sound/core/control.c

   1 /*
   2  *  Routines for driver control interface
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/threads.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/module.h>
  25 #include <linux/slab.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/time.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/info.h>
  31 #include <sound/control.h>
  32
  33 /* max number of user-defined controls */
  34 #define MAX_USER_CONTROLS       32
  35 #define MAX_CONTROL_COUNT       1028
  36
  37 struct snd_kctl_ioctl {
  38         struct list_head list;          /* list of all ioctls */
  39         snd_kctl_ioctl_func_t fioctl;
  40 };
  41
  42 static DECLARE_RWSEM(snd_ioctl_rwsem);
  43 static LIST_HEAD(snd_control_ioctls);
  44 #ifdef CONFIG_COMPAT
  45 static LIST_HEAD(snd_control_compat_ioctls);
  46 #endif
  47
  48 static int snd_ctl_open(struct inode *inode, struct file *file)
  49 {
  50         unsigned long flags;
  51         struct snd_card *card;
  52         struct snd_ctl_file *ctl;
  53         int err;
  54
  55         err = nonseekable_open(inode, file);
  56         if (err < 0)
  57                 return err;
  58
  59         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  60         if (!card) {
  61                 err = -ENODEV;
  62                 goto __error1;
  63         }
  64         err = snd_card_file_add(card, file);
  65         if (err < 0) {
  66                 err = -ENODEV;
  67                 goto __error1;
  68         }
  69         if (!try_module_get(card->module)) {
  70                 err = -EFAULT;
  71                 goto __error2;
  72         }
  73         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  74         if (ctl == NULL) {
  75                 err = -ENOMEM;
  76                 goto __error;
  77         }
  78         INIT_LIST_HEAD(&ctl->events);
  79         init_waitqueue_head(&ctl->change_sleep);
  80         spin_lock_init(&ctl->read_lock);
  81         ctl->card = card;
  82         ctl->prefer_pcm_subdevice = -1;
  83         ctl->prefer_rawmidi_subdevice = -1;
  84         ctl->pid = get_pid(task_pid(current));
  85         file->private_data = ctl;
  86         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  87         list_add_tail(&ctl->list, &card->ctl_files);
  88         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  89         snd_card_unref(card);
  90         return 0;
  91
  92       __error:
  93         module_put(card->module);
  94       __error2:
  95         snd_card_file_remove(card, file);
  96       __error1:
  97         if (card)
  98                 snd_card_unref(card);
  99         return err;
 100 }
 101
 102 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
 103 {
 104         unsigned long flags;
 105         struct snd_kctl_event *cread;
 106
 107         spin_lock_irqsave(&ctl->read_lock, flags);
 108         while (!list_empty(&ctl->events)) {
 109                 cread = snd_kctl_event(ctl->events.next);
 110                 list_del(&cread->list);
 111                 kfree(cread);
 112         }
 113         spin_unlock_irqrestore(&ctl->read_lock, flags);
 114 }
 115
 116 static int snd_ctl_release(struct inode *inode, struct file *file)
 117 {
 118         unsigned long flags;
 119         struct snd_card *card;
 120         struct snd_ctl_file *ctl;
 121         struct snd_kcontrol *control;
 122         unsigned int idx;
 123
 124         ctl = file->private_data;
 125         file->private_data = NULL;
 126         card = ctl->card;
 127         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 128         list_del(&ctl->list);
 129         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 130         down_write(&card->controls_rwsem);
 131         list_for_each_entry(control, &card->controls, list)
 132                 for (idx = 0; idx < control->count; idx++)
 133                         if (control->vd[idx].owner == ctl)
 134                                 control->vd[idx].owner = NULL;
 135         up_write(&card->controls_rwsem);
 136         snd_ctl_empty_read_queue(ctl);
 137         put_pid(ctl->pid);
 138         kfree(ctl);
 139         module_put(card->module);
 140         snd_card_file_remove(card, file);
 141         return 0;
 142 }
 143
 144 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 145                     struct snd_ctl_elem_id *id)
 146 {
 147         unsigned long flags;
 148         struct snd_ctl_file *ctl;
 149         struct snd_kctl_event *ev;
 150
 151         if (snd_BUG_ON(!card || !id))
 152                 return;
 153         read_lock(&card->ctl_files_rwlock);
 154 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 155         card->mixer_oss_change_count++;
 156 #endif
 157         list_for_each_entry(ctl, &card->ctl_files, list) {
 158                 if (!ctl->subscribed)
 159                         continue;
 160                 spin_lock_irqsave(&ctl->read_lock, flags);
 161                 list_for_each_entry(ev, &ctl->events, list) {
 162                         if (ev->id.numid == id->numid) {
 163                                 ev->mask |= mask;
 164                                 goto _found;
 165                         }
 166                 }
 167                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 168                 if (ev) {
 169                         ev->id = *id;
 170                         ev->mask = mask;
 171                         list_add_tail(&ev->list, &ctl->events);
 172                 } else {
 173                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 174                 }
 175         _found:
 176                 wake_up(&ctl->change_sleep);
 177                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 178                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 179         }
 180         read_unlock(&card->ctl_files_rwlock);
 181 }
 182
 183 EXPORT_SYMBOL(snd_ctl_notify);
 184
 185 /**
 186  * snd_ctl_new - create a control instance from the template
 187  * @control: the control template
 188  * @access: the default control access
 189  *
 190  * Allocates a new struct snd_kcontrol instance and copies the given template
 191  * to the new instance. It does not copy volatile data (access).
 192  *
 193  * Returns the pointer of the new instance, or NULL on failure.
 194  */
 195 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 196                                         unsigned int access)
 197 {
 198         struct snd_kcontrol *kctl;
 199         unsigned int idx;
 200
 201         if (snd_BUG_ON(!control || !control->count))
 202                 return NULL;
 203
 204         if (control->count > MAX_CONTROL_COUNT)
 205                 return NULL;
 206
 207         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 208         if (kctl == NULL) {
 209                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 210                 return NULL;
 211         }
 212         *kctl = *control;
 213         for (idx = 0; idx < kctl->count; idx++)
 214                 kctl->vd[idx].access = access;
 215         return kctl;
 216 }
 217
 218 /**
 219  * snd_ctl_new1 - create a control instance from the template
 220  * @ncontrol: the initialization record
 221  * @private_data: the private data to set
 222  *
 223  * Allocates a new struct snd_kcontrol instance and initialize from the given
 224  * template.  When the access field of ncontrol is 0, it's assumed as
 225  * READWRITE access. When the count field is 0, it's assumes as one.
 226  *
 227  * Returns the pointer of the newly generated instance, or NULL on failure.
 228  */
 229 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 230                                   void *private_data)
 231 {
 232         struct snd_kcontrol kctl;
 233         unsigned int access;
 234
 235         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 236                 return NULL;
 237         memset(&kctl, 0, sizeof(kctl));
 238         kctl.id.iface = ncontrol->iface;
 239         kctl.id.device = ncontrol->device;
 240         kctl.id.subdevice = ncontrol->subdevice;
 241         if (ncontrol->name) {
 242                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 243                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 244                         snd_printk(KERN_WARNING
 245                                    "Control name '%s' truncated to '%s'\n",
 246                                    ncontrol->name, kctl.id.name);
 247         }
 248         kctl.id.index = ncontrol->index;
 249         kctl.count = ncontrol->count ? ncontrol->count : 1;
 250         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 251                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 252                                       SNDRV_CTL_ELEM_ACCESS_VOLATILE|
 253                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 254                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 255                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 256                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 257         kctl.info = ncontrol->info;
 258         kctl.get = ncontrol->get;
 259         kctl.put = ncontrol->put;
 260         kctl.tlv.p = ncontrol->tlv.p;
 261         kctl.private_value = ncontrol->private_value;
 262         kctl.private_data = private_data;
 263         return snd_ctl_new(&kctl, access);
 264 }
 265
 266 EXPORT_SYMBOL(snd_ctl_new1);
 267
 268 /**
 269  * snd_ctl_free_one - release the control instance
 270  * @kcontrol: the control instance
 271  *
 272  * Releases the control instance created via snd_ctl_new()
 273  * or snd_ctl_new1().
 274  * Don't call this after the control was added to the card.
 275  */
 276 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 277 {
 278         if (kcontrol) {
 279                 if (kcontrol->private_free)
 280                         kcontrol->private_free(kcontrol);
 281                 kfree(kcontrol);
 282         }
 283 }
 284
 285 EXPORT_SYMBOL(snd_ctl_free_one);
 286
 287 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 288                                           unsigned int count)
 289 {
 290         struct snd_kcontrol *kctl;
 291
 292         list_for_each_entry(kctl, &card->controls, list) {
 293                 if (kctl->id.numid < card->last_numid + 1 + count &&
 294                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 295                         card->last_numid = kctl->id.numid + kctl->count - 1;
 296                         return true;
 297                 }
 298         }
 299         return false;
 300 }
 301
 302 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 303 {
 304         unsigned int iter = 100000;
 305
 306         while (snd_ctl_remove_numid_conflict(card, count)) {
 307                 if (--iter == 0) {
 308                         /* this situation is very unlikely */
 309                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 310                         return -ENOMEM;
 311                 }
 312         }
 313         return 0;
 314 }
 315
 316 /**
 317  * snd_ctl_add - add the control instance to the card
 318  * @card: the card instance
 319  * @kcontrol: the control instance to add
 320  *
 321  * Adds the control instance created via snd_ctl_new() or
 322  * snd_ctl_new1() to the given card. Assigns also an unique
 323  * numid used for fast search.
 324  *
 325  * Returns zero if successful, or a negative error code on failure.
 326  *
 327  * It frees automatically the control which cannot be added.
 328  */
 329 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 330 {
 331         struct snd_ctl_elem_id id;
 332         unsigned int idx;
 333         int err = -EINVAL;
 334
 335         if (! kcontrol)
 336                 return err;
 337         if (snd_BUG_ON(!card || !kcontrol->info))
 338                 goto error;
 339         id = kcontrol->id;
 340         down_write(&card->controls_rwsem);
 341         if (snd_ctl_find_id(card, &id)) {
 342                 up_write(&card->controls_rwsem);
 343                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 344                                         id.iface,
 345                                         id.device,
 346                                         id.subdevice,
 347                                         id.name,
 348                                         id.index);
 349                 err = -EBUSY;
 350                 goto error;
 351         }
 352         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 353                 up_write(&card->controls_rwsem);
 354                 err = -ENOMEM;
 355                 goto error;
 356         }
 357         list_add_tail(&kcontrol->list, &card->controls);
 358         card->controls_count += kcontrol->count;
 359         kcontrol->id.numid = card->last_numid + 1;
 360         card->last_numid += kcontrol->count;
 361         up_write(&card->controls_rwsem);
 362         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 363                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 364         return 0;
 365
 366  error:
 367         snd_ctl_free_one(kcontrol);
 368         return err;
 369 }
 370
 371 EXPORT_SYMBOL(snd_ctl_add);
 372
 373 /**
 374  * snd_ctl_replace - replace the control instance of the card
 375  * @card: the card instance
 376  * @kcontrol: the control instance to replace
 377  * @add_on_replace: add the control if not already added
 378  *
 379  * Replaces the given control.  If the given control does not exist
 380  * and the add_on_replace flag is set, the control is added.  If the
 381  * control exists, it is destroyed first.
 382  *
 383  * Returns zero if successful, or a negative error code on failure.
 384  *
 385  * It frees automatically the control which cannot be added or replaced.
 386  */
 387 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 388                     bool add_on_replace)
 389 {
 390         struct snd_ctl_elem_id id;
 391         unsigned int idx;
 392         struct snd_kcontrol *old;
 393         int ret;
 394
 395         if (!kcontrol)
 396                 return -EINVAL;
 397         if (snd_BUG_ON(!card || !kcontrol->info)) {
 398                 ret = -EINVAL;
 399                 goto error;
 400         }
 401         id = kcontrol->id;
 402         down_write(&card->controls_rwsem);
 403         old = snd_ctl_find_id(card, &id);
 404         if (!old) {
 405                 if (add_on_replace)
 406                         goto add;
 407                 up_write(&card->controls_rwsem);
 408                 ret = -EINVAL;
 409                 goto error;
 410         }
 411         ret = snd_ctl_remove(card, old);
 412         if (ret < 0) {
 413                 up_write(&card->controls_rwsem);
 414                 goto error;
 415         }
 416 add:
 417         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 418                 up_write(&card->controls_rwsem);
 419                 ret = -ENOMEM;
 420                 goto error;
 421         }
 422         list_add_tail(&kcontrol->list, &card->controls);
 423         card->controls_count += kcontrol->count;
 424         kcontrol->id.numid = card->last_numid + 1;
 425         card->last_numid += kcontrol->count;
 426         up_write(&card->controls_rwsem);
 427         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 428                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 429         return 0;
 430
 431 error:
 432         snd_ctl_free_one(kcontrol);
 433         return ret;
 434 }
 435 EXPORT_SYMBOL(snd_ctl_replace);
 436
 437 /**
 438  * snd_ctl_remove - remove the control from the card and release it
 439  * @card: the card instance
 440  * @kcontrol: the control instance to remove
 441  *
 442  * Removes the control from the card and then releases the instance.
 443  * You don't need to call snd_ctl_free_one(). You must be in
 444  * the write lock - down_write(&card->controls_rwsem).
 445  *
 446  * Returns 0 if successful, or a negative error code on failure.
 447  */
 448 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 449 {
 450         struct snd_ctl_elem_id id;
 451         unsigned int idx;
 452
 453         if (snd_BUG_ON(!card || !kcontrol))
 454                 return -EINVAL;
 455         list_del(&kcontrol->list);
 456         card->controls_count -= kcontrol->count;
 457         id = kcontrol->id;
 458         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 459                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 460         snd_ctl_free_one(kcontrol);
 461         return 0;
 462 }
 463
 464 EXPORT_SYMBOL(snd_ctl_remove);
 465
 466 /**
 467  * snd_ctl_remove_id - remove the control of the given id and release it
 468  * @card: the card instance
 469  * @id: the control id to remove
 470  *
 471  * Finds the control instance with the given id, removes it from the
 472  * card list and releases it.
 473  *
 474  * Returns 0 if successful, or a negative error code on failure.
 475  */
 476 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 477 {
 478         struct snd_kcontrol *kctl;
 479         int ret;
 480
 481         down_write(&card->controls_rwsem);
 482         kctl = snd_ctl_find_id(card, id);
 483         if (kctl == NULL) {
 484                 up_write(&card->controls_rwsem);
 485                 return -ENOENT;
 486         }
 487         ret = snd_ctl_remove(card, kctl);
 488         up_write(&card->controls_rwsem);
 489         return ret;
 490 }
 491
 492 EXPORT_SYMBOL(snd_ctl_remove_id);
 493
 494 /**
 495  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 496  * @file: active control handle
 497  * @id: the control id to remove
 498  *
 499  * Finds the control instance with the given id, removes it from the
 500  * card list and releases it.
 501  *
 502  * Returns 0 if successful, or a negative error code on failure.
 503  */
 504 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 505                                    struct snd_ctl_elem_id *id)
 506 {
 507         struct snd_card *card = file->card;
 508         struct snd_kcontrol *kctl;
 509         int idx, ret;
 510
 511         down_write(&card->controls_rwsem);
 512         kctl = snd_ctl_find_id(card, id);
 513         if (kctl == NULL) {
 514                 ret = -ENOENT;
 515                 goto error;
 516         }
 517         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 518                 ret = -EINVAL;
 519                 goto error;
 520         }
 521         for (idx = 0; idx < kctl->count; idx++)
 522                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 523                         ret = -EBUSY;
 524                         goto error;
 525                 }
 526         ret = snd_ctl_remove(card, kctl);
 527         if (ret < 0)
 528                 goto error;
 529         card->user_ctl_count--;
 530 error:
 531         up_write(&card->controls_rwsem);
 532         return ret;
 533 }
 534
 535 /**
 536  * snd_ctl_activate_id - activate/inactivate the control of the given id
 537  * @card: the card instance
 538  * @id: the control id to activate/inactivate
 539  * @active: non-zero to activate
 540  *
 541  * Finds the control instance with the given id, and activate or
 542  * inactivate the control together with notification, if changed.
 543  *
 544  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 545  */
 546 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 547                         int active)
 548 {
 549         struct snd_kcontrol *kctl;
 550         struct snd_kcontrol_volatile *vd;
 551         unsigned int index_offset;
 552         int ret;
 553
 554         down_write(&card->controls_rwsem);
 555         kctl = snd_ctl_find_id(card, id);
 556         if (kctl == NULL) {
 557                 ret = -ENOENT;
 558                 goto unlock;
 559         }
 560         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 561         vd = &kctl->vd[index_offset];
 562         ret = 0;
 563         if (active) {
 564                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 565                         goto unlock;
 566                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 567         } else {
 568                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 569                         goto unlock;
 570                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 571         }
 572         ret = 1;
 573  unlock:
 574         up_write(&card->controls_rwsem);
 575         if (ret > 0)
 576                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 577         return ret;
 578 }
 579 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 580
 581 /**
 582  * snd_ctl_rename_id - replace the id of a control on the card
 583  * @card: the card instance
 584  * @src_id: the old id
 585  * @dst_id: the new id
 586  *
 587  * Finds the control with the old id from the card, and replaces the
 588  * id with the new one.
 589  *
 590  * Returns zero if successful, or a negative error code on failure.
 591  */
 592 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 593                       struct snd_ctl_elem_id *dst_id)
 594 {
 595         struct snd_kcontrol *kctl;
 596
 597         down_write(&card->controls_rwsem);
 598         kctl = snd_ctl_find_id(card, src_id);
 599         if (kctl == NULL) {
 600                 up_write(&card->controls_rwsem);
 601                 return -ENOENT;
 602         }
 603         kctl->id = *dst_id;
 604         kctl->id.numid = card->last_numid + 1;
 605         card->last_numid += kctl->count;
 606         up_write(&card->controls_rwsem);
 607         return 0;
 608 }
 609
 610 EXPORT_SYMBOL(snd_ctl_rename_id);
 611
 612 /**
 613  * snd_ctl_find_numid - find the control instance with the given number-id
 614  * @card: the card instance
 615  * @numid: the number-id to search
 616  *
 617  * Finds the control instance with the given number-id from the card.
 618  *
 619  * Returns the pointer of the instance if found, or NULL if not.
 620  *
 621  * The caller must down card->controls_rwsem before calling this function
 622  * (if the race condition can happen).
 623  */
 624 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 625 {
 626         struct snd_kcontrol *kctl;
 627
 628         if (snd_BUG_ON(!card || !numid))
 629                 return NULL;
 630         list_for_each_entry(kctl, &card->controls, list) {
 631                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 632                         return kctl;
 633         }
 634         return NULL;
 635 }
 636
 637 EXPORT_SYMBOL(snd_ctl_find_numid);
 638
 639 /**
 640  * snd_ctl_find_id - find the control instance with the given id
 641  * @card: the card instance
 642  * @id: the id to search
 643  *
 644  * Finds the control instance with the given id from the card.
 645  *
 646  * Returns the pointer of the instance if found, or NULL if not.
 647  *
 648  * The caller must down card->controls_rwsem before calling this function
 649  * (if the race condition can happen).
 650  */
 651 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 652                                      struct snd_ctl_elem_id *id)
 653 {
 654         struct snd_kcontrol *kctl;
 655
 656         if (snd_BUG_ON(!card || !id))
 657                 return NULL;
 658         if (id->numid != 0)
 659                 return snd_ctl_find_numid(card, id->numid);
 660         list_for_each_entry(kctl, &card->controls, list) {
 661                 if (kctl->id.iface != id->iface)
 662                         continue;
 663                 if (kctl->id.device != id->device)
 664                         continue;
 665                 if (kctl->id.subdevice != id->subdevice)
 666                         continue;
 667                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 668                         continue;
 669                 if (kctl->id.index > id->index)
 670                         continue;
 671                 if (kctl->id.index + kctl->count <= id->index)
 672                         continue;
 673                 return kctl;
 674         }
 675         return NULL;
 676 }
 677
 678 EXPORT_SYMBOL(snd_ctl_find_id);
 679
 680 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 681                              unsigned int cmd, void __user *arg)
 682 {
 683         struct snd_ctl_card_info *info;
 684
 685         info = kzalloc(sizeof(*info), GFP_KERNEL);
 686         if (! info)
 687                 return -ENOMEM;
 688         down_read(&snd_ioctl_rwsem);
 689         info->card = card->number;
 690         strlcpy(info->id, card->id, sizeof(info->id));
 691         strlcpy(info->driver, card->driver, sizeof(info->driver));
 692         strlcpy(info->name, card->shortname, sizeof(info->name));
 693         strlcpy(info->longname, card->longname, sizeof(info->longname));
 694         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 695         strlcpy(info->components, card->components, sizeof(info->components));
 696         up_read(&snd_ioctl_rwsem);
 697         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 698                 kfree(info);
 699                 return -EFAULT;
 700         }
 701         kfree(info);
 702         return 0;
 703 }
 704
 705 static int snd_ctl_elem_list(struct snd_card *card,
 706                              struct snd_ctl_elem_list __user *_list)
 707 {
 708         struct list_head *plist;
 709         struct snd_ctl_elem_list list;
 710         struct snd_kcontrol *kctl;
 711         struct snd_ctl_elem_id *dst, *id;
 712         unsigned int offset, space, jidx;
 713
 714         if (copy_from_user(&list, _list, sizeof(list)))
 715                 return -EFAULT;
 716         offset = list.offset;
 717         space = list.space;
 718         /* try limit maximum space */
 719         if (space > 16384)
 720                 return -ENOMEM;
 721         if (space > 0) {
 722                 /* allocate temporary buffer for atomic operation */
 723                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 724                 if (dst == NULL)
 725                         return -ENOMEM;
 726                 down_read(&card->controls_rwsem);
 727                 list.count = card->controls_count;
 728                 plist = card->controls.next;
 729                 while (plist != &card->controls) {
 730                         if (offset == 0)
 731                                 break;
 732                         kctl = snd_kcontrol(plist);
 733                         if (offset < kctl->count)
 734                                 break;
 735                         offset -= kctl->count;
 736                         plist = plist->next;
 737                 }
 738                 list.used = 0;
 739                 id = dst;
 740                 while (space > 0 && plist != &card->controls) {
 741                         kctl = snd_kcontrol(plist);
 742                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 743                                 snd_ctl_build_ioff(id, kctl, jidx);
 744                                 id++;
 745                                 space--;
 746                                 list.used++;
 747                         }
 748                         plist = plist->next;
 749                         offset = 0;
 750                 }
 751                 up_read(&card->controls_rwsem);
 752                 if (list.used > 0 &&
 753                     copy_to_user(list.pids, dst,
 754                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 755                         vfree(dst);
 756                         return -EFAULT;
 757                 }
 758                 vfree(dst);
 759         } else {
 760                 down_read(&card->controls_rwsem);
 761                 list.count = card->controls_count;
 762                 up_read(&card->controls_rwsem);
 763         }
 764         if (copy_to_user(_list, &list, sizeof(list)))
 765                 return -EFAULT;
 766         return 0;
 767 }
 768
 769 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 770                              struct snd_ctl_elem_info *info)
 771 {
 772         struct snd_card *card = ctl->card;
 773         struct snd_kcontrol *kctl;
 774         struct snd_kcontrol_volatile *vd;
 775         unsigned int index_offset;
 776         int result;
 777
 778         down_read(&card->controls_rwsem);
 779         kctl = snd_ctl_find_id(card, &info->id);
 780         if (kctl == NULL) {
 781                 up_read(&card->controls_rwsem);
 782                 return -ENOENT;
 783         }
 784 #ifdef CONFIG_SND_DEBUG
 785         info->access = 0;
 786 #endif
 787         result = kctl->info(kctl, info);
 788         if (result >= 0) {
 789                 snd_BUG_ON(info->access);
 790                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 791                 vd = &kctl->vd[index_offset];
 792                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 793                 info->access = vd->access;
 794                 if (vd->owner) {
 795                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 796                         if (vd->owner == ctl)
 797                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 798                         info->owner = pid_vnr(vd->owner->pid);
 799                 } else {
 800                         info->owner = -1;
 801                 }
 802         }
 803         up_read(&card->controls_rwsem);
 804         return result;
 805 }
 806
 807 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 808                                   struct snd_ctl_elem_info __user *_info)
 809 {
 810         struct snd_ctl_elem_info info;
 811         int result;
 812
 813         if (copy_from_user(&info, _info, sizeof(info)))
 814                 return -EFAULT;
 815         snd_power_lock(ctl->card);
 816         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 817         if (result >= 0)
 818                 result = snd_ctl_elem_info(ctl, &info);
 819         snd_power_unlock(ctl->card);
 820         if (result >= 0)
 821                 if (copy_to_user(_info, &info, sizeof(info)))
 822                         return -EFAULT;
 823         return result;
 824 }
 825
 826 static int snd_ctl_elem_read(struct snd_card *card,
 827                              struct snd_ctl_elem_value *control)
 828 {
 829         struct snd_kcontrol *kctl;
 830         struct snd_kcontrol_volatile *vd;
 831         unsigned int index_offset;
 832         int result;
 833
 834         down_read(&card->controls_rwsem);
 835         kctl = snd_ctl_find_id(card, &control->id);
 836         if (kctl == NULL) {
 837                 result = -ENOENT;
 838         } else {
 839                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 840                 vd = &kctl->vd[index_offset];
 841                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 842                     kctl->get != NULL) {
 843                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 844                         result = kctl->get(kctl, control);
 845                 } else
 846                         result = -EPERM;
 847         }
 848         up_read(&card->controls_rwsem);
 849         return result;
 850 }
 851
 852 static int snd_ctl_elem_read_user(struct snd_card *card,
 853                                   struct snd_ctl_elem_value __user *_control)
 854 {
 855         struct snd_ctl_elem_value *control;
 856         int result;
 857
 858         control = memdup_user(_control, sizeof(*control));
 859         if (IS_ERR(control))
 860                 return PTR_ERR(control);
 861
 862         snd_power_lock(card);
 863         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 864         if (result >= 0)
 865                 result = snd_ctl_elem_read(card, control);
 866         snd_power_unlock(card);
 867         if (result >= 0)
 868                 if (copy_to_user(_control, control, sizeof(*control)))
 869                         result = -EFAULT;
 870         kfree(control);
 871         return result;
 872 }
 873
 874 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 875                               struct snd_ctl_elem_value *control)
 876 {
 877         struct snd_kcontrol *kctl;
 878         struct snd_kcontrol_volatile *vd;
 879         unsigned int index_offset;
 880         int result;
 881
 882         down_read(&card->controls_rwsem);
 883         kctl = snd_ctl_find_id(card, &control->id);
 884         if (kctl == NULL) {
 885                 result = -ENOENT;
 886         } else {
 887                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 888                 vd = &kctl->vd[index_offset];
 889                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 890                     kctl->put == NULL ||
 891                     (file && vd->owner && vd->owner != file)) {
 892                         result = -EPERM;
 893                 } else {
 894                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 895                         result = kctl->put(kctl, control);
 896                 }
 897                 if (result > 0) {
 898                         up_read(&card->controls_rwsem);
 899                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 900                                        &control->id);
 901                         return 0;
 902                 }
 903         }
 904         up_read(&card->controls_rwsem);
 905         return result;
 906 }
 907
 908 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 909                                    struct snd_ctl_elem_value __user *_control)
 910 {
 911         struct snd_ctl_elem_value *control;
 912         struct snd_card *card;
 913         int result;
 914
 915         control = memdup_user(_control, sizeof(*control));
 916         if (IS_ERR(control))
 917                 return PTR_ERR(control);
 918
 919         card = file->card;
 920         snd_power_lock(card);
 921         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 922         if (result >= 0)
 923                 result = snd_ctl_elem_write(card, file, control);
 924         snd_power_unlock(card);
 925         if (result >= 0)
 926                 if (copy_to_user(_control, control, sizeof(*control)))
 927                         result = -EFAULT;
 928         kfree(control);
 929         return result;
 930 }
 931
 932 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 933                              struct snd_ctl_elem_id __user *_id)
 934 {
 935         struct snd_card *card = file->card;
 936         struct snd_ctl_elem_id id;
 937         struct snd_kcontrol *kctl;
 938         struct snd_kcontrol_volatile *vd;
 939         int result;
 940
 941         if (copy_from_user(&id, _id, sizeof(id)))
 942                 return -EFAULT;
 943         down_write(&card->controls_rwsem);
 944         kctl = snd_ctl_find_id(card, &id);
 945         if (kctl == NULL) {
 946                 result = -ENOENT;
 947         } else {
 948                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 949                 if (vd->owner != NULL)
 950                         result = -EBUSY;
 951                 else {
 952                         vd->owner = file;
 953                         result = 0;
 954                 }
 955         }
 956         up_write(&card->controls_rwsem);
 957         return result;
 958 }
 959
 960 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 961                                struct snd_ctl_elem_id __user *_id)
 962 {
 963         struct snd_card *card = file->card;
 964         struct snd_ctl_elem_id id;
 965         struct snd_kcontrol *kctl;
 966         struct snd_kcontrol_volatile *vd;
 967         int result;
 968
 969         if (copy_from_user(&id, _id, sizeof(id)))
 970                 return -EFAULT;
 971         down_write(&card->controls_rwsem);
 972         kctl = snd_ctl_find_id(card, &id);
 973         if (kctl == NULL) {
 974                 result = -ENOENT;
 975         } else {
 976                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 977                 if (vd->owner == NULL)
 978                         result = -EINVAL;
 979                 else if (vd->owner != file)
 980                         result = -EPERM;
 981                 else {
 982                         vd->owner = NULL;
 983                         result = 0;
 984                 }
 985         }
 986         up_write(&card->controls_rwsem);
 987         return result;
 988 }
 989
 990 struct user_element {
 991         struct snd_ctl_elem_info info;
 992         void *elem_data;                /* element data */
 993         unsigned long elem_data_size;   /* size of element data in bytes */
 994         void *tlv_data;                 /* TLV data */
 995         unsigned long tlv_data_size;    /* TLV data size */
 996         void *priv_data;                /* private data (like strings for enumerated type) */
 997 };
 998
 999 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1000                                   struct snd_ctl_elem_info *uinfo)
1001 {
1002         struct user_element *ue = kcontrol->private_data;
1003
1004         *uinfo = ue->info;
1005         return 0;
1006 }
1007
1008 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1009                                        struct snd_ctl_elem_info *uinfo)
1010 {
1011         struct user_element *ue = kcontrol->private_data;
1012         const char *names;
1013         unsigned int item;
1014
1015         item = uinfo->value.enumerated.item;
1016
1017         *uinfo = ue->info;
1018
1019         item = min(item, uinfo->value.enumerated.items - 1);
1020         uinfo->value.enumerated.item = item;
1021
1022         names = ue->priv_data;
1023         for (; item > 0; --item)
1024                 names += strlen(names) + 1;
1025         strcpy(uinfo->value.enumerated.name, names);
1026
1027         return 0;
1028 }
1029
1030 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1031                                  struct snd_ctl_elem_value *ucontrol)
1032 {
1033         struct user_element *ue = kcontrol->private_data;
1034
1035         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1036         return 0;
1037 }
1038
1039 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1040                                  struct snd_ctl_elem_value *ucontrol)
1041 {
1042         int change;
1043         struct user_element *ue = kcontrol->private_data;
1044
1045         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1046         if (change)
1047                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1048         return change;
1049 }
1050
1051 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1052                                  int op_flag,
1053                                  unsigned int size,
1054                                  unsigned int __user *tlv)
1055 {
1056         struct user_element *ue = kcontrol->private_data;
1057         int change = 0;
1058         void *new_data;
1059
1060         if (op_flag > 0) {
1061                 if (size > 1024 * 128)  /* sane value */
1062                         return -EINVAL;
1063
1064                 new_data = memdup_user(tlv, size);
1065                 if (IS_ERR(new_data))
1066                         return PTR_ERR(new_data);
1067                 change = ue->tlv_data_size != size;
1068                 if (!change)
1069                         change = memcmp(ue->tlv_data, new_data, size);
1070                 kfree(ue->tlv_data);
1071                 ue->tlv_data = new_data;
1072                 ue->tlv_data_size = size;
1073         } else {
1074                 if (! ue->tlv_data_size || ! ue->tlv_data)
1075                         return -ENXIO;
1076                 if (size < ue->tlv_data_size)
1077                         return -ENOSPC;
1078                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1079                         return -EFAULT;
1080         }
1081         return change;
1082 }
1083
1084 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1085 {
1086         char *names, *p;
1087         size_t buf_len, name_len;
1088         unsigned int i;
1089         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1090
1091         if (ue->info.value.enumerated.names_length > 64 * 1024)
1092                 return -EINVAL;
1093
1094         names = memdup_user((const void __user *)user_ptrval,
1095                 ue->info.value.enumerated.names_length);
1096         if (IS_ERR(names))
1097                 return PTR_ERR(names);
1098
1099         /* check that there are enough valid names */
1100         buf_len = ue->info.value.enumerated.names_length;
1101         p = names;
1102         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1103                 name_len = strnlen(p, buf_len);
1104                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1105                         kfree(names);
1106                         return -EINVAL;
1107                 }
1108                 p += name_len + 1;
1109                 buf_len -= name_len + 1;
1110         }
1111
1112         ue->priv_data = names;
1113         ue->info.value.enumerated.names_ptr = 0;
1114
1115         return 0;
1116 }
1117
1118 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1119 {
1120         struct user_element *ue = kcontrol->private_data;
1121
1122         kfree(ue->tlv_data);
1123         kfree(ue->priv_data);
1124         kfree(ue);
1125 }
1126
1127 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1128                             struct snd_ctl_elem_info *info, int replace)
1129 {
1130         struct snd_card *card = file->card;
1131         struct snd_kcontrol kctl, *_kctl;
1132         unsigned int access;
1133         long private_size;
1134         struct user_element *ue;
1135         int idx, err;
1136
1137         if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1138                 return -ENOMEM;
1139         if (info->count < 1)
1140                 return -EINVAL;
1141         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1142                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1143                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1144                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1145         info->id.numid = 0;
1146         memset(&kctl, 0, sizeof(kctl));
1147         down_write(&card->controls_rwsem);
1148         _kctl = snd_ctl_find_id(card, &info->id);
1149         err = 0;
1150         if (_kctl) {
1151                 if (replace)
1152                         err = snd_ctl_remove(card, _kctl);
1153                 else
1154                         err = -EBUSY;
1155         } else {
1156                 if (replace)
1157                         err = -ENOENT;
1158         }
1159         up_write(&card->controls_rwsem);
1160         if (err < 0)
1161                 return err;
1162         memcpy(&kctl.id, &info->id, sizeof(info->id));
1163         kctl.count = info->owner ? info->owner : 1;
1164         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1165         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1166                 kctl.info = snd_ctl_elem_user_enum_info;
1167         else
1168                 kctl.info = snd_ctl_elem_user_info;
1169         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1170                 kctl.get = snd_ctl_elem_user_get;
1171         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1172                 kctl.put = snd_ctl_elem_user_put;
1173         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1174                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1175                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1176         }
1177         switch (info->type) {
1178         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1179         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1180                 private_size = sizeof(long);
1181                 if (info->count > 128)
1182                         return -EINVAL;
1183                 break;
1184         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1185                 private_size = sizeof(long long);
1186                 if (info->count > 64)
1187                         return -EINVAL;
1188                 break;
1189         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1190                 private_size = sizeof(unsigned int);
1191                 if (info->count > 128 || info->value.enumerated.items == 0)
1192                         return -EINVAL;
1193                 break;
1194         case SNDRV_CTL_ELEM_TYPE_BYTES:
1195                 private_size = sizeof(unsigned char);
1196                 if (info->count > 512)
1197                         return -EINVAL;
1198                 break;
1199         case SNDRV_CTL_ELEM_TYPE_IEC958:
1200                 private_size = sizeof(struct snd_aes_iec958);
1201                 if (info->count != 1)
1202                         return -EINVAL;
1203                 break;
1204         default:
1205                 return -EINVAL;
1206         }
1207         private_size *= info->count;
1208         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1209         if (ue == NULL)
1210                 return -ENOMEM;
1211         ue->info = *info;
1212         ue->info.access = 0;
1213         ue->elem_data = (char *)ue + sizeof(*ue);
1214         ue->elem_data_size = private_size;
1215         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1216                 err = snd_ctl_elem_init_enum_names(ue);
1217                 if (err < 0) {
1218                         kfree(ue);
1219                         return err;
1220                 }
1221         }
1222         kctl.private_free = snd_ctl_elem_user_free;
1223         _kctl = snd_ctl_new(&kctl, access);
1224         if (_kctl == NULL) {
1225                 kfree(ue->priv_data);
1226                 kfree(ue);
1227                 return -ENOMEM;
1228         }
1229         _kctl->private_data = ue;
1230         for (idx = 0; idx < _kctl->count; idx++)
1231                 _kctl->vd[idx].owner = file;
1232         err = snd_ctl_add(card, _kctl);
1233         if (err < 0)
1234                 return err;
1235
1236         down_write(&card->controls_rwsem);
1237         card->user_ctl_count++;
1238         up_write(&card->controls_rwsem);
1239
1240         return 0;
1241 }
1242
1243 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1244                                  struct snd_ctl_elem_info __user *_info, int replace)
1245 {
1246         struct snd_ctl_elem_info info;
1247         if (copy_from_user(&info, _info, sizeof(info)))
1248                 return -EFAULT;
1249         return snd_ctl_elem_add(file, &info, replace);
1250 }
1251
1252 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1253                                struct snd_ctl_elem_id __user *_id)
1254 {
1255         struct snd_ctl_elem_id id;
1256
1257         if (copy_from_user(&id, _id, sizeof(id)))
1258                 return -EFAULT;
1259         return snd_ctl_remove_user_ctl(file, &id);
1260 }
1261
1262 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1263 {
1264         int subscribe;
1265         if (get_user(subscribe, ptr))
1266                 return -EFAULT;
1267         if (subscribe < 0) {
1268                 subscribe = file->subscribed;
1269                 if (put_user(subscribe, ptr))
1270                         return -EFAULT;
1271                 return 0;
1272         }
1273         if (subscribe) {
1274                 file->subscribed = 1;
1275                 return 0;
1276         } else if (file->subscribed) {
1277                 snd_ctl_empty_read_queue(file);
1278                 file->subscribed = 0;
1279         }
1280         return 0;
1281 }
1282
1283 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1284                              struct snd_ctl_tlv __user *_tlv,
1285                              int op_flag)
1286 {
1287         struct snd_card *card = file->card;
1288         struct snd_ctl_tlv tlv;
1289         struct snd_kcontrol *kctl;
1290         struct snd_kcontrol_volatile *vd;
1291         unsigned int len;
1292         int err = 0;
1293
1294         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1295                 return -EFAULT;
1296         if (tlv.length < sizeof(unsigned int) * 2)
1297                 return -EINVAL;
1298         down_read(&card->controls_rwsem);
1299         kctl = snd_ctl_find_numid(card, tlv.numid);
1300         if (kctl == NULL) {
1301                 err = -ENOENT;
1302                 goto __kctl_end;
1303         }
1304         if (kctl->tlv.p == NULL) {
1305                 err = -ENXIO;
1306                 goto __kctl_end;
1307         }
1308         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1309         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1310             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1311             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1312                 err = -ENXIO;
1313                 goto __kctl_end;
1314         }
1315         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1316                 if (vd->owner != NULL && vd->owner != file) {
1317                         err = -EPERM;
1318                         goto __kctl_end;
1319                 }
1320                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1321                 if (err > 0) {
1322                         up_read(&card->controls_rwsem);
1323                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1324                         return 0;
1325                 }
1326         } else {
1327                 if (op_flag) {
1328                         err = -ENXIO;
1329                         goto __kctl_end;
1330                 }
1331                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1332                 if (tlv.length < len) {
1333                         err = -ENOMEM;
1334                         goto __kctl_end;
1335                 }
1336                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1337                         err = -EFAULT;
1338         }
1339       __kctl_end:
1340         up_read(&card->controls_rwsem);
1341         return err;
1342 }
1343
1344 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1345 {
1346         struct snd_ctl_file *ctl;
1347         struct snd_card *card;
1348         struct snd_kctl_ioctl *p;
1349         void __user *argp = (void __user *)arg;
1350         int __user *ip = argp;
1351         int err;
1352
1353         ctl = file->private_data;
1354         card = ctl->card;
1355         if (snd_BUG_ON(!card))
1356                 return -ENXIO;
1357         switch (cmd) {
1358         case SNDRV_CTL_IOCTL_PVERSION:
1359                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1360         case SNDRV_CTL_IOCTL_CARD_INFO:
1361                 return snd_ctl_card_info(card, ctl, cmd, argp);
1362         case SNDRV_CTL_IOCTL_ELEM_LIST:
1363                 return snd_ctl_elem_list(card, argp);
1364         case SNDRV_CTL_IOCTL_ELEM_INFO:
1365                 return snd_ctl_elem_info_user(ctl, argp);
1366         case SNDRV_CTL_IOCTL_ELEM_READ:
1367                 return snd_ctl_elem_read_user(card, argp);
1368         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1369                 return snd_ctl_elem_write_user(ctl, argp);
1370         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1371                 return snd_ctl_elem_lock(ctl, argp);
1372         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1373                 return snd_ctl_elem_unlock(ctl, argp);
1374         case SNDRV_CTL_IOCTL_ELEM_ADD:
1375                 return snd_ctl_elem_add_user(ctl, argp, 0);
1376         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1377                 return snd_ctl_elem_add_user(ctl, argp, 1);
1378         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1379                 return snd_ctl_elem_remove(ctl, argp);
1380         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1381                 return snd_ctl_subscribe_events(ctl, ip);
1382         case SNDRV_CTL_IOCTL_TLV_READ:
1383                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1384         case SNDRV_CTL_IOCTL_TLV_WRITE:
1385                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1386         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1387                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1388         case SNDRV_CTL_IOCTL_POWER:
1389                 return -ENOPROTOOPT;
1390         case SNDRV_CTL_IOCTL_POWER_STATE:
1391 #ifdef CONFIG_PM
1392                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1393 #else
1394                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1395 #endif
1396         }
1397         down_read(&snd_ioctl_rwsem);
1398         list_for_each_entry(p, &snd_control_ioctls, list) {
1399                 err = p->fioctl(card, ctl, cmd, arg);
1400                 if (err != -ENOIOCTLCMD) {
1401                         up_read(&snd_ioctl_rwsem);
1402                         return err;
1403                 }
1404         }
1405         up_read(&snd_ioctl_rwsem);
1406         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1407         return -ENOTTY;
1408 }
1409
1410 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1411                             size_t count, loff_t * offset)
1412 {
1413         struct snd_ctl_file *ctl;
1414         int err = 0;
1415         ssize_t result = 0;
1416
1417         ctl = file->private_data;
1418         if (snd_BUG_ON(!ctl || !ctl->card))
1419                 return -ENXIO;
1420         if (!ctl->subscribed)
1421                 return -EBADFD;
1422         if (count < sizeof(struct snd_ctl_event))
1423                 return -EINVAL;
1424         spin_lock_irq(&ctl->read_lock);
1425         while (count >= sizeof(struct snd_ctl_event)) {
1426                 struct snd_ctl_event ev;
1427                 struct snd_kctl_event *kev;
1428                 while (list_empty(&ctl->events)) {
1429                         wait_queue_t wait;
1430                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1431                                 err = -EAGAIN;
1432                                 goto __end_lock;
1433                         }
1434                         init_waitqueue_entry(&wait, current);
1435                         add_wait_queue(&ctl->change_sleep, &wait);
1436                         set_current_state(TASK_INTERRUPTIBLE);
1437                         spin_unlock_irq(&ctl->read_lock);
1438                         schedule();
1439                         remove_wait_queue(&ctl->change_sleep, &wait);
1440                         if (ctl->card->shutdown)
1441                                 return -ENODEV;
1442                         if (signal_pending(current))
1443                                 return -ERESTARTSYS;
1444                         spin_lock_irq(&ctl->read_lock);
1445                 }
1446                 kev = snd_kctl_event(ctl->events.next);
1447                 ev.type = SNDRV_CTL_EVENT_ELEM;
1448                 ev.data.elem.mask = kev->mask;
1449                 ev.data.elem.id = kev->id;
1450                 list_del(&kev->list);
1451                 spin_unlock_irq(&ctl->read_lock);
1452                 kfree(kev);
1453                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1454                         err = -EFAULT;
1455                         goto __end;
1456                 }
1457                 spin_lock_irq(&ctl->read_lock);
1458                 buffer += sizeof(struct snd_ctl_event);
1459                 count -= sizeof(struct snd_ctl_event);
1460                 result += sizeof(struct snd_ctl_event);
1461         }
1462       __end_lock:
1463         spin_unlock_irq(&ctl->read_lock);
1464       __end:
1465         return result > 0 ? result : err;
1466 }
1467
1468 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1469 {
1470         unsigned int mask;
1471         struct snd_ctl_file *ctl;
1472
1473         ctl = file->private_data;
1474         if (!ctl->subscribed)
1475                 return 0;
1476         poll_wait(file, &ctl->change_sleep, wait);
1477
1478         mask = 0;
1479         if (!list_empty(&ctl->events))
1480                 mask |= POLLIN | POLLRDNORM;
1481
1482         return mask;
1483 }
1484
1485 /*
1486  * register the device-specific control-ioctls.
1487  * called from each device manager like pcm.c, hwdep.c, etc.
1488  */
1489 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1490 {
1491         struct snd_kctl_ioctl *pn;
1492
1493         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1494         if (pn == NULL)
1495                 return -ENOMEM;
1496         pn->fioctl = fcn;
1497         down_write(&snd_ioctl_rwsem);
1498         list_add_tail(&pn->list, lists);
1499         up_write(&snd_ioctl_rwsem);
1500         return 0;
1501 }
1502
1503 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1504 {
1505         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1506 }
1507
1508 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1509
1510 #ifdef CONFIG_COMPAT
1511 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1512 {
1513         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1514 }
1515
1516 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1517 #endif
1518
1519 /*
1520  * de-register the device-specific control-ioctls.
1521  */
1522 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1523                                      struct list_head *lists)
1524 {
1525         struct snd_kctl_ioctl *p;
1526
1527         if (snd_BUG_ON(!fcn))
1528                 return -EINVAL;
1529         down_write(&snd_ioctl_rwsem);
1530         list_for_each_entry(p, lists, list) {
1531                 if (p->fioctl == fcn) {
1532                         list_del(&p->list);
1533                         up_write(&snd_ioctl_rwsem);
1534                         kfree(p);
1535                         return 0;
1536                 }
1537         }
1538         up_write(&snd_ioctl_rwsem);
1539         snd_BUG();
1540         return -EINVAL;
1541 }
1542
1543 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1544 {
1545         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1546 }
1547
1548 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1549
1550 #ifdef CONFIG_COMPAT
1551 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1552 {
1553         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1554 }
1555
1556 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1557 #endif
1558
1559 static int snd_ctl_fasync(int fd, struct file * file, int on)
1560 {
1561         struct snd_ctl_file *ctl;
1562
1563         ctl = file->private_data;
1564         return fasync_helper(fd, file, on, &ctl->fasync);
1565 }
1566
1567 /*
1568  * ioctl32 compat
1569  */
1570 #ifdef CONFIG_COMPAT
1571 #include "control_compat.c"
1572 #else
1573 #define snd_ctl_ioctl_compat    NULL
1574 #endif
1575
1576 /*
1577  *  INIT PART
1578  */
1579
1580 static const struct file_operations snd_ctl_f_ops =
1581 {
1582         .owner =        THIS_MODULE,
1583         .read =         snd_ctl_read,
1584         .open =         snd_ctl_open,
1585         .release =      snd_ctl_release,
1586         .llseek =       no_llseek,
1587         .poll =         snd_ctl_poll,
1588         .unlocked_ioctl =       snd_ctl_ioctl,
1589         .compat_ioctl = snd_ctl_ioctl_compat,
1590         .fasync =       snd_ctl_fasync,
1591 };
1592
1593 /*
1594  * registration of the control device
1595  */
1596 static int snd_ctl_dev_register(struct snd_device *device)
1597 {
1598         struct snd_card *card = device->device_data;
1599         int err, cardnum;
1600         char name[16];
1601
1602         if (snd_BUG_ON(!card))
1603                 return -ENXIO;
1604         cardnum = card->number;
1605         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1606                 return -ENXIO;
1607         sprintf(name, "controlC%i", cardnum);
1608         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1609                                        &snd_ctl_f_ops, card, name)) < 0)
1610                 return err;
1611         return 0;
1612 }
1613
1614 /*
1615  * disconnection of the control device
1616  */
1617 static int snd_ctl_dev_disconnect(struct snd_device *device)
1618 {
1619         struct snd_card *card = device->device_data;
1620         struct snd_ctl_file *ctl;
1621         int err, cardnum;
1622
1623         if (snd_BUG_ON(!card))
1624                 return -ENXIO;
1625         cardnum = card->number;
1626         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1627                 return -ENXIO;
1628
1629         read_lock(&card->ctl_files_rwlock);
1630         list_for_each_entry(ctl, &card->ctl_files, list) {
1631                 wake_up(&ctl->change_sleep);
1632                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1633         }
1634         read_unlock(&card->ctl_files_rwlock);
1635
1636         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1637                                          card, -1)) < 0)
1638                 return err;
1639         return 0;
1640 }
1641
1642 /*
1643  * free all controls
1644  */
1645 static int snd_ctl_dev_free(struct snd_device *device)
1646 {
1647         struct snd_card *card = device->device_data;
1648         struct snd_kcontrol *control;
1649
1650         down_write(&card->controls_rwsem);
1651         while (!list_empty(&card->controls)) {
1652                 control = snd_kcontrol(card->controls.next);
1653                 snd_ctl_remove(card, control);
1654         }
1655         up_write(&card->controls_rwsem);
1656         return 0;
1657 }
1658
1659 /*
1660  * create control core:
1661  * called from init.c
1662  */
1663 int snd_ctl_create(struct snd_card *card)
1664 {
1665         static struct snd_device_ops ops = {
1666                 .dev_free = snd_ctl_dev_free,
1667                 .dev_register = snd_ctl_dev_register,
1668                 .dev_disconnect = snd_ctl_dev_disconnect,
1669         };
1670
1671         if (snd_BUG_ON(!card))
1672                 return -ENXIO;
1673         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1674 }
1675
1676 /*
1677  * Frequently used control callbacks/helpers
1678  */
1679 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1680                               struct snd_ctl_elem_info *uinfo)
1681 {
1682         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1683         uinfo->count = 1;
1684         uinfo->value.integer.min = 0;
1685         uinfo->value.integer.max = 1;
1686         return 0;
1687 }
1688
1689 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1690
1691 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1692                                 struct snd_ctl_elem_info *uinfo)
1693 {
1694         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1695         uinfo->count = 2;
1696         uinfo->value.integer.min = 0;
1697         uinfo->value.integer.max = 1;
1698         return 0;
1699 }
1700
1701 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1702
1703 /**
1704  * snd_ctl_enum_info - fills the info structure for an enumerated control
1705  * @info: the structure to be filled
1706  * @channels: the number of the control's channels; often one
1707  * @items: the number of control values; also the size of @names
1708  * @names: an array containing the names of all control values
1709  *
1710  * Sets all required fields in @info to their appropriate values.
1711  * If the control's accessibility is not the default (readable and writable),
1712  * the caller has to fill @info->access.
1713  */
1714 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1715                       unsigned int items, const char *const names[])
1716 {
1717         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1718         info->count = channels;
1719         info->value.enumerated.items = items;
1720         if (info->value.enumerated.item >= items)
1721                 info->value.enumerated.item = items - 1;
1722         strlcpy(info->value.enumerated.name,
1723                 names[info->value.enumerated.item],
1724                 sizeof(info->value.enumerated.name));
1725         return 0;
1726 }
1727 EXPORT_SYMBOL(snd_ctl_enum_info);