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         /* Make sure that the ids assigned to the control do not wrap around */
 293         if (card->last_numid >= UINT_MAX - count)
 294                 card->last_numid = 0;
 295
 296         list_for_each_entry(kctl, &card->controls, list) {
 297                 if (kctl->id.numid < card->last_numid + 1 + count &&
 298                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 299                         card->last_numid = kctl->id.numid + kctl->count - 1;
 300                         return true;
 301                 }
 302         }
 303         return false;
 304 }
 305
 306 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 307 {
 308         unsigned int iter = 100000;
 309
 310         while (snd_ctl_remove_numid_conflict(card, count)) {
 311                 if (--iter == 0) {
 312                         /* this situation is very unlikely */
 313                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 314                         return -ENOMEM;
 315                 }
 316         }
 317         return 0;
 318 }
 319
 320 /**
 321  * snd_ctl_add - add the control instance to the card
 322  * @card: the card instance
 323  * @kcontrol: the control instance to add
 324  *
 325  * Adds the control instance created via snd_ctl_new() or
 326  * snd_ctl_new1() to the given card. Assigns also an unique
 327  * numid used for fast search.
 328  *
 329  * It frees automatically the control which cannot be added.
 330  *
 331  * Return: Zero if successful, or a negative error code on failure.
 332  *
 333  */
 334 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 335 {
 336         struct snd_ctl_elem_id id;
 337         unsigned int idx;
 338         unsigned int count;
 339         int err = -EINVAL;
 340
 341         if (! kcontrol)
 342                 return err;
 343         if (snd_BUG_ON(!card || !kcontrol->info))
 344                 goto error;
 345         id = kcontrol->id;
 346         if (id.index > UINT_MAX - kcontrol->count)
 347                 goto error;
 348
 349         down_write(&card->controls_rwsem);
 350         if (snd_ctl_find_id(card, &id)) {
 351                 up_write(&card->controls_rwsem);
 352                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 353                                         id.iface,
 354                                         id.device,
 355                                         id.subdevice,
 356                                         id.name,
 357                                         id.index);
 358                 err = -EBUSY;
 359                 goto error;
 360         }
 361         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 362                 up_write(&card->controls_rwsem);
 363                 err = -ENOMEM;
 364                 goto error;
 365         }
 366         list_add_tail(&kcontrol->list, &card->controls);
 367         card->controls_count += kcontrol->count;
 368         kcontrol->id.numid = card->last_numid + 1;
 369         card->last_numid += kcontrol->count;
 370         count = kcontrol->count;
 371         up_write(&card->controls_rwsem);
 372         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 373                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 374         return 0;
 375
 376  error:
 377         snd_ctl_free_one(kcontrol);
 378         return err;
 379 }
 380
 381 EXPORT_SYMBOL(snd_ctl_add);
 382
 383 /**
 384  * snd_ctl_replace - replace the control instance of the card
 385  * @card: the card instance
 386  * @kcontrol: the control instance to replace
 387  * @add_on_replace: add the control if not already added
 388  *
 389  * Replaces the given control.  If the given control does not exist
 390  * and the add_on_replace flag is set, the control is added.  If the
 391  * control exists, it is destroyed first.
 392  *
 393  * It frees automatically the control which cannot be added or replaced.
 394  *
 395  * Return: Zero if successful, or a negative error code on failure.
 396  */
 397 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 398                     bool add_on_replace)
 399 {
 400         struct snd_ctl_elem_id id;
 401         unsigned int count;
 402         unsigned int idx;
 403         struct snd_kcontrol *old;
 404         int ret;
 405
 406         if (!kcontrol)
 407                 return -EINVAL;
 408         if (snd_BUG_ON(!card || !kcontrol->info)) {
 409                 ret = -EINVAL;
 410                 goto error;
 411         }
 412         id = kcontrol->id;
 413         down_write(&card->controls_rwsem);
 414         old = snd_ctl_find_id(card, &id);
 415         if (!old) {
 416                 if (add_on_replace)
 417                         goto add;
 418                 up_write(&card->controls_rwsem);
 419                 ret = -EINVAL;
 420                 goto error;
 421         }
 422         ret = snd_ctl_remove(card, old);
 423         if (ret < 0) {
 424                 up_write(&card->controls_rwsem);
 425                 goto error;
 426         }
 427 add:
 428         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 429                 up_write(&card->controls_rwsem);
 430                 ret = -ENOMEM;
 431                 goto error;
 432         }
 433         list_add_tail(&kcontrol->list, &card->controls);
 434         card->controls_count += kcontrol->count;
 435         kcontrol->id.numid = card->last_numid + 1;
 436         card->last_numid += kcontrol->count;
 437         count = kcontrol->count;
 438         up_write(&card->controls_rwsem);
 439         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 440                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 441         return 0;
 442
 443 error:
 444         snd_ctl_free_one(kcontrol);
 445         return ret;
 446 }
 447 EXPORT_SYMBOL(snd_ctl_replace);
 448
 449 /**
 450  * snd_ctl_remove - remove the control from the card and release it
 451  * @card: the card instance
 452  * @kcontrol: the control instance to remove
 453  *
 454  * Removes the control from the card and then releases the instance.
 455  * You don't need to call snd_ctl_free_one(). You must be in
 456  * the write lock - down_write(&card->controls_rwsem).
 457  *
 458  * Return: 0 if successful, or a negative error code on failure.
 459  */
 460 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 461 {
 462         struct snd_ctl_elem_id id;
 463         unsigned int idx;
 464
 465         if (snd_BUG_ON(!card || !kcontrol))
 466                 return -EINVAL;
 467         list_del(&kcontrol->list);
 468         card->controls_count -= kcontrol->count;
 469         id = kcontrol->id;
 470         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 471                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 472         snd_ctl_free_one(kcontrol);
 473         return 0;
 474 }
 475
 476 EXPORT_SYMBOL(snd_ctl_remove);
 477
 478 /**
 479  * snd_ctl_remove_id - remove the control of the given id and release it
 480  * @card: the card instance
 481  * @id: the control id to remove
 482  *
 483  * Finds the control instance with the given id, removes it from the
 484  * card list and releases it.
 485  *
 486  * Return: 0 if successful, or a negative error code on failure.
 487  */
 488 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 489 {
 490         struct snd_kcontrol *kctl;
 491         int ret;
 492
 493         down_write(&card->controls_rwsem);
 494         kctl = snd_ctl_find_id(card, id);
 495         if (kctl == NULL) {
 496                 up_write(&card->controls_rwsem);
 497                 return -ENOENT;
 498         }
 499         ret = snd_ctl_remove(card, kctl);
 500         up_write(&card->controls_rwsem);
 501         return ret;
 502 }
 503
 504 EXPORT_SYMBOL(snd_ctl_remove_id);
 505
 506 /**
 507  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 508  * @file: active control handle
 509  * @id: the control id to remove
 510  *
 511  * Finds the control instance with the given id, removes it from the
 512  * card list and releases it.
 513  *
 514  * Return: 0 if successful, or a negative error code on failure.
 515  */
 516 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 517                                    struct snd_ctl_elem_id *id)
 518 {
 519         struct snd_card *card = file->card;
 520         struct snd_kcontrol *kctl;
 521         int idx, ret;
 522
 523         down_write(&card->controls_rwsem);
 524         kctl = snd_ctl_find_id(card, id);
 525         if (kctl == NULL) {
 526                 ret = -ENOENT;
 527                 goto error;
 528         }
 529         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 530                 ret = -EINVAL;
 531                 goto error;
 532         }
 533         for (idx = 0; idx < kctl->count; idx++)
 534                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 535                         ret = -EBUSY;
 536                         goto error;
 537                 }
 538         ret = snd_ctl_remove(card, kctl);
 539         if (ret < 0)
 540                 goto error;
 541         card->user_ctl_count--;
 542 error:
 543         up_write(&card->controls_rwsem);
 544         return ret;
 545 }
 546
 547 /**
 548  * snd_ctl_activate_id - activate/inactivate the control of the given id
 549  * @card: the card instance
 550  * @id: the control id to activate/inactivate
 551  * @active: non-zero to activate
 552  *
 553  * Finds the control instance with the given id, and activate or
 554  * inactivate the control together with notification, if changed.
 555  *
 556  * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
 557  */
 558 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 559                         int active)
 560 {
 561         struct snd_kcontrol *kctl;
 562         struct snd_kcontrol_volatile *vd;
 563         unsigned int index_offset;
 564         int ret;
 565
 566         down_write(&card->controls_rwsem);
 567         kctl = snd_ctl_find_id(card, id);
 568         if (kctl == NULL) {
 569                 ret = -ENOENT;
 570                 goto unlock;
 571         }
 572         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 573         vd = &kctl->vd[index_offset];
 574         ret = 0;
 575         if (active) {
 576                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 577                         goto unlock;
 578                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 579         } else {
 580                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 581                         goto unlock;
 582                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 583         }
 584         ret = 1;
 585  unlock:
 586         up_write(&card->controls_rwsem);
 587         if (ret > 0)
 588                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 589         return ret;
 590 }
 591 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 592
 593 /**
 594  * snd_ctl_rename_id - replace the id of a control on the card
 595  * @card: the card instance
 596  * @src_id: the old id
 597  * @dst_id: the new id
 598  *
 599  * Finds the control with the old id from the card, and replaces the
 600  * id with the new one.
 601  *
 602  * Return: Zero if successful, or a negative error code on failure.
 603  */
 604 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 605                       struct snd_ctl_elem_id *dst_id)
 606 {
 607         struct snd_kcontrol *kctl;
 608
 609         down_write(&card->controls_rwsem);
 610         kctl = snd_ctl_find_id(card, src_id);
 611         if (kctl == NULL) {
 612                 up_write(&card->controls_rwsem);
 613                 return -ENOENT;
 614         }
 615         kctl->id = *dst_id;
 616         kctl->id.numid = card->last_numid + 1;
 617         card->last_numid += kctl->count;
 618         up_write(&card->controls_rwsem);
 619         return 0;
 620 }
 621
 622 EXPORT_SYMBOL(snd_ctl_rename_id);
 623
 624 /**
 625  * snd_ctl_find_numid - find the control instance with the given number-id
 626  * @card: the card instance
 627  * @numid: the number-id to search
 628  *
 629  * Finds the control instance with the given number-id from the card.
 630  *
 631  * The caller must down card->controls_rwsem before calling this function
 632  * (if the race condition can happen).
 633  *
 634  * Return: The pointer of the instance if found, or %NULL if not.
 635  *
 636  */
 637 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 638 {
 639         struct snd_kcontrol *kctl;
 640
 641         if (snd_BUG_ON(!card || !numid))
 642                 return NULL;
 643         list_for_each_entry(kctl, &card->controls, list) {
 644                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 645                         return kctl;
 646         }
 647         return NULL;
 648 }
 649
 650 EXPORT_SYMBOL(snd_ctl_find_numid);
 651
 652 /**
 653  * snd_ctl_find_id - find the control instance with the given id
 654  * @card: the card instance
 655  * @id: the id to search
 656  *
 657  * Finds the control instance with the given id from the card.
 658  *
 659  * The caller must down card->controls_rwsem before calling this function
 660  * (if the race condition can happen).
 661  *
 662  * Return: The pointer of the instance if found, or %NULL if not.
 663  *
 664  */
 665 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 666                                      struct snd_ctl_elem_id *id)
 667 {
 668         struct snd_kcontrol *kctl;
 669
 670         if (snd_BUG_ON(!card || !id))
 671                 return NULL;
 672         if (id->numid != 0)
 673                 return snd_ctl_find_numid(card, id->numid);
 674         list_for_each_entry(kctl, &card->controls, list) {
 675                 if (kctl->id.iface != id->iface)
 676                         continue;
 677                 if (kctl->id.device != id->device)
 678                         continue;
 679                 if (kctl->id.subdevice != id->subdevice)
 680                         continue;
 681                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 682                         continue;
 683                 if (kctl->id.index > id->index)
 684                         continue;
 685                 if (kctl->id.index + kctl->count <= id->index)
 686                         continue;
 687                 return kctl;
 688         }
 689         return NULL;
 690 }
 691
 692 EXPORT_SYMBOL(snd_ctl_find_id);
 693
 694 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 695                              unsigned int cmd, void __user *arg)
 696 {
 697         struct snd_ctl_card_info *info;
 698
 699         info = kzalloc(sizeof(*info), GFP_KERNEL);
 700         if (! info)
 701                 return -ENOMEM;
 702         down_read(&snd_ioctl_rwsem);
 703         info->card = card->number;
 704         strlcpy(info->id, card->id, sizeof(info->id));
 705         strlcpy(info->driver, card->driver, sizeof(info->driver));
 706         strlcpy(info->name, card->shortname, sizeof(info->name));
 707         strlcpy(info->longname, card->longname, sizeof(info->longname));
 708         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 709         strlcpy(info->components, card->components, sizeof(info->components));
 710         up_read(&snd_ioctl_rwsem);
 711         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 712                 kfree(info);
 713                 return -EFAULT;
 714         }
 715         kfree(info);
 716         return 0;
 717 }
 718
 719 static int snd_ctl_elem_list(struct snd_card *card,
 720                              struct snd_ctl_elem_list __user *_list)
 721 {
 722         struct list_head *plist;
 723         struct snd_ctl_elem_list list;
 724         struct snd_kcontrol *kctl;
 725         struct snd_ctl_elem_id *dst, *id;
 726         unsigned int offset, space, jidx;
 727
 728         if (copy_from_user(&list, _list, sizeof(list)))
 729                 return -EFAULT;
 730         offset = list.offset;
 731         space = list.space;
 732         /* try limit maximum space */
 733         if (space > 16384)
 734                 return -ENOMEM;
 735         if (space > 0) {
 736                 /* allocate temporary buffer for atomic operation */
 737                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 738                 if (dst == NULL)
 739                         return -ENOMEM;
 740                 down_read(&card->controls_rwsem);
 741                 list.count = card->controls_count;
 742                 plist = card->controls.next;
 743                 while (plist != &card->controls) {
 744                         if (offset == 0)
 745                                 break;
 746                         kctl = snd_kcontrol(plist);
 747                         if (offset < kctl->count)
 748                                 break;
 749                         offset -= kctl->count;
 750                         plist = plist->next;
 751                 }
 752                 list.used = 0;
 753                 id = dst;
 754                 while (space > 0 && plist != &card->controls) {
 755                         kctl = snd_kcontrol(plist);
 756                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 757                                 snd_ctl_build_ioff(id, kctl, jidx);
 758                                 id++;
 759                                 space--;
 760                                 list.used++;
 761                         }
 762                         plist = plist->next;
 763                         offset = 0;
 764                 }
 765                 up_read(&card->controls_rwsem);
 766                 if (list.used > 0 &&
 767                     copy_to_user(list.pids, dst,
 768                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 769                         vfree(dst);
 770                         return -EFAULT;
 771                 }
 772                 vfree(dst);
 773         } else {
 774                 down_read(&card->controls_rwsem);
 775                 list.count = card->controls_count;
 776                 up_read(&card->controls_rwsem);
 777         }
 778         if (copy_to_user(_list, &list, sizeof(list)))
 779                 return -EFAULT;
 780         return 0;
 781 }
 782
 783 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 784                              struct snd_ctl_elem_info *info)
 785 {
 786         struct snd_card *card = ctl->card;
 787         struct snd_kcontrol *kctl;
 788         struct snd_kcontrol_volatile *vd;
 789         unsigned int index_offset;
 790         int result;
 791
 792         down_read(&card->controls_rwsem);
 793         kctl = snd_ctl_find_id(card, &info->id);
 794         if (kctl == NULL) {
 795                 up_read(&card->controls_rwsem);
 796                 return -ENOENT;
 797         }
 798 #ifdef CONFIG_SND_DEBUG
 799         info->access = 0;
 800 #endif
 801         result = kctl->info(kctl, info);
 802         if (result >= 0) {
 803                 snd_BUG_ON(info->access);
 804                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 805                 vd = &kctl->vd[index_offset];
 806                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 807                 info->access = vd->access;
 808                 if (vd->owner) {
 809                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 810                         if (vd->owner == ctl)
 811                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 812                         info->owner = pid_vnr(vd->owner->pid);
 813                 } else {
 814                         info->owner = -1;
 815                 }
 816         }
 817         up_read(&card->controls_rwsem);
 818         return result;
 819 }
 820
 821 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 822                                   struct snd_ctl_elem_info __user *_info)
 823 {
 824         struct snd_ctl_elem_info info;
 825         int result;
 826
 827         if (copy_from_user(&info, _info, sizeof(info)))
 828                 return -EFAULT;
 829         snd_power_lock(ctl->card);
 830         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 831         if (result >= 0)
 832                 result = snd_ctl_elem_info(ctl, &info);
 833         snd_power_unlock(ctl->card);
 834         if (result >= 0)
 835                 if (copy_to_user(_info, &info, sizeof(info)))
 836                         return -EFAULT;
 837         return result;
 838 }
 839
 840 static int snd_ctl_elem_read(struct snd_card *card,
 841                              struct snd_ctl_elem_value *control)
 842 {
 843         struct snd_kcontrol *kctl;
 844         struct snd_kcontrol_volatile *vd;
 845         unsigned int index_offset;
 846         int result;
 847
 848         down_read(&card->controls_rwsem);
 849         kctl = snd_ctl_find_id(card, &control->id);
 850         if (kctl == NULL) {
 851                 result = -ENOENT;
 852         } else {
 853                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 854                 vd = &kctl->vd[index_offset];
 855                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 856                     kctl->get != NULL) {
 857                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 858                         result = kctl->get(kctl, control);
 859                 } else
 860                         result = -EPERM;
 861         }
 862         up_read(&card->controls_rwsem);
 863         return result;
 864 }
 865
 866 static int snd_ctl_elem_read_user(struct snd_card *card,
 867                                   struct snd_ctl_elem_value __user *_control)
 868 {
 869         struct snd_ctl_elem_value *control;
 870         int result;
 871
 872         control = memdup_user(_control, sizeof(*control));
 873         if (IS_ERR(control))
 874                 return PTR_ERR(control);
 875
 876         snd_power_lock(card);
 877         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 878         if (result >= 0)
 879                 result = snd_ctl_elem_read(card, control);
 880         snd_power_unlock(card);
 881         if (result >= 0)
 882                 if (copy_to_user(_control, control, sizeof(*control)))
 883                         result = -EFAULT;
 884         kfree(control);
 885         return result;
 886 }
 887
 888 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 889                               struct snd_ctl_elem_value *control)
 890 {
 891         struct snd_kcontrol *kctl;
 892         struct snd_kcontrol_volatile *vd;
 893         unsigned int index_offset;
 894         int result;
 895
 896         down_read(&card->controls_rwsem);
 897         kctl = snd_ctl_find_id(card, &control->id);
 898         if (kctl == NULL) {
 899                 result = -ENOENT;
 900         } else {
 901                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 902                 vd = &kctl->vd[index_offset];
 903                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 904                     kctl->put == NULL ||
 905                     (file && vd->owner && vd->owner != file)) {
 906                         result = -EPERM;
 907                 } else {
 908                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
 909                         result = kctl->put(kctl, control);
 910                 }
 911                 if (result > 0) {
 912                         struct snd_ctl_elem_id id = control->id;
 913                         up_read(&card->controls_rwsem);
 914                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
 915                         return 0;
 916                 }
 917         }
 918         up_read(&card->controls_rwsem);
 919         return result;
 920 }
 921
 922 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 923                                    struct snd_ctl_elem_value __user *_control)
 924 {
 925         struct snd_ctl_elem_value *control;
 926         struct snd_card *card;
 927         int result;
 928
 929         control = memdup_user(_control, sizeof(*control));
 930         if (IS_ERR(control))
 931                 return PTR_ERR(control);
 932
 933         card = file->card;
 934         snd_power_lock(card);
 935         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 936         if (result >= 0)
 937                 result = snd_ctl_elem_write(card, file, control);
 938         snd_power_unlock(card);
 939         if (result >= 0)
 940                 if (copy_to_user(_control, control, sizeof(*control)))
 941                         result = -EFAULT;
 942         kfree(control);
 943         return result;
 944 }
 945
 946 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 947                              struct snd_ctl_elem_id __user *_id)
 948 {
 949         struct snd_card *card = file->card;
 950         struct snd_ctl_elem_id id;
 951         struct snd_kcontrol *kctl;
 952         struct snd_kcontrol_volatile *vd;
 953         int result;
 954
 955         if (copy_from_user(&id, _id, sizeof(id)))
 956                 return -EFAULT;
 957         down_write(&card->controls_rwsem);
 958         kctl = snd_ctl_find_id(card, &id);
 959         if (kctl == NULL) {
 960                 result = -ENOENT;
 961         } else {
 962                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 963                 if (vd->owner != NULL)
 964                         result = -EBUSY;
 965                 else {
 966                         vd->owner = file;
 967                         result = 0;
 968                 }
 969         }
 970         up_write(&card->controls_rwsem);
 971         return result;
 972 }
 973
 974 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 975                                struct snd_ctl_elem_id __user *_id)
 976 {
 977         struct snd_card *card = file->card;
 978         struct snd_ctl_elem_id id;
 979         struct snd_kcontrol *kctl;
 980         struct snd_kcontrol_volatile *vd;
 981         int result;
 982
 983         if (copy_from_user(&id, _id, sizeof(id)))
 984                 return -EFAULT;
 985         down_write(&card->controls_rwsem);
 986         kctl = snd_ctl_find_id(card, &id);
 987         if (kctl == NULL) {
 988                 result = -ENOENT;
 989         } else {
 990                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 991                 if (vd->owner == NULL)
 992                         result = -EINVAL;
 993                 else if (vd->owner != file)
 994                         result = -EPERM;
 995                 else {
 996                         vd->owner = NULL;
 997                         result = 0;
 998                 }
 999         }
1000         up_write(&card->controls_rwsem);
1001         return result;
1002 }
1003
1004 struct user_element {
1005         struct snd_ctl_elem_info info;
1006         struct snd_card *card;
1007         void *elem_data;                /* element data */
1008         unsigned long elem_data_size;   /* size of element data in bytes */
1009         void *tlv_data;                 /* TLV data */
1010         unsigned long tlv_data_size;    /* TLV data size */
1011         void *priv_data;                /* private data (like strings for enumerated type) */
1012 };
1013
1014 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1015                                   struct snd_ctl_elem_info *uinfo)
1016 {
1017         struct user_element *ue = kcontrol->private_data;
1018
1019         *uinfo = ue->info;
1020         return 0;
1021 }
1022
1023 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1024                                        struct snd_ctl_elem_info *uinfo)
1025 {
1026         struct user_element *ue = kcontrol->private_data;
1027         const char *names;
1028         unsigned int item;
1029
1030         item = uinfo->value.enumerated.item;
1031
1032         *uinfo = ue->info;
1033
1034         item = min(item, uinfo->value.enumerated.items - 1);
1035         uinfo->value.enumerated.item = item;
1036
1037         names = ue->priv_data;
1038         for (; item > 0; --item)
1039                 names += strlen(names) + 1;
1040         strcpy(uinfo->value.enumerated.name, names);
1041
1042         return 0;
1043 }
1044
1045 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1046                                  struct snd_ctl_elem_value *ucontrol)
1047 {
1048         struct user_element *ue = kcontrol->private_data;
1049
1050         mutex_lock(&ue->card->user_ctl_lock);
1051         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1052         mutex_unlock(&ue->card->user_ctl_lock);
1053         return 0;
1054 }
1055
1056 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1057                                  struct snd_ctl_elem_value *ucontrol)
1058 {
1059         int change;
1060         struct user_element *ue = kcontrol->private_data;
1061
1062         mutex_lock(&ue->card->user_ctl_lock);
1063         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1064         if (change)
1065                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1066         mutex_unlock(&ue->card->user_ctl_lock);
1067         return change;
1068 }
1069
1070 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1071                                  int op_flag,
1072                                  unsigned int size,
1073                                  unsigned int __user *tlv)
1074 {
1075         struct user_element *ue = kcontrol->private_data;
1076         int change = 0;
1077         void *new_data;
1078
1079         if (op_flag > 0) {
1080                 if (size > 1024 * 128)  /* sane value */
1081                         return -EINVAL;
1082
1083                 new_data = memdup_user(tlv, size);
1084                 if (IS_ERR(new_data))
1085                         return PTR_ERR(new_data);
1086                 mutex_lock(&ue->card->user_ctl_lock);
1087                 change = ue->tlv_data_size != size;
1088                 if (!change)
1089                         change = memcmp(ue->tlv_data, new_data, size);
1090                 kfree(ue->tlv_data);
1091                 ue->tlv_data = new_data;
1092                 ue->tlv_data_size = size;
1093                 mutex_unlock(&ue->card->user_ctl_lock);
1094         } else {
1095                 int ret = 0;
1096
1097                 mutex_lock(&ue->card->user_ctl_lock);
1098                 if (!ue->tlv_data_size || !ue->tlv_data) {
1099                         ret = -ENXIO;
1100                         goto err_unlock;
1101                 }
1102                 if (size < ue->tlv_data_size) {
1103                         ret = -ENOSPC;
1104                         goto err_unlock;
1105                 }
1106                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1107                         ret = -EFAULT;
1108 err_unlock:
1109                 mutex_unlock(&ue->card->user_ctl_lock);
1110                 if (ret)
1111                         return ret;
1112         }
1113         return change;
1114 }
1115
1116 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1117 {
1118         char *names, *p;
1119         size_t buf_len, name_len;
1120         unsigned int i;
1121         const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1122
1123         if (ue->info.value.enumerated.names_length > 64 * 1024)
1124                 return -EINVAL;
1125
1126         names = memdup_user((const void __user *)user_ptrval,
1127                 ue->info.value.enumerated.names_length);
1128         if (IS_ERR(names))
1129                 return PTR_ERR(names);
1130
1131         /* check that there are enough valid names */
1132         buf_len = ue->info.value.enumerated.names_length;
1133         p = names;
1134         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1135                 name_len = strnlen(p, buf_len);
1136                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1137                         kfree(names);
1138                         return -EINVAL;
1139                 }
1140                 p += name_len + 1;
1141                 buf_len -= name_len + 1;
1142         }
1143
1144         ue->priv_data = names;
1145         ue->info.value.enumerated.names_ptr = 0;
1146
1147         return 0;
1148 }
1149
1150 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1151 {
1152         struct user_element *ue = kcontrol->private_data;
1153
1154         kfree(ue->tlv_data);
1155         kfree(ue->priv_data);
1156         kfree(ue);
1157 }
1158
1159 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1160                             struct snd_ctl_elem_info *info, int replace)
1161 {
1162         struct snd_card *card = file->card;
1163         struct snd_kcontrol kctl, *_kctl;
1164         unsigned int access;
1165         long private_size;
1166         struct user_element *ue;
1167         int idx, err;
1168
1169         if (info->count < 1)
1170                 return -EINVAL;
1171         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1172                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1173                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1174                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1175         info->id.numid = 0;
1176         memset(&kctl, 0, sizeof(kctl));
1177
1178         if (replace) {
1179                 err = snd_ctl_remove_user_ctl(file, &info->id);
1180                 if (err)
1181                         return err;
1182         }
1183
1184         if (card->user_ctl_count >= MAX_USER_CONTROLS)
1185                 return -ENOMEM;
1186
1187         memcpy(&kctl.id, &info->id, sizeof(info->id));
1188         kctl.count = info->owner ? info->owner : 1;
1189         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1190         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1191                 kctl.info = snd_ctl_elem_user_enum_info;
1192         else
1193                 kctl.info = snd_ctl_elem_user_info;
1194         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1195                 kctl.get = snd_ctl_elem_user_get;
1196         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1197                 kctl.put = snd_ctl_elem_user_put;
1198         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1199                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1200                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1201         }
1202         switch (info->type) {
1203         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1204         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1205                 private_size = sizeof(long);
1206                 if (info->count > 128)
1207                         return -EINVAL;
1208                 break;
1209         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1210                 private_size = sizeof(long long);
1211                 if (info->count > 64)
1212                         return -EINVAL;
1213                 break;
1214         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1215                 private_size = sizeof(unsigned int);
1216                 if (info->count > 128 || info->value.enumerated.items == 0)
1217                         return -EINVAL;
1218                 break;
1219         case SNDRV_CTL_ELEM_TYPE_BYTES:
1220                 private_size = sizeof(unsigned char);
1221                 if (info->count > 512)
1222                         return -EINVAL;
1223                 break;
1224         case SNDRV_CTL_ELEM_TYPE_IEC958:
1225                 private_size = sizeof(struct snd_aes_iec958);
1226                 if (info->count != 1)
1227                         return -EINVAL;
1228                 break;
1229         default:
1230                 return -EINVAL;
1231         }
1232         private_size *= info->count;
1233         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1234         if (ue == NULL)
1235                 return -ENOMEM;
1236         ue->card = card;
1237         ue->info = *info;
1238         ue->info.access = 0;
1239         ue->elem_data = (char *)ue + sizeof(*ue);
1240         ue->elem_data_size = private_size;
1241         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1242                 err = snd_ctl_elem_init_enum_names(ue);
1243                 if (err < 0) {
1244                         kfree(ue);
1245                         return err;
1246                 }
1247         }
1248         kctl.private_free = snd_ctl_elem_user_free;
1249         _kctl = snd_ctl_new(&kctl, access);
1250         if (_kctl == NULL) {
1251                 kfree(ue->priv_data);
1252                 kfree(ue);
1253                 return -ENOMEM;
1254         }
1255         _kctl->private_data = ue;
1256         for (idx = 0; idx < _kctl->count; idx++)
1257                 _kctl->vd[idx].owner = file;
1258         err = snd_ctl_add(card, _kctl);
1259         if (err < 0)
1260                 return err;
1261
1262         down_write(&card->controls_rwsem);
1263         card->user_ctl_count++;
1264         up_write(&card->controls_rwsem);
1265
1266         return 0;
1267 }
1268
1269 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1270                                  struct snd_ctl_elem_info __user *_info, int replace)
1271 {
1272         struct snd_ctl_elem_info info;
1273         if (copy_from_user(&info, _info, sizeof(info)))
1274                 return -EFAULT;
1275         return snd_ctl_elem_add(file, &info, replace);
1276 }
1277
1278 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1279                                struct snd_ctl_elem_id __user *_id)
1280 {
1281         struct snd_ctl_elem_id id;
1282
1283         if (copy_from_user(&id, _id, sizeof(id)))
1284                 return -EFAULT;
1285         return snd_ctl_remove_user_ctl(file, &id);
1286 }
1287
1288 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1289 {
1290         int subscribe;
1291         if (get_user(subscribe, ptr))
1292                 return -EFAULT;
1293         if (subscribe < 0) {
1294                 subscribe = file->subscribed;
1295                 if (put_user(subscribe, ptr))
1296                         return -EFAULT;
1297                 return 0;
1298         }
1299         if (subscribe) {
1300                 file->subscribed = 1;
1301                 return 0;
1302         } else if (file->subscribed) {
1303                 snd_ctl_empty_read_queue(file);
1304                 file->subscribed = 0;
1305         }
1306         return 0;
1307 }
1308
1309 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1310                              struct snd_ctl_tlv __user *_tlv,
1311                              int op_flag)
1312 {
1313         struct snd_card *card = file->card;
1314         struct snd_ctl_tlv tlv;
1315         struct snd_kcontrol *kctl;
1316         struct snd_kcontrol_volatile *vd;
1317         unsigned int len;
1318         int err = 0;
1319
1320         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1321                 return -EFAULT;
1322         if (tlv.length < sizeof(unsigned int) * 2)
1323                 return -EINVAL;
1324         down_read(&card->controls_rwsem);
1325         kctl = snd_ctl_find_numid(card, tlv.numid);
1326         if (kctl == NULL) {
1327                 err = -ENOENT;
1328                 goto __kctl_end;
1329         }
1330         if (kctl->tlv.p == NULL) {
1331                 err = -ENXIO;
1332                 goto __kctl_end;
1333         }
1334         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1335         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1336             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1337             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1338                 err = -ENXIO;
1339                 goto __kctl_end;
1340         }
1341         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1342                 if (vd->owner != NULL && vd->owner != file) {
1343                         err = -EPERM;
1344                         goto __kctl_end;
1345                 }
1346                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1347                 if (err > 0) {
1348                         struct snd_ctl_elem_id id = kctl->id;
1349                         up_read(&card->controls_rwsem);
1350                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1351                         return 0;
1352                 }
1353         } else {
1354                 if (op_flag) {
1355                         err = -ENXIO;
1356                         goto __kctl_end;
1357                 }
1358                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1359                 if (tlv.length < len) {
1360                         err = -ENOMEM;
1361                         goto __kctl_end;
1362                 }
1363                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1364                         err = -EFAULT;
1365         }
1366       __kctl_end:
1367         up_read(&card->controls_rwsem);
1368         return err;
1369 }
1370
1371 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1372 {
1373         struct snd_ctl_file *ctl;
1374         struct snd_card *card;
1375         struct snd_kctl_ioctl *p;
1376         void __user *argp = (void __user *)arg;
1377         int __user *ip = argp;
1378         int err;
1379
1380         ctl = file->private_data;
1381         card = ctl->card;
1382         if (snd_BUG_ON(!card))
1383                 return -ENXIO;
1384         switch (cmd) {
1385         case SNDRV_CTL_IOCTL_PVERSION:
1386                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1387         case SNDRV_CTL_IOCTL_CARD_INFO:
1388                 return snd_ctl_card_info(card, ctl, cmd, argp);
1389         case SNDRV_CTL_IOCTL_ELEM_LIST:
1390                 return snd_ctl_elem_list(card, argp);
1391         case SNDRV_CTL_IOCTL_ELEM_INFO:
1392                 return snd_ctl_elem_info_user(ctl, argp);
1393         case SNDRV_CTL_IOCTL_ELEM_READ:
1394                 return snd_ctl_elem_read_user(card, argp);
1395         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1396                 return snd_ctl_elem_write_user(ctl, argp);
1397         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1398                 return snd_ctl_elem_lock(ctl, argp);
1399         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1400                 return snd_ctl_elem_unlock(ctl, argp);
1401         case SNDRV_CTL_IOCTL_ELEM_ADD:
1402                 return snd_ctl_elem_add_user(ctl, argp, 0);
1403         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1404                 return snd_ctl_elem_add_user(ctl, argp, 1);
1405         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1406                 return snd_ctl_elem_remove(ctl, argp);
1407         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1408                 return snd_ctl_subscribe_events(ctl, ip);
1409         case SNDRV_CTL_IOCTL_TLV_READ:
1410                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1411         case SNDRV_CTL_IOCTL_TLV_WRITE:
1412                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1413         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1414                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1415         case SNDRV_CTL_IOCTL_POWER:
1416                 return -ENOPROTOOPT;
1417         case SNDRV_CTL_IOCTL_POWER_STATE:
1418 #ifdef CONFIG_PM
1419                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1420 #else
1421                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1422 #endif
1423         }
1424         down_read(&snd_ioctl_rwsem);
1425         list_for_each_entry(p, &snd_control_ioctls, list) {
1426                 err = p->fioctl(card, ctl, cmd, arg);
1427                 if (err != -ENOIOCTLCMD) {
1428                         up_read(&snd_ioctl_rwsem);
1429                         return err;
1430                 }
1431         }
1432         up_read(&snd_ioctl_rwsem);
1433         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1434         return -ENOTTY;
1435 }
1436
1437 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1438                             size_t count, loff_t * offset)
1439 {
1440         struct snd_ctl_file *ctl;
1441         int err = 0;
1442         ssize_t result = 0;
1443
1444         ctl = file->private_data;
1445         if (snd_BUG_ON(!ctl || !ctl->card))
1446                 return -ENXIO;
1447         if (!ctl->subscribed)
1448                 return -EBADFD;
1449         if (count < sizeof(struct snd_ctl_event))
1450                 return -EINVAL;
1451         spin_lock_irq(&ctl->read_lock);
1452         while (count >= sizeof(struct snd_ctl_event)) {
1453                 struct snd_ctl_event ev;
1454                 struct snd_kctl_event *kev;
1455                 while (list_empty(&ctl->events)) {
1456                         wait_queue_t wait;
1457                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1458                                 err = -EAGAIN;
1459                                 goto __end_lock;
1460                         }
1461                         init_waitqueue_entry(&wait, current);
1462                         add_wait_queue(&ctl->change_sleep, &wait);
1463                         set_current_state(TASK_INTERRUPTIBLE);
1464                         spin_unlock_irq(&ctl->read_lock);
1465                         schedule();
1466                         remove_wait_queue(&ctl->change_sleep, &wait);
1467                         if (ctl->card->shutdown)
1468                                 return -ENODEV;
1469                         if (signal_pending(current))
1470                                 return -ERESTARTSYS;
1471                         spin_lock_irq(&ctl->read_lock);
1472                 }
1473                 kev = snd_kctl_event(ctl->events.next);
1474                 ev.type = SNDRV_CTL_EVENT_ELEM;
1475                 ev.data.elem.mask = kev->mask;
1476                 ev.data.elem.id = kev->id;
1477                 list_del(&kev->list);
1478                 spin_unlock_irq(&ctl->read_lock);
1479                 kfree(kev);
1480                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1481                         err = -EFAULT;
1482                         goto __end;
1483                 }
1484                 spin_lock_irq(&ctl->read_lock);
1485                 buffer += sizeof(struct snd_ctl_event);
1486                 count -= sizeof(struct snd_ctl_event);
1487                 result += sizeof(struct snd_ctl_event);
1488         }
1489       __end_lock:
1490         spin_unlock_irq(&ctl->read_lock);
1491       __end:
1492         return result > 0 ? result : err;
1493 }
1494
1495 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1496 {
1497         unsigned int mask;
1498         struct snd_ctl_file *ctl;
1499
1500         ctl = file->private_data;
1501         if (!ctl->subscribed)
1502                 return 0;
1503         poll_wait(file, &ctl->change_sleep, wait);
1504
1505         mask = 0;
1506         if (!list_empty(&ctl->events))
1507                 mask |= POLLIN | POLLRDNORM;
1508
1509         return mask;
1510 }
1511
1512 /*
1513  * register the device-specific control-ioctls.
1514  * called from each device manager like pcm.c, hwdep.c, etc.
1515  */
1516 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1517 {
1518         struct snd_kctl_ioctl *pn;
1519
1520         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1521         if (pn == NULL)
1522                 return -ENOMEM;
1523         pn->fioctl = fcn;
1524         down_write(&snd_ioctl_rwsem);
1525         list_add_tail(&pn->list, lists);
1526         up_write(&snd_ioctl_rwsem);
1527         return 0;
1528 }
1529
1530 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1531 {
1532         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1533 }
1534
1535 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1536
1537 #ifdef CONFIG_COMPAT
1538 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1539 {
1540         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1541 }
1542
1543 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1544 #endif
1545
1546 /*
1547  * de-register the device-specific control-ioctls.
1548  */
1549 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1550                                      struct list_head *lists)
1551 {
1552         struct snd_kctl_ioctl *p;
1553
1554         if (snd_BUG_ON(!fcn))
1555                 return -EINVAL;
1556         down_write(&snd_ioctl_rwsem);
1557         list_for_each_entry(p, lists, list) {
1558                 if (p->fioctl == fcn) {
1559                         list_del(&p->list);
1560                         up_write(&snd_ioctl_rwsem);
1561                         kfree(p);
1562                         return 0;
1563                 }
1564         }
1565         up_write(&snd_ioctl_rwsem);
1566         snd_BUG();
1567         return -EINVAL;
1568 }
1569
1570 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1571 {
1572         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1573 }
1574
1575 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1576
1577 #ifdef CONFIG_COMPAT
1578 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1579 {
1580         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1581 }
1582
1583 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1584 #endif
1585
1586 static int snd_ctl_fasync(int fd, struct file * file, int on)
1587 {
1588         struct snd_ctl_file *ctl;
1589
1590         ctl = file->private_data;
1591         return fasync_helper(fd, file, on, &ctl->fasync);
1592 }
1593
1594 /*
1595  * ioctl32 compat
1596  */
1597 #ifdef CONFIG_COMPAT
1598 #include "control_compat.c"
1599 #else
1600 #define snd_ctl_ioctl_compat    NULL
1601 #endif
1602
1603 /*
1604  *  INIT PART
1605  */
1606
1607 static const struct file_operations snd_ctl_f_ops =
1608 {
1609         .owner =        THIS_MODULE,
1610         .read =         snd_ctl_read,
1611         .open =         snd_ctl_open,
1612         .release =      snd_ctl_release,
1613         .llseek =       no_llseek,
1614         .poll =         snd_ctl_poll,
1615         .unlocked_ioctl =       snd_ctl_ioctl,
1616         .compat_ioctl = snd_ctl_ioctl_compat,
1617         .fasync =       snd_ctl_fasync,
1618 };
1619
1620 /*
1621  * registration of the control device
1622  */
1623 static int snd_ctl_dev_register(struct snd_device *device)
1624 {
1625         struct snd_card *card = device->device_data;
1626         int err, cardnum;
1627         char name[16];
1628
1629         if (snd_BUG_ON(!card))
1630                 return -ENXIO;
1631         cardnum = card->number;
1632         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1633                 return -ENXIO;
1634         sprintf(name, "controlC%i", cardnum);
1635         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1636                                        &snd_ctl_f_ops, card, name)) < 0)
1637                 return err;
1638         return 0;
1639 }
1640
1641 /*
1642  * disconnection of the control device
1643  */
1644 static int snd_ctl_dev_disconnect(struct snd_device *device)
1645 {
1646         struct snd_card *card = device->device_data;
1647         struct snd_ctl_file *ctl;
1648         int err, cardnum;
1649
1650         if (snd_BUG_ON(!card))
1651                 return -ENXIO;
1652         cardnum = card->number;
1653         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1654                 return -ENXIO;
1655
1656         read_lock(&card->ctl_files_rwlock);
1657         list_for_each_entry(ctl, &card->ctl_files, list) {
1658                 wake_up(&ctl->change_sleep);
1659                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1660         }
1661         read_unlock(&card->ctl_files_rwlock);
1662
1663         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1664                                          card, -1)) < 0)
1665                 return err;
1666         return 0;
1667 }
1668
1669 /*
1670  * free all controls
1671  */
1672 static int snd_ctl_dev_free(struct snd_device *device)
1673 {
1674         struct snd_card *card = device->device_data;
1675         struct snd_kcontrol *control;
1676
1677         down_write(&card->controls_rwsem);
1678         while (!list_empty(&card->controls)) {
1679                 control = snd_kcontrol(card->controls.next);
1680                 snd_ctl_remove(card, control);
1681         }
1682         up_write(&card->controls_rwsem);
1683         return 0;
1684 }
1685
1686 /*
1687  * create control core:
1688  * called from init.c
1689  */
1690 int snd_ctl_create(struct snd_card *card)
1691 {
1692         static struct snd_device_ops ops = {
1693                 .dev_free = snd_ctl_dev_free,
1694                 .dev_register = snd_ctl_dev_register,
1695                 .dev_disconnect = snd_ctl_dev_disconnect,
1696         };
1697
1698         if (snd_BUG_ON(!card))
1699                 return -ENXIO;
1700         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1701 }
1702
1703 /*
1704  * Frequently used control callbacks/helpers
1705  */
1706 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1707                               struct snd_ctl_elem_info *uinfo)
1708 {
1709         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1710         uinfo->count = 1;
1711         uinfo->value.integer.min = 0;
1712         uinfo->value.integer.max = 1;
1713         return 0;
1714 }
1715
1716 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1717
1718 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1719                                 struct snd_ctl_elem_info *uinfo)
1720 {
1721         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1722         uinfo->count = 2;
1723         uinfo->value.integer.min = 0;
1724         uinfo->value.integer.max = 1;
1725         return 0;
1726 }
1727
1728 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1729
1730 /**
1731  * snd_ctl_enum_info - fills the info structure for an enumerated control
1732  * @info: the structure to be filled
1733  * @channels: the number of the control's channels; often one
1734  * @items: the number of control values; also the size of @names
1735  * @names: an array containing the names of all control values
1736  *
1737  * Sets all required fields in @info to their appropriate values.
1738  * If the control's accessibility is not the default (readable and writable),
1739  * the caller has to fill @info->access.
1740  *
1741  * Return: Zero.
1742  */
1743 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1744                       unsigned int items, const char *const names[])
1745 {
1746         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1747         info->count = channels;
1748         info->value.enumerated.items = items;
1749         if (info->value.enumerated.item >= items)
1750                 info->value.enumerated.item = items - 1;
1751         strlcpy(info->value.enumerated.name,
1752                 names[info->value.enumerated.item],
1753                 sizeof(info->value.enumerated.name));
1754         return 0;
1755 }
1756 EXPORT_SYMBOL(snd_ctl_enum_info);