctl.id.index = ncontrol->index;
 239         kctl.count = ncontrol->count ? ncontrol->count : 1;
 240         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 241                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 242                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 243                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
 244                                       SNDRV_CTL_ELEM_ACCESS_INDIRECT|
 245                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 246                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 247         kctl.info = ncontrol->info;
 248         kctl.get = ncontrol->get;
 249         kctl.put = ncontrol->put;
 250         kctl.tlv.p = ncontrol->tlv.p;
 251         kctl.private_value = ncontrol->private_value;
 252         kctl.private_data = private_data;
 253         return snd_ctl_new(&kctl, access);
 254 }
 255
 256 EXPORT_SYMBOL(snd_ctl_new1);
 257
 258 /**
 259  * snd_ctl_free_one - release the control instance
 260  * @kcontrol: the control instance
 261  *
 262  * Releases the control instance created via snd_ctl_new()
 263  * or snd_ctl_new1().
 264  * Don't call this after the control was added to the card.
 265  */
 266 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 267 {
 268         if (kcontrol) {
 269                 if (kcontrol->private_free)
 270                         kcontrol->private_free(kcontrol);
 271                 kfree(kcontrol);
 272         }
 273 }
 274
 275 EXPORT_SYMBOL(snd_ctl_free_one);
 276
 277 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 278                                        unsigned int count)
 279 {
 280         struct list_head *list;
 281         struct snd_kcontrol *kctl;
 282
 283         list_for_each(list, &card->controls) {
 284                 kctl = snd_kcontrol(list);
 285                 if ((kctl->id.numid <= card->last_numid &&
 286                      kctl->id.numid + kctl->count > card->last_numid) ||
 287                     (kctl->id.numid <= card->last_numid + count - 1 &&
 288                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 289                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 290         }
 291         return card->last_numid;
 292 }
 293
 294 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 295 {
 296         unsigned int last_numid, iter = 100000;
 297
 298         last_numid = card->last_numid;
 299         while (last_numid != snd_ctl_hole_check(card, count)) {
 300                 if (--iter == 0) {
 301                         /* this situation is very unlikely */
 302                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 303                         return -ENOMEM;
 304                 }
 305                 last_numid = card->last_numid;
 306         }
 307         return 0;
 308 }
 309
 310 /**
 311  * snd_ctl_add - add the control instance to the card
 312  * @card: the card instance
 313  * @kcontrol: the control instance to add
 314  *
 315  * Adds the control instance created via snd_ctl_new() or
 316  * snd_ctl_new1() to the given card. Assigns also an unique
 317  * numid used for fast search.
 318  *
 319  * Returns zero if successful, or a negative error code on failure.
 320  *
 321  * It frees automatically the control which cannot be added.
 322  */
 323 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 324 {
 325         struct snd_ctl_elem_id id;
 326         unsigned int idx;
 327         int err = -EINVAL;
 328
 329         if (! kcontrol)
 330                 return err;
 331         snd_assert(card != NULL, goto error);
 332         snd_assert(kcontrol->info != NULL, goto error);
 333         id = kcontrol->id;
 334         down_write(&card->controls_rwsem);
 335         if (snd_ctl_find_id(card, &id)) {
 336                 up_write(&card->controls_rwsem);
 337                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 338                                         id.iface,
 339                                         id.device,
 340                                         id.subdevice,
 341                                         id.name,
 342                                         id.index);
 343                 err = -EBUSY;
 344                 goto error;
 345         }
 346         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 347                 up_write(&card->controls_rwsem);
 348                 err = -ENOMEM;
 349                 goto error;
 350         }
 351         list_add_tail(&kcontrol->list, &card->controls);
 352         card->controls_count += kcontrol->count;
 353         kcontrol->id.numid = card->last_numid + 1;
 354         card->last_numid += kcontrol->count;
 355         up_write(&card->controls_rwsem);
 356         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 357                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 358         return 0;
 359
 360  error:
 361         snd_ctl_free_one(kcontrol);
 362         return err;
 363 }
 364
 365 EXPORT_SYMBOL(snd_ctl_add);
 366
 367 /**
 368  * snd_ctl_remove - remove the control from the card and release it
 369  * @card: the card instance
 370  * @kcontrol: the control instance to remove
 371  *
 372  * Removes the control from the card and then releases the instance.
 373  * You don't need to call snd_ctl_free_one(). You must be in
 374  * the write lock - down_write(&card->controls_rwsem).
 375  *
 376  * Returns 0 if successful, or a negative error code on failure.
 377  */
 378 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 379 {
 380         struct snd_ctl_elem_id id;
 381         unsigned int idx;
 382
 383         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 384         list_del(&kcontrol->list);
 385         card->controls_count -= kcontrol->count;
 386         id = kcontrol->id;
 387         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 388                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 389         snd_ctl_free_one(kcontrol);
 390         return 0;
 391 }
 392
 393 EXPORT_SYMBOL(snd_ctl_remove);
 394
 395 /**
 396  * snd_ctl_remove_id - remove the control of the given id and release it
 397  * @card: the card instance
 398  * @id: the control id to remove
 399  *
 400  * Finds the control instance with the given id, removes it from the
 401  * card list and releases it.
 402  *
 403  * Returns 0 if successful, or a negative error code on failure.
 404  */
 405 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 406 {
 407         struct snd_kcontrol *kctl;
 408         int 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         ret = snd_ctl_remove(card, kctl);
 417         up_write(&card->controls_rwsem);
 418         return ret;
 419 }
 420
 421 EXPORT_SYMBOL(snd_ctl_remove_id);
 422
 423 /**
 424  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 425  * @file: active control handle
 426  * @id: the control id to remove
 427  *
 428  * Finds the control instance with the given id, removes it from the
 429  * card list and releases it.
 430  *
 431  * Returns 0 if successful, or a negative error code on failure.
 432  */
 433 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 434                                       struct snd_ctl_elem_id *id)
 435 {
 436         struct snd_card *card = file->card;
 437         struct snd_kcontrol *kctl;
 438         int idx, ret;
 439
 440         down_write(&card->controls_rwsem);
 441         kctl = snd_ctl_find_id(card, id);
 442         if (kctl == NULL) {
 443                 up_write(&card->controls_rwsem);
 444                 return -ENOENT;
 445         }
 446         for (idx = 0; idx < kctl->count; idx++)
 447                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 448                         up_write(&card->controls_rwsem);
 449                         return -EBUSY;
 450                 }
 451         ret = snd_ctl_remove(card, kctl);
 452         up_write(&card->controls_rwsem);
 453         return ret;
 454 }
 455
 456 /**
 457  * snd_ctl_rename_id - replace the id of a control on the card
 458  * @card: the card instance
 459  * @src_id: the old id
 460  * @dst_id: the new id
 461  *
 462  * Finds the control with the old id from the card, and replaces the
 463  * id with the new one.
 464  *
 465  * Returns zero if successful, or a negative error code on failure.
 466  */
 467 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 468                       struct snd_ctl_elem_id *dst_id)
 469 {
 470         struct snd_kcontrol *kctl;
 471
 472         down_write(&card->controls_rwsem);
 473         kctl = snd_ctl_find_id(card, src_id);
 474         if (kctl == NULL) {
 475                 up_write(&card->controls_rwsem);
 476                 return -ENOENT;
 477         }
 478         kctl->id = *dst_id;
 479         kctl->id.numid = card->last_numid + 1;
 480         card->last_numid += kctl->count;
 481         up_write(&card->controls_rwsem);
 482         return 0;
 483 }
 484
 485 EXPORT_SYMBOL(snd_ctl_rename_id);
 486
 487 /**
 488  * snd_ctl_find_numid - find the control instance with the given number-id
 489  * @card: the card instance
 490  * @numid: the number-id to search
 491  *
 492  * Finds the control instance with the given number-id from the card.
 493  *
 494  * Returns the pointer of the instance if found, or NULL if not.
 495  *
 496  * The caller must down card->controls_rwsem before calling this function
 497  * (if the race condition can happen).
 498  */
 499 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 500 {
 501         struct list_head *list;
 502         struct snd_kcontrol *kctl;
 503
 504         snd_assert(card != NULL && numid != 0, return NULL);
 505         list_for_each(list, &card->controls) {
 506                 kctl = snd_kcontrol(list);
 507                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 508                         return kctl;
 509         }
 510         return NULL;
 511 }
 512
 513 EXPORT_SYMBOL(snd_ctl_find_numid);
 514
 515 /**
 516  * snd_ctl_find_id - find the control instance with the given id
 517  * @card: the card instance
 518  * @id: the id to search
 519  *
 520  * Finds the control instance with the given id from the card.
 521  *
 522  * Returns the pointer of the instance if found, or NULL if not.
 523  *
 524  * The caller must down card->controls_rwsem before calling this function
 525  * (if the race condition can happen).
 526  */
 527 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 528                                      struct snd_ctl_elem_id *id)
 529 {
 530         struct list_head *list;
 531         struct snd_kcontrol *kctl;
 532
 533         snd_assert(card != NULL && id != NULL, return NULL);
 534         if (id->numid != 0)
 535                 return snd_ctl_find_numid(card, id->numid);
 536         list_for_each(list, &card->controls) {
 537                 kctl = snd_kcontrol(list);
 538                 if (kctl->id.iface != id->iface)
 539                         continue;
 540                 if (kctl->id.device != id->device)
 541                         continue;
 542                 if (kctl->id.subdevice != id->subdevice)
 543                         continue;
 544                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 545                         continue;
 546                 if (kctl->id.index > id->index)
 547                         continue;
 548                 if (kctl->id.index + kctl->count <= id->index)
 549                         continue;
 550                 return kctl;
 551         }
 552         return NULL;
 553 }
 554
 555 EXPORT_SYMBOL(snd_ctl_find_id);
 556
 557 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 558                              unsigned int cmd, void __user *arg)
 559 {
 560         struct snd_ctl_card_info *info;
 561
 562         info = kzalloc(sizeof(*info), GFP_KERNEL);
 563         if (! info)
 564                 return -ENOMEM;
 565         down_read(&snd_ioctl_rwsem);
 566         info->card = card->number;
 567         strlcpy(info->id, card->id, sizeof(info->id));
 568         strlcpy(info->driver, card->driver, sizeof(info->driver));
 569         strlcpy(info->name, card->shortname, sizeof(info->name));
 570         strlcpy(info->longname, card->longname, sizeof(info->longname));
 571         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 572         strlcpy(info->components, card->components, sizeof(info->components));
 573         up_read(&snd_ioctl_rwsem);
 574         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 575                 kfree(info);
 576                 return -EFAULT;
 577         }
 578         kfree(info);
 579         return 0;
 580 }
 581
 582 static int snd_ctl_elem_list(struct snd_card *card,
 583                              struct snd_ctl_elem_list __user *_list)
 584 {
 585         struct list_head *plist;
 586         struct snd_ctl_elem_list list;
 587         struct snd_kcontrol *kctl;
 588         struct snd_ctl_elem_id *dst, *id;
 589         unsigned int offset, space, first, jidx;
 590
 591         if (copy_from_user(&list, _list, sizeof(list)))
 592                 return -EFAULT;
 593         offset = list.offset;
 594         space = list.space;
 595         first = 0;
 596         /* try limit maximum space */
 597         if (space > 16384)
 598                 return -ENOMEM;
 599         if (space > 0) {
 600                 /* allocate temporary buffer for atomic operation */
 601                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 602                 if (dst == NULL)
 603                         return -ENOMEM;
 604                 down_read(&card->controls_rwsem);
 605                 list.count = card->controls_count;
 606                 plist = card->controls.next;
 607                 while (plist != &card->controls) {
 608                         if (offset == 0)
 609                                 break;
 610                         kctl = snd_kcontrol(plist);
 611                         if (offset < kctl->count)
 612                                 break;
 613                         offset -= kctl->count;
 614                         plist = plist->next;
 615                 }
 616                 list.used = 0;
 617                 id = dst;
 618                 while (space > 0 && plist != &card->controls) {
 619                         kctl = snd_kcontrol(plist);
 620                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 621                                 snd_ctl_build_ioff(id, kctl, jidx);
 622                                 id++;
 623                                 space--;
 624                                 list.used++;
 625                         }
 626                         plist = plist->next;
 627                         offset = 0;
 628                 }
 629                 up_read(&card->controls_rwsem);
 630                 if (list.used > 0 &&
 631                     copy_to_user(list.pids, dst,
 632                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 633                         vfree(dst);
 634                         return -EFAULT;
 635                 }
 636                 vfree(dst);
 637         } else {
 638                 down_read(&card->controls_rwsem);
 639                 list.count = card->controls_count;
 640                 up_read(&card->controls_rwsem);
 641         }
 642         if (copy_to_user(_list, &list, sizeof(list)))
 643                 return -EFAULT;
 644         return 0;
 645 }
 646
 647 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 648                              struct snd_ctl_elem_info *info)
 649 {
 650         struct snd_card *card = ctl->card;
 651         struct snd_kcontrol *kctl;
 652         struct snd_kcontrol_volatile *vd;
 653         unsigned int index_offset;
 654         int result;
 655
 656         down_read(&card->controls_rwsem);
 657         kctl = snd_ctl_find_id(card, &info->id);
 658         if (kctl == NULL) {
 659                 up_read(&card->controls_rwsem);
 660                 return -ENOENT;
 661         }
 662 #ifdef CONFIG_SND_DEBUG
 663         info->access = 0;
 664 #endif
 665         result = kctl->info(kctl, info);
 666         if (result >= 0) {
 667                 snd_assert(info->access == 0, );
 668                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 669                 vd = &kctl->vd[index_offset];
 670                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 671                 info->access = vd->access;
 672                 if (vd->owner) {
 673                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 674                         if (vd->owner == ctl)
 675                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 676                         info->owner = vd->owner_pid;
 677                 } else {
 678                         info->owner = -1;
 679                 }
 680         }
 681         up_read(&card->controls_rwsem);
 682         return result;
 683 }
 684
 685 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 686                                   struct snd_ctl_elem_info __user *_info)
 687 {
 688         struct snd_ctl_elem_info info;
 689         int result;
 690
 691         if (copy_from_user(&info, _info, sizeof(info)))
 692                 return -EFAULT;
 693         snd_power_lock(ctl->card);
 694         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 695         if (result >= 0)
 696                 result = snd_ctl_elem_info(ctl, &info);
 697         snd_power_unlock(ctl->card);
 698         if (result >= 0)
 699                 if (copy_to_user(_info, &info, sizeof(info)))
 700                         return -EFAULT;
 701         return result;
 702 }
 703
 704 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
 705 {
 706         struct snd_kcontrol *kctl;
 707         struct snd_kcontrol_volatile *vd;
 708         unsigned int index_offset;
 709         int result, indirect;
 710
 711         down_read(&card->controls_rwsem);
 712         kctl = snd_ctl_find_id(card, &control->id);
 713         if (kctl == NULL) {
 714                 result = -ENOENT;
 715         } else {
 716                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 717                 vd = &kctl->vd[index_offset];
 718                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 719                 if (control->indirect != indirect) {
 720                         result = -EACCES;
 721                 } else {
 722                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 723                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 724                                 result = kctl->get(kctl, control);
 725                         } else {
 726                                 result = -EPERM;
 727                         }
 728                 }
 729         }
 730         up_read(&card->controls_rwsem);
 731         return result;
 732 }
 733
 734 EXPORT_SYMBOL(snd_ctl_elem_read);
 735
 736 static int snd_ctl_elem_read_user(struct snd_card *card,
 737                                   struct snd_ctl_elem_value __user *_control)
 738 {
 739         struct snd_ctl_elem_value *control;
 740         int result;
 741
 742         control = kmalloc(sizeof(*control), GFP_KERNEL);
 743         if (control == NULL)
 744                 return -ENOMEM;
 745         if (copy_from_user(control, _control, sizeof(*control))) {
 746                 kfree(control);
 747                 return -EFAULT;
 748         }
 749         snd_power_lock(card);
 750         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 751         if (result >= 0)
 752                 result = snd_ctl_elem_read(card, control);
 753         snd_power_unlock(card);
 754         if (result >= 0)
 755                 if (copy_to_user(_control, control, sizeof(*control)))
 756                         result = -EFAULT;
 757         kfree(control);
 758         return result;
 759 }
 760
 761 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 762                        struct snd_ctl_elem_value *control)
 763 {
 764         struct snd_kcontrol *kctl;
 765         struct snd_kcontrol_volatile *vd;
 766         unsigned int index_offset;
 767         int result, indirect;
 768
 769         down_read(&card->controls_rwsem);
 770         kctl = snd_ctl_find_id(card, &control->id);
 771         if (kctl == NULL) {
 772                 result = -ENOENT;
 773         } else {
 774                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 775                 vd = &kctl->vd[index_offset];
 776                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 777                 if (control->indirect != indirect) {
 778                         result = -EACCES;
 779                 } else {
 780                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 781                             kctl->put == NULL ||
 782                             (file && vd->owner != NULL && vd->owner != file)) {
 783                                 result = -EPERM;
 784                         } else {
 785                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 786                                 result = kctl->put(kctl, control);
 787                         }
 788                         if (result > 0) {
 789                                 up_read(&card->controls_rwsem);
 790                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 791                                 return 0;
 792                         }
 793                 }
 794         }
 795         up_read(&card->controls_rwsem);
 796         return result;
 797 }
 798
 799 EXPORT_SYMBOL(snd_ctl_elem_write);
 800
 801 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 802                                    struct snd_ctl_elem_value __user *_control)
 803 {
 804         struct snd_ctl_elem_value *control;
 805         struct snd_card *card;
 806         int result;
 807
 808         control = kmalloc(sizeof(*control), GFP_KERNEL);
 809         if (control == NULL)
 810                 return -ENOMEM;
 811         if (copy_from_user(control, _control, sizeof(*control))) {
 812                 kfree(control);
 813                 return -EFAULT;
 814         }
 815         card = file->card;
 816         snd_power_lock(card);
 817         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 818         if (result >= 0)
 819                 result = snd_ctl_elem_write(card, file, control);
 820         snd_power_unlock(card);
 821         if (result >= 0)
 822                 if (copy_to_user(_control, control, sizeof(*control)))
 823                         result = -EFAULT;
 824         kfree(control);
 825         return result;
 826 }
 827
 828 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 829                              struct snd_ctl_elem_id __user *_id)
 830 {
 831         struct snd_card *card = file->card;
 832         struct snd_ctl_elem_id id;
 833         struct snd_kcontrol *kctl;
 834         struct snd_kcontrol_volatile *vd;
 835         int result;
 836
 837         if (copy_from_user(&id, _id, sizeof(id)))
 838                 return -EFAULT;
 839         down_write(&card->controls_rwsem);
 840         kctl = snd_ctl_find_id(card, &id);
 841         if (kctl == NULL) {
 842                 result = -ENOENT;
 843         } else {
 844                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 845                 if (vd->owner != NULL)
 846                         result = -EBUSY;
 847                 else {
 848                         vd->owner = file;
 849                         vd->owner_pid = current->pid;
 850                         result = 0;
 851                 }
 852         }
 853         up_write(&card->controls_rwsem);
 854         return result;
 855 }
 856
 857 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 858                                struct snd_ctl_elem_id __user *_id)
 859 {
 860         struct snd_card *card = file->card;
 861         struct snd_ctl_elem_id id;
 862         struct snd_kcontrol *kctl;
 863         struct snd_kcontrol_volatile *vd;
 864         int result;
 865
 866         if (copy_from_user(&id, _id, sizeof(id)))
 867                 return -EFAULT;
 868         down_write(&card->controls_rwsem);
 869         kctl = snd_ctl_find_id(card, &id);
 870         if (kctl == NULL) {
 871                 result = -ENOENT;
 872         } else {
 873                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 874                 if (vd->owner == NULL)
 875                         result = -EINVAL;
 876                 else if (vd->owner != file)
 877                         result = -EPERM;
 878                 else {
 879                         vd->owner = NULL;
 880                         vd->owner_pid = 0;
 881                         result = 0;
 882                 }
 883         }
 884         up_write(&card->controls_rwsem);
 885         return result;
 886 }
 887
 888 struct user_element {
 889         struct snd_ctl_elem_info info;
 890         void *elem_data;                /* element data */
 891         unsigned long elem_data_size;   /* size of element data in bytes */
 892         void *tlv_data;                 /* TLV data */
 893         unsigned long tlv_data_size;    /* TLV data size */
 894         void *priv_data;                /* private data (like strings for enumerated type) */
 895         unsigned long priv_data_size;   /* size of private data in bytes */
 896 };
 897
 898 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 899                                   struct snd_ctl_elem_info *uinfo)
 900 {
 901         struct user_element *ue = kcontrol->private_data;
 902
 903         *uinfo = ue->info;
 904         return 0;
 905 }
 906
 907 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 908                                  struct snd_ctl_elem_value *ucontrol)
 909 {
 910         struct user_element *ue = kcontrol->private_data;
 911
 912         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 913         return 0;
 914 }
 915
 916 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 917                                  struct snd_ctl_elem_value *ucontrol)
 918 {
 919         int change;
 920         struct user_element *ue = kcontrol->private_data;
 921
 922         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 923         if (change)
 924                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 925         return change;
 926 }
 927
 928 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 929                                  int op_flag,
 930                                  unsigned int size,
 931                                  unsigned int __user *tlv)
 932 {
 933         struct user_element *ue = kcontrol->private_data;
 934         int change = 0;
 935         void *new_data;
 936
 937         if (op_flag > 0) {
 938                 if (size > 1024 * 128)  /* sane value */
 939                         return -EINVAL;
 940                 new_data = kmalloc(size, GFP_KERNEL);
 941                 if (new_data == NULL)
 942                         return -ENOMEM;
 943                 if (copy_from_user(new_data, tlv, size)) {
 944                         kfree(new_data);
 945                         return -EFAULT;
 946                 }
 947                 change = ue->tlv_data_size != size;
 948                 if (!change)
 949                         change = memcmp(ue->tlv_data, new_data, size);
 950                 kfree(ue->tlv_data);
 951                 ue->tlv_data = new_data;
 952                 ue->tlv_data_size = size;
 953         } else {
 954                 if (! ue->tlv_data_size || ! ue->tlv_data)
 955                         return -ENXIO;
 956                 if (size < ue->tlv_data_size)
 957                         return -ENOSPC;
 958                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 959                         return -EFAULT;
 960         }
 961         return change;
 962 }
 963
 964 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 965 {
 966         struct user_element *ue = kcontrol->private_data;
 967         if (ue->tlv_data)
 968                 kfree(ue->tlv_data);
 969         kfree(ue);
 970 }
 971
 972 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 973                             struct snd_ctl_elem_info *info, int replace)
 974 {
 975         struct snd_card *card = file->card;
 976         struct snd_kcontrol kctl, *_kctl;
 977         unsigned int access;
 978         long private_size;
 979         struct user_element *ue;
 980         int idx, err;
 981
 982         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 983                 return -ENOMEM;
 984         if (info->count > 1024)
 985                 return -EINVAL;
 986         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 987                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 988                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 989                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 990         info->id.numid = 0;
 991         memset(&kctl, 0, sizeof(kctl));
 992         down_write(&card->controls_rwsem);
 993         _kctl = snd_ctl_find_id(card, &info->id);
 994         err = 0;
 995         if (_kctl) {
 996                 if (replace)
 997                         err = snd_ctl_remove(card, _kctl);
 998                 else
 999                         err = -EBUSY;
1000         } else {
1001                 if (replace)
1002                         err = -ENOENT;
1003         }
1004         up_write(&card->controls_rwsem);
1005         if (err < 0)
1006                 return err;
1007         memcpy(&kctl.id, &info->id, sizeof(info->id));
1008         kctl.count = info->owner ? info->owner : 1;
1009         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1010         kctl.info = snd_ctl_elem_user_info;
1011         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1012                 kctl.get = snd_ctl_elem_user_get;
1013         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1014                 kctl.put = snd_ctl_elem_user_put;
1015         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1016                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1017                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1018         }
1019         switch (info->type) {
1020         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1021         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1022                 private_size = sizeof(long);
1023                 if (info->count > 128)
1024                         return -EINVAL;
1025                 break;
1026         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1027                 private_size = sizeof(long long);
1028                 if (info->count > 64)
1029                         return -EINVAL;
1030                 break;
1031         case SNDRV_CTL_ELEM_TYPE_BYTES:
1032                 private_size = sizeof(unsigned char);
1033                 if (info->count > 512)
1034                         return -EINVAL;
1035                 break;
1036         case SNDRV_CTL_ELEM_TYPE_IEC958:
1037                 private_size = sizeof(struct snd_aes_iec958);
1038                 if (info->count != 1)
1039                         return -EINVAL;
1040                 break;
1041         default:
1042                 return -EINVAL;
1043         }
1044         private_size *= info->count;
1045         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1046         if (ue == NULL)
1047                 return -ENOMEM;
1048         ue->info = *info;
1049         ue->info.access = 0;
1050         ue->elem_data = (char *)ue + sizeof(*ue);
1051         ue->elem_data_size = private_size;
1052         kctl.private_free = snd_ctl_elem_user_free;
1053         _kctl = snd_ctl_new(&kctl, access);
1054         if (_kctl == NULL) {
1055                 kfree(ue);
1056                 return -ENOMEM;
1057         }
1058         _kctl->private_data = ue;
1059         for (idx = 0; idx < _kctl->count; idx++)
1060                 _kctl->vd[idx].owner = file;
1061         err = snd_ctl_add(card, _kctl);
1062         if (err < 0)
1063                 return err;
1064
1065         down_write(&card->controls_rwsem);
1066         card->user_ctl_count++;
1067         up_write(&card->controls_rwsem);
1068
1069         return 0;
1070 }
1071
1072 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1073                                  struct snd_ctl_elem_info __user *_info, int replace)
1074 {
1075         struct snd_ctl_elem_info info;
1076         if (copy_from_user(&info, _info, sizeof(info)))
1077                 return -EFAULT;
1078         return snd_ctl_elem_add(file, &info, replace);
1079 }
1080
1081 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1082                                struct snd_ctl_elem_id __user *_id)
1083 {
1084         struct snd_ctl_elem_id id;
1085         int err;
1086
1087         if (copy_from_user(&id, _id, sizeof(id)))
1088                 return -EFAULT;
1089         err = snd_ctl_remove_unlocked_id(file, &id);
1090         if (! err) {
1091                 struct snd_card *card = file->card;
1092                 down_write(&card->controls_rwsem);
1093                 card->user_ctl_count--;
1094                 up_write(&card->controls_rwsem);
1095         }
1096         return err;
1097 }
1098
1099 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1100 {
1101         int subscribe;
1102         if (get_user(subscribe, ptr))
1103                 return -EFAULT;
1104         if (subscribe < 0) {
1105                 subscribe = file->subscribed;
1106                 if (put_user(subscribe, ptr))
1107                         return -EFAULT;
1108                 return 0;
1109         }
1110         if (subscribe) {
1111                 file->subscribed = 1;
1112                 return 0;
1113         } else if (file->subscribed) {
1114                 snd_ctl_empty_read_queue(file);
1115                 file->subscribed = 0;
1116         }
1117         return 0;
1118 }
1119
1120 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1121                              struct snd_ctl_tlv __user *_tlv,
1122                              int op_flag)
1123 {
1124         struct snd_card *card = file->card;
1125         struct snd_ctl_tlv tlv;
1126         struct snd_kcontrol *kctl;
1127         struct snd_kcontrol_volatile *vd;
1128         unsigned int len;
1129         int err = 0;
1130
1131         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1132                 return -EFAULT;
1133         if (tlv.length < sizeof(unsigned int) * 3)
1134                 return -EINVAL;
1135         down_read(&card->controls_rwsem);
1136         kctl = snd_ctl_find_numid(card, tlv.numid);
1137         if (kctl == NULL) {
1138                 err = -ENOENT;
1139                 goto __kctl_end;
1140         }
1141         if (kctl->tlv.p == NULL) {
1142                 err = -ENXIO;
1143                 goto __kctl_end;
1144         }
1145         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1146         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1147             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1148             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1149                 err = -ENXIO;
1150                 goto __kctl_end;
1151         }
1152         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1153                 if (file && vd->owner != NULL && vd->owner != file) {
1154                         err = -EPERM;
1155                         goto __kctl_end;
1156                 }
1157                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1158                 if (err > 0) {
1159                         up_read(&card->controls_rwsem);
1160                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1161                         return 0;
1162                 }
1163         } else {
1164                 if (op_flag) {
1165                         err = -ENXIO;
1166                         goto __kctl_end;
1167                 }
1168                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1169                 if (tlv.length < len) {
1170                         err = -ENOMEM;
1171                         goto __kctl_end;
1172                 }
1173                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1174                         err = -EFAULT;
1175         }
1176       __kctl_end:
1177         up_read(&card->controls_rwsem);
1178         return err;
1179 }
1180
1181 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1182 {
1183         struct snd_ctl_file *ctl;
1184         struct snd_card *card;
1185         struct list_head *list;
1186         struct snd_kctl_ioctl *p;
1187         void __user *argp = (void __user *)arg;
1188         int __user *ip = argp;
1189         int err;
1190
1191         ctl = file->private_data;
1192         card = ctl->card;
1193         snd_assert(card != NULL, return -ENXIO);
1194         switch (cmd) {
1195         case SNDRV_CTL_IOCTL_PVERSION:
1196                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1197         case SNDRV_CTL_IOCTL_CARD_INFO:
1198                 return snd_ctl_card_info(card, ctl, cmd, argp);
1199         case SNDRV_CTL_IOCTL_ELEM_LIST:
1200                 return snd_ctl_elem_list(card, argp);
1201         case SNDRV_CTL_IOCTL_ELEM_INFO:
1202                 return snd_ctl_elem_info_user(ctl, argp);
1203         case SNDRV_CTL_IOCTL_ELEM_READ:
1204                 return snd_ctl_elem_read_user(card, argp);
1205         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1206                 return snd_ctl_elem_write_user(ctl, argp);
1207         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1208                 return snd_ctl_elem_lock(ctl, argp);
1209         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1210                 return snd_ctl_elem_unlock(ctl, argp);
1211         case SNDRV_CTL_IOCTL_ELEM_ADD:
1212                 return snd_ctl_elem_add_user(ctl, argp, 0);
1213         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1214                 return snd_ctl_elem_add_user(ctl, argp, 1);
1215         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1216                 return snd_ctl_elem_remove(ctl, argp);
1217         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1218                 return snd_ctl_subscribe_events(ctl, ip);
1219         case SNDRV_CTL_IOCTL_TLV_READ:
1220                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1221         case SNDRV_CTL_IOCTL_TLV_WRITE:
1222                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1223         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1224                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1225         case SNDRV_CTL_IOCTL_POWER:
1226                 return -ENOPROTOOPT;
1227         case SNDRV_CTL_IOCTL_POWER_STATE:
1228 #ifdef CONFIG_PM
1229                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1230 #else
1231                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1232 #endif
1233         }
1234         down_read(&snd_ioctl_rwsem);
1235         list_for_each(list, &snd_control_ioctls) {
1236                 p = list_entry(list, struct snd_kctl_ioctl, list);
1237                 err = p->fioctl(card, ctl, cmd, arg);
1238                 if (err != -ENOIOCTLCMD) {
1239                         up_read(&snd_ioctl_rwsem);
1240                         return err;
1241                 }
1242         }
1243         up_read(&snd_ioctl_rwsem);
1244         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1245         return -ENOTTY;
1246 }
1247
1248 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1249                             size_t count, loff_t * offset)
1250 {
1251         struct snd_ctl_file *ctl;
1252         int err = 0;
1253         ssize_t result = 0;
1254
1255         ctl = file->private_data;
1256         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1257         if (!ctl->subscribed)
1258                 return -EBADFD;
1259         if (count < sizeof(struct snd_ctl_event))
1260                 return -EINVAL;
1261         spin_lock_irq(&ctl->read_lock);
1262         while (count >= sizeof(struct snd_ctl_event)) {
1263                 struct snd_ctl_event ev;
1264                 struct snd_kctl_event *kev;
1265                 while (list_empty(&ctl->events)) {
1266                         wait_queue_t wait;
1267                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1268                                 err = -EAGAIN;
1269                                 goto __end_lock;
1270                         }
1271                         init_waitqueue_entry(&wait, current);
1272                         add_wait_queue(&ctl->change_sleep, &wait);
1273                         set_current_state(TASK_INTERRUPTIBLE);
1274                         spin_unlock_irq(&ctl->read_lock);
1275                         schedule();
1276                         remove_wait_queue(&ctl->change_sleep, &wait);
1277                         if (signal_pending(current))
1278                                 return -ERESTARTSYS;
1279                         spin_lock_irq(&ctl->read_lock);
1280                 }
1281                 kev = snd_kctl_event(ctl->events.next);
1282                 ev.type = SNDRV_CTL_EVENT_ELEM;
1283                 ev.data.elem.mask = kev->mask;
1284                 ev.data.elem.id = kev->id;
1285                 list_del(&kev->list);
1286                 spin_unlock_irq(&ctl->read_lock);
1287                 kfree(kev);
1288                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1289                         err = -EFAULT;
1290                         goto __end;
1291                 }
1292                 spin_lock_irq(&ctl->read_lock);
1293                 buffer += sizeof(struct snd_ctl_event);
1294                 count -= sizeof(struct snd_ctl_event);
1295                 result += sizeof(struct snd_ctl_event);
1296         }
1297       __end_lock:
1298         spin_unlock_irq(&ctl->read_lock);
1299       __end:
1300         return result > 0 ? result : err;
1301 }
1302
1303 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1304 {
1305         unsigned int mask;
1306         struct snd_ctl_file *ctl;
1307
1308         ctl = file->private_data;
1309         if (!ctl->subscribed)
1310                 return 0;
1311         poll_wait(file, &ctl->change_sleep, wait);
1312
1313         mask = 0;
1314         if (!list_empty(&ctl->events))
1315                 mask |= POLLIN | POLLRDNORM;
1316
1317         return mask;
1318 }
1319
1320 /*
1321  * register the device-specific control-ioctls.
1322  * called from each device manager like pcm.c, hwdep.c, etc.
1323  */
1324 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1325 {
1326         struct snd_kctl_ioctl *pn;
1327
1328         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1329         if (pn == NULL)
1330                 return -ENOMEM;
1331         pn->fioctl = fcn;
1332         down_write(&snd_ioctl_rwsem);
1333         list_add_tail(&pn->list, lists);
1334         up_write(&snd_ioctl_rwsem);
1335         return 0;
1336 }
1337
1338 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1339 {
1340         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1341 }
1342
1343 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1344
1345 #ifdef CONFIG_COMPAT
1346 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1347 {
1348         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1349 }
1350
1351 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1352 #endif
1353
1354 /*
1355  * de-register the device-specific control-ioctls.
1356  */
1357 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1358                                      struct list_head *lists)
1359 {
1360         struct list_head *list;
1361         struct snd_kctl_ioctl *p;
1362
1363         snd_assert(fcn != NULL, return -EINVAL);
1364         down_write(&snd_ioctl_rwsem);
1365         list_for_each(list, lists) {
1366                 p = list_entry(list, struct snd_kctl_ioctl, list);
1367                 if (p->fioctl == fcn) {
1368                         list_del(&p->list);
1369                         up_write(&snd_ioctl_rwsem);
1370                         kfree(p);
1371                         return 0;
1372                 }
1373         }
1374         up_write(&snd_ioctl_rwsem);
1375         snd_BUG();
1376         return -EINVAL;
1377 }
1378
1379 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1380 {
1381         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1382 }
1383
1384 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1385
1386 #ifdef CONFIG_COMPAT
1387 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1388 {
1389         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1390 }
1391
1392 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1393 #endif
1394
1395 static int snd_ctl_fasync(int fd, struct file * file, int on)
1396 {
1397         struct snd_ctl_file *ctl;
1398         int err;
1399         ctl = file->private_data;
1400         err = fasync_helper(fd, file, on, &ctl->fasync);
1401         if (err < 0)
1402                 return err;
1403         return 0;
1404 }
1405
1406 /*
1407  * ioctl32 compat
1408  */
1409 #ifdef CONFIG_COMPAT
1410 #include "control_compat.c"
1411 #else
1412 #define snd_ctl_ioctl_compat    NULL
1413 #endif
1414
1415 /*
1416  *  INIT PART
1417  */
1418
1419 static struct file_operations snd_ctl_f_ops =
1420 {
1421         .owner =        THIS_MODULE,
1422         .read =         snd_ctl_read,
1423         .open =         snd_ctl_open,
1424         .release =      snd_ctl_release,
1425         .poll =         snd_ctl_poll,
1426         .unlocked_ioctl =       snd_ctl_ioctl,
1427         .compat_ioctl = snd_ctl_ioctl_compat,
1428         .fasync =       snd_ctl_fasync,
1429 };
1430
1431 /*
1432  * registration of the control device
1433  */
1434 static int snd_ctl_dev_register(struct snd_device *device)
1435 {
1436         struct snd_card *card = device->device_data;
1437         int err, cardnum;
1438         char name[16];
1439
1440         snd_assert(card != NULL, return -ENXIO);
1441         cardnum = card->number;
1442         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1443         sprintf(name, "controlC%i", cardnum);
1444         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1445                                        &snd_ctl_f_ops, card, name)) < 0)
1446                 return err;
1447         return 0;
1448 }
1449
1450 /*
1451  * disconnection of the control device
1452  */
1453 static int snd_ctl_dev_disconnect(struct snd_device *device)
1454 {
1455         struct snd_card *card = device->device_data;
1456         struct list_head *flist;
1457         struct snd_ctl_file *ctl;
1458         int err, cardnum;
1459
1460         snd_assert(card != NULL, return -ENXIO);
1461         cardnum = card->number;
1462         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1463
1464         down_read(&card->controls_rwsem);
1465         list_for_each(flist, &card->ctl_files) {
1466                 ctl = snd_ctl_file(flist);
1467                 wake_up(&ctl->change_sleep);
1468                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1469         }
1470         up_read(&card->controls_rwsem);
1471
1472         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1473                                          card, -1)) < 0)
1474                 return err;
1475         return 0;
1476 }
1477
1478 /*
1479  * free all controls
1480  */
1481 static int snd_ctl_dev_free(struct snd_device *device)
1482 {
1483         struct snd_card *card = device->device_data;
1484         struct snd_kcontrol *control;
1485
1486         down_write(&card->controls_rwsem);
1487         while (!list_empty(&card->controls)) {
1488                 control = snd_kcontrol(card->controls.next);
1489                 snd_ctl_remove(card, control);
1490         }
1491         up_write(&card->controls_rwsem);
1492         return 0;
1493 }
1494
1495 /*
1496  * create control core:
1497  * called from init.c
1498  */
1499 int snd_ctl_create(struct snd_card *card)
1500 {
1501         static struct snd_device_ops ops = {
1502                 .dev_free = snd_ctl_dev_free,
1503                 .dev_register = snd_ctl_dev_register,
1504                 .dev_disconnect = snd_ctl_dev_disconnect,
1505         };
1506
1507         snd_assert(card != NULL, return -ENXIO);
1508         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1509 }