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 IS_ENABLED(CONFIG_SND_MIXER_OSS)
 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                         dev_err(card->dev, "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  * Return: 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                 pr_err("ALSA: 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  * Return: 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                         pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
 245                                 ncontrol->name, kctl.id.name);
 246         }
 247         kctl.id.index = ncontrol->index;
 248         kctl.count = ncontrol->count ? ncontrol->count : 1;
 249         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 250                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 251                                       SNDRV_CTL_ELEM_ACCESS_VOLATILE|
 252                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 253                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 254                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 255                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 256         kctl.info = ncontrol->info;
 257         kctl.get = ncontrol->get;
 258         kctl.put = ncontrol->put;
 259         kctl.tlv.p = ncontrol->tlv.p;
 260         kctl.private_value = ncontrol->private_value;
 261         kctl.private_data = private_data;
 262         return snd_ctl_new(&kctl, access);
 263 }
 264
 265 EXPORT_SYMBOL(snd_ctl_new1);
 266
 267 /**
 268  * snd_ctl_free_one - release the control instance
 269  * @kcontrol: the control instance
 270  *
 271  * Releases the control instance created via snd_ctl_new()
 272  * or snd_ctl_new1().
 273  * Don't call this after the control was added to the card.
 274  */
 275 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 276 {
 277         if (kcontrol) {
 278                 if (kcontrol->private_free)
 279                         kcontrol->private_free(kcontrol);
 280                 kfree(kcontrol);
 281         }
 282 }
 283
 284 EXPORT_SYMBOL(snd_ctl_free_one);
 285
 286 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 287                                           unsigned int count)
 288 {
 289         struct snd_kcontrol *kctl;
 290
 291         /* Make sure that the ids assigned to the control do not wrap around */
 292         if (card->last_numid >= UINT_MAX - count)
 293                 card->last_numid = 0;
 294
 295         list_for_each_entry(kctl, &card->controls, list) {
 296                 if (kctl->id.numid < card->last_numid + 1 + count &&
 297                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 298                         card->last_numid = kctl->id.numid + kctl->count - 1;
 299                         return true;
 300                 }
 301         }
 302         return false;
 303 }
 304
 305 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 306 {
 307         unsigned int iter = 100000;
 308
 309         while (snd_ctl_remove_numid_conflict(card, count)) {
 310                 if (--iter == 0) {
 311                         /* this situation is very unlikely */
 312                         dev_err(card->dev, "unable to allocate new control numid\n");
 313                         return -ENOMEM;
 314                 }
 315         }
 316         return 0;
 317 }
 318
 319 /**
 320  * snd_ctl_add - add the control instance to the card
 321  * @card: the card instance
 322  * @kcontrol: the control instance to add
 323  *
 324  * Adds the control instance created via snd_ctl_new() or
 325  * snd_ctl_new1() to the given card. Assigns also an unique
 326  * numid used for fast search.
 327  *
 328  * It frees automatically the control which cannot be added.
 329  *
 330  * Return: Zero if successful, or a negative error code on failure.
 331  *
 332  */
 333 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 334 {
 335         struct snd_ctl_elem_id id;
 336         unsigned int idx;
 337         unsigned int count;
 338         int err = -EINVAL;
 339
 340         if (! kcontrol)
 341                 return err;
 342         if (snd_BUG_ON(!card || !kcontrol->info))
 343                 goto error;
 344         id = kcontrol->id;
 345         if (id.index > UINT_MAX - kcontrol->count)
 346                 goto error;
 347
 348         down_write(&card->controls_rwsem);
 349         if (snd_ctl_find_id(card, &id)) {
 350                 up_write(&card->controls_rwsem);
 351                 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
 352                                         id.iface,
 353                                         id.device,
 354                                         id.subdevice,
 355                                         id.name,
 356                                         id.index);
 357                 err = -EBUSY;
 358                 goto error;
 359         }
 360         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 361                 up_write(&card->controls_rwsem);
 362                 err = -ENOMEM;
 363                 goto error;
 364         }
 365         list_add_tail(&kcontrol->list, &card->controls);
 366         card->controls_count += kcontrol->count;
 367         kcontrol->id.numid = card->last_numid + 1;
 368         card->last_numid += kcontrol->count;
 369         count = kcontrol->count;
 370         up_write(&card->controls_rwsem);
 371         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 372                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 373         return 0;
 374
 375  error:
 376         snd_ctl_free_one(kcontrol);
 377         return err;
 378 }
 379
 380 EXPORT_SYMBOL(snd_ctl_add);
 381
 382 /**
 383  * snd_ctl_replace - replace the control instance of the card
 384  * @card: the card instance
 385  * @kcontrol: the control instance to replace
 386  * @add_on_replace: add the control if not already added
 387  *
 388  * Replaces the given control.  If the given control does not exist
 389  * and the add_on_replace flag is set, the control is added.  If the
 390  * control exists, it is destroyed first.
 391  *
 392  * It frees automatically the control which cannot be added or replaced.
 393  *
 394  * Return: Zero if successful, or a negative error code on failure.
 395  */
 396 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 397                     bool add_on_replace)
 398 {
 399         struct snd_ctl_elem_id id;
 400         unsigned int count;
 401         unsigned int idx;
 402         struct snd_kcontrol *old;
 403         int ret;
 404
 405         if (!kcontrol)
 406                 return -EINVAL;
 407         if (snd_BUG_ON(!card || !kcontrol->info)) {
 408                 ret = -EINVAL;
 409                 goto error;
 410         }
 411         id = kcontrol->id;
 412         down_write(&card->controls_rwsem);
 413         old = snd_ctl_find_id(card, &id);
 414         if (!old) {
 415                 if (add_on_replace)
 416                         goto add;
 417                 up_write(&card->controls_rwsem);
 418                 ret = -EINVAL;
 419                 goto error;
 420         }
 421         ret = snd_ctl_remove(card, old);
 422         if (ret < 0) {
 423                 up_write(&card->controls_rwsem);
 424                 goto error;
 425         }
 426 add:
 427         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 428                 up_write(&card->controls_rwsem);
 429                 ret = -ENOMEM;
 430                 goto error;
 431         }
 432         list_add_tail(&kcontrol->list, &card->controls);
 433         card->controls_count += kcontrol->count;
 434         kcontrol->id.numid = card->last_numid + 1;
 435         card->last_numid += kcontrol->count;
 436         count = kcontrol->count;
 437         up_write(&card->controls_rwsem);
 438         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 439                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 440         return 0;
 441
 442 error:
 443         snd_ctl_free_one(kcontrol);
 444         return ret;
 445 }
 446 EXPORT_SYMBOL(snd_ctl_replace);
 447
 448 /**
 449  * snd_ctl_remove - remove the control from the card and release it
 450  * @card: the card instance
 451  * @kcontrol: the control instance to remove
 452  *
 453  * Removes the control from the card and then releases the instance.
 454  * You don't need to call snd_ctl_free_one(). You must be in
 455  * the write lock - down_write(&card->controls_rwsem).
 456  *
 457  * Return: 0 if successful, or a negative error code on failure.
 458  */
 459 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 460 {
 461         struct snd_ctl_elem_id id;
 462         unsigned int idx;
 463
 464         if (snd_BUG_ON(!card || !kcontrol))
 465                 return -EINVAL;
 466         list_del(&kcontrol->list);
 467         card->controls_count -= kcontrol->count;
 468         id = kcontrol->id;
 469         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 470                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 471         snd_ctl_free_one(kcontrol);
 472         return 0;
 473 }
 474
 475 EXPORT_SYMBOL(snd_ctl_remove);
 476
 477 /**
 478  * snd_ctl_remove_id - remove the control of the given id and release it
 479  * @card: the card instance
 480  * @id: the control id to remove
 481  *
 482  * Finds the control instance with the given id, removes it from the
 483  * card list and releases it.
 484  *
 485  * Return: 0 if successful, or a negative error code on failure.
 486  */
 487 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 488 {
 489         struct snd_kcontrol *kctl;
 490         int ret;
 491
 492         down_write(&card->controls_rwsem);
 493         kctl = snd_ctl_find_id(card, id);
 494         if (kctl == NULL) {
 495                 up_write(&card->controls_rwsem);
 496                 return -ENOENT;
 497         }
 498         ret = snd_ctl_remove(card, kctl);
 499         up_write(&card->controls_rwsem);
 500         return ret;
 501 }
 502
 503 EXPORT_SYMBOL(snd_ctl_remove_id);
 504
 505 /**
 506  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 507  * @file: active control handle
 508  * @id: the control id to remove
 509  *
 510  * Finds the control instance with the given id, removes it from the
 511  * card list and releases it.
 512  *
 513  * Return: 0 if successful, or a negative error code on failure.
 514  */
 515 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 516                                    struct snd_ctl_elem_id *id)
 517 {
 518         struct snd_card *card = file->card;
 519         struct snd_kcontrol *kctl;
 520         int idx, ret;
 521
 522         down_write(&card->controls_rwsem);
 523         kctl = snd_ctl_find_id(card, id);
 524         if (kctl == NULL) {
 525                 ret = -ENOENT;
 526                 goto error;
 527         }
 528         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 529                 ret = -EINVAL;
 530                 goto error;
 531         }
 532         for (idx = 0; idx < kctl->count; idx++)
 533                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 534                         ret = -EBUSY;
 535                         goto error;
 536                 }
 537         ret = snd_ctl_remove(card, kctl);
 538         if (ret < 0)
 539                 goto error;
 540         card->user_ctl_count--;
 541 error:
 542         up_write(&card->controls_rwsem);
 543         return ret;
 544 }
 545
 546 /**
 547  * snd_ctl_activate_id - activate/inactivate the control of the given id
 548  * @card: the card instance
 549  * @id: the control id to activate/inactivate
 550  * @active: non-zero to activate
 551  *
 552  * Finds the control instance with the given id, and activate or
 553  * inactivate the control together with notification, if changed.
 554  *
 555  * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
 556  */
 557 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 558                         int active)
 559 {
 560         struct snd_kcontrol *kctl;
 561         struct snd_kcontrol_volatile *vd;
 562         unsigned int index_offset;
 563         int ret;
 564
 565         down_write(&card->controls_rwsem);
 566         kctl = snd_ctl_find_id(card, id);
 567         if (kctl == NULL) {
 568                 ret = -ENOENT;
 569                 goto unlock;
 570         }
 571         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 572         vd = &kctl->vd[index_offset];
 573         ret = 0;
 574         if (active) {
 575                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 576                         goto unlock;
 577                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 578         } else {
 579                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 580                         goto unlock;
 581                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 582         }
 583         ret = 1;
 584  unlock:
 585         up_write(&card->controls_rwsem);
 586         if (ret > 0)
 587                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 588         return ret;
 589 }
 590 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 591
 592 /**
 593  * snd_ctl_rename_id - replace the id of a control on the card
 594  * @card: the card instance
 595  * @src_id: the old id
 596  * @dst_id: the new id
 597  *
 598  * Finds the control with the old id from the card, and replaces the
 599  * id with the new one.
 600  *
 601  * Return: Zero if successful, or a negative error code on failure.
 602  */
 603 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 604                       struct snd_ctl_elem_id *dst_id)
 605 {
 606         struct snd_kcontrol *kctl;
 607
 608         down_write(&card->controls_rwsem);
 609         kctl = snd_ctl_find_id(card, src_id);
 610         if (kctl == NULL) {
 611                 up_write(&card->controls_rwsem);
 612                 return -ENOENT;
 613         }
 614         kctl->id = *dst_id;
 615         kctl->id.numid = card->last_numid + 1;
 616         card->last_numid += kctl->count;
 617         up_write(&card->controls_rwsem);
 618         return 0;
 619 }
 620
 621 EXPORT_SYMBOL(snd_ctl_rename_id);
 622
 623 /**
 624  * snd_ctl_find_numid - find the control instance with the given number-id
 625  * @card: the card instance
 626  * @numid: the number-id to search
 627  *
 628  * Finds the control instance with the given number-id from the card.
 629  *
 630  * The caller must down card->controls_rwsem before calling this function
 631  * (if the race condition can happen).
 632  *
 633  * Return: The pointer of the instance if found, or %NULL if not.
 634  *
 635  */
 636 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 637 {
 638         struct snd_kcontrol *kctl;
 639
 640         if (snd_BUG_ON(!card || !numid))
 641                 return NULL;
 642         list_for_each_entry(kctl, &card->controls, list) {
 643                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 644                         return kctl;
 645         }
 646         return NULL;
 647 }
 648
 649 EXPORT_SYMBOL(snd_ctl_find_numid);
 650
 651 /**
 652  * snd_ctl_find_id - find the control instance with the given id
 653  * @card: the card instance
 654  * @id: the id to search
 655  *
 656  * Finds the control instance with the given id from the card.
 657  *
 658  * The caller must down card->controls_rwsem before calling this function
 659  * (if the race condition can happen).
 660  *
 661  * Return: The pointer of the instance if found, or %NULL if not.
 662  *
 663  */
 664 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 665                                      struct snd_ctl_elem_id *id)
 666 {
 667         struct snd_kcontrol *kctl;
 668
 669         if (snd_BUG_ON(!card || !id))
 670                 return NULL;
 671         if (id->numid != 0)
 672                 return snd_ctl_find_numid(card, id->numid);
 673         list_for_each_entry(kctl, &card->controls, list) {
 674                 if (kctl->id.iface != id->iface)
 675                         continue;
 676                 if (kctl->id.device != id->device)
 677                         continue;
 678                 if (kctl->id.subdevice != id->subdevice)
 679                         continue;
 680                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 681                         continue;
 682                 if (kctl->id.index > id->index)
 683                         continue;
 684                 if (kctl->id.index + kctl->count <= id->index)
 685                         continue;
 686                 return kctl;
 687         }
 688         return NULL;
 689 }
 690
 691 EXPORT_SYMBOL(snd_ctl_find_id);
 692
 693 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 694                              unsigned int cmd, void __user *arg)
 695 {
 696         struct snd_ctl_card_info *info;
 697
 698         info = kzalloc(sizeof(*info), GFP_KERNEL);
 699         if (! info)
 700                 return -ENOMEM;
 701         down_read(&snd_ioctl_rwsem);
 702         info->card = card->number;
 703         strlcpy(info->id, card->id, sizeof(info->id));
 704         strlcpy(info->driver, card->driver, sizeof(info->driver));
 705         strlcpy(info->name, card->shortname, sizeof(info->name));
 706         strlcpy(info->longname, card->longname, sizeof(info->longname));
 707         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 708         strlcpy(info->components, card->components, sizeof(info->components));
 709         up_read(&snd_ioctl_rwsem);
 710         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 711                 kfree(info);
 712                 return -EFAULT;
 713         }
 714         kfree(info);
 715         return 0;
 716 }
 717
 718 static int snd_ctl_elem_list(struct snd_card *card,
 719                              struct snd_ctl_elem_list __user *_list)
 720 {
 721         struct list_head *plist;
 722         struct snd_ctl_elem_list list;
 723         struct snd_kcontrol *kctl;
 724         struct snd_ctl_elem_id *dst, *id;
 725         unsigned int offset, space, jidx;
 726
 727         if (copy_from_user(&list, _list, sizeof(list)))
 728                 return -EFAULT;
 729         offset = list.offset;
 730         space = list.space;
 731         /* try limit maximum space */
 732         if (space > 16384)
 733                 return -ENOMEM;
 734         if (space > 0) {
 735                 /* allocate temporary buffer for atomic operation */
 736                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 737                 if (dst == NULL)
 738                         return -ENOMEM;
 739                 down_read(&card->controls_rwsem);
 740                 list.count = card->controls_count;
 741                 plist = card->controls.next;
 742                 while (plist != &card->controls) {
 743                         if (offset == 0)
 744                                 break;
 745                         kctl = snd_kcontrol(plist);
 746                         if (offset < kctl->count)
 747                                 break;
 748                         offset -= kctl->count;
 749                         plist = plist->next;
 750                 }
 751                 list.used = 0;
 752                 id = dst;
 753                 while (space > 0 && plist != &card->controls) {
 754                         kctl = snd_kcontrol(plist);
 755                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 756                                 snd_ctl_build_ioff(id, kctl, jidx);
 757                                 id++;
 758                                 space--;
 759                                 list.used++;
 760                         }
 761                         plist = plist->next;
 762                         offset = 0;
 763                 }
 764                 up_read(&card->controls_rwsem);
 765                 if (list.used > 0 &&
 766                     copy_to_user(list.pids, dst,
 767                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 768                         vfree(dst);
 769                         return -EFAULT;
 770                 }
 771                 vfree(dst);
 772         } else {
 773                 down_read(&card->controls_rwsem);
 774                 list.count = card->controls_count;
 775                 up_read(&card->controls_rwsem);
 776         }
 777         if (copy_to_user(_list, &list, sizeof(list)))
 778                 return -EFAULT;
 779         return 0;
 780 }
 781
 782 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 783                              struct snd_ctl_elem_info *info)
 784 {
 785         struct snd_card *card = ctl->card;
 786         struct snd_kcontrol *kctl;
 787         struct snd_kcontrol_volatile *vd;
 788         unsigned int index_offset;
 789         int result;
 790
 791         down_read(&card->controls_rwsem);
 792         kctl = snd_ctl_find_id(card, &info->id);
 793         if (kctl == NULL) {
 794                 up_read(&card->controls_rwsem);
 795                 return -ENOENT;
 796         }
 797 #ifdef CONFIG_SND_DEBUG
 798         info->access = 0;
 799 #endif
 800         result = kctl->info(kctl, info);
 801         if (result >= 0) {
 802                 snd_BUG_ON(info->access);
 803                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 804                 vd = &kctl->vd[index_offset];
 805                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 806                 info->access = vd->access;
 807                 if (vd->owner) {
 808                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 809                         if (vd->owner == ctl)
 810                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 811                         info->owner = pid_vnr(vd->owner->pid);
 812                 } else {
 813                         info->owner = -1;
 814                 }
 815         }
 816         up_read(&card->controls_rwsem);
 817         return result;
 818 }
 819
 820 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 821                                   struct snd_ctl_elem_info __user *_info)
 822 {
 823         struct snd_ctl_elem_info info;
 824         int result;
 825
 826         if (copy_from_user(&info, _info, sizeof(info)))
 827                 return -EFAULT;
 828         snd_power_lock(ctl->card);
 829         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 830         if (result >= 0)
 831                 result = snd_ctl_elem_info(ctl, &info);
 832         snd_power_unlock(ctl->card);
 833         if (result >= 0)
 834                 if (copy_to_user(_info, &info, sizeof(info)))
 835                         return -EFAULT;
 836         return result;
 837 }
 838
 839 static int snd_ctl_elem_read(struct snd_card *card,
 840                              struct snd_ctl_elem_value *control)
 841 {
 842         struct snd_kcontrol *kctl;
 843         struct snd_kcontrol_volatile *vd;
 844         unsigned int index_offset;
 845         int result;
 846
 847         down_read(&card->controls_rwsem);
 848         kctl = snd_ctl_find_id(card, &control->id);
 849         if (kctl == NULL) {
 850                 result = -ENOENT;
 851         } else {
 852                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 853                 vd = &kctl->vd[index_offset];
 854                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 855                     kctl->get != NULL) {
 856                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 857                         result = kctl->get(kctl, control);
 858                 } else
 859                         result = -EPERM;
 860         }
 861         up_read(&card->controls_rwsem);
 862         return result;
 863 }
 864
 865 static int snd_ctl_elem_read_user(struct snd_card *card,
 866                                   struct snd_ctl_elem_value __user *_control)
 867 {
 868         struct snd_ctl_elem_value *control;
 869         int result;
 870
 871         control = memdup_user(_control, sizeof(*control));
 872         if (IS_ERR(control))
 873                 return PTR_ERR(control);
 874
 875         snd_power_lock(card);
 876         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 877         if (result >= 0)
 878                 result = snd_ctl_elem_read(card, control);
 879         snd_power_unlock(card);
 880         if (result >= 0)
 881                 if (copy_to_user(_control, control, sizeof(*control)))
 882                         result = -EFAULT;
 883         kfree(control);
 884         return result;
 885 }
 886
 887 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 888                               struct snd_ctl_elem_value *control)
 889 {
 890         struct snd_kcontrol *kctl;
 891         struct snd_kcontrol_volatile *vd;
 892         unsigned int index_offset;
 893         int result;
 894
 895         down_read(&card->controls_rwsem);
 896         kctl = snd_ctl_find_id(card, &control->id);
 897         if (kctl == NULL) {
 898                 result = -ENOENT;
 899         } else {
 900                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 901                 vd = &kctl->vd[index_offset];
 902                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 903                     kctl->put == NULL ||
 904                     (file && vd->owner && vd->owner != file)) {
 905                         result = -EPERM;
 906                 } else {
 907                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 908                         result = kctl->put(kctl, control);
 909                 }
 910                 if (result > 0) {
 911                         struct snd_ctl_elem_id id = control->id;
 912                         up_read(&card->controls_rwsem);
 913                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
 914                         return 0;
 915                 }
 916         }
 917         up_read(&card->controls_rwsem);
 918         return result;
 919 }
 920
 921 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 922                                    struct snd_ctl_elem_value __user *_control)
 923 {
 924         struct snd_ctl_elem_value *control;
 925         struct snd_card *card;
 926         int result;
 927
 928         control = memdup_user(_control, sizeof(*control));
 929         if (IS_ERR(control))
 930                 return PTR_ERR(control);
 931
 932         card = file->card;
 933         snd_power_lock(card);
 934         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 935         if (result >= 0)
 936                 result = snd_ctl_elem_write(card, file, control);
 937         snd_power_unlock(card);
 938         if (result >= 0)
 939                 if (copy_to_user(_control, control, sizeof(*control)))
 940                         result = -EFAULT;
 941         kfree(control);
 942         return result;
 943 }
 944
 945 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 946                              struct snd_ctl_elem_id __user *_id)
 947 {
 948         struct snd_card *card = file->card;
 949         struct snd_ctl_elem_id id;
 950         struct snd_kcontrol *kctl;
 951         struct snd_kcontrol_volatile *vd;
 952         int result;
 953
 954         if (copy_from_user(&id, _id, sizeof(id)))
 955                 return -EFAULT;
 956         down_write(&card->controls_rwsem);
 957         kctl = snd_ctl_find_id(card, &id);
 958         if (kctl == NULL) {
 959                 result = -ENOENT;
 960         } else {
 961                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 962                 if (vd->owner != NULL)
 963                         result = -EBUSY;
 964                 else {
 965                         vd->owner = file;
 966                         result = 0;
 967                 }
 968         }
 969         up_write(&card->controls_rwsem);
 970         return result;
 971 }
 972
 973 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 974                                struct snd_ctl_elem_id __user *_id)
 975 {
 976         struct snd_card *card = file->card;
 977         struct snd_ctl_elem_id id;
 978         struct snd_kcontrol *kctl;
 979         struct snd_kcontrol_volatile *vd;
 980         int result;
 981
 982         if (copy_from_user(&id, _id, sizeof(id)))
 983                 return -EFAULT;
 984         down_write(&card->controls_rwsem);
 985         kctl = snd_ctl_find_id(card, &id);
 986         if (kctl == NULL) {
 987                 result = -ENOENT;
 988         } else {
 989                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 990                 if (vd->owner == NULL)
 991                         result = -EINVAL;
 992                 else if (vd->owner != file)
 993                         result = -EPERM;
 994                 else {
 995                         vd->owner = NULL;
 996                         result = 0;
 997                 }
 998         }
 999         up_write(&card->controls_rwsem);
1000         return result;
1001 }
1002
1003 struct user_element {
1004         struct snd_ctl_elem_info info;
1005         struct snd_card *card;
1006         void *elem_data;                /* element data */
1007         unsigned long elem_data_size;   /* size of element data in bytes */
1008         void *tlv_data;                 /* TLV data */
1009         unsigned long tlv_data_size;    /* TLV data size */
1010         void *priv_data;                /* private data (like strings for enumerated type) */
1011 };
1012
1013 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1014                                   struct snd_ctl_elem_info *uinfo)
1015 {
1016         struct user_element *ue = kcontrol->private_data;
1017
1018         *uinfo = ue->info;
1019         return 0;
1020 }
1021
1022 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1023                                        struct snd_ctl_elem_info *uinfo)
1024 {
1025         struct user_element *ue = kcontrol->private_data;
1026         const char *names;
1027         unsigned int item;
1028
1029         item = uinfo->value.enumerated.item;
1030
1031         *uinfo = ue->info;
1032
1033         item = min(item, uinfo->value.enumerated.items - 1);
1034         uinfo->value.enumerated.item = item;
1035
1036         names = ue->priv_data;
1037         for (; item > 0; --item)
1038                 names += strlen(names) + 1;
1039         strcpy(uinfo->value.enumerated.name, names);
1040
1041         return 0;
1042 }
1043
1044 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1045                                  struct snd_ctl_elem_value *ucontrol)
1046 {
1047         struct user_element *ue = kcontrol->private_data;
1048
1049         mutex_lock(&ue->card->user_ctl_lock);
1050         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1051         mutex_unlock(&ue->card->user_ctl_lock);
1052         return 0;
1053 }
1054
1055 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1056                                  struct snd_ctl_elem_value *ucontrol)
1057 {
1058         int change;
1059         struct user_element *ue = kcontrol->private_data;
1060
1061         mutex_lock(&ue->card->user_ctl_lock);
1062         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1063         if (change)
1064                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1065         mutex_unlock(&ue->card->user_ctl_lock);
1066         return change;
1067 }
1068
1069 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1070                                  int op_flag,
1071                                  unsigned int size,
1072                                  unsigned int __user *tlv)
1073 {
1074         struct user_element *ue = kcontrol->private_data;
1075         int change = 0;
1076         void *new_data;
1077
1078         if (op_flag > 0) {
1079                 if (size > 1024 * 128)  /* sane value */
1080                         return -EINVAL;
1081
1082                 new_data = memdup_user(tlv, size);
1083                 if (IS_ERR(new_data))
1084                         return PTR_ERR(new_data);
1085                 mutex_lock(&ue->card->user_ctl_lock);
1086                 change = ue->tlv_data_size != size;
1087                 if (!change)
1088                         change = memcmp(ue->tlv_data, new_data, size);
1089                 kfree(ue->tlv_data);
1090                 ue->tlv_data = new_data;
1091                 ue->tlv_data_size = size;
1092                 mutex_unlock(&ue->card->user_ctl_lock);
1093         } else {
1094                 int ret = 0;
1095
1096                 mutex_lock(&ue->card->user_ctl_lock);
1097                 if (!ue->tlv_data_size || !ue->tlv_data) {
1098                         ret = -ENXIO;
1099                         goto err_unlock;
1100                 }
1101                 if (size < ue->tlv_data_size) {
1102                         ret = -ENOSPC;
1103                         goto err_unlock;
1104                 }
1105                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1106                         ret = -EFAULT;
1107 err_unlock:
1108                 mutex_unlock(&ue->card->user_ctl_lock);
1109                 if (ret)
1110                         return ret;
1111         }
1112         return change;
1113 }
1114
1115 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1116 {
1117         char *names, *p;
1118         size_t buf_len, name_len;
1119         unsigned int i;
1120         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1121
1122         if (ue->info.value.enumerated.names_length > 64 * 1024)
1123                 return -EINVAL;
1124
1125         names = memdup_user((const void __user *)user_ptrval,
1126                 ue->info.value.enumerated.names_length);
1127         if (IS_ERR(names))
1128                 return PTR_ERR(names);
1129
1130         /* check that there are enough valid names */
1131         buf_len = ue->info.value.enumerated.names_length;
1132         p = names;
1133         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1134                 name_len = strnlen(p, buf_len);
1135                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1136                         kfree(names);
1137                         return -EINVAL;
1138                 }
1139                 p += name_len + 1;
1140                 buf_len -= name_len + 1;
1141         }
1142
1143         ue->priv_data = names;
1144         ue->info.value.enumerated.names_ptr = 0;
1145
1146         return 0;
1147 }
1148
1149 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1150 {
1151         struct user_element *ue = kcontrol->private_data;
1152
1153         kfree(ue->tlv_data);
1154         kfree(ue->priv_data);
1155         kfree(ue);
1156 }
1157
1158 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1159                             struct snd_ctl_elem_info *info, int replace)
1160 {
1161         struct snd_card *card = file->card;
1162         struct snd_kcontrol kctl, *_kctl;
1163         unsigned int access;
1164         long private_size;
1165         struct user_element *ue;
1166         int idx, err;
1167
1168         if (info->count < 1)
1169                 return -EINVAL;
1170         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1171                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1172                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1173                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1174         info->id.numid = 0;
1175         memset(&kctl, 0, sizeof(kctl));
1176
1177         if (replace) {
1178                 err = snd_ctl_remove_user_ctl(file, &info->id);
1179                 if (err)
1180                         return err;
1181         }
1182
1183         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1184                 return -ENOMEM;
1185
1186         memcpy(&kctl.id, &info->id, sizeof(info->id));
1187         kctl.count = info->owner ? info->owner : 1;
1188         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1189         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1190                 kctl.info = snd_ctl_elem_user_enum_info;
1191         else
1192                 kctl.info = snd_ctl_elem_user_info;
1193         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1194                 kctl.get = snd_ctl_elem_user_get;
1195         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1196                 kctl.put = snd_ctl_elem_user_put;
1197         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1198                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1199                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1200         }
1201         switch (info->type) {
1202         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1203         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1204                 private_size = sizeof(long);
1205                 if (info->count > 128)
1206                         return -EINVAL;
1207                 break;
1208         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1209                 private_size = sizeof(long long);
1210                 if (info->count > 64)
1211                         return -EINVAL;
1212                 break;
1213         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1214                 private_size = sizeof(unsigned int);
1215                 if (info->count > 128 || info->value.enumerated.items == 0)
1216                         return -EINVAL;
1217                 break;
1218         case SNDRV_CTL_ELEM_TYPE_BYTES:
1219                 private_size = sizeof(unsigned char);
1220                 if (info->count > 512)
1221                         return -EINVAL;
1222                 break;
1223         case SNDRV_CTL_ELEM_TYPE_IEC958:
1224                 private_size = sizeof(struct snd_aes_iec958);
1225                 if (info->count != 1)
1226                         return -EINVAL;
1227                 break;
1228         default:
1229                 return -EINVAL;
1230         }
1231         private_size *= info->count;
1232         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1233         if (ue == NULL)
1234                 return -ENOMEM;
1235         ue->card = card;
1236         ue->info = *info;
1237         ue->info.access = 0;
1238         ue->elem_data = (char *)ue + sizeof(*ue);
1239         ue->elem_data_size = private_size;
1240         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1241                 err = snd_ctl_elem_init_enum_names(ue);
1242                 if (err < 0) {
1243                         kfree(ue);
1244                         return err;
1245                 }
1246         }
1247         kctl.private_free = snd_ctl_elem_user_free;
1248         _kctl = snd_ctl_new(&kctl, access);
1249         if (_kctl == NULL) {
1250                 kfree(ue->priv_data);
1251                 kfree(ue);
1252                 return -ENOMEM;
1253         }
1254         _kctl->private_data = ue;
1255         for (idx = 0; idx < _kctl->count; idx++)
1256                 _kctl->vd[idx].owner = file;
1257         err = snd_ctl_add(card, _kctl);
1258         if (err < 0)
1259                 return err;
1260
1261         down_write(&card->controls_rwsem);
1262         card->user_ctl_count++;
1263         up_write(&card->controls_rwsem);
1264
1265         return 0;
1266 }
1267
1268 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1269                                  struct snd_ctl_elem_info __user *_info, int replace)
1270 {
1271         struct snd_ctl_elem_info info;
1272         if (copy_from_user(&info, _info, sizeof(info)))
1273                 return -EFAULT;
1274         return snd_ctl_elem_add(file, &info, replace);
1275 }
1276
1277 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1278                                struct snd_ctl_elem_id __user *_id)
1279 {
1280         struct snd_ctl_elem_id id;
1281
1282         if (copy_from_user(&id, _id, sizeof(id)))
1283                 return -EFAULT;
1284         return snd_ctl_remove_user_ctl(file, &id);
1285 }
1286
1287 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1288 {
1289         int subscribe;
1290         if (get_user(subscribe, ptr))
1291                 return -EFAULT;
1292         if (subscribe < 0) {
1293                 subscribe = file->subscribed;
1294                 if (put_user(subscribe, ptr))
1295                         return -EFAULT;
1296                 return 0;
1297         }
1298         if (subscribe) {
1299                 file->subscribed = 1;
1300                 return 0;
1301         } else if (file->subscribed) {
1302                 snd_ctl_empty_read_queue(file);
1303                 file->subscribed = 0;
1304         }
1305         return 0;
1306 }
1307
1308 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1309                              struct snd_ctl_tlv __user *_tlv,
1310                              int op_flag)
1311 {
1312         struct snd_card *card = file->card;
1313         struct snd_ctl_tlv tlv;
1314         struct snd_kcontrol *kctl;
1315         struct snd_kcontrol_volatile *vd;
1316         unsigned int len;
1317         int err = 0;
1318
1319         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1320                 return -EFAULT;
1321         if (tlv.length < sizeof(unsigned int) * 2)
1322                 return -EINVAL;
1323         down_read(&card->controls_rwsem);
1324         kctl = snd_ctl_find_numid(card, tlv.numid);
1325         if (kctl == NULL) {
1326                 err = -ENOENT;
1327                 goto __kctl_end;
1328         }
1329         if (kctl->tlv.p == NULL) {
1330                 err = -ENXIO;
1331                 goto __kctl_end;
1332         }
1333         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1334         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1335             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1336             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1337                 err = -ENXIO;
1338                 goto __kctl_end;
1339         }
1340         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1341                 if (vd->owner != NULL && vd->owner != file) {
1342                         err = -EPERM;
1343                         goto __kctl_end;
1344                 }
1345                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1346                 if (err > 0) {
1347                         struct snd_ctl_elem_id id = kctl->id;
1348                         up_read(&card->controls_rwsem);
1349                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1350                         return 0;
1351                 }
1352         } else {
1353                 if (op_flag) {
1354                         err = -ENXIO;
1355                         goto __kctl_end;
1356                 }
1357                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1358                 if (tlv.length < len) {
1359                         err = -ENOMEM;
1360                         goto __kctl_end;
1361                 }
1362                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1363                         err = -EFAULT;
1364         }
1365       __kctl_end:
1366         up_read(&card->controls_rwsem);
1367         return err;
1368 }
1369
1370 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1371 {
1372         struct snd_ctl_file *ctl;
1373         struct snd_card *card;
1374         struct snd_kctl_ioctl *p;
1375         void __user *argp = (void __user *)arg;
1376         int __user *ip = argp;
1377         int err;
1378
1379         ctl = file->private_data;
1380         card = ctl->card;
1381         if (snd_BUG_ON(!card))
1382                 return -ENXIO;
1383         switch (cmd) {
1384         case SNDRV_CTL_IOCTL_PVERSION:
1385                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1386         case SNDRV_CTL_IOCTL_CARD_INFO:
1387                 return snd_ctl_card_info(card, ctl, cmd, argp);
1388         case SNDRV_CTL_IOCTL_ELEM_LIST:
1389                 return snd_ctl_elem_list(card, argp);
1390         case SNDRV_CTL_IOCTL_ELEM_INFO:
1391                 return snd_ctl_elem_info_user(ctl, argp);
1392         case SNDRV_CTL_IOCTL_ELEM_READ:
1393                 return snd_ctl_elem_read_user(card, argp);
1394         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1395                 return snd_ctl_elem_write_user(ctl, argp);
1396         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1397                 return snd_ctl_elem_lock(ctl, argp);
1398         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1399                 return snd_ctl_elem_unlock(ctl, argp);
1400         case SNDRV_CTL_IOCTL_ELEM_ADD:
1401                 return snd_ctl_elem_add_user(ctl, argp, 0);
1402         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1403                 return snd_ctl_elem_add_user(ctl, argp, 1);
1404         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1405                 return snd_ctl_elem_remove(ctl, argp);
1406         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1407                 return snd_ctl_subscribe_events(ctl, ip);
1408         case SNDRV_CTL_IOCTL_TLV_READ:
1409                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1410         case SNDRV_CTL_IOCTL_TLV_WRITE:
1411                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1412         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1413                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1414         case SNDRV_CTL_IOCTL_POWER:
1415                 return -ENOPROTOOPT;
1416         case SNDRV_CTL_IOCTL_POWER_STATE:
1417 #ifdef CONFIG_PM
1418                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1419 #else
1420                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1421 #endif
1422         }
1423         down_read(&snd_ioctl_rwsem);
1424         list_for_each_entry(p, &snd_control_ioctls, list) {
1425                 err = p->fioctl(card, ctl, cmd, arg);
1426                 if (err != -ENOIOCTLCMD) {
1427                         up_read(&snd_ioctl_rwsem);
1428                         return err;
1429                 }
1430         }
1431         up_read(&snd_ioctl_rwsem);
1432         dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1433         return -ENOTTY;
1434 }
1435
1436 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1437                             size_t count, loff_t * offset)
1438 {
1439         struct snd_ctl_file *ctl;
1440         int err = 0;
1441         ssize_t result = 0;
1442
1443         ctl = file->private_data;
1444         if (snd_BUG_ON(!ctl || !ctl->card))
1445                 return -ENXIO;
1446         if (!ctl->subscribed)
1447                 return -EBADFD;
1448         if (count < sizeof(struct snd_ctl_event))
1449                 return -EINVAL;
1450         spin_lock_irq(&ctl->read_lock);
1451         while (count >= sizeof(struct snd_ctl_event)) {
1452                 struct snd_ctl_event ev;
1453                 struct snd_kctl_event *kev;
1454                 while (list_empty(&ctl->events)) {
1455                         wait_queue_t wait;
1456                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1457                                 err = -EAGAIN;
1458                                 goto __end_lock;
1459                         }
1460                         init_waitqueue_entry(&wait, current);
1461                         add_wait_queue(&ctl->change_sleep, &wait);
1462                         set_current_state(TASK_INTERRUPTIBLE);
1463                         spin_unlock_irq(&ctl->read_lock);
1464                         schedule();
1465                         remove_wait_queue(&ctl->change_sleep, &wait);
1466                         if (ctl->card->shutdown)
1467                                 return -ENODEV;
1468                         if (signal_pending(current))
1469                                 return -ERESTARTSYS;
1470                         spin_lock_irq(&ctl->read_lock);
1471                 }
1472                 kev = snd_kctl_event(ctl->events.next);
1473                 ev.type = SNDRV_CTL_EVENT_ELEM;
1474                 ev.data.elem.mask = kev->mask;
1475                 ev.data.elem.id = kev->id;
1476                 list_del(&kev->list);
1477                 spin_unlock_irq(&ctl->read_lock);
1478                 kfree(kev);
1479                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1480                         err = -EFAULT;
1481                         goto __end;
1482                 }
1483                 spin_lock_irq(&ctl->read_lock);
1484                 buffer += sizeof(struct snd_ctl_event);
1485                 count -= sizeof(struct snd_ctl_event);
1486                 result += sizeof(struct snd_ctl_event);
1487         }
1488       __end_lock:
1489         spin_unlock_irq(&ctl->read_lock);
1490       __end:
1491         return result > 0 ? result : err;
1492 }
1493
1494 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1495 {
1496         unsigned int mask;
1497         struct snd_ctl_file *ctl;
1498
1499         ctl = file->private_data;
1500         if (!ctl->subscribed)
1501                 return 0;
1502         poll_wait(file, &ctl->change_sleep, wait);
1503
1504         mask = 0;
1505         if (!list_empty(&ctl->events))
1506                 mask |= POLLIN | POLLRDNORM;
1507
1508         return mask;
1509 }
1510
1511 /*
1512  * register the device-specific control-ioctls.
1513  * called from each device manager like pcm.c, hwdep.c, etc.
1514  */
1515 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1516 {
1517         struct snd_kctl_ioctl *pn;
1518
1519         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1520         if (pn == NULL)
1521                 return -ENOMEM;
1522         pn->fioctl = fcn;
1523         down_write(&snd_ioctl_rwsem);
1524         list_add_tail(&pn->list, lists);
1525         up_write(&snd_ioctl_rwsem);
1526         return 0;
1527 }
1528
1529 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1530 {
1531         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1532 }
1533
1534 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1535
1536 #ifdef CONFIG_COMPAT
1537 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1538 {
1539         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1540 }
1541
1542 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1543 #endif
1544
1545 /*
1546  * de-register the device-specific control-ioctls.
1547  */
1548 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1549                                      struct list_head *lists)
1550 {
1551         struct snd_kctl_ioctl *p;
1552
1553         if (snd_BUG_ON(!fcn))
1554                 return -EINVAL;
1555         down_write(&snd_ioctl_rwsem);
1556         list_for_each_entry(p, lists, list) {
1557                 if (p->fioctl == fcn) {
1558                         list_del(&p->list);
1559                         up_write(&snd_ioctl_rwsem);
1560                         kfree(p);
1561                         return 0;
1562                 }
1563         }
1564         up_write(&snd_ioctl_rwsem);
1565         snd_BUG();
1566         return -EINVAL;
1567 }
1568
1569 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1570 {
1571         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1572 }
1573
1574 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1575
1576 #ifdef CONFIG_COMPAT
1577 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1578 {
1579         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1580 }
1581
1582 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1583 #endif
1584
1585 static int snd_ctl_fasync(int fd, struct file * file, int on)
1586 {
1587         struct snd_ctl_file *ctl;
1588
1589         ctl = file->private_data;
1590         return fasync_helper(fd, file, on, &ctl->fasync);
1591 }
1592
1593 /*
1594  * ioctl32 compat
1595  */
1596 #ifdef CONFIG_COMPAT
1597 #include "control_compat.c"
1598 #else
1599 #define snd_ctl_ioctl_compat    NULL
1600 #endif
1601
1602 /*
1603  *  INIT PART
1604  */
1605
1606 static const struct file_operations snd_ctl_f_ops =
1607 {
1608         .owner =        THIS_MODULE,
1609         .read =         snd_ctl_read,
1610         .open =         snd_ctl_open,
1611         .release =      snd_ctl_release,
1612         .llseek =       no_llseek,
1613         .poll =         snd_ctl_poll,
1614         .unlocked_ioctl =       snd_ctl_ioctl,
1615         .compat_ioctl = snd_ctl_ioctl_compat,
1616         .fasync =       snd_ctl_fasync,
1617 };
1618
1619 /*
1620  * registration of the control device
1621  */
1622 static int snd_ctl_dev_register(struct snd_device *device)
1623 {
1624         struct snd_card *card = device->device_data;
1625         int err, cardnum;
1626         char name[16];
1627
1628         if (snd_BUG_ON(!card))
1629                 return -ENXIO;
1630         cardnum = card->number;
1631         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1632                 return -ENXIO;
1633         sprintf(name, "controlC%i", cardnum);
1634         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1635                                        &snd_ctl_f_ops, card, name)) < 0)
1636                 return err;
1637         return 0;
1638 }
1639
1640 /*
1641  * disconnection of the control device
1642  */
1643 static int snd_ctl_dev_disconnect(struct snd_device *device)
1644 {
1645         struct snd_card *card = device->device_data;
1646         struct snd_ctl_file *ctl;
1647         int err, cardnum;
1648
1649         if (snd_BUG_ON(!card))
1650                 return -ENXIO;
1651         cardnum = card->number;
1652         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1653                 return -ENXIO;
1654
1655         read_lock(&card->ctl_files_rwlock);
1656         list_for_each_entry(ctl, &card->ctl_files, list) {
1657                 wake_up(&ctl->change_sleep);
1658                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1659         }
1660         read_unlock(&card->ctl_files_rwlock);
1661
1662         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1663                                          card, -1)) < 0)
1664                 return err;
1665         return 0;
1666 }
1667
1668 /*
1669  * free all controls
1670  */
1671 static int snd_ctl_dev_free(struct snd_device *device)
1672 {
1673         struct snd_card *card = device->device_data;
1674         struct snd_kcontrol *control;
1675
1676         down_write(&card->controls_rwsem);
1677         while (!list_empty(&card->controls)) {
1678                 control = snd_kcontrol(card->controls.next);
1679                 snd_ctl_remove(card, control);
1680         }
1681         up_write(&card->controls_rwsem);
1682         return 0;
1683 }
1684
1685 /*
1686  * create control core:
1687  * called from init.c
1688  */
1689 int snd_ctl_create(struct snd_card *card)
1690 {
1691         static struct snd_device_ops ops = {
1692                 .dev_free = snd_ctl_dev_free,
1693                 .dev_register = snd_ctl_dev_register,
1694                 .dev_disconnect = snd_ctl_dev_disconnect,
1695         };
1696
1697         if (snd_BUG_ON(!card))
1698                 return -ENXIO;
1699         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1700 }
1701
1702 /*
1703  * Frequently used control callbacks/helpers
1704  */
1705 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1706                               struct snd_ctl_elem_info *uinfo)
1707 {
1708         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1709         uinfo->count = 1;
1710         uinfo->value.integer.min = 0;
1711         uinfo->value.integer.max = 1;
1712         return 0;
1713 }
1714
1715 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1716
1717 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1718                                 struct snd_ctl_elem_info *uinfo)
1719 {
1720         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1721         uinfo->count = 2;
1722         uinfo->value.integer.min = 0;
1723         uinfo->value.integer.max = 1;
1724         return 0;
1725 }
1726
1727 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1728
1729 /**
1730  * snd_ctl_enum_info - fills the info structure for an enumerated control
1731  * @info: the structure to be filled
1732  * @channels: the number of the control's channels; often one
1733  * @items: the number of control values; also the size of @names
1734  * @names: an array containing the names of all control values
1735  *
1736  * Sets all required fields in @info to their appropriate values.
1737  * If the control's accessibility is not the default (readable and writable),
1738  * the caller has to fill @info->access.
1739  *
1740  * Return: Zero.
1741  */
1742 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1743                       unsigned int items, const char *const names[])
1744 {
1745         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1746         info->count = channels;
1747         info->value.enumerated.items = items;
1748         if (info->value.enumerated.item >= items)
1749                 info->value.enumerated.item = items - 1;
1750         strlcpy(info->value.enumerated.name,
1751                 names[info->value.enumerated.item],
1752                 sizeof(info->value.enumerated.name));
1753         return 0;
1754 }
1755 EXPORT_SYMBOL(snd_ctl_enum_info);