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         list_for_each_entry(kctl, &card->controls, list) {
 292                 if (kctl->id.numid < card->last_numid + 1 + count &&
 293                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 294                         card->last_numid = kctl->id.numid + kctl->count - 1;
 295                         return true;
 296                 }
 297         }
 298         return false;
 299 }
 300
 301 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 302 {
 303         unsigned int iter = 100000;
 304
 305         while (snd_ctl_remove_numid_conflict(card, count)) {
 306                 if (--iter == 0) {
 307                         /* this situation is very unlikely */
 308                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 309                         return -ENOMEM;
 310                 }
 311         }
 312         return 0;
 313 }
 314
 315 /**
 316  * snd_ctl_add - add the control instance to the card
 317  * @card: the card instance
 318  * @kcontrol: the control instance to add
 319  *
 320  * Adds the control instance created via snd_ctl_new() or
 321  * snd_ctl_new1() to the given card. Assigns also an unique
 322  * numid used for fast search.
 323  *
 324  * Returns zero if successful, or a negative error code on failure.
 325  *
 326  * It frees automatically the control which cannot be added.
 327  */
 328 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 329 {
 330         struct snd_ctl_elem_id id;
 331         unsigned int idx;
 332         unsigned int count;
 333         int err = -EINVAL;
 334
 335         if (! kcontrol)
 336                 return err;
 337         if (snd_BUG_ON(!card || !kcontrol->info))
 338                 goto error;
 339         id = kcontrol->id;
 340         down_write(&card->controls_rwsem);
 341         if (snd_ctl_find_id(card, &id)) {
 342                 up_write(&card->controls_rwsem);
 343                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 344                                         id.iface,
 345                                         id.device,
 346                                         id.subdevice,
 347                                         id.name,
 348                                         id.index);
 349                 err = -EBUSY;
 350                 goto error;
 351         }
 352         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 353                 up_write(&card->controls_rwsem);
 354                 err = -ENOMEM;
 355                 goto error;
 356         }
 357         list_add_tail(&kcontrol->list, &card->controls);
 358         card->controls_count += kcontrol->count;
 359         kcontrol->id.numid = card->last_numid + 1;
 360         card->last_numid += kcontrol->count;
 361         count = kcontrol->count;
 362         up_write(&card->controls_rwsem);
 363         for (idx = 0; idx < 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  * Returns zero if successful, or a negative error code on failure.
 385  *
 386  * It frees automatically the control which cannot be added or replaced.
 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 count;
 393         unsigned int idx;
 394         struct snd_kcontrol *old;
 395         int ret;
 396
 397         if (!kcontrol)
 398                 return -EINVAL;
 399         if (snd_BUG_ON(!card || !kcontrol->info)) {
 400                 ret = -EINVAL;
 401                 goto error;
 402         }
 403         id = kcontrol->id;
 404         down_write(&card->controls_rwsem);
 405         old = snd_ctl_find_id(card, &id);
 406         if (!old) {
 407                 if (add_on_replace)
 408                         goto add;
 409                 up_write(&card->controls_rwsem);
 410                 ret = -EINVAL;
 411                 goto error;
 412         }
 413         ret = snd_ctl_remove(card, old);
 414         if (ret < 0) {
 415                 up_write(&card->controls_rwsem);
 416                 goto error;
 417         }
 418 add:
 419         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 420                 up_write(&card->controls_rwsem);
 421                 ret = -ENOMEM;
 422                 goto error;
 423         }
 424         list_add_tail(&kcontrol->list, &card->controls);
 425         card->controls_count += kcontrol->count;
 426         kcontrol->id.numid = card->last_numid + 1;
 427         card->last_numid += kcontrol->count;
 428         count = kcontrol->count;
 429         up_write(&card->controls_rwsem);
 430         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 431                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 432         return 0;
 433
 434 error:
 435         snd_ctl_free_one(kcontrol);
 436         return ret;
 437 }
 438 EXPORT_SYMBOL(snd_ctl_replace);
 439
 440 /**
 441  * snd_ctl_remove - remove the control from the card and release it
 442  * @card: the card instance
 443  * @kcontrol: the control instance to remove
 444  *
 445  * Removes the control from the card and then releases the instance.
 446  * You don't need to call snd_ctl_free_one(). You must be in
 447  * the write lock - down_write(&card->controls_rwsem).
 448  *
 449  * Returns 0 if successful, or a negative error code on failure.
 450  */
 451 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 452 {
 453         struct snd_ctl_elem_id id;
 454         unsigned int idx;
 455
 456         if (snd_BUG_ON(!card || !kcontrol))
 457                 return -EINVAL;
 458         list_del(&kcontrol->list);
 459         card->controls_count -= kcontrol->count;
 460         id = kcontrol->id;
 461         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 462                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 463         snd_ctl_free_one(kcontrol);
 464         return 0;
 465 }
 466
 467 EXPORT_SYMBOL(snd_ctl_remove);
 468
 469 /**
 470  * snd_ctl_remove_id - remove the control of the given id and release it
 471  * @card: the card instance
 472  * @id: the control id to remove
 473  *
 474  * Finds the control instance with the given id, removes it from the
 475  * card list and releases it.
 476  *
 477  * Returns 0 if successful, or a negative error code on failure.
 478  */
 479 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 480 {
 481         struct snd_kcontrol *kctl;
 482         int ret;
 483
 484         down_write(&card->controls_rwsem);
 485         kctl = snd_ctl_find_id(card, id);
 486         if (kctl == NULL) {
 487                 up_write(&card->controls_rwsem);
 488                 return -ENOENT;
 489         }
 490         ret = snd_ctl_remove(card, kctl);
 491         up_write(&card->controls_rwsem);
 492         return ret;
 493 }
 494
 495 EXPORT_SYMBOL(snd_ctl_remove_id);
 496
 497 /**
 498  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 499  * @file: active control handle
 500  * @id: the control id to remove
 501  *
 502  * Finds the control instance with the given id, removes it from the
 503  * card list and releases it.
 504  *
 505  * Returns 0 if successful, or a negative error code on failure.
 506  */
 507 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 508                                    struct snd_ctl_elem_id *id)
 509 {
 510         struct snd_card *card = file->card;
 511         struct snd_kcontrol *kctl;
 512         int idx, ret;
 513
 514         down_write(&card->controls_rwsem);
 515         kctl = snd_ctl_find_id(card, id);
 516         if (kctl == NULL) {
 517                 ret = -ENOENT;
 518                 goto error;
 519         }
 520         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 521                 ret = -EINVAL;
 522                 goto error;
 523         }
 524         for (idx = 0; idx < kctl->count; idx++)
 525                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 526                         ret = -EBUSY;
 527                         goto error;
 528                 }
 529         ret = snd_ctl_remove(card, kctl);
 530         if (ret < 0)
 531                 goto error;
 532         card->user_ctl_count--;
 533 error:
 534         up_write(&card->controls_rwsem);
 535         return ret;
 536 }
 537
 538 /**
 539  * snd_ctl_activate_id - activate/inactivate the control of the given id
 540  * @card: the card instance
 541  * @id: the control id to activate/inactivate
 542  * @active: non-zero to activate
 543  *
 544  * Finds the control instance with the given id, and activate or
 545  * inactivate the control together with notification, if changed.
 546  *
 547  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 548  */
 549 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 550                         int active)
 551 {
 552         struct snd_kcontrol *kctl;
 553         struct snd_kcontrol_volatile *vd;
 554         unsigned int index_offset;
 555         int ret;
 556
 557         down_write(&card->controls_rwsem);
 558         kctl = snd_ctl_find_id(card, id);
 559         if (kctl == NULL) {
 560                 ret = -ENOENT;
 561                 goto unlock;
 562         }
 563         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 564         vd = &kctl->vd[index_offset];
 565         ret = 0;
 566         if (active) {
 567                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 568                         goto unlock;
 569                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 570         } else {
 571                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 572                         goto unlock;
 573                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 574         }
 575         ret = 1;
 576  unlock:
 577         up_write(&card->controls_rwsem);
 578         if (ret > 0)
 579                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 580         return ret;
 581 }
 582 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 583
 584 /**
 585  * snd_ctl_rename_id - replace the id of a control on the card
 586  * @card: the card instance
 587  * @src_id: the old id
 588  * @dst_id: the new id
 589  *
 590  * Finds the control with the old id from the card, and replaces the
 591  * id with the new one.
 592  *
 593  * Returns zero if successful, or a negative error code on failure.
 594  */
 595 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 596                       struct snd_ctl_elem_id *dst_id)
 597 {
 598         struct snd_kcontrol *kctl;
 599
 600         down_write(&card->controls_rwsem);
 601         kctl = snd_ctl_find_id(card, src_id);
 602         if (kctl == NULL) {
 603                 up_write(&card->controls_rwsem);
 604                 return -ENOENT;
 605         }
 606         kctl->id = *dst_id;
 607         kctl->id.numid = card->last_numid + 1;
 608         card->last_numid += kctl->count;
 609         up_write(&card->controls_rwsem);
 610         return 0;
 611 }
 612
 613 EXPORT_SYMBOL(snd_ctl_rename_id);
 614
 615 /**
 616  * snd_ctl_find_numid - find the control instance with the given number-id
 617  * @card: the card instance
 618  * @numid: the number-id to search
 619  *
 620  * Finds the control instance with the given number-id from the card.
 621  *
 622  * Returns the pointer of the instance if found, or NULL if not.
 623  *
 624  * The caller must down card->controls_rwsem before calling this function
 625  * (if the race condition can happen).
 626  */
 627 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 628 {
 629         struct snd_kcontrol *kctl;
 630
 631         if (snd_BUG_ON(!card || !numid))
 632                 return NULL;
 633         list_for_each_entry(kctl, &card->controls, list) {
 634                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 635                         return kctl;
 636         }
 637         return NULL;
 638 }
 639
 640 EXPORT_SYMBOL(snd_ctl_find_numid);
 641
 642 /**
 643  * snd_ctl_find_id - find the control instance with the given id
 644  * @card: the card instance
 645  * @id: the id to search
 646  *
 647  * Finds the control instance with the given id from the card.
 648  *
 649  * Returns the pointer of the instance if found, or NULL if not.
 650  *
 651  * The caller must down card->controls_rwsem before calling this function
 652  * (if the race condition can happen).
 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                         struct snd_ctl_elem_id id = control->id;
 902                         up_read(&card->controls_rwsem);
 903                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &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         struct snd_card *card;
 996         void *elem_data;                /* element data */
 997         unsigned long elem_data_size;   /* size of element data in bytes */
 998         void *tlv_data;                 /* TLV data */
 999         unsigned long tlv_data_size;    /* TLV data size */
1000         void *priv_data;                /* private data (like strings for enumerated type) */
1001 };
1002
1003 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1004                                   struct snd_ctl_elem_info *uinfo)
1005 {
1006         struct user_element *ue = kcontrol->private_data;
1007
1008         *uinfo = ue->info;
1009         return 0;
1010 }
1011
1012 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1013                                        struct snd_ctl_elem_info *uinfo)
1014 {
1015         struct user_element *ue = kcontrol->private_data;
1016         const char *names;
1017         unsigned int item;
1018
1019         item = uinfo->value.enumerated.item;
1020
1021         *uinfo = ue->info;
1022
1023         item = min(item, uinfo->value.enumerated.items - 1);
1024         uinfo->value.enumerated.item = item;
1025
1026         names = ue->priv_data;
1027         for (; item > 0; --item)
1028                 names += strlen(names) + 1;
1029         strcpy(uinfo->value.enumerated.name, names);
1030
1031         return 0;
1032 }
1033
1034 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1035                                  struct snd_ctl_elem_value *ucontrol)
1036 {
1037         struct user_element *ue = kcontrol->private_data;
1038
1039         mutex_lock(&ue->card->user_ctl_lock);
1040         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1041         mutex_unlock(&ue->card->user_ctl_lock);
1042         return 0;
1043 }
1044
1045 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1046                                  struct snd_ctl_elem_value *ucontrol)
1047 {
1048         int change;
1049         struct user_element *ue = kcontrol->private_data;
1050
1051         mutex_lock(&ue->card->user_ctl_lock);
1052         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1053         if (change)
1054                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1055         mutex_unlock(&ue->card->user_ctl_lock);
1056         return change;
1057 }
1058
1059 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1060                                  int op_flag,
1061                                  unsigned int size,
1062                                  unsigned int __user *tlv)
1063 {
1064         struct user_element *ue = kcontrol->private_data;
1065         int change = 0;
1066         void *new_data;
1067
1068         if (op_flag > 0) {
1069                 if (size > 1024 * 128)  /* sane value */
1070                         return -EINVAL;
1071
1072                 new_data = memdup_user(tlv, size);
1073                 if (IS_ERR(new_data))
1074                         return PTR_ERR(new_data);
1075                 mutex_lock(&ue->card->user_ctl_lock);
1076                 change = ue->tlv_data_size != size;
1077                 if (!change)
1078                         change = memcmp(ue->tlv_data, new_data, size);
1079                 kfree(ue->tlv_data);
1080                 ue->tlv_data = new_data;
1081                 ue->tlv_data_size = size;
1082                 mutex_unlock(&ue->card->user_ctl_lock);
1083         } else {
1084                 int ret = 0;
1085
1086                 mutex_lock(&ue->card->user_ctl_lock);
1087                 if (!ue->tlv_data_size || !ue->tlv_data) {
1088                         ret = -ENXIO;
1089                         goto err_unlock;
1090                 }
1091                 if (size < ue->tlv_data_size) {
1092                         ret = -ENOSPC;
1093                         goto err_unlock;
1094                 }
1095                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1096                         ret = -EFAULT;
1097 err_unlock:
1098                 mutex_unlock(&ue->card->user_ctl_lock);
1099                 if (ret)
1100                         return ret;
1101         }
1102         return change;
1103 }
1104
1105 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1106 {
1107         char *names, *p;
1108         size_t buf_len, name_len;
1109         unsigned int i;
1110         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1111
1112         if (ue->info.value.enumerated.names_length > 64 * 1024)
1113                 return -EINVAL;
1114
1115         names = memdup_user((const void __user *)user_ptrval,
1116                 ue->info.value.enumerated.names_length);
1117         if (IS_ERR(names))
1118                 return PTR_ERR(names);
1119
1120         /* check that there are enough valid names */
1121         buf_len = ue->info.value.enumerated.names_length;
1122         p = names;
1123         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1124                 name_len = strnlen(p, buf_len);
1125                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1126                         kfree(names);
1127                         return -EINVAL;
1128                 }
1129                 p += name_len + 1;
1130                 buf_len -= name_len + 1;
1131         }
1132
1133         ue->priv_data = names;
1134         ue->info.value.enumerated.names_ptr = 0;
1135
1136         return 0;
1137 }
1138
1139 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1140 {
1141         struct user_element *ue = kcontrol->private_data;
1142
1143         kfree(ue->tlv_data);
1144         kfree(ue->priv_data);
1145         kfree(ue);
1146 }
1147
1148 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1149                             struct snd_ctl_elem_info *info, int replace)
1150 {
1151         struct snd_card *card = file->card;
1152         struct snd_kcontrol kctl, *_kctl;
1153         unsigned int access;
1154         long private_size;
1155         struct user_element *ue;
1156         int idx, err;
1157
1158         if (info->count < 1)
1159                 return -EINVAL;
1160         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1161                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1162                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1163                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1164         info->id.numid = 0;
1165         memset(&kctl, 0, sizeof(kctl));
1166
1167         if (replace) {
1168                 err = snd_ctl_remove_user_ctl(file, &info->id);
1169                 if (err)
1170                         return err;
1171         }
1172
1173         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1174                 return -ENOMEM;
1175
1176         memcpy(&kctl.id, &info->id, sizeof(info->id));
1177         kctl.count = info->owner ? info->owner : 1;
1178         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1179         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1180                 kctl.info = snd_ctl_elem_user_enum_info;
1181         else
1182                 kctl.info = snd_ctl_elem_user_info;
1183         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1184                 kctl.get = snd_ctl_elem_user_get;
1185         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1186                 kctl.put = snd_ctl_elem_user_put;
1187         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1188                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1189                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1190         }
1191         switch (info->type) {
1192         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1193         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1194                 private_size = sizeof(long);
1195                 if (info->count > 128)
1196                         return -EINVAL;
1197                 break;
1198         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1199                 private_size = sizeof(long long);
1200                 if (info->count > 64)
1201                         return -EINVAL;
1202                 break;
1203         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1204                 private_size = sizeof(unsigned int);
1205                 if (info->count > 128 || info->value.enumerated.items == 0)
1206                         return -EINVAL;
1207                 break;
1208         case SNDRV_CTL_ELEM_TYPE_BYTES:
1209                 private_size = sizeof(unsigned char);
1210                 if (info->count > 512)
1211                         return -EINVAL;
1212                 break;
1213         case SNDRV_CTL_ELEM_TYPE_IEC958:
1214                 private_size = sizeof(struct snd_aes_iec958);
1215                 if (info->count != 1)
1216                         return -EINVAL;
1217                 break;
1218         default:
1219                 return -EINVAL;
1220         }
1221         private_size *= info->count;
1222         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1223         if (ue == NULL)
1224                 return -ENOMEM;
1225         ue->card = card;
1226         ue->info = *info;
1227         ue->info.access = 0;
1228         ue->elem_data = (char *)ue + sizeof(*ue);
1229         ue->elem_data_size = private_size;
1230         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1231                 err = snd_ctl_elem_init_enum_names(ue);
1232                 if (err < 0) {
1233                         kfree(ue);
1234                         return err;
1235                 }
1236         }
1237         kctl.private_free = snd_ctl_elem_user_free;
1238         _kctl = snd_ctl_new(&kctl, access);
1239         if (_kctl == NULL) {
1240                 kfree(ue->priv_data);
1241                 kfree(ue);
1242                 return -ENOMEM;
1243         }
1244         _kctl->private_data = ue;
1245         for (idx = 0; idx < _kctl->count; idx++)
1246                 _kctl->vd[idx].owner = file;
1247         err = snd_ctl_add(card, _kctl);
1248         if (err < 0)
1249                 return err;
1250
1251         down_write(&card->controls_rwsem);
1252         card->user_ctl_count++;
1253         up_write(&card->controls_rwsem);
1254
1255         return 0;
1256 }
1257
1258 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1259                                  struct snd_ctl_elem_info __user *_info, int replace)
1260 {
1261         struct snd_ctl_elem_info info;
1262         if (copy_from_user(&info, _info, sizeof(info)))
1263                 return -EFAULT;
1264         return snd_ctl_elem_add(file, &info, replace);
1265 }
1266
1267 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1268                                struct snd_ctl_elem_id __user *_id)
1269 {
1270         struct snd_ctl_elem_id id;
1271
1272         if (copy_from_user(&id, _id, sizeof(id)))
1273                 return -EFAULT;
1274         return snd_ctl_remove_user_ctl(file, &id);
1275 }
1276
1277 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1278 {
1279         int subscribe;
1280         if (get_user(subscribe, ptr))
1281                 return -EFAULT;
1282         if (subscribe < 0) {
1283                 subscribe = file->subscribed;
1284                 if (put_user(subscribe, ptr))
1285                         return -EFAULT;
1286                 return 0;
1287         }
1288         if (subscribe) {
1289                 file->subscribed = 1;
1290                 return 0;
1291         } else if (file->subscribed) {
1292                 snd_ctl_empty_read_queue(file);
1293                 file->subscribed = 0;
1294         }
1295         return 0;
1296 }
1297
1298 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1299                              struct snd_ctl_tlv __user *_tlv,
1300                              int op_flag)
1301 {
1302         struct snd_card *card = file->card;
1303         struct snd_ctl_tlv tlv;
1304         struct snd_kcontrol *kctl;
1305         struct snd_kcontrol_volatile *vd;
1306         unsigned int len;
1307         int err = 0;
1308
1309         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1310                 return -EFAULT;
1311         if (tlv.length < sizeof(unsigned int) * 2)
1312                 return -EINVAL;
1313         down_read(&card->controls_rwsem);
1314         kctl = snd_ctl_find_numid(card, tlv.numid);
1315         if (kctl == NULL) {
1316                 err = -ENOENT;
1317                 goto __kctl_end;
1318         }
1319         if (kctl->tlv.p == NULL) {
1320                 err = -ENXIO;
1321                 goto __kctl_end;
1322         }
1323         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1324         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1325             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1326             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1327                 err = -ENXIO;
1328                 goto __kctl_end;
1329         }
1330         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1331                 if (vd->owner != NULL && vd->owner != file) {
1332                         err = -EPERM;
1333                         goto __kctl_end;
1334                 }
1335                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1336                 if (err > 0) {
1337                         struct snd_ctl_elem_id id = kctl->id;
1338                         up_read(&card->controls_rwsem);
1339                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1340                         return 0;
1341                 }
1342         } else {
1343                 if (op_flag) {
1344                         err = -ENXIO;
1345                         goto __kctl_end;
1346                 }
1347                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1348                 if (tlv.length < len) {
1349                         err = -ENOMEM;
1350                         goto __kctl_end;
1351                 }
1352                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1353                         err = -EFAULT;
1354         }
1355       __kctl_end:
1356         up_read(&card->controls_rwsem);
1357         return err;
1358 }
1359
1360 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1361 {
1362         struct snd_ctl_file *ctl;
1363         struct snd_card *card;
1364         struct snd_kctl_ioctl *p;
1365         void __user *argp = (void __user *)arg;
1366         int __user *ip = argp;
1367         int err;
1368
1369         ctl = file->private_data;
1370         card = ctl->card;
1371         if (snd_BUG_ON(!card))
1372                 return -ENXIO;
1373         switch (cmd) {
1374         case SNDRV_CTL_IOCTL_PVERSION:
1375                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1376         case SNDRV_CTL_IOCTL_CARD_INFO:
1377                 return snd_ctl_card_info(card, ctl, cmd, argp);
1378         case SNDRV_CTL_IOCTL_ELEM_LIST:
1379                 return snd_ctl_elem_list(card, argp);
1380         case SNDRV_CTL_IOCTL_ELEM_INFO:
1381                 return snd_ctl_elem_info_user(ctl, argp);
1382         case SNDRV_CTL_IOCTL_ELEM_READ:
1383                 return snd_ctl_elem_read_user(card, argp);
1384         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1385                 return snd_ctl_elem_write_user(ctl, argp);
1386         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1387                 return snd_ctl_elem_lock(ctl, argp);
1388         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1389                 return snd_ctl_elem_unlock(ctl, argp);
1390         case SNDRV_CTL_IOCTL_ELEM_ADD:
1391                 return snd_ctl_elem_add_user(ctl, argp, 0);
1392         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1393                 return snd_ctl_elem_add_user(ctl, argp, 1);
1394         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1395                 return snd_ctl_elem_remove(ctl, argp);
1396         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1397                 return snd_ctl_subscribe_events(ctl, ip);
1398         case SNDRV_CTL_IOCTL_TLV_READ:
1399                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1400         case SNDRV_CTL_IOCTL_TLV_WRITE:
1401                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1402         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1403                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1404         case SNDRV_CTL_IOCTL_POWER:
1405                 return -ENOPROTOOPT;
1406         case SNDRV_CTL_IOCTL_POWER_STATE:
1407 #ifdef CONFIG_PM
1408                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1409 #else
1410                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1411 #endif
1412         }
1413         down_read(&snd_ioctl_rwsem);
1414         list_for_each_entry(p, &snd_control_ioctls, list) {
1415                 err = p->fioctl(card, ctl, cmd, arg);
1416                 if (err != -ENOIOCTLCMD) {
1417                         up_read(&snd_ioctl_rwsem);
1418                         return err;
1419                 }
1420         }
1421         up_read(&snd_ioctl_rwsem);
1422         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1423         return -ENOTTY;
1424 }
1425
1426 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1427                             size_t count, loff_t * offset)
1428 {
1429         struct snd_ctl_file *ctl;
1430         int err = 0;
1431         ssize_t result = 0;
1432
1433         ctl = file->private_data;
1434         if (snd_BUG_ON(!ctl || !ctl->card))
1435                 return -ENXIO;
1436         if (!ctl->subscribed)
1437                 return -EBADFD;
1438         if (count < sizeof(struct snd_ctl_event))
1439                 return -EINVAL;
1440         spin_lock_irq(&ctl->read_lock);
1441         while (count >= sizeof(struct snd_ctl_event)) {
1442                 struct snd_ctl_event ev;
1443                 struct snd_kctl_event *kev;
1444                 while (list_empty(&ctl->events)) {
1445                         wait_queue_t wait;
1446                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1447                                 err = -EAGAIN;
1448                                 goto __end_lock;
1449                         }
1450                         init_waitqueue_entry(&wait, current);
1451                         add_wait_queue(&ctl->change_sleep, &wait);
1452                         set_current_state(TASK_INTERRUPTIBLE);
1453                         spin_unlock_irq(&ctl->read_lock);
1454                         schedule();
1455                         remove_wait_queue(&ctl->change_sleep, &wait);
1456                         if (ctl->card->shutdown)
1457                                 return -ENODEV;
1458                         if (signal_pending(current))
1459                                 return -ERESTARTSYS;
1460                         spin_lock_irq(&ctl->read_lock);
1461                 }
1462                 kev = snd_kctl_event(ctl->events.next);
1463                 ev.type = SNDRV_CTL_EVENT_ELEM;
1464                 ev.data.elem.mask = kev->mask;
1465                 ev.data.elem.id = kev->id;
1466                 list_del(&kev->list);
1467                 spin_unlock_irq(&ctl->read_lock);
1468                 kfree(kev);
1469                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1470                         err = -EFAULT;
1471                         goto __end;
1472                 }
1473                 spin_lock_irq(&ctl->read_lock);
1474                 buffer += sizeof(struct snd_ctl_event);
1475                 count -= sizeof(struct snd_ctl_event);
1476                 result += sizeof(struct snd_ctl_event);
1477         }
1478       __end_lock:
1479         spin_unlock_irq(&ctl->read_lock);
1480       __end:
1481         return result > 0 ? result : err;
1482 }
1483
1484 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1485 {
1486         unsigned int mask;
1487         struct snd_ctl_file *ctl;
1488
1489         ctl = file->private_data;
1490         if (!ctl->subscribed)
1491                 return 0;
1492         poll_wait(file, &ctl->change_sleep, wait);
1493
1494         mask = 0;
1495         if (!list_empty(&ctl->events))
1496                 mask |= POLLIN | POLLRDNORM;
1497
1498         return mask;
1499 }
1500
1501 /*
1502  * register the device-specific control-ioctls.
1503  * called from each device manager like pcm.c, hwdep.c, etc.
1504  */
1505 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1506 {
1507         struct snd_kctl_ioctl *pn;
1508
1509         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1510         if (pn == NULL)
1511                 return -ENOMEM;
1512         pn->fioctl = fcn;
1513         down_write(&snd_ioctl_rwsem);
1514         list_add_tail(&pn->list, lists);
1515         up_write(&snd_ioctl_rwsem);
1516         return 0;
1517 }
1518
1519 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1520 {
1521         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1522 }
1523
1524 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1525
1526 #ifdef CONFIG_COMPAT
1527 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1528 {
1529         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1530 }
1531
1532 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1533 #endif
1534
1535 /*
1536  * de-register the device-specific control-ioctls.
1537  */
1538 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1539                                      struct list_head *lists)
1540 {
1541         struct snd_kctl_ioctl *p;
1542
1543         if (snd_BUG_ON(!fcn))
1544                 return -EINVAL;
1545         down_write(&snd_ioctl_rwsem);
1546         list_for_each_entry(p, lists, list) {
1547                 if (p->fioctl == fcn) {
1548                         list_del(&p->list);
1549                         up_write(&snd_ioctl_rwsem);
1550                         kfree(p);
1551                         return 0;
1552                 }
1553         }
1554         up_write(&snd_ioctl_rwsem);
1555         snd_BUG();
1556         return -EINVAL;
1557 }
1558
1559 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1560 {
1561         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1562 }
1563
1564 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1565
1566 #ifdef CONFIG_COMPAT
1567 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1568 {
1569         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1570 }
1571
1572 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1573 #endif
1574
1575 static int snd_ctl_fasync(int fd, struct file * file, int on)
1576 {
1577         struct snd_ctl_file *ctl;
1578
1579         ctl = file->private_data;
1580         return fasync_helper(fd, file, on, &ctl->fasync);
1581 }
1582
1583 /*
1584  * ioctl32 compat
1585  */
1586 #ifdef CONFIG_COMPAT
1587 #include "control_compat.c"
1588 #else
1589 #define snd_ctl_ioctl_compat    NULL
1590 #endif
1591
1592 /*
1593  *  INIT PART
1594  */
1595
1596 static const struct file_operations snd_ctl_f_ops =
1597 {
1598         .owner =        THIS_MODULE,
1599         .read =         snd_ctl_read,
1600         .open =         snd_ctl_open,
1601         .release =      snd_ctl_release,
1602         .llseek =       no_llseek,
1603         .poll =         snd_ctl_poll,
1604         .unlocked_ioctl =       snd_ctl_ioctl,
1605         .compat_ioctl = snd_ctl_ioctl_compat,
1606         .fasync =       snd_ctl_fasync,
1607 };
1608
1609 /*
1610  * registration of the control device
1611  */
1612 static int snd_ctl_dev_register(struct snd_device *device)
1613 {
1614         struct snd_card *card = device->device_data;
1615         int err, cardnum;
1616         char name[16];
1617
1618         if (snd_BUG_ON(!card))
1619                 return -ENXIO;
1620         cardnum = card->number;
1621         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1622                 return -ENXIO;
1623         sprintf(name, "controlC%i", cardnum);
1624         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1625                                        &snd_ctl_f_ops, card, name)) < 0)
1626                 return err;
1627         return 0;
1628 }
1629
1630 /*
1631  * disconnection of the control device
1632  */
1633 static int snd_ctl_dev_disconnect(struct snd_device *device)
1634 {
1635         struct snd_card *card = device->device_data;
1636         struct snd_ctl_file *ctl;
1637         int err, cardnum;
1638
1639         if (snd_BUG_ON(!card))
1640                 return -ENXIO;
1641         cardnum = card->number;
1642         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1643                 return -ENXIO;
1644
1645         read_lock(&card->ctl_files_rwlock);
1646         list_for_each_entry(ctl, &card->ctl_files, list) {
1647                 wake_up(&ctl->change_sleep);
1648                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1649         }
1650         read_unlock(&card->ctl_files_rwlock);
1651
1652         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1653                                          card, -1)) < 0)
1654                 return err;
1655         return 0;
1656 }
1657
1658 /*
1659  * free all controls
1660  */
1661 static int snd_ctl_dev_free(struct snd_device *device)
1662 {
1663         struct snd_card *card = device->device_data;
1664         struct snd_kcontrol *control;
1665
1666         down_write(&card->controls_rwsem);
1667         while (!list_empty(&card->controls)) {
1668                 control = snd_kcontrol(card->controls.next);
1669                 snd_ctl_remove(card, control);
1670         }
1671         up_write(&card->controls_rwsem);
1672         return 0;
1673 }
1674
1675 /*
1676  * create control core:
1677  * called from init.c
1678  */
1679 int snd_ctl_create(struct snd_card *card)
1680 {
1681         static struct snd_device_ops ops = {
1682                 .dev_free = snd_ctl_dev_free,
1683                 .dev_register = snd_ctl_dev_register,
1684                 .dev_disconnect = snd_ctl_dev_disconnect,
1685         };
1686
1687         if (snd_BUG_ON(!card))
1688                 return -ENXIO;
1689         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1690 }
1691
1692 /*
1693  * Frequently used control callbacks/helpers
1694  */
1695 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1696                               struct snd_ctl_elem_info *uinfo)
1697 {
1698         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1699         uinfo->count = 1;
1700         uinfo->value.integer.min = 0;
1701         uinfo->value.integer.max = 1;
1702         return 0;
1703 }
1704
1705 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1706
1707 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1708                                 struct snd_ctl_elem_info *uinfo)
1709 {
1710         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1711         uinfo->count = 2;
1712         uinfo->value.integer.min = 0;
1713         uinfo->value.integer.max = 1;
1714         return 0;
1715 }
1716
1717 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1718
1719 /**
1720  * snd_ctl_enum_info - fills the info structure for an enumerated control
1721  * @info: the structure to be filled
1722  * @channels: the number of the control's channels; often one
1723  * @items: the number of control values; also the size of @names
1724  * @names: an array containing the names of all control values
1725  *
1726  * Sets all required fields in @info to their appropriate values.
1727  * If the control's accessibility is not the default (readable and writable),
1728  * the caller has to fill @info->access.
1729  */
1730 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1731                       unsigned int items, const char *const names[])
1732 {
1733         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1734         info->count = channels;
1735         info->value.enumerated.items = items;
1736         if (info->value.enumerated.item >= items)
1737                 info->value.enumerated.item = items - 1;
1738         strlcpy(info->value.enumerated.name,
1739                 names[info->value.enumerated.item],
1740                 sizeof(info->value.enumerated.name));
1741         return 0;
1742 }
1743 EXPORT_SYMBOL(snd_ctl_enum_info);