sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/threads.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/slab.h>
  25 #include <linux/vmalloc.h>
  26 #include <linux/time.h>
  27 #include <sound/core.h>
  28 #include <sound/minors.h>
  29 #include <sound/info.h>
  30 #include <sound/control.h>
  31
  32 /* max number of user-defined controls */
  33 #define MAX_USER_CONTROLS       32
  34 #define MAX_CONTROL_COUNT       1028
  35
  36 struct snd_kctl_ioctl {
  37         struct list_head list;          /* list of all ioctls */
  38         snd_kctl_ioctl_func_t fioctl;
  39 };
  40
  41 static DECLARE_RWSEM(snd_ioctl_rwsem);
  42 static LIST_HEAD(snd_control_ioctls);
  43 #ifdef CONFIG_COMPAT
  44 static LIST_HEAD(snd_control_compat_ioctls);
  45 #endif
  46
  47 static int snd_ctl_open(struct inode *inode, struct file *file)
  48 {
  49         unsigned long flags;
  50         struct snd_card *card;
  51         struct snd_ctl_file *ctl;
  52         int err;
  53
  54         err = nonseekable_open(inode, file);
  55         if (err < 0)
  56                 return err;
  57
  58         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  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 = kzalloc(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->prefer_pcm_subdevice = -1;
  82         ctl->prefer_rawmidi_subdevice = -1;
  83         ctl->pid = get_pid(task_pid(current));
  84         file->private_data = ctl;
  85         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  86         list_add_tail(&ctl->list, &card->ctl_files);
  87         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  88         return 0;
  89
  90       __error:
  91         module_put(card->module);
  92       __error2:
  93         snd_card_file_remove(card, file);
  94       __error1:
  95         return err;
  96 }
  97
  98 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  99 {
 100         unsigned long flags;
 101         struct snd_kctl_event *cread;
 102
 103         spin_lock_irqsave(&ctl->read_lock, flags);
 104         while (!list_empty(&ctl->events)) {
 105                 cread = snd_kctl_event(ctl->events.next);
 106                 list_del(&cread->list);
 107                 kfree(cread);
 108         }
 109         spin_unlock_irqrestore(&ctl->read_lock, flags);
 110 }
 111
 112 static int snd_ctl_release(struct inode *inode, struct file *file)
 113 {
 114         unsigned long flags;
 115         struct snd_card *card;
 116         struct snd_ctl_file *ctl;
 117         struct snd_kcontrol *control;
 118         unsigned int idx;
 119
 120         ctl = file->private_data;
 121         file->private_data = NULL;
 122         card = ctl->card;
 123         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 124         list_del(&ctl->list);
 125         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 126         down_write(&card->controls_rwsem);
 127         list_for_each_entry(control, &card->controls, list)
 128                 for (idx = 0; idx < control->count; idx++)
 129                         if (control->vd[idx].owner == ctl)
 130                                 control->vd[idx].owner = NULL;
 131         up_write(&card->controls_rwsem);
 132         snd_ctl_empty_read_queue(ctl);
 133         put_pid(ctl->pid);
 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(struct snd_card *card, unsigned int mask,
 141                     struct snd_ctl_elem_id *id)
 142 {
 143         unsigned long flags;
 144         struct snd_ctl_file *ctl;
 145         struct snd_kctl_event *ev;
 146
 147         if (snd_BUG_ON(!card || !id))
 148                 return;
 149         read_lock(&card->ctl_files_rwlock);
 150 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 151         card->mixer_oss_change_count++;
 152 #endif
 153         list_for_each_entry(ctl, &card->ctl_files, list) {
 154                 if (!ctl->subscribed)
 155                         continue;
 156                 spin_lock_irqsave(&ctl->read_lock, flags);
 157                 list_for_each_entry(ev, &ctl->events, list) {
 158                         if (ev->id.numid == id->numid) {
 159                                 ev->mask |= mask;
 160                                 goto _found;
 161                         }
 162                 }
 163                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 164                 if (ev) {
 165                         ev->id = *id;
 166                         ev->mask = mask;
 167                         list_add_tail(&ev->list, &ctl->events);
 168                 } else {
 169                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 170                 }
 171         _found:
 172                 wake_up(&ctl->change_sleep);
 173                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 174                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 175         }
 176         read_unlock(&card->ctl_files_rwlock);
 177 }
 178
 179 EXPORT_SYMBOL(snd_ctl_notify);
 180
 181 /**
 182  * snd_ctl_new - create a control instance from the template
 183  * @control: the control template
 184  * @access: the default control access
 185  *
 186  * Allocates a new struct snd_kcontrol instance and copies the given template
 187  * to the new instance. It does not copy volatile data (access).
 188  *
 189  * Returns the pointer of the new instance, or NULL on failure.
 190  */
 191 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 192                                         unsigned int access)
 193 {
 194         struct snd_kcontrol *kctl;
 195         unsigned int idx;
 196
 197         if (snd_BUG_ON(!control || !control->count))
 198                 return NULL;
 199
 200         if (control->count > MAX_CONTROL_COUNT)
 201                 return NULL;
 202
 203         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 204         if (kctl == NULL) {
 205                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 206                 return NULL;
 207         }
 208         *kctl = *control;
 209         for (idx = 0; idx < kctl->count; idx++)
 210                 kctl->vd[idx].access = access;
 211         return kctl;
 212 }
 213
 214 /**
 215  * snd_ctl_new1 - create a control instance from the template
 216  * @ncontrol: the initialization record
 217  * @private_data: the private data to set
 218  *
 219  * Allocates a new struct snd_kcontrol instance and initialize from the given
 220  * template.  When the access field of ncontrol is 0, it's assumed as
 221  * READWRITE access. When the count field is 0, it's assumes as one.
 222  *
 223  * Returns the pointer of the newly generated instance, or NULL on failure.
 224  */
 225 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 226                                   void *private_data)
 227 {
 228         struct snd_kcontrol kctl;
 229         unsigned int access;
 230
 231         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 232                 return NULL;
 233         memset(&kctl, 0, sizeof(kctl));
 234         kctl.id.iface = ncontrol->iface;
 235         kctl.id.device = ncontrol->device;
 236         kctl.id.subdevice = ncontrol->subdevice;
 237         if (ncontrol->name) {
 238                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 239                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 240                         snd_printk(KERN_WARNING
 241                                    "Control name '%s' truncated to '%s'\n",
 242                                    ncontrol->name, kctl.id.name);
 243         }
 244         kctl.id.index = ncontrol->index;
 245         kctl.count = ncontrol->count ? ncontrol->count : 1;
 246         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 247                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 248                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 249                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 250                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 251                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 252         kctl.info = ncontrol->info;
 253         kctl.get = ncontrol->get;
 254         kctl.put = ncontrol->put;
 255         kctl.tlv.p = ncontrol->tlv.p;
 256         kctl.private_value = ncontrol->private_value;
 257         kctl.private_data = private_data;
 258         return snd_ctl_new(&kctl, access);
 259 }
 260
 261 EXPORT_SYMBOL(snd_ctl_new1);
 262
 263 /**
 264  * snd_ctl_free_one - release the control instance
 265  * @kcontrol: the control instance
 266  *
 267  * Releases the control instance created via snd_ctl_new()
 268  * or snd_ctl_new1().
 269  * Don't call this after the control was added to the card.
 270  */
 271 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 272 {
 273         if (kcontrol) {
 274                 if (kcontrol->private_free)
 275                         kcontrol->private_free(kcontrol);
 276                 kfree(kcontrol);
 277         }
 278 }
 279
 280 EXPORT_SYMBOL(snd_ctl_free_one);
 281
 282 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 283                                           unsigned int count)
 284 {
 285         struct snd_kcontrol *kctl;
 286
 287         list_for_each_entry(kctl, &card->controls, list) {
 288                 if (kctl->id.numid < card->last_numid + 1 + count &&
 289                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 290                         card->last_numid = kctl->id.numid + kctl->count - 1;
 291                         return true;
 292                 }
 293         }
 294         return false;
 295 }
 296
 297 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 298 {
 299         unsigned int iter = 100000;
 300
 301         while (snd_ctl_remove_numid_conflict(card, count)) {
 302                 if (--iter == 0) {
 303                         /* this situation is very unlikely */
 304                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 305                         return -ENOMEM;
 306                 }
 307         }
 308         return 0;
 309 }
 310
 311 /**
 312  * snd_ctl_add - add the control instance to the card
 313  * @card: the card instance
 314  * @kcontrol: the control instance to add
 315  *
 316  * Adds the control instance created via snd_ctl_new() or
 317  * snd_ctl_new1() to the given card. Assigns also an unique
 318  * numid used for fast search.
 319  *
 320  * Returns zero if successful, or a negative error code on failure.
 321  *
 322  * It frees automatically the control which cannot be added.
 323  */
 324 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 325 {
 326         struct snd_ctl_elem_id id;
 327         unsigned int idx;
 328         int err = -EINVAL;
 329
 330         if (! kcontrol)
 331                 return err;
 332         if (snd_BUG_ON(!card || !kcontrol->info))
 333                 goto error;
 334         id = kcontrol->id;
 335         down_write(&card->controls_rwsem);
 336         if (snd_ctl_find_id(card, &id)) {
 337                 up_write(&card->controls_rwsem);
 338                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 339                                         id.iface,
 340                                         id.device,
 341                                         id.subdevice,
 342                                         id.name,
 343                                         id.index);
 344                 err = -EBUSY;
 345                 goto error;
 346         }
 347         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 348                 up_write(&card->controls_rwsem);
 349                 err = -ENOMEM;
 350                 goto error;
 351         }
 352         list_add_tail(&kcontrol->list, &card->controls);
 353         card->controls_count += kcontrol->count;
 354         kcontrol->id.numid = card->last_numid + 1;
 355         card->last_numid += kcontrol->count;
 356         up_write(&card->controls_rwsem);
 357         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 358                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 359         return 0;
 360
 361  error:
 362         snd_ctl_free_one(kcontrol);
 363         return err;
 364 }
 365
 366 EXPORT_SYMBOL(snd_ctl_add);
 367
 368 /**
 369  * snd_ctl_remove - remove the control from the card and release it
 370  * @card: the card instance
 371  * @kcontrol: the control instance to remove
 372  *
 373  * Removes the control from the card and then releases the instance.
 374  * You don't need to call snd_ctl_free_one(). You must be in
 375  * the write lock - down_write(&card->controls_rwsem).
 376  *
 377  * Returns 0 if successful, or a negative error code on failure.
 378  */
 379 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 380 {
 381         struct snd_ctl_elem_id id;
 382         unsigned int idx;
 383
 384         if (snd_BUG_ON(!card || !kcontrol))
 385                 return -EINVAL;
 386         list_del(&kcontrol->list);
 387         card->controls_count -= kcontrol->count;
 388         id = kcontrol->id;
 389         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 390                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 391         snd_ctl_free_one(kcontrol);
 392         return 0;
 393 }
 394
 395 EXPORT_SYMBOL(snd_ctl_remove);
 396
 397 /**
 398  * snd_ctl_remove_id - remove the control of the given id and release it
 399  * @card: the card instance
 400  * @id: the control id to remove
 401  *
 402  * Finds the control instance with the given id, removes it from the
 403  * card list and releases it.
 404  *
 405  * Returns 0 if successful, or a negative error code on failure.
 406  */
 407 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 408 {
 409         struct snd_kcontrol *kctl;
 410         int ret;
 411
 412         down_write(&card->controls_rwsem);
 413         kctl = snd_ctl_find_id(card, id);
 414         if (kctl == NULL) {
 415                 up_write(&card->controls_rwsem);
 416                 return -ENOENT;
 417         }
 418         ret = snd_ctl_remove(card, kctl);
 419         up_write(&card->controls_rwsem);
 420         return ret;
 421 }
 422
 423 EXPORT_SYMBOL(snd_ctl_remove_id);
 424
 425 /**
 426  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 427  * @file: active control handle
 428  * @id: the control id to remove
 429  *
 430  * Finds the control instance with the given id, removes it from the
 431  * card list and releases it.
 432  *
 433  * Returns 0 if successful, or a negative error code on failure.
 434  */
 435 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 436                                    struct snd_ctl_elem_id *id)
 437 {
 438         struct snd_card *card = file->card;
 439         struct snd_kcontrol *kctl;
 440         int idx, ret;
 441
 442         down_write(&card->controls_rwsem);
 443         kctl = snd_ctl_find_id(card, id);
 444         if (kctl == NULL) {
 445                 ret = -ENOENT;
 446                 goto error;
 447         }
 448         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 449                 ret = -EINVAL;
 450                 goto error;
 451         }
 452         for (idx = 0; idx < kctl->count; idx++)
 453                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 454                         ret = -EBUSY;
 455                         goto error;
 456                 }
 457         ret = snd_ctl_remove(card, kctl);
 458         if (ret < 0)
 459                 goto error;
 460         card->user_ctl_count--;
 461 error:
 462         up_write(&card->controls_rwsem);
 463         return ret;
 464 }
 465
 466 /**
 467  * snd_ctl_rename_id - replace the id of a control on the card
 468  * @card: the card instance
 469  * @src_id: the old id
 470  * @dst_id: the new id
 471  *
 472  * Finds the control with the old id from the card, and replaces the
 473  * id with the new one.
 474  *
 475  * Returns zero if successful, or a negative error code on failure.
 476  */
 477 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 478                       struct snd_ctl_elem_id *dst_id)
 479 {
 480         struct snd_kcontrol *kctl;
 481
 482         down_write(&card->controls_rwsem);
 483         kctl = snd_ctl_find_id(card, src_id);
 484         if (kctl == NULL) {
 485                 up_write(&card->controls_rwsem);
 486                 return -ENOENT;
 487         }
 488         kctl->id = *dst_id;
 489         kctl->id.numid = card->last_numid + 1;
 490         card->last_numid += kctl->count;
 491         up_write(&card->controls_rwsem);
 492         return 0;
 493 }
 494
 495 EXPORT_SYMBOL(snd_ctl_rename_id);
 496
 497 /**
 498  * snd_ctl_find_numid - find the control instance with the given number-id
 499  * @card: the card instance
 500  * @numid: the number-id to search
 501  *
 502  * Finds the control instance with the given number-id from the card.
 503  *
 504  * Returns the pointer of the instance if found, or NULL if not.
 505  *
 506  * The caller must down card->controls_rwsem before calling this function
 507  * (if the race condition can happen).
 508  */
 509 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 510 {
 511         struct snd_kcontrol *kctl;
 512
 513         if (snd_BUG_ON(!card || !numid))
 514                 return NULL;
 515         list_for_each_entry(kctl, &card->controls, list) {
 516                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 517                         return kctl;
 518         }
 519         return NULL;
 520 }
 521
 522 EXPORT_SYMBOL(snd_ctl_find_numid);
 523
 524 /**
 525  * snd_ctl_find_id - find the control instance with the given id
 526  * @card: the card instance
 527  * @id: the id to search
 528  *
 529  * Finds the control instance with the given id from the card.
 530  *
 531  * Returns the pointer of the instance if found, or NULL if not.
 532  *
 533  * The caller must down card->controls_rwsem before calling this function
 534  * (if the race condition can happen).
 535  */
 536 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 537                                      struct snd_ctl_elem_id *id)
 538 {
 539         struct snd_kcontrol *kctl;
 540
 541         if (snd_BUG_ON(!card || !id))
 542                 return NULL;
 543         if (id->numid != 0)
 544                 return snd_ctl_find_numid(card, id->numid);
 545         list_for_each_entry(kctl, &card->controls, list) {
 546                 if (kctl->id.iface != id->iface)
 547                         continue;
 548                 if (kctl->id.device != id->device)
 549                         continue;
 550                 if (kctl->id.subdevice != id->subdevice)
 551                         continue;
 552                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 553                         continue;
 554                 if (kctl->id.index > id->index)
 555                         continue;
 556                 if (kctl->id.index + kctl->count <= id->index)
 557                         continue;
 558                 return kctl;
 559         }
 560         return NULL;
 561 }
 562
 563 EXPORT_SYMBOL(snd_ctl_find_id);
 564
 565 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 566                              unsigned int cmd, void __user *arg)
 567 {
 568         struct snd_ctl_card_info *info;
 569
 570         info = kzalloc(sizeof(*info), GFP_KERNEL);
 571         if (! info)
 572                 return -ENOMEM;
 573         down_read(&snd_ioctl_rwsem);
 574         info->card = card->number;
 575         strlcpy(info->id, card->id, sizeof(info->id));
 576         strlcpy(info->driver, card->driver, sizeof(info->driver));
 577         strlcpy(info->name, card->shortname, sizeof(info->name));
 578         strlcpy(info->longname, card->longname, sizeof(info->longname));
 579         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 580         strlcpy(info->components, card->components, sizeof(info->components));
 581         up_read(&snd_ioctl_rwsem);
 582         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 583                 kfree(info);
 584                 return -EFAULT;
 585         }
 586         kfree(info);
 587         return 0;
 588 }
 589
 590 static int snd_ctl_elem_list(struct snd_card *card,
 591                              struct snd_ctl_elem_list __user *_list)
 592 {
 593         struct list_head *plist;
 594         struct snd_ctl_elem_list list;
 595         struct snd_kcontrol *kctl;
 596         struct snd_ctl_elem_id *dst, *id;
 597         unsigned int offset, space, first, jidx;
 598
 599         if (copy_from_user(&list, _list, sizeof(list)))
 600                 return -EFAULT;
 601         offset = list.offset;
 602         space = list.space;
 603         first = 0;
 604         /* try limit maximum space */
 605         if (space > 16384)
 606                 return -ENOMEM;
 607         if (space > 0) {
 608                 /* allocate temporary buffer for atomic operation */
 609                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 610                 if (dst == NULL)
 611                         return -ENOMEM;
 612                 down_read(&card->controls_rwsem);
 613                 list.count = card->controls_count;
 614                 plist = card->controls.next;
 615                 while (plist != &card->controls) {
 616                         if (offset == 0)
 617                                 break;
 618                         kctl = snd_kcontrol(plist);
 619                         if (offset < kctl->count)
 620                                 break;
 621                         offset -= kctl->count;
 622                         plist = plist->next;
 623                 }
 624                 list.used = 0;
 625                 id = dst;
 626                 while (space > 0 && plist != &card->controls) {
 627                         kctl = snd_kcontrol(plist);
 628                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 629                                 snd_ctl_build_ioff(id, kctl, jidx);
 630                                 id++;
 631                                 space--;
 632                                 list.used++;
 633                         }
 634                         plist = plist->next;
 635                         offset = 0;
 636                 }
 637                 up_read(&card->controls_rwsem);
 638                 if (list.used > 0 &&
 639                     copy_to_user(list.pids, dst,
 640                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 641                         vfree(dst);
 642                         return -EFAULT;
 643                 }
 644                 vfree(dst);
 645         } else {
 646                 down_read(&card->controls_rwsem);
 647                 list.count = card->controls_count;
 648                 up_read(&card->controls_rwsem);
 649         }
 650         if (copy_to_user(_list, &list, sizeof(list)))
 651                 return -EFAULT;
 652         return 0;
 653 }
 654
 655 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 656                              struct snd_ctl_elem_info *info)
 657 {
 658         struct snd_card *card = ctl->card;
 659         struct snd_kcontrol *kctl;
 660         struct snd_kcontrol_volatile *vd;
 661         unsigned int index_offset;
 662         int result;
 663
 664         down_read(&card->controls_rwsem);
 665         kctl = snd_ctl_find_id(card, &info->id);
 666         if (kctl == NULL) {
 667                 up_read(&card->controls_rwsem);
 668                 return -ENOENT;
 669         }
 670 #ifdef CONFIG_SND_DEBUG
 671         info->access = 0;
 672 #endif
 673         result = kctl->info(kctl, info);
 674         if (result >= 0) {
 675                 snd_BUG_ON(info->access);
 676                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 677                 vd = &kctl->vd[index_offset];
 678                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 679                 info->access = vd->access;
 680                 if (vd->owner) {
 681                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 682                         if (vd->owner == ctl)
 683                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 684                         info->owner = pid_vnr(vd->owner->pid);
 685                 } else {
 686                         info->owner = -1;
 687                 }
 688         }
 689         up_read(&card->controls_rwsem);
 690         return result;
 691 }
 692
 693 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 694                                   struct snd_ctl_elem_info __user *_info)
 695 {
 696         struct snd_ctl_elem_info info;
 697         int result;
 698
 699         if (copy_from_user(&info, _info, sizeof(info)))
 700                 return -EFAULT;
 701         snd_power_lock(ctl->card);
 702         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 703         if (result >= 0)
 704                 result = snd_ctl_elem_info(ctl, &info);
 705         snd_power_unlock(ctl->card);
 706         if (result >= 0)
 707                 if (copy_to_user(_info, &info, sizeof(info)))
 708                         return -EFAULT;
 709         return result;
 710 }
 711
 712 static int snd_ctl_elem_read(struct snd_card *card,
 713                              struct snd_ctl_elem_value *control)
 714 {
 715         struct snd_kcontrol *kctl;
 716         struct snd_kcontrol_volatile *vd;
 717         unsigned int index_offset;
 718         int result;
 719
 720         down_read(&card->controls_rwsem);
 721         kctl = snd_ctl_find_id(card, &control->id);
 722         if (kctl == NULL) {
 723                 result = -ENOENT;
 724         } else {
 725                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 726                 vd = &kctl->vd[index_offset];
 727                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 728                     kctl->get != NULL) {
 729                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 730                         result = kctl->get(kctl, control);
 731                 } else
 732                         result = -EPERM;
 733         }
 734         up_read(&card->controls_rwsem);
 735         return result;
 736 }
 737
 738 static int snd_ctl_elem_read_user(struct snd_card *card,
 739                                   struct snd_ctl_elem_value __user *_control)
 740 {
 741         struct snd_ctl_elem_value *control;
 742         int result;
 743
 744         control = memdup_user(_control, sizeof(*control));
 745         if (IS_ERR(control))
 746                 return PTR_ERR(control);
 747
 748         snd_power_lock(card);
 749         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 750         if (result >= 0)
 751                 result = snd_ctl_elem_read(card, control);
 752         snd_power_unlock(card);
 753         if (result >= 0)
 754                 if (copy_to_user(_control, control, sizeof(*control)))
 755                         result = -EFAULT;
 756         kfree(control);
 757         return result;
 758 }
 759
 760 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 761                               struct snd_ctl_elem_value *control)
 762 {
 763         struct snd_kcontrol *kctl;
 764         struct snd_kcontrol_volatile *vd;
 765         unsigned int index_offset;
 766         int result;
 767
 768         down_read(&card->controls_rwsem);
 769         kctl = snd_ctl_find_id(card, &control->id);
 770         if (kctl == NULL) {
 771                 result = -ENOENT;
 772         } else {
 773                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 774                 vd = &kctl->vd[index_offset];
 775                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 776                     kctl->put == NULL ||
 777                     (file && vd->owner && vd->owner != file)) {
 778                         result = -EPERM;
 779                 } else {
 780                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 781                         result = kctl->put(kctl, control);
 782                 }
 783                 if (result > 0) {
 784                         up_read(&card->controls_rwsem);
 785                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 786                                        &control->id);
 787                         return 0;
 788                 }
 789         }
 790         up_read(&card->controls_rwsem);
 791         return result;
 792 }
 793
 794 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 795                                    struct snd_ctl_elem_value __user *_control)
 796 {
 797         struct snd_ctl_elem_value *control;
 798         struct snd_card *card;
 799         int result;
 800
 801         control = memdup_user(_control, sizeof(*control));
 802         if (IS_ERR(control))
 803                 return PTR_ERR(control);
 804
 805         card = file->card;
 806         snd_power_lock(card);
 807         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 808         if (result >= 0)
 809                 result = snd_ctl_elem_write(card, file, control);
 810         snd_power_unlock(card);
 811         if (result >= 0)
 812                 if (copy_to_user(_control, control, sizeof(*control)))
 813                         result = -EFAULT;
 814         kfree(control);
 815         return result;
 816 }
 817
 818 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 819                              struct snd_ctl_elem_id __user *_id)
 820 {
 821         struct snd_card *card = file->card;
 822         struct snd_ctl_elem_id id;
 823         struct snd_kcontrol *kctl;
 824         struct snd_kcontrol_volatile *vd;
 825         int result;
 826
 827         if (copy_from_user(&id, _id, sizeof(id)))
 828                 return -EFAULT;
 829         down_write(&card->controls_rwsem);
 830         kctl = snd_ctl_find_id(card, &id);
 831         if (kctl == NULL) {
 832                 result = -ENOENT;
 833         } else {
 834                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 835                 if (vd->owner != NULL)
 836                         result = -EBUSY;
 837                 else {
 838                         vd->owner = file;
 839                         result = 0;
 840                 }
 841         }
 842         up_write(&card->controls_rwsem);
 843         return result;
 844 }
 845
 846 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 847                                struct snd_ctl_elem_id __user *_id)
 848 {
 849         struct snd_card *card = file->card;
 850         struct snd_ctl_elem_id id;
 851         struct snd_kcontrol *kctl;
 852         struct snd_kcontrol_volatile *vd;
 853         int result;
 854
 855         if (copy_from_user(&id, _id, sizeof(id)))
 856                 return -EFAULT;
 857         down_write(&card->controls_rwsem);
 858         kctl = snd_ctl_find_id(card, &id);
 859         if (kctl == NULL) {
 860                 result = -ENOENT;
 861         } else {
 862                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 863                 if (vd->owner == NULL)
 864                         result = -EINVAL;
 865                 else if (vd->owner != file)
 866                         result = -EPERM;
 867                 else {
 868                         vd->owner = NULL;
 869                         result = 0;
 870                 }
 871         }
 872         up_write(&card->controls_rwsem);
 873         return result;
 874 }
 875
 876 struct user_element {
 877         struct snd_ctl_elem_info info;
 878         void *elem_data;                /* element data */
 879         unsigned long elem_data_size;   /* size of element data in bytes */
 880         void *tlv_data;                 /* TLV data */
 881         unsigned long tlv_data_size;    /* TLV data size */
 882         void *priv_data;                /* private data (like strings for enumerated type) */
 883         unsigned long priv_data_size;   /* size of private data in bytes */
 884 };
 885
 886 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 887                                   struct snd_ctl_elem_info *uinfo)
 888 {
 889         struct user_element *ue = kcontrol->private_data;
 890
 891         *uinfo = ue->info;
 892         return 0;
 893 }
 894
 895 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 896                                  struct snd_ctl_elem_value *ucontrol)
 897 {
 898         struct user_element *ue = kcontrol->private_data;
 899
 900         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 901         return 0;
 902 }
 903
 904 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 905                                  struct snd_ctl_elem_value *ucontrol)
 906 {
 907         int change;
 908         struct user_element *ue = kcontrol->private_data;
 909
 910         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 911         if (change)
 912                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 913         return change;
 914 }
 915
 916 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 917                                  int op_flag,
 918                                  unsigned int size,
 919                                  unsigned int __user *tlv)
 920 {
 921         struct user_element *ue = kcontrol->private_data;
 922         int change = 0;
 923         void *new_data;
 924
 925         if (op_flag > 0) {
 926                 if (size > 1024 * 128)  /* sane value */
 927                         return -EINVAL;
 928
 929                 new_data = memdup_user(tlv, size);
 930                 if (IS_ERR(new_data))
 931                         return PTR_ERR(new_data);
 932                 change = ue->tlv_data_size != size;
 933                 if (!change)
 934                         change = memcmp(ue->tlv_data, new_data, size);
 935                 kfree(ue->tlv_data);
 936                 ue->tlv_data = new_data;
 937                 ue->tlv_data_size = size;
 938         } else {
 939                 if (! ue->tlv_data_size || ! ue->tlv_data)
 940                         return -ENXIO;
 941                 if (size < ue->tlv_data_size)
 942                         return -ENOSPC;
 943                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 944                         return -EFAULT;
 945         }
 946         return change;
 947 }
 948
 949 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 950 {
 951         struct user_element *ue = kcontrol->private_data;
 952         if (ue->tlv_data)
 953                 kfree(ue->tlv_data);
 954         kfree(ue);
 955 }
 956
 957 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 958                             struct snd_ctl_elem_info *info, int replace)
 959 {
 960         struct snd_card *card = file->card;
 961         struct snd_kcontrol kctl, *_kctl;
 962         unsigned int access;
 963         long private_size;
 964         struct user_element *ue;
 965         int idx, err;
 966
 967         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 968                 return -ENOMEM;
 969         if (info->count < 1)
 970                 return -EINVAL;
 971         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 972                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 973                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 974                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 975         info->id.numid = 0;
 976         memset(&kctl, 0, sizeof(kctl));
 977         down_write(&card->controls_rwsem);
 978         _kctl = snd_ctl_find_id(card, &info->id);
 979         err = 0;
 980         if (_kctl) {
 981                 if (replace)
 982                         err = snd_ctl_remove(card, _kctl);
 983                 else
 984                         err = -EBUSY;
 985         } else {
 986                 if (replace)
 987                         err = -ENOENT;
 988         }
 989         up_write(&card->controls_rwsem);
 990         if (err < 0)
 991                 return err;
 992         memcpy(&kctl.id, &info->id, sizeof(info->id));
 993         kctl.count = info->owner ? info->owner : 1;
 994         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 995         kctl.info = snd_ctl_elem_user_info;
 996         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 997                 kctl.get = snd_ctl_elem_user_get;
 998         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 999                 kctl.put = snd_ctl_elem_user_put;
1000         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1001                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1002                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1003         }
1004         switch (info->type) {
1005         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1006         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1007                 private_size = sizeof(long);
1008                 if (info->count > 128)
1009                         return -EINVAL;
1010                 break;
1011         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1012                 private_size = sizeof(long long);
1013                 if (info->count > 64)
1014                         return -EINVAL;
1015                 break;
1016         case SNDRV_CTL_ELEM_TYPE_BYTES:
1017                 private_size = sizeof(unsigned char);
1018                 if (info->count > 512)
1019                         return -EINVAL;
1020                 break;
1021         case SNDRV_CTL_ELEM_TYPE_IEC958:
1022                 private_size = sizeof(struct snd_aes_iec958);
1023                 if (info->count != 1)
1024                         return -EINVAL;
1025                 break;
1026         default:
1027                 return -EINVAL;
1028         }
1029         private_size *= info->count;
1030         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1031         if (ue == NULL)
1032                 return -ENOMEM;
1033         ue->info = *info;
1034         ue->info.access = 0;
1035         ue->elem_data = (char *)ue + sizeof(*ue);
1036         ue->elem_data_size = private_size;
1037         kctl.private_free = snd_ctl_elem_user_free;
1038         _kctl = snd_ctl_new(&kctl, access);
1039         if (_kctl == NULL) {
1040                 kfree(ue);
1041                 return -ENOMEM;
1042         }
1043         _kctl->private_data = ue;
1044         for (idx = 0; idx < _kctl->count; idx++)
1045                 _kctl->vd[idx].owner = file;
1046         err = snd_ctl_add(card, _kctl);
1047         if (err < 0)
1048                 return err;
1049
1050         down_write(&card->controls_rwsem);
1051         card->user_ctl_count++;
1052         up_write(&card->controls_rwsem);
1053
1054         return 0;
1055 }
1056
1057 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1058                                  struct snd_ctl_elem_info __user *_info, int replace)
1059 {
1060         struct snd_ctl_elem_info info;
1061         if (copy_from_user(&info, _info, sizeof(info)))
1062                 return -EFAULT;
1063         return snd_ctl_elem_add(file, &info, replace);
1064 }
1065
1066 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1067                                struct snd_ctl_elem_id __user *_id)
1068 {
1069         struct snd_ctl_elem_id id;
1070
1071         if (copy_from_user(&id, _id, sizeof(id)))
1072                 return -EFAULT;
1073         return snd_ctl_remove_user_ctl(file, &id);
1074 }
1075
1076 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1077 {
1078         int subscribe;
1079         if (get_user(subscribe, ptr))
1080                 return -EFAULT;
1081         if (subscribe < 0) {
1082                 subscribe = file->subscribed;
1083                 if (put_user(subscribe, ptr))
1084                         return -EFAULT;
1085                 return 0;
1086         }
1087         if (subscribe) {
1088                 file->subscribed = 1;
1089                 return 0;
1090         } else if (file->subscribed) {
1091                 snd_ctl_empty_read_queue(file);
1092                 file->subscribed = 0;
1093         }
1094         return 0;
1095 }
1096
1097 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1098                              struct snd_ctl_tlv __user *_tlv,
1099                              int op_flag)
1100 {
1101         struct snd_card *card = file->card;
1102         struct snd_ctl_tlv tlv;
1103         struct snd_kcontrol *kctl;
1104         struct snd_kcontrol_volatile *vd;
1105         unsigned int len;
1106         int err = 0;
1107
1108         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1109                 return -EFAULT;
1110         if (tlv.length < sizeof(unsigned int) * 2)
1111                 return -EINVAL;
1112         down_read(&card->controls_rwsem);
1113         kctl = snd_ctl_find_numid(card, tlv.numid);
1114         if (kctl == NULL) {
1115                 err = -ENOENT;
1116                 goto __kctl_end;
1117         }
1118         if (kctl->tlv.p == NULL) {
1119                 err = -ENXIO;
1120                 goto __kctl_end;
1121         }
1122         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1123         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1124             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1125             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1126                 err = -ENXIO;
1127                 goto __kctl_end;
1128         }
1129         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1130                 if (vd->owner != NULL && vd->owner != file) {
1131                         err = -EPERM;
1132                         goto __kctl_end;
1133                 }
1134                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1135                 if (err > 0) {
1136                         up_read(&card->controls_rwsem);
1137                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1138                         return 0;
1139                 }
1140         } else {
1141                 if (op_flag) {
1142                         err = -ENXIO;
1143                         goto __kctl_end;
1144                 }
1145                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1146                 if (tlv.length < len) {
1147                         err = -ENOMEM;
1148                         goto __kctl_end;
1149                 }
1150                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1151                         err = -EFAULT;
1152         }
1153       __kctl_end:
1154         up_read(&card->controls_rwsem);
1155         return err;
1156 }
1157
1158 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1159 {
1160         struct snd_ctl_file *ctl;
1161         struct snd_card *card;
1162         struct snd_kctl_ioctl *p;
1163         void __user *argp = (void __user *)arg;
1164         int __user *ip = argp;
1165         int err;
1166
1167         ctl = file->private_data;
1168         card = ctl->card;
1169         if (snd_BUG_ON(!card))
1170                 return -ENXIO;
1171         switch (cmd) {
1172         case SNDRV_CTL_IOCTL_PVERSION:
1173                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1174         case SNDRV_CTL_IOCTL_CARD_INFO:
1175                 return snd_ctl_card_info(card, ctl, cmd, argp);
1176         case SNDRV_CTL_IOCTL_ELEM_LIST:
1177                 return snd_ctl_elem_list(card, argp);
1178         case SNDRV_CTL_IOCTL_ELEM_INFO:
1179                 return snd_ctl_elem_info_user(ctl, argp);
1180         case SNDRV_CTL_IOCTL_ELEM_READ:
1181                 return snd_ctl_elem_read_user(card, argp);
1182         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1183                 return snd_ctl_elem_write_user(ctl, argp);
1184         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1185                 return snd_ctl_elem_lock(ctl, argp);
1186         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1187                 return snd_ctl_elem_unlock(ctl, argp);
1188         case SNDRV_CTL_IOCTL_ELEM_ADD:
1189                 return snd_ctl_elem_add_user(ctl, argp, 0);
1190         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1191                 return snd_ctl_elem_add_user(ctl, argp, 1);
1192         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1193                 return snd_ctl_elem_remove(ctl, argp);
1194         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1195                 return snd_ctl_subscribe_events(ctl, ip);
1196         case SNDRV_CTL_IOCTL_TLV_READ:
1197                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1198         case SNDRV_CTL_IOCTL_TLV_WRITE:
1199                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1200         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1201                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1202         case SNDRV_CTL_IOCTL_POWER:
1203                 return -ENOPROTOOPT;
1204         case SNDRV_CTL_IOCTL_POWER_STATE:
1205 #ifdef CONFIG_PM
1206                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1207 #else
1208                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1209 #endif
1210         }
1211         down_read(&snd_ioctl_rwsem);
1212         list_for_each_entry(p, &snd_control_ioctls, list) {
1213                 err = p->fioctl(card, ctl, cmd, arg);
1214                 if (err != -ENOIOCTLCMD) {
1215                         up_read(&snd_ioctl_rwsem);
1216                         return err;
1217                 }
1218         }
1219         up_read(&snd_ioctl_rwsem);
1220         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1221         return -ENOTTY;
1222 }
1223
1224 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1225                             size_t count, loff_t * offset)
1226 {
1227         struct snd_ctl_file *ctl;
1228         int err = 0;
1229         ssize_t result = 0;
1230
1231         ctl = file->private_data;
1232         if (snd_BUG_ON(!ctl || !ctl->card))
1233                 return -ENXIO;
1234         if (!ctl->subscribed)
1235                 return -EBADFD;
1236         if (count < sizeof(struct snd_ctl_event))
1237                 return -EINVAL;
1238         spin_lock_irq(&ctl->read_lock);
1239         while (count >= sizeof(struct snd_ctl_event)) {
1240                 struct snd_ctl_event ev;
1241                 struct snd_kctl_event *kev;
1242                 while (list_empty(&ctl->events)) {
1243                         wait_queue_t wait;
1244                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1245                                 err = -EAGAIN;
1246                                 goto __end_lock;
1247                         }
1248                         init_waitqueue_entry(&wait, current);
1249                         add_wait_queue(&ctl->change_sleep, &wait);
1250                         set_current_state(TASK_INTERRUPTIBLE);
1251                         spin_unlock_irq(&ctl->read_lock);
1252                         schedule();
1253                         remove_wait_queue(&ctl->change_sleep, &wait);
1254                         if (signal_pending(current))
1255                                 return -ERESTARTSYS;
1256                         spin_lock_irq(&ctl->read_lock);
1257                 }
1258                 kev = snd_kctl_event(ctl->events.next);
1259                 ev.type = SNDRV_CTL_EVENT_ELEM;
1260                 ev.data.elem.mask = kev->mask;
1261                 ev.data.elem.id = kev->id;
1262                 list_del(&kev->list);
1263                 spin_unlock_irq(&ctl->read_lock);
1264                 kfree(kev);
1265                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1266                         err = -EFAULT;
1267                         goto __end;
1268                 }
1269                 spin_lock_irq(&ctl->read_lock);
1270                 buffer += sizeof(struct snd_ctl_event);
1271                 count -= sizeof(struct snd_ctl_event);
1272                 result += sizeof(struct snd_ctl_event);
1273         }
1274       __end_lock:
1275         spin_unlock_irq(&ctl->read_lock);
1276       __end:
1277         return result > 0 ? result : err;
1278 }
1279
1280 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1281 {
1282         unsigned int mask;
1283         struct snd_ctl_file *ctl;
1284
1285         ctl = file->private_data;
1286         if (!ctl->subscribed)
1287                 return 0;
1288         poll_wait(file, &ctl->change_sleep, wait);
1289
1290         mask = 0;
1291         if (!list_empty(&ctl->events))
1292                 mask |= POLLIN | POLLRDNORM;
1293
1294         return mask;
1295 }
1296
1297 /*
1298  * register the device-specific control-ioctls.
1299  * called from each device manager like pcm.c, hwdep.c, etc.
1300  */
1301 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1302 {
1303         struct snd_kctl_ioctl *pn;
1304
1305         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1306         if (pn == NULL)
1307                 return -ENOMEM;
1308         pn->fioctl = fcn;
1309         down_write(&snd_ioctl_rwsem);
1310         list_add_tail(&pn->list, lists);
1311         up_write(&snd_ioctl_rwsem);
1312         return 0;
1313 }
1314
1315 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1316 {
1317         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1318 }
1319
1320 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1321
1322 #ifdef CONFIG_COMPAT
1323 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1324 {
1325         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1326 }
1327
1328 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1329 #endif
1330
1331 /*
1332  * de-register the device-specific control-ioctls.
1333  */
1334 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1335                                      struct list_head *lists)
1336 {
1337         struct snd_kctl_ioctl *p;
1338
1339         if (snd_BUG_ON(!fcn))
1340                 return -EINVAL;
1341         down_write(&snd_ioctl_rwsem);
1342         list_for_each_entry(p, lists, list) {
1343                 if (p->fioctl == fcn) {
1344                         list_del(&p->list);
1345                         up_write(&snd_ioctl_rwsem);
1346                         kfree(p);
1347                         return 0;
1348                 }
1349         }
1350         up_write(&snd_ioctl_rwsem);
1351         snd_BUG();
1352         return -EINVAL;
1353 }
1354
1355 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1356 {
1357         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1358 }
1359
1360 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1361
1362 #ifdef CONFIG_COMPAT
1363 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1364 {
1365         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1366 }
1367
1368 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1369 #endif
1370
1371 static int snd_ctl_fasync(int fd, struct file * file, int on)
1372 {
1373         struct snd_ctl_file *ctl;
1374
1375         ctl = file->private_data;
1376         return fasync_helper(fd, file, on, &ctl->fasync);
1377 }
1378
1379 /*
1380  * ioctl32 compat
1381  */
1382 #ifdef CONFIG_COMPAT
1383 #include "control_compat.c"
1384 #else
1385 #define snd_ctl_ioctl_compat    NULL
1386 #endif
1387
1388 /*
1389  *  INIT PART
1390  */
1391
1392 static const struct file_operations snd_ctl_f_ops =
1393 {
1394         .owner =        THIS_MODULE,
1395         .read =         snd_ctl_read,
1396         .open =         snd_ctl_open,
1397         .release =      snd_ctl_release,
1398         .llseek =       no_llseek,
1399         .poll =         snd_ctl_poll,
1400         .unlocked_ioctl =       snd_ctl_ioctl,
1401         .compat_ioctl = snd_ctl_ioctl_compat,
1402         .fasync =       snd_ctl_fasync,
1403 };
1404
1405 /*
1406  * registration of the control device
1407  */
1408 static int snd_ctl_dev_register(struct snd_device *device)
1409 {
1410         struct snd_card *card = device->device_data;
1411         int err, cardnum;
1412         char name[16];
1413
1414         if (snd_BUG_ON(!card))
1415                 return -ENXIO;
1416         cardnum = card->number;
1417         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1418                 return -ENXIO;
1419         sprintf(name, "controlC%i", cardnum);
1420         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1421                                        &snd_ctl_f_ops, card, name)) < 0)
1422                 return err;
1423         return 0;
1424 }
1425
1426 /*
1427  * disconnection of the control device
1428  */
1429 static int snd_ctl_dev_disconnect(struct snd_device *device)
1430 {
1431         struct snd_card *card = device->device_data;
1432         struct snd_ctl_file *ctl;
1433         int err, cardnum;
1434
1435         if (snd_BUG_ON(!card))
1436                 return -ENXIO;
1437         cardnum = card->number;
1438         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1439                 return -ENXIO;
1440
1441         read_lock(&card->ctl_files_rwlock);
1442         list_for_each_entry(ctl, &card->ctl_files, list) {
1443                 wake_up(&ctl->change_sleep);
1444                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1445         }
1446         read_unlock(&card->ctl_files_rwlock);
1447
1448         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1449                                          card, -1)) < 0)
1450                 return err;
1451         return 0;
1452 }
1453
1454 /*
1455  * free all controls
1456  */
1457 static int snd_ctl_dev_free(struct snd_device *device)
1458 {
1459         struct snd_card *card = device->device_data;
1460         struct snd_kcontrol *control;
1461
1462         down_write(&card->controls_rwsem);
1463         while (!list_empty(&card->controls)) {
1464                 control = snd_kcontrol(card->controls.next);
1465                 snd_ctl_remove(card, control);
1466         }
1467         up_write(&card->controls_rwsem);
1468         return 0;
1469 }
1470
1471 /*
1472  * create control core:
1473  * called from init.c
1474  */
1475 int snd_ctl_create(struct snd_card *card)
1476 {
1477         static struct snd_device_ops ops = {
1478                 .dev_free = snd_ctl_dev_free,
1479                 .dev_register = snd_ctl_dev_register,
1480                 .dev_disconnect = snd_ctl_dev_disconnect,
1481         };
1482
1483         if (snd_BUG_ON(!card))
1484                 return -ENXIO;
1485         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1486 }
1487
1488 /*
1489  * Frequently used control callbacks/helpers
1490  */
1491 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1492                               struct snd_ctl_elem_info *uinfo)
1493 {
1494         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1495         uinfo->count = 1;
1496         uinfo->value.integer.min = 0;
1497         uinfo->value.integer.max = 1;
1498         return 0;
1499 }
1500
1501 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1502
1503 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1504                                 struct snd_ctl_elem_info *uinfo)
1505 {
1506         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1507         uinfo->count = 2;
1508         uinfo->value.integer.min = 0;
1509         uinfo->value.integer.max = 1;
1510         return 0;
1511 }
1512
1513 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1514
1515 /**
1516  * snd_ctl_enum_info - fills the info structure for an enumerated control
1517  * @info: the structure to be filled
1518  * @channels: the number of the control's channels; often one
1519  * @items: the number of control values; also the size of @names
1520  * @names: an array containing the names of all control values
1521  *
1522  * Sets all required fields in @info to their appropriate values.
1523  * If the control's accessibility is not the default (readable and writable),
1524  * the caller has to fill @info->access.
1525  */
1526 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1527                       unsigned int items, const char *const names[])
1528 {
1529         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1530         info->count = channels;
1531         info->value.enumerated.items = items;
1532         if (info->value.enumerated.item >= items)
1533                 info->value.enumerated.item = items - 1;
1534         strlcpy(info->value.enumerated.name,
1535                 names[info->value.enumerated.item],
1536                 sizeof(info->value.enumerated.name));
1537         return 0;
1538 }
1539 EXPORT_SYMBOL(snd_ctl_enum_info);