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