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_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                         snd_printk(KERN_ERR "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  * Returns zero if successful, or a negative error code on failure.
 329  *
 330  * It frees automatically the control which cannot be added.
 331  */
 332 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 333 {
 334         struct snd_ctl_elem_id id;
 335         unsigned int idx;
 336         unsigned int count;
 337         int err = -EINVAL;
 338
 339         if (! kcontrol)
 340                 return err;
 341         if (snd_BUG_ON(!card || !kcontrol->info))
 342                 goto error;
 343         id = kcontrol->id;
 344         if (id.index > UINT_MAX - kcontrol->count)
 345                 goto error;
 346
 347         down_write(&card->controls_rwsem);
 348         if (snd_ctl_find_id(card, &id)) {
 349                 up_write(&card->controls_rwsem);
 350                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 351                                         id.iface,
 352                                         id.device,
 353                                         id.subdevice,
 354                                         id.name,
 355                                         id.index);
 356                 err = -EBUSY;
 357                 goto error;
 358         }
 359         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 360                 up_write(&card->controls_rwsem);
 361                 err = -ENOMEM;
 362                 goto error;
 363         }
 364         list_add_tail(&kcontrol->list, &card->controls);
 365         card->controls_count += kcontrol->count;
 366         kcontrol->id.numid = card->last_numid + 1;
 367         card->last_numid += kcontrol->count;
 368         count = kcontrol->count;
 369         up_write(&card->controls_rwsem);
 370         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 371                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 372         return 0;
 373
 374  error:
 375         snd_ctl_free_one(kcontrol);
 376         return err;
 377 }
 378
 379 EXPORT_SYMBOL(snd_ctl_add);
 380
 381 /**
 382  * snd_ctl_replace - replace the control instance of the card
 383  * @card: the card instance
 384  * @kcontrol: the control instance to replace
 385  * @add_on_replace: add the control if not already added
 386  *
 387  * Replaces the given control.  If the given control does not exist
 388  * and the add_on_replace flag is set, the control is added.  If the
 389  * control exists, it is destroyed first.
 390  *
 391  * Returns zero if successful, or a negative error code on failure.
 392  *
 393  * It frees automatically the control which cannot be added or replaced.
 394  */
 395 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 396                     bool add_on_replace)
 397 {
 398         struct snd_ctl_elem_id id;
 399         unsigned int count;
 400         unsigned int idx;
 401         struct snd_kcontrol *old;
 402         int ret;
 403
 404         if (!kcontrol)
 405                 return -EINVAL;
 406         if (snd_BUG_ON(!card || !kcontrol->info)) {
 407                 ret = -EINVAL;
 408                 goto error;
 409         }
 410         id = kcontrol->id;
 411         down_write(&card->controls_rwsem);
 412         old = snd_ctl_find_id(card, &id);
 413         if (!old) {
 414                 if (add_on_replace)
 415                         goto add;
 416                 up_write(&card->controls_rwsem);
 417                 ret = -EINVAL;
 418                 goto error;
 419         }
 420         ret = snd_ctl_remove(card, old);
 421         if (ret < 0) {
 422                 up_write(&card->controls_rwsem);
 423                 goto error;
 424         }
 425 add:
 426         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 427                 up_write(&card->controls_rwsem);
 428                 ret = -ENOMEM;
 429                 goto error;
 430         }
 431         list_add_tail(&kcontrol->list, &card->controls);
 432         card->controls_count += kcontrol->count;
 433         kcontrol->id.numid = card->last_numid + 1;
 434         card->last_numid += kcontrol->count;
 435         count = kcontrol->count;
 436         up_write(&card->controls_rwsem);
 437         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 438                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 439         return 0;
 440
 441 error:
 442         snd_ctl_free_one(kcontrol);
 443         return ret;
 444 }
 445 EXPORT_SYMBOL(snd_ctl_replace);
 446
 447 /**
 448  * snd_ctl_remove - remove the control from the card and release it
 449  * @card: the card instance
 450  * @kcontrol: the control instance to remove
 451  *
 452  * Removes the control from the card and then releases the instance.
 453  * You don't need to call snd_ctl_free_one(). You must be in
 454  * the write lock - down_write(&card->controls_rwsem).
 455  *
 456  * Returns 0 if successful, or a negative error code on failure.
 457  */
 458 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 459 {
 460         struct snd_ctl_elem_id id;
 461         unsigned int idx;
 462
 463         if (snd_BUG_ON(!card || !kcontrol))
 464                 return -EINVAL;
 465         list_del(&kcontrol->list);
 466         card->controls_count -= kcontrol->count;
 467         id = kcontrol->id;
 468         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 469                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 470         snd_ctl_free_one(kcontrol);
 471         return 0;
 472 }
 473
 474 EXPORT_SYMBOL(snd_ctl_remove);
 475
 476 /**
 477  * snd_ctl_remove_id - remove the control of the given id and release it
 478  * @card: the card instance
 479  * @id: the control id to remove
 480  *
 481  * Finds the control instance with the given id, removes it from the
 482  * card list and releases it.
 483  *
 484  * Returns 0 if successful, or a negative error code on failure.
 485  */
 486 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 487 {
 488         struct snd_kcontrol *kctl;
 489         int ret;
 490
 491         down_write(&card->controls_rwsem);
 492         kctl = snd_ctl_find_id(card, id);
 493         if (kctl == NULL) {
 494                 up_write(&card->controls_rwsem);
 495                 return -ENOENT;
 496         }
 497         ret = snd_ctl_remove(card, kctl);
 498         up_write(&card->controls_rwsem);
 499         return ret;
 500 }
 501
 502 EXPORT_SYMBOL(snd_ctl_remove_id);
 503
 504 /**
 505  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 506  * @file: active control handle
 507  * @id: the control id to remove
 508  *
 509  * Finds the control instance with the given id, removes it from the
 510  * card list and releases it.
 511  *
 512  * Returns 0 if successful, or a negative error code on failure.
 513  */
 514 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 515                                    struct snd_ctl_elem_id *id)
 516 {
 517         struct snd_card *card = file->card;
 518         struct snd_kcontrol *kctl;
 519         int idx, ret;
 520
 521         down_write(&card->controls_rwsem);
 522         kctl = snd_ctl_find_id(card, id);
 523         if (kctl == NULL) {
 524                 ret = -ENOENT;
 525                 goto error;
 526         }
 527         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 528                 ret = -EINVAL;
 529                 goto error;
 530         }
 531         for (idx = 0; idx < kctl->count; idx++)
 532                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 533                         ret = -EBUSY;
 534                         goto error;
 535                 }
 536         ret = snd_ctl_remove(card, kctl);
 537         if (ret < 0)
 538                 goto error;
 539         card->user_ctl_count--;
 540 error:
 541         up_write(&card->controls_rwsem);
 542         return ret;
 543 }
 544
 545 /**
 546  * snd_ctl_activate_id - activate/inactivate the control of the given id
 547  * @card: the card instance
 548  * @id: the control id to activate/inactivate
 549  * @active: non-zero to activate
 550  *
 551  * Finds the control instance with the given id, and activate or
 552  * inactivate the control together with notification, if changed.
 553  *
 554  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 555  */
 556 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 557                         int active)
 558 {
 559         struct snd_kcontrol *kctl;
 560         struct snd_kcontrol_volatile *vd;
 561         unsigned int index_offset;
 562         int ret;
 563
 564         down_write(&card->controls_rwsem);
 565         kctl = snd_ctl_find_id(card, id);
 566         if (kctl == NULL) {
 567                 ret = -ENOENT;
 568                 goto unlock;
 569         }
 570         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 571         vd = &kctl->vd[index_offset];
 572         ret = 0;
 573         if (active) {
 574                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 575                         goto unlock;
 576                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 577         } else {
 578                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 579                         goto unlock;
 580                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 581         }
 582         ret = 1;
 583  unlock:
 584         up_write(&card->controls_rwsem);
 585         if (ret > 0)
 586                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 587         return ret;
 588 }
 589 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 590
 591 /**
 592  * snd_ctl_rename_id - replace the id of a control on the card
 593  * @card: the card instance
 594  * @src_id: the old id
 595  * @dst_id: the new id
 596  *
 597  * Finds the control with the old id from the card, and replaces the
 598  * id with the new one.
 599  *
 600  * Returns zero if successful, or a negative error code on failure.
 601  */
 602 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 603                       struct snd_ctl_elem_id *dst_id)
 604 {
 605         struct snd_kcontrol *kctl;
 606
 607         down_write(&card->controls_rwsem);
 608         kctl = snd_ctl_find_id(card, src_id);
 609         if (kctl == NULL) {
 610                 up_write(&card->controls_rwsem);
 611                 return -ENOENT;
 612         }
 613         kctl->id = *dst_id;
 614         kctl->id.numid = card->last_numid + 1;
 615         card->last_numid += kctl->count;
 616         up_write(&card->controls_rwsem);
 617         return 0;
 618 }
 619
 620 EXPORT_SYMBOL(snd_ctl_rename_id);
 621
 622 /**
 623  * snd_ctl_find_numid - find the control instance with the given number-id
 624  * @card: the card instance
 625  * @numid: the number-id to search
 626  *
 627  * Finds the control instance with the given number-id from the card.
 628  *
 629  * Returns the pointer of the instance if found, or NULL if not.
 630  *
 631  * The caller must down card->controls_rwsem before calling this function
 632  * (if the race condition can happen).
 633  */
 634 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 635 {
 636         struct snd_kcontrol *kctl;
 637
 638         if (snd_BUG_ON(!card || !numid))
 639                 return NULL;
 640         list_for_each_entry(kctl, &card->controls, list) {
 641                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 642                         return kctl;
 643         }
 644         return NULL;
 645 }
 646
 647 EXPORT_SYMBOL(snd_ctl_find_numid);
 648
 649 /**
 650  * snd_ctl_find_id - find the control instance with the given id
 651  * @card: the card instance
 652  * @id: the id to search
 653  *
 654  * Finds the control instance with the given id from the card.
 655  *
 656  * Returns the pointer of the instance if found, or NULL if not.
 657  *
 658  * The caller must down card->controls_rwsem before calling this function
 659  * (if the race condition can happen).
 660  */
 661 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 662                                      struct snd_ctl_elem_id *id)
 663 {
 664         struct snd_kcontrol *kctl;
 665
 666         if (snd_BUG_ON(!card || !id))
 667                 return NULL;
 668         if (id->numid != 0)
 669                 return snd_ctl_find_numid(card, id->numid);
 670         list_for_each_entry(kctl, &card->controls, list) {
 671                 if (kctl->id.iface != id->iface)
 672                         continue;
 673                 if (kctl->id.device != id->device)
 674                         continue;
 675                 if (kctl->id.subdevice != id->subdevice)
 676                         continue;
 677                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 678                         continue;
 679                 if (kctl->id.index > id->index)
 680                         continue;
 681                 if (kctl->id.index + kctl->count <= id->index)
 682                         continue;
 683                 return kctl;
 684         }
 685         return NULL;
 686 }
 687
 688 EXPORT_SYMBOL(snd_ctl_find_id);
 689
 690 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 691                              unsigned int cmd, void __user *arg)
 692 {
 693         struct snd_ctl_card_info *info;
 694
 695         info = kzalloc(sizeof(*info), GFP_KERNEL);
 696         if (! info)
 697                 return -ENOMEM;
 698         down_read(&snd_ioctl_rwsem);
 699         info->card = card->number;
 700         strlcpy(info->id, card->id, sizeof(info->id));
 701         strlcpy(info->driver, card->driver, sizeof(info->driver));
 702         strlcpy(info->name, card->shortname, sizeof(info->name));
 703         strlcpy(info->longname, card->longname, sizeof(info->longname));
 704         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 705         strlcpy(info->components, card->components, sizeof(info->components));
 706         up_read(&snd_ioctl_rwsem);
 707         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 708                 kfree(info);
 709                 return -EFAULT;
 710         }
 711         kfree(info);
 712         return 0;
 713 }
 714
 715 static int snd_ctl_elem_list(struct snd_card *card,
 716                              struct snd_ctl_elem_list __user *_list)
 717 {
 718         struct list_head *plist;
 719         struct snd_ctl_elem_list list;
 720         struct snd_kcontrol *kctl;
 721         struct snd_ctl_elem_id *dst, *id;
 722         unsigned int offset, space, jidx;
 723
 724         if (copy_from_user(&list, _list, sizeof(list)))
 725                 return -EFAULT;
 726         offset = list.offset;
 727         space = list.space;
 728         /* try limit maximum space */
 729         if (space > 16384)
 730                 return -ENOMEM;
 731         if (space > 0) {
 732                 /* allocate temporary buffer for atomic operation */
 733                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 734                 if (dst == NULL)
 735                         return -ENOMEM;
 736                 down_read(&card->controls_rwsem);
 737                 list.count = card->controls_count;
 738                 plist = card->controls.next;
 739                 while (plist != &card->controls) {
 740                         if (offset == 0)
 741                                 break;
 742                         kctl = snd_kcontrol(plist);
 743                         if (offset < kctl->count)
 744                                 break;
 745                         offset -= kctl->count;
 746                         plist = plist->next;
 747                 }
 748                 list.used = 0;
 749                 id = dst;
 750                 while (space > 0 && plist != &card->controls) {
 751                         kctl = snd_kcontrol(plist);
 752                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 753                                 snd_ctl_build_ioff(id, kctl, jidx);
 754                                 id++;
 755                                 space--;
 756                                 list.used++;
 757                         }
 758                         plist = plist->next;
 759                         offset = 0;
 760                 }
 761                 up_read(&card->controls_rwsem);
 762                 if (list.used > 0 &&
 763                     copy_to_user(list.pids, dst,
 764                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 765                         vfree(dst);
 766                         return -EFAULT;
 767                 }
 768                 vfree(dst);
 769         } else {
 770                 down_read(&card->controls_rwsem);
 771                 list.count = card->controls_count;
 772                 up_read(&card->controls_rwsem);
 773         }
 774         if (copy_to_user(_list, &list, sizeof(list)))
 775                 return -EFAULT;
 776         return 0;
 777 }
 778
 779 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 780                              struct snd_ctl_elem_info *info)
 781 {
 782         struct snd_card *card = ctl->card;
 783         struct snd_kcontrol *kctl;
 784         struct snd_kcontrol_volatile *vd;
 785         unsigned int index_offset;
 786         int result;
 787
 788         down_read(&card->controls_rwsem);
 789         kctl = snd_ctl_find_id(card, &info->id);
 790         if (kctl == NULL) {
 791                 up_read(&card->controls_rwsem);
 792                 return -ENOENT;
 793         }
 794 #ifdef CONFIG_SND_DEBUG
 795         info->access = 0;
 796 #endif
 797         result = kctl->info(kctl, info);
 798         if (result >= 0) {
 799                 snd_BUG_ON(info->access);
 800                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 801                 vd = &kctl->vd[index_offset];
 802                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 803                 info->access = vd->access;
 804                 if (vd->owner) {
 805                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 806                         if (vd->owner == ctl)
 807                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 808                         info->owner = pid_vnr(vd->owner->pid);
 809                 } else {
 810                         info->owner = -1;
 811                 }
 812         }
 813         up_read(&card->controls_rwsem);
 814         return result;
 815 }
 816
 817 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 818                                   struct snd_ctl_elem_info __user *_info)
 819 {
 820         struct snd_ctl_elem_info info;
 821         int result;
 822
 823         if (copy_from_user(&info, _info, sizeof(info)))
 824                 return -EFAULT;
 825         snd_power_lock(ctl->card);
 826         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 827         if (result >= 0)
 828                 result = snd_ctl_elem_info(ctl, &info);
 829         snd_power_unlock(ctl->card);
 830         if (result >= 0)
 831                 if (copy_to_user(_info, &info, sizeof(info)))
 832                         return -EFAULT;
 833         return result;
 834 }
 835
 836 static int snd_ctl_elem_read(struct snd_card *card,
 837                              struct snd_ctl_elem_value *control)
 838 {
 839         struct snd_kcontrol *kctl;
 840         struct snd_kcontrol_volatile *vd;
 841         unsigned int index_offset;
 842         int result;
 843
 844         down_read(&card->controls_rwsem);
 845         kctl = snd_ctl_find_id(card, &control->id);
 846         if (kctl == NULL) {
 847                 result = -ENOENT;
 848         } else {
 849                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 850                 vd = &kctl->vd[index_offset];
 851                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 852                     kctl->get != NULL) {
 853                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 854                         result = kctl->get(kctl, control);
 855                 } else
 856                         result = -EPERM;
 857         }
 858         up_read(&card->controls_rwsem);
 859         return result;
 860 }
 861
 862 static int snd_ctl_elem_read_user(struct snd_card *card,
 863                                   struct snd_ctl_elem_value __user *_control)
 864 {
 865         struct snd_ctl_elem_value *control;
 866         int result;
 867
 868         control = memdup_user(_control, sizeof(*control));
 869         if (IS_ERR(control))
 870                 return PTR_ERR(control);
 871
 872         snd_power_lock(card);
 873         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 874         if (result >= 0)
 875                 result = snd_ctl_elem_read(card, control);
 876         snd_power_unlock(card);
 877         if (result >= 0)
 878                 if (copy_to_user(_control, control, sizeof(*control)))
 879                         result = -EFAULT;
 880         kfree(control);
 881         return result;
 882 }
 883
 884 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 885                               struct snd_ctl_elem_value *control)
 886 {
 887         struct snd_kcontrol *kctl;
 888         struct snd_kcontrol_volatile *vd;
 889         unsigned int index_offset;
 890         int result;
 891
 892         down_read(&card->controls_rwsem);
 893         kctl = snd_ctl_find_id(card, &control->id);
 894         if (kctl == NULL) {
 895                 result = -ENOENT;
 896         } else {
 897                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 898                 vd = &kctl->vd[index_offset];
 899                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 900                     kctl->put == NULL ||
 901                     (file && vd->owner && vd->owner != file)) {
 902                         result = -EPERM;
 903                 } else {
 904                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 905                         result = kctl->put(kctl, control);
 906                 }
 907                 if (result > 0) {
 908                         struct snd_ctl_elem_id id = control->id;
 909                         up_read(&card->controls_rwsem);
 910                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
 911                         return 0;
 912                 }
 913         }
 914         up_read(&card->controls_rwsem);
 915         return result;
 916 }
 917
 918 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 919                                    struct snd_ctl_elem_value __user *_control)
 920 {
 921         struct snd_ctl_elem_value *control;
 922         struct snd_card *card;
 923         int result;
 924
 925         control = memdup_user(_control, sizeof(*control));
 926         if (IS_ERR(control))
 927                 return PTR_ERR(control);
 928
 929         card = file->card;
 930         snd_power_lock(card);
 931         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 932         if (result >= 0)
 933                 result = snd_ctl_elem_write(card, file, control);
 934         snd_power_unlock(card);
 935         if (result >= 0)
 936                 if (copy_to_user(_control, control, sizeof(*control)))
 937                         result = -EFAULT;
 938         kfree(control);
 939         return result;
 940 }
 941
 942 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 943                              struct snd_ctl_elem_id __user *_id)
 944 {
 945         struct snd_card *card = file->card;
 946         struct snd_ctl_elem_id id;
 947         struct snd_kcontrol *kctl;
 948         struct snd_kcontrol_volatile *vd;
 949         int result;
 950
 951         if (copy_from_user(&id, _id, sizeof(id)))
 952                 return -EFAULT;
 953         down_write(&card->controls_rwsem);
 954         kctl = snd_ctl_find_id(card, &id);
 955         if (kctl == NULL) {
 956                 result = -ENOENT;
 957         } else {
 958                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 959                 if (vd->owner != NULL)
 960                         result = -EBUSY;
 961                 else {
 962                         vd->owner = file;
 963                         result = 0;
 964                 }
 965         }
 966         up_write(&card->controls_rwsem);
 967         return result;
 968 }
 969
 970 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 971                                struct snd_ctl_elem_id __user *_id)
 972 {
 973         struct snd_card *card = file->card;
 974         struct snd_ctl_elem_id id;
 975         struct snd_kcontrol *kctl;
 976         struct snd_kcontrol_volatile *vd;
 977         int result;
 978
 979         if (copy_from_user(&id, _id, sizeof(id)))
 980                 return -EFAULT;
 981         down_write(&card->controls_rwsem);
 982         kctl = snd_ctl_find_id(card, &id);
 983         if (kctl == NULL) {
 984                 result = -ENOENT;
 985         } else {
 986                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 987                 if (vd->owner == NULL)
 988                         result = -EINVAL;
 989                 else if (vd->owner != file)
 990                         result = -EPERM;
 991                 else {
 992                         vd->owner = NULL;
 993                         result = 0;
 994                 }
 995         }
 996         up_write(&card->controls_rwsem);
 997         return result;
 998 }
 999
1000 struct user_element {
1001         struct snd_ctl_elem_info info;
1002         struct snd_card *card;
1003         void *elem_data;                /* element data */
1004         unsigned long elem_data_size;   /* size of element data in bytes */
1005         void *tlv_data;                 /* TLV data */
1006         unsigned long tlv_data_size;    /* TLV data size */
1007         void *priv_data;                /* private data (like strings for enumerated type) */
1008 };
1009
1010 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1011                                   struct snd_ctl_elem_info *uinfo)
1012 {
1013         struct user_element *ue = kcontrol->private_data;
1014
1015         *uinfo = ue->info;
1016         return 0;
1017 }
1018
1019 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1020                                        struct snd_ctl_elem_info *uinfo)
1021 {
1022         struct user_element *ue = kcontrol->private_data;
1023         const char *names;
1024         unsigned int item;
1025
1026         item = uinfo->value.enumerated.item;
1027
1028         *uinfo = ue->info;
1029
1030         item = min(item, uinfo->value.enumerated.items - 1);
1031         uinfo->value.enumerated.item = item;
1032
1033         names = ue->priv_data;
1034         for (; item > 0; --item)
1035                 names += strlen(names) + 1;
1036         strcpy(uinfo->value.enumerated.name, names);
1037
1038         return 0;
1039 }
1040
1041 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1042                                  struct snd_ctl_elem_value *ucontrol)
1043 {
1044         struct user_element *ue = kcontrol->private_data;
1045
1046         mutex_lock(&ue->card->user_ctl_lock);
1047         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1048         mutex_unlock(&ue->card->user_ctl_lock);
1049         return 0;
1050 }
1051
1052 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1053                                  struct snd_ctl_elem_value *ucontrol)
1054 {
1055         int change;
1056         struct user_element *ue = kcontrol->private_data;
1057
1058         mutex_lock(&ue->card->user_ctl_lock);
1059         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1060         if (change)
1061                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1062         mutex_unlock(&ue->card->user_ctl_lock);
1063         return change;
1064 }
1065
1066 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1067                                  int op_flag,
1068                                  unsigned int size,
1069                                  unsigned int __user *tlv)
1070 {
1071         struct user_element *ue = kcontrol->private_data;
1072         int change = 0;
1073         void *new_data;
1074
1075         if (op_flag > 0) {
1076                 if (size > 1024 * 128)  /* sane value */
1077                         return -EINVAL;
1078
1079                 new_data = memdup_user(tlv, size);
1080                 if (IS_ERR(new_data))
1081                         return PTR_ERR(new_data);
1082                 mutex_lock(&ue->card->user_ctl_lock);
1083                 change = ue->tlv_data_size != size;
1084                 if (!change)
1085                         change = memcmp(ue->tlv_data, new_data, size);
1086                 kfree(ue->tlv_data);
1087                 ue->tlv_data = new_data;
1088                 ue->tlv_data_size = size;
1089                 mutex_unlock(&ue->card->user_ctl_lock);
1090         } else {
1091                 int ret = 0;
1092
1093                 mutex_lock(&ue->card->user_ctl_lock);
1094                 if (!ue->tlv_data_size || !ue->tlv_data) {
1095                         ret = -ENXIO;
1096                         goto err_unlock;
1097                 }
1098                 if (size < ue->tlv_data_size) {
1099                         ret = -ENOSPC;
1100                         goto err_unlock;
1101                 }
1102                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1103                         ret = -EFAULT;
1104 err_unlock:
1105                 mutex_unlock(&ue->card->user_ctl_lock);
1106                 if (ret)
1107                         return ret;
1108         }
1109         return change;
1110 }
1111
1112 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1113 {
1114         char *names, *p;
1115         size_t buf_len, name_len;
1116         unsigned int i;
1117         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1118
1119         if (ue->info.value.enumerated.names_length > 64 * 1024)
1120                 return -EINVAL;
1121
1122         names = memdup_user((const void __user *)user_ptrval,
1123                 ue->info.value.enumerated.names_length);
1124         if (IS_ERR(names))
1125                 return PTR_ERR(names);
1126
1127         /* check that there are enough valid names */
1128         buf_len = ue->info.value.enumerated.names_length;
1129         p = names;
1130         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1131                 name_len = strnlen(p, buf_len);
1132                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1133                         kfree(names);
1134                         return -EINVAL;
1135                 }
1136                 p += name_len + 1;
1137                 buf_len -= name_len + 1;
1138         }
1139
1140         ue->priv_data = names;
1141         ue->info.value.enumerated.names_ptr = 0;
1142
1143         return 0;
1144 }
1145
1146 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1147 {
1148         struct user_element *ue = kcontrol->private_data;
1149
1150         kfree(ue->tlv_data);
1151         kfree(ue->priv_data);
1152         kfree(ue);
1153 }
1154
1155 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1156                             struct snd_ctl_elem_info *info, int replace)
1157 {
1158         struct snd_card *card = file->card;
1159         struct snd_kcontrol kctl, *_kctl;
1160         unsigned int access;
1161         long private_size;
1162         struct user_element *ue;
1163         int idx, err;
1164
1165         if (info->count < 1)
1166                 return -EINVAL;
1167         if (!*info->id.name)
1168                 return -EINVAL;
1169         if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1170                 return -EINVAL;
1171         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1172                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1173                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1174                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1175         info->id.numid = 0;
1176         memset(&kctl, 0, sizeof(kctl));
1177
1178         if (replace) {
1179                 err = snd_ctl_remove_user_ctl(file, &info->id);
1180                 if (err)
1181                         return err;
1182         }
1183
1184         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1185                 return -ENOMEM;
1186
1187         memcpy(&kctl.id, &info->id, sizeof(info->id));
1188         kctl.count = info->owner ? info->owner : 1;
1189         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1190         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1191                 kctl.info = snd_ctl_elem_user_enum_info;
1192         else
1193                 kctl.info = snd_ctl_elem_user_info;
1194         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1195                 kctl.get = snd_ctl_elem_user_get;
1196         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1197                 kctl.put = snd_ctl_elem_user_put;
1198         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1199                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1200                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1201         }
1202         switch (info->type) {
1203         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1204         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1205                 private_size = sizeof(long);
1206                 if (info->count > 128)
1207                         return -EINVAL;
1208                 break;
1209         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1210                 private_size = sizeof(long long);
1211                 if (info->count > 64)
1212                         return -EINVAL;
1213                 break;
1214         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1215                 private_size = sizeof(unsigned int);
1216                 if (info->count > 128 || info->value.enumerated.items == 0)
1217                         return -EINVAL;
1218                 break;
1219         case SNDRV_CTL_ELEM_TYPE_BYTES:
1220                 private_size = sizeof(unsigned char);
1221                 if (info->count > 512)
1222                         return -EINVAL;
1223                 break;
1224         case SNDRV_CTL_ELEM_TYPE_IEC958:
1225                 private_size = sizeof(struct snd_aes_iec958);
1226                 if (info->count != 1)
1227                         return -EINVAL;
1228                 break;
1229         default:
1230                 return -EINVAL;
1231         }
1232         private_size *= info->count;
1233         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1234         if (ue == NULL)
1235                 return -ENOMEM;
1236         ue->card = card;
1237         ue->info = *info;
1238         ue->info.access = 0;
1239         ue->elem_data = (char *)ue + sizeof(*ue);
1240         ue->elem_data_size = private_size;
1241         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1242                 err = snd_ctl_elem_init_enum_names(ue);
1243                 if (err < 0) {
1244                         kfree(ue);
1245                         return err;
1246                 }
1247         }
1248         kctl.private_free = snd_ctl_elem_user_free;
1249         _kctl = snd_ctl_new(&kctl, access);
1250         if (_kctl == NULL) {
1251                 kfree(ue->priv_data);
1252                 kfree(ue);
1253                 return -ENOMEM;
1254         }
1255         _kctl->private_data = ue;
1256         for (idx = 0; idx < _kctl->count; idx++)
1257                 _kctl->vd[idx].owner = file;
1258         err = snd_ctl_add(card, _kctl);
1259         if (err < 0)
1260                 return err;
1261
1262         down_write(&card->controls_rwsem);
1263         card->user_ctl_count++;
1264         up_write(&card->controls_rwsem);
1265
1266         return 0;
1267 }
1268
1269 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1270                                  struct snd_ctl_elem_info __user *_info, int replace)
1271 {
1272         struct snd_ctl_elem_info info;
1273         if (copy_from_user(&info, _info, sizeof(info)))
1274                 return -EFAULT;
1275         return snd_ctl_elem_add(file, &info, replace);
1276 }
1277
1278 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1279                                struct snd_ctl_elem_id __user *_id)
1280 {
1281         struct snd_ctl_elem_id id;
1282
1283         if (copy_from_user(&id, _id, sizeof(id)))
1284                 return -EFAULT;
1285         return snd_ctl_remove_user_ctl(file, &id);
1286 }
1287
1288 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1289 {
1290         int subscribe;
1291         if (get_user(subscribe, ptr))
1292                 return -EFAULT;
1293         if (subscribe < 0) {
1294                 subscribe = file->subscribed;
1295                 if (put_user(subscribe, ptr))
1296                         return -EFAULT;
1297                 return 0;
1298         }
1299         if (subscribe) {
1300                 file->subscribed = 1;
1301                 return 0;
1302         } else if (file->subscribed) {
1303                 snd_ctl_empty_read_queue(file);
1304                 file->subscribed = 0;
1305         }
1306         return 0;
1307 }
1308
1309 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1310                              struct snd_ctl_tlv __user *_tlv,
1311                              int op_flag)
1312 {
1313         struct snd_card *card = file->card;
1314         struct snd_ctl_tlv tlv;
1315         struct snd_kcontrol *kctl;
1316         struct snd_kcontrol_volatile *vd;
1317         unsigned int len;
1318         int err = 0;
1319
1320         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1321                 return -EFAULT;
1322         if (tlv.length < sizeof(unsigned int) * 2)
1323                 return -EINVAL;
1324         if (!tlv.numid)
1325                 return -EINVAL;
1326         down_read(&card->controls_rwsem);
1327         kctl = snd_ctl_find_numid(card, tlv.numid);
1328         if (kctl == NULL) {
1329                 err = -ENOENT;
1330                 goto __kctl_end;
1331         }
1332         if (kctl->tlv.p == NULL) {
1333                 err = -ENXIO;
1334                 goto __kctl_end;
1335         }
1336         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1337         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1338             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1339             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1340                 err = -ENXIO;
1341                 goto __kctl_end;
1342         }
1343         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1344                 if (vd->owner != NULL && vd->owner != file) {
1345                         err = -EPERM;
1346                         goto __kctl_end;
1347                 }
1348                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1349                 if (err > 0) {
1350                         struct snd_ctl_elem_id id = kctl->id;
1351                         up_read(&card->controls_rwsem);
1352                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1353                         return 0;
1354                 }
1355         } else {
1356                 if (op_flag) {
1357                         err = -ENXIO;
1358                         goto __kctl_end;
1359                 }
1360                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1361                 if (tlv.length < len) {
1362                         err = -ENOMEM;
1363                         goto __kctl_end;
1364                 }
1365                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1366                         err = -EFAULT;
1367         }
1368       __kctl_end:
1369         up_read(&card->controls_rwsem);
1370         return err;
1371 }
1372
1373 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1374 {
1375         struct snd_ctl_file *ctl;
1376         struct snd_card *card;
1377         struct snd_kctl_ioctl *p;
1378         void __user *argp = (void __user *)arg;
1379         int __user *ip = argp;
1380         int err;
1381
1382         ctl = file->private_data;
1383         card = ctl->card;
1384         if (snd_BUG_ON(!card))
1385                 return -ENXIO;
1386         switch (cmd) {
1387         case SNDRV_CTL_IOCTL_PVERSION:
1388                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1389         case SNDRV_CTL_IOCTL_CARD_INFO:
1390                 return snd_ctl_card_info(card, ctl, cmd, argp);
1391         case SNDRV_CTL_IOCTL_ELEM_LIST:
1392                 return snd_ctl_elem_list(card, argp);
1393         case SNDRV_CTL_IOCTL_ELEM_INFO:
1394                 return snd_ctl_elem_info_user(ctl, argp);
1395         case SNDRV_CTL_IOCTL_ELEM_READ:
1396                 return snd_ctl_elem_read_user(card, argp);
1397         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1398                 return snd_ctl_elem_write_user(ctl, argp);
1399         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1400                 return snd_ctl_elem_lock(ctl, argp);
1401         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1402                 return snd_ctl_elem_unlock(ctl, argp);
1403         case SNDRV_CTL_IOCTL_ELEM_ADD:
1404                 return snd_ctl_elem_add_user(ctl, argp, 0);
1405         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1406                 return snd_ctl_elem_add_user(ctl, argp, 1);
1407         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1408                 return snd_ctl_elem_remove(ctl, argp);
1409         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1410                 return snd_ctl_subscribe_events(ctl, ip);
1411         case SNDRV_CTL_IOCTL_TLV_READ:
1412                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1413         case SNDRV_CTL_IOCTL_TLV_WRITE:
1414                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1415         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1416                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1417         case SNDRV_CTL_IOCTL_POWER:
1418                 return -ENOPROTOOPT;
1419         case SNDRV_CTL_IOCTL_POWER_STATE:
1420 #ifdef CONFIG_PM
1421                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1422 #else
1423                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1424 #endif
1425         }
1426         down_read(&snd_ioctl_rwsem);
1427         list_for_each_entry(p, &snd_control_ioctls, list) {
1428                 err = p->fioctl(card, ctl, cmd, arg);
1429                 if (err != -ENOIOCTLCMD) {
1430                         up_read(&snd_ioctl_rwsem);
1431                         return err;
1432                 }
1433         }
1434         up_read(&snd_ioctl_rwsem);
1435         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1436         return -ENOTTY;
1437 }
1438
1439 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1440                             size_t count, loff_t * offset)
1441 {
1442         struct snd_ctl_file *ctl;
1443         int err = 0;
1444         ssize_t result = 0;
1445
1446         ctl = file->private_data;
1447         if (snd_BUG_ON(!ctl || !ctl->card))
1448                 return -ENXIO;
1449         if (!ctl->subscribed)
1450                 return -EBADFD;
1451         if (count < sizeof(struct snd_ctl_event))
1452                 return -EINVAL;
1453         spin_lock_irq(&ctl->read_lock);
1454         while (count >= sizeof(struct snd_ctl_event)) {
1455                 struct snd_ctl_event ev;
1456                 struct snd_kctl_event *kev;
1457                 while (list_empty(&ctl->events)) {
1458                         wait_queue_t wait;
1459                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1460                                 err = -EAGAIN;
1461                                 goto __end_lock;
1462                         }
1463                         init_waitqueue_entry(&wait, current);
1464                         add_wait_queue(&ctl->change_sleep, &wait);
1465                         set_current_state(TASK_INTERRUPTIBLE);
1466                         spin_unlock_irq(&ctl->read_lock);
1467                         schedule();
1468                         remove_wait_queue(&ctl->change_sleep, &wait);
1469                         if (ctl->card->shutdown)
1470                                 return -ENODEV;
1471                         if (signal_pending(current))
1472                                 return -ERESTARTSYS;
1473                         spin_lock_irq(&ctl->read_lock);
1474                 }
1475                 kev = snd_kctl_event(ctl->events.next);
1476                 ev.type = SNDRV_CTL_EVENT_ELEM;
1477                 ev.data.elem.mask = kev->mask;
1478                 ev.data.elem.id = kev->id;
1479                 list_del(&kev->list);
1480                 spin_unlock_irq(&ctl->read_lock);
1481                 kfree(kev);
1482                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1483                         err = -EFAULT;
1484                         goto __end;
1485                 }
1486                 spin_lock_irq(&ctl->read_lock);
1487                 buffer += sizeof(struct snd_ctl_event);
1488                 count -= sizeof(struct snd_ctl_event);
1489                 result += sizeof(struct snd_ctl_event);
1490         }
1491       __end_lock:
1492         spin_unlock_irq(&ctl->read_lock);
1493       __end:
1494         return result > 0 ? result : err;
1495 }
1496
1497 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1498 {
1499         unsigned int mask;
1500         struct snd_ctl_file *ctl;
1501
1502         ctl = file->private_data;
1503         if (!ctl->subscribed)
1504                 return 0;
1505         poll_wait(file, &ctl->change_sleep, wait);
1506
1507         mask = 0;
1508         if (!list_empty(&ctl->events))
1509                 mask |= POLLIN | POLLRDNORM;
1510
1511         return mask;
1512 }
1513
1514 /*
1515  * register the device-specific control-ioctls.
1516  * called from each device manager like pcm.c, hwdep.c, etc.
1517  */
1518 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1519 {
1520         struct snd_kctl_ioctl *pn;
1521
1522         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1523         if (pn == NULL)
1524                 return -ENOMEM;
1525         pn->fioctl = fcn;
1526         down_write(&snd_ioctl_rwsem);
1527         list_add_tail(&pn->list, lists);
1528         up_write(&snd_ioctl_rwsem);
1529         return 0;
1530 }
1531
1532 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1533 {
1534         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1535 }
1536
1537 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1538
1539 #ifdef CONFIG_COMPAT
1540 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1541 {
1542         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1543 }
1544
1545 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1546 #endif
1547
1548 /*
1549  * de-register the device-specific control-ioctls.
1550  */
1551 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1552                                      struct list_head *lists)
1553 {
1554         struct snd_kctl_ioctl *p;
1555
1556         if (snd_BUG_ON(!fcn))
1557                 return -EINVAL;
1558         down_write(&snd_ioctl_rwsem);
1559         list_for_each_entry(p, lists, list) {
1560                 if (p->fioctl == fcn) {
1561                         list_del(&p->list);
1562                         up_write(&snd_ioctl_rwsem);
1563                         kfree(p);
1564                         return 0;
1565                 }
1566         }
1567         up_write(&snd_ioctl_rwsem);
1568         snd_BUG();
1569         return -EINVAL;
1570 }
1571
1572 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1573 {
1574         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1575 }
1576
1577 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1578
1579 #ifdef CONFIG_COMPAT
1580 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1581 {
1582         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1583 }
1584
1585 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1586 #endif
1587
1588 static int snd_ctl_fasync(int fd, struct file * file, int on)
1589 {
1590         struct snd_ctl_file *ctl;
1591
1592         ctl = file->private_data;
1593         return fasync_helper(fd, file, on, &ctl->fasync);
1594 }
1595
1596 /*
1597  * ioctl32 compat
1598  */
1599 #ifdef CONFIG_COMPAT
1600 #include "control_compat.c"
1601 #else
1602 #define snd_ctl_ioctl_compat    NULL
1603 #endif
1604
1605 /*
1606  *  INIT PART
1607  */
1608
1609 static const struct file_operations snd_ctl_f_ops =
1610 {
1611         .owner =        THIS_MODULE,
1612         .read =         snd_ctl_read,
1613         .open =         snd_ctl_open,
1614         .release =      snd_ctl_release,
1615         .llseek =       no_llseek,
1616         .poll =         snd_ctl_poll,
1617         .unlocked_ioctl =       snd_ctl_ioctl,
1618         .compat_ioctl = snd_ctl_ioctl_compat,
1619         .fasync =       snd_ctl_fasync,
1620 };
1621
1622 /*
1623  * registration of the control device
1624  */
1625 static int snd_ctl_dev_register(struct snd_device *device)
1626 {
1627         struct snd_card *card = device->device_data;
1628         int err, cardnum;
1629         char name[16];
1630
1631         if (snd_BUG_ON(!card))
1632                 return -ENXIO;
1633         cardnum = card->number;
1634         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1635                 return -ENXIO;
1636         sprintf(name, "controlC%i", cardnum);
1637         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1638                                        &snd_ctl_f_ops, card, name)) < 0)
1639                 return err;
1640         return 0;
1641 }
1642
1643 /*
1644  * disconnection of the control device
1645  */
1646 static int snd_ctl_dev_disconnect(struct snd_device *device)
1647 {
1648         struct snd_card *card = device->device_data;
1649         struct snd_ctl_file *ctl;
1650         int err, cardnum;
1651
1652         if (snd_BUG_ON(!card))
1653                 return -ENXIO;
1654         cardnum = card->number;
1655         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1656                 return -ENXIO;
1657
1658         read_lock(&card->ctl_files_rwlock);
1659         list_for_each_entry(ctl, &card->ctl_files, list) {
1660                 wake_up(&ctl->change_sleep);
1661                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1662         }
1663         read_unlock(&card->ctl_files_rwlock);
1664
1665         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1666                                          card, -1)) < 0)
1667                 return err;
1668         return 0;
1669 }
1670
1671 /*
1672  * free all controls
1673  */
1674 static int snd_ctl_dev_free(struct snd_device *device)
1675 {
1676         struct snd_card *card = device->device_data;
1677         struct snd_kcontrol *control;
1678
1679         down_write(&card->controls_rwsem);
1680         while (!list_empty(&card->controls)) {
1681                 control = snd_kcontrol(card->controls.next);
1682                 snd_ctl_remove(card, control);
1683         }
1684         up_write(&card->controls_rwsem);
1685         return 0;
1686 }
1687
1688 /*
1689  * create control core:
1690  * called from init.c
1691  */
1692 int snd_ctl_create(struct snd_card *card)
1693 {
1694         static struct snd_device_ops ops = {
1695                 .dev_free = snd_ctl_dev_free,
1696                 .dev_register = snd_ctl_dev_register,
1697                 .dev_disconnect = snd_ctl_dev_disconnect,
1698         };
1699
1700         if (snd_BUG_ON(!card))
1701                 return -ENXIO;
1702         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1703 }
1704
1705 /*
1706  * Frequently used control callbacks/helpers
1707  */
1708 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1709                               struct snd_ctl_elem_info *uinfo)
1710 {
1711         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1712         uinfo->count = 1;
1713         uinfo->value.integer.min = 0;
1714         uinfo->value.integer.max = 1;
1715         return 0;
1716 }
1717
1718 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1719
1720 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1721                                 struct snd_ctl_elem_info *uinfo)
1722 {
1723         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1724         uinfo->count = 2;
1725         uinfo->value.integer.min = 0;
1726         uinfo->value.integer.max = 1;
1727         return 0;
1728 }
1729
1730 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1731
1732 /**
1733  * snd_ctl_enum_info - fills the info structure for an enumerated control
1734  * @info: the structure to be filled
1735  * @channels: the number of the control's channels; often one
1736  * @items: the number of control values; also the size of @names
1737  * @names: an array containing the names of all control values
1738  *
1739  * Sets all required fields in @info to their appropriate values.
1740  * If the control's accessibility is not the default (readable and writable),
1741  * the caller has to fill @info->access.
1742  */
1743 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1744                       unsigned int items, const char *const names[])
1745 {
1746         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1747         info->count = channels;
1748         info->value.enumerated.items = items;
1749         if (info->value.enumerated.item >= items)
1750                 info->value.enumerated.item = items - 1;
1751         strlcpy(info->value.enumerated.name,
1752                 names[info->value.enumerated.item],
1753                 sizeof(info->value.enumerated.name));
1754         return 0;
1755 }
1756 EXPORT_SYMBOL(snd_ctl_enum_info);