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 /**
 145  * snd_ctl_notify - Send notification to user-space for a control change
 146  * @card: the card to send notification
 147  * @mask: the event mask, SNDRV_CTL_EVENT_*
 148  * @id: the ctl element id to send notification
 149  *
 150  * This function adds an event record with the given id and mask, appends
 151  * to the list and wakes up the user-space for notification.  This can be
 152  * called in the atomic context.
 153  */
 154 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 155                     struct snd_ctl_elem_id *id)
 156 {
 157         unsigned long flags;
 158         struct snd_ctl_file *ctl;
 159         struct snd_kctl_event *ev;
 160
 161         if (snd_BUG_ON(!card || !id))
 162                 return;
 163         read_lock(&card->ctl_files_rwlock);
 164 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
 165         card->mixer_oss_change_count++;
 166 #endif
 167         list_for_each_entry(ctl, &card->ctl_files, list) {
 168                 if (!ctl->subscribed)
 169                         continue;
 170                 spin_lock_irqsave(&ctl->read_lock, flags);
 171                 list_for_each_entry(ev, &ctl->events, list) {
 172                         if (ev->id.numid == id->numid) {
 173                                 ev->mask |= mask;
 174                                 goto _found;
 175                         }
 176                 }
 177                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 178                 if (ev) {
 179                         ev->id = *id;
 180                         ev->mask = mask;
 181                         list_add_tail(&ev->list, &ctl->events);
 182                 } else {
 183                         dev_err(card->dev, "No memory available to allocate event\n");
 184                 }
 185         _found:
 186                 wake_up(&ctl->change_sleep);
 187                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 188                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 189         }
 190         read_unlock(&card->ctl_files_rwlock);
 191 }
 192 EXPORT_SYMBOL(snd_ctl_notify);
 193
 194 /**
 195  * snd_ctl_new - create a control instance from the template
 196  * @control: the control template
 197  * @access: the default control access
 198  *
 199  * Allocates a new struct snd_kcontrol instance and copies the given template
 200  * to the new instance. It does not copy volatile data (access).
 201  *
 202  * Return: The pointer of the new instance, or %NULL on failure.
 203  */
 204 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 205                                         unsigned int access)
 206 {
 207         struct snd_kcontrol *kctl;
 208         unsigned int idx;
 209
 210         if (snd_BUG_ON(!control || !control->count))
 211                 return NULL;
 212
 213         if (control->count > MAX_CONTROL_COUNT)
 214                 return NULL;
 215
 216         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 217         if (kctl == NULL) {
 218                 pr_err("ALSA: Cannot allocate control instance\n");
 219                 return NULL;
 220         }
 221         *kctl = *control;
 222         for (idx = 0; idx < kctl->count; idx++)
 223                 kctl->vd[idx].access = access;
 224         return kctl;
 225 }
 226
 227 /**
 228  * snd_ctl_new1 - create a control instance from the template
 229  * @ncontrol: the initialization record
 230  * @private_data: the private data to set
 231  *
 232  * Allocates a new struct snd_kcontrol instance and initialize from the given
 233  * template.  When the access field of ncontrol is 0, it's assumed as
 234  * READWRITE access. When the count field is 0, it's assumes as one.
 235  *
 236  * Return: The pointer of the newly generated instance, or %NULL on failure.
 237  */
 238 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 239                                   void *private_data)
 240 {
 241         struct snd_kcontrol kctl;
 242         unsigned int access;
 243
 244         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 245                 return NULL;
 246         memset(&kctl, 0, sizeof(kctl));
 247         kctl.id.iface = ncontrol->iface;
 248         kctl.id.device = ncontrol->device;
 249         kctl.id.subdevice = ncontrol->subdevice;
 250         if (ncontrol->name) {
 251                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 252                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
 253                         pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
 254                                 ncontrol->name, kctl.id.name);
 255         }
 256         kctl.id.index = ncontrol->index;
 257         kctl.count = ncontrol->count ? ncontrol->count : 1;
 258         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 259                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 260                                       SNDRV_CTL_ELEM_ACCESS_VOLATILE|
 261                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 262                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 263                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 264                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 265         kctl.info = ncontrol->info;
 266         kctl.get = ncontrol->get;
 267         kctl.put = ncontrol->put;
 268         kctl.tlv.p = ncontrol->tlv.p;
 269         kctl.private_value = ncontrol->private_value;
 270         kctl.private_data = private_data;
 271         return snd_ctl_new(&kctl, access);
 272 }
 273 EXPORT_SYMBOL(snd_ctl_new1);
 274
 275 /**
 276  * snd_ctl_free_one - release the control instance
 277  * @kcontrol: the control instance
 278  *
 279  * Releases the control instance created via snd_ctl_new()
 280  * or snd_ctl_new1().
 281  * Don't call this after the control was added to the card.
 282  */
 283 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 284 {
 285         if (kcontrol) {
 286                 if (kcontrol->private_free)
 287                         kcontrol->private_free(kcontrol);
 288                 kfree(kcontrol);
 289         }
 290 }
 291 EXPORT_SYMBOL(snd_ctl_free_one);
 292
 293 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 294                                           unsigned int count)
 295 {
 296         struct snd_kcontrol *kctl;
 297
 298         /* Make sure that the ids assigned to the control do not wrap around */
 299         if (card->last_numid >= UINT_MAX - count)
 300                 card->last_numid = 0;
 301
 302         list_for_each_entry(kctl, &card->controls, list) {
 303                 if (kctl->id.numid < card->last_numid + 1 + count &&
 304                     kctl->id.numid + kctl->count > card->last_numid + 1) {
 305                         card->last_numid = kctl->id.numid + kctl->count - 1;
 306                         return true;
 307                 }
 308         }
 309         return false;
 310 }
 311
 312 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 313 {
 314         unsigned int iter = 100000;
 315
 316         while (snd_ctl_remove_numid_conflict(card, count)) {
 317                 if (--iter == 0) {
 318                         /* this situation is very unlikely */
 319                         dev_err(card->dev, "unable to allocate new control numid\n");
 320                         return -ENOMEM;
 321                 }
 322         }
 323         return 0;
 324 }
 325
 326 /**
 327  * snd_ctl_add - add the control instance to the card
 328  * @card: the card instance
 329  * @kcontrol: the control instance to add
 330  *
 331  * Adds the control instance created via snd_ctl_new() or
 332  * snd_ctl_new1() to the given card. Assigns also an unique
 333  * numid used for fast search.
 334  *
 335  * It frees automatically the control which cannot be added.
 336  *
 337  * Return: Zero if successful, or a negative error code on failure.
 338  *
 339  */
 340 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 341 {
 342         struct snd_ctl_elem_id id;
 343         unsigned int idx;
 344         unsigned int count;
 345         int err = -EINVAL;
 346
 347         if (! kcontrol)
 348                 return err;
 349         if (snd_BUG_ON(!card || !kcontrol->info))
 350                 goto error;
 351         id = kcontrol->id;
 352         if (id.index > UINT_MAX - kcontrol->count)
 353                 goto error;
 354
 355         down_write(&card->controls_rwsem);
 356         if (snd_ctl_find_id(card, &id)) {
 357                 up_write(&card->controls_rwsem);
 358                 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
 359                                         id.iface,
 360                                         id.device,
 361                                         id.subdevice,
 362                                         id.name,
 363                                         id.index);
 364                 err = -EBUSY;
 365                 goto error;
 366         }
 367         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 368                 up_write(&card->controls_rwsem);
 369                 err = -ENOMEM;
 370                 goto error;
 371         }
 372         list_add_tail(&kcontrol->list, &card->controls);
 373         card->controls_count += kcontrol->count;
 374         kcontrol->id.numid = card->last_numid + 1;
 375         card->last_numid += kcontrol->count;
 376         count = kcontrol->count;
 377         up_write(&card->controls_rwsem);
 378         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 379                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 380         return 0;
 381
 382  error:
 383         snd_ctl_free_one(kcontrol);
 384         return err;
 385 }
 386 EXPORT_SYMBOL(snd_ctl_add);
 387
 388 /**
 389  * snd_ctl_replace - replace the control instance of the card
 390  * @card: the card instance
 391  * @kcontrol: the control instance to replace
 392  * @add_on_replace: add the control if not already added
 393  *
 394  * Replaces the given control.  If the given control does not exist
 395  * and the add_on_replace flag is set, the control is added.  If the
 396  * control exists, it is destroyed first.
 397  *
 398  * It frees automatically the control which cannot be added or replaced.
 399  *
 400  * Return: Zero if successful, or a negative error code on failure.
 401  */
 402 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 403                     bool add_on_replace)
 404 {
 405         struct snd_ctl_elem_id id;
 406         unsigned int count;
 407         unsigned int idx;
 408         struct snd_kcontrol *old;
 409         int ret;
 410
 411         if (!kcontrol)
 412                 return -EINVAL;
 413         if (snd_BUG_ON(!card || !kcontrol->info)) {
 414                 ret = -EINVAL;
 415                 goto error;
 416         }
 417         id = kcontrol->id;
 418         down_write(&card->controls_rwsem);
 419         old = snd_ctl_find_id(card, &id);
 420         if (!old) {
 421                 if (add_on_replace)
 422                         goto add;
 423                 up_write(&card->controls_rwsem);
 424                 ret = -EINVAL;
 425                 goto error;
 426         }
 427         ret = snd_ctl_remove(card, old);
 428         if (ret < 0) {
 429                 up_write(&card->controls_rwsem);
 430                 goto error;
 431         }
 432 add:
 433         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 434                 up_write(&card->controls_rwsem);
 435                 ret = -ENOMEM;
 436                 goto error;
 437         }
 438         list_add_tail(&kcontrol->list, &card->controls);
 439         card->controls_count += kcontrol->count;
 440         kcontrol->id.numid = card->last_numid + 1;
 441         card->last_numid += kcontrol->count;
 442         count = kcontrol->count;
 443         up_write(&card->controls_rwsem);
 444         for (idx = 0; idx < count; idx++, id.index++, id.numid++)
 445                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 446         return 0;
 447
 448 error:
 449         snd_ctl_free_one(kcontrol);
 450         return ret;
 451 }
 452 EXPORT_SYMBOL(snd_ctl_replace);
 453
 454 /**
 455  * snd_ctl_remove - remove the control from the card and release it
 456  * @card: the card instance
 457  * @kcontrol: the control instance to remove
 458  *
 459  * Removes the control from the card and then releases the instance.
 460  * You don't need to call snd_ctl_free_one(). You must be in
 461  * the write lock - down_write(&card->controls_rwsem).
 462  *
 463  * Return: 0 if successful, or a negative error code on failure.
 464  */
 465 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 466 {
 467         struct snd_ctl_elem_id id;
 468         unsigned int idx;
 469
 470         if (snd_BUG_ON(!card || !kcontrol))
 471                 return -EINVAL;
 472         list_del(&kcontrol->list);
 473         card->controls_count -= kcontrol->count;
 474         id = kcontrol->id;
 475         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 476                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 477         snd_ctl_free_one(kcontrol);
 478         return 0;
 479 }
 480 EXPORT_SYMBOL(snd_ctl_remove);
 481
 482 /**
 483  * snd_ctl_remove_id - remove the control of the given id and release it
 484  * @card: the card instance
 485  * @id: the control id to remove
 486  *
 487  * Finds the control instance with the given id, removes it from the
 488  * card list and releases it.
 489  *
 490  * Return: 0 if successful, or a negative error code on failure.
 491  */
 492 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 493 {
 494         struct snd_kcontrol *kctl;
 495         int ret;
 496
 497         down_write(&card->controls_rwsem);
 498         kctl = snd_ctl_find_id(card, id);
 499         if (kctl == NULL) {
 500                 up_write(&card->controls_rwsem);
 501                 return -ENOENT;
 502         }
 503         ret = snd_ctl_remove(card, kctl);
 504         up_write(&card->controls_rwsem);
 505         return ret;
 506 }
 507 EXPORT_SYMBOL(snd_ctl_remove_id);
 508
 509 /**
 510  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 511  * @file: active control handle
 512  * @id: the control id to remove
 513  *
 514  * Finds the control instance with the given id, removes it from the
 515  * card list and releases it.
 516  *
 517  * Return: 0 if successful, or a negative error code on failure.
 518  */
 519 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 520                                    struct snd_ctl_elem_id *id)
 521 {
 522         struct snd_card *card = file->card;
 523         struct snd_kcontrol *kctl;
 524         int idx, ret;
 525
 526         down_write(&card->controls_rwsem);
 527         kctl = snd_ctl_find_id(card, id);
 528         if (kctl == NULL) {
 529                 ret = -ENOENT;
 530                 goto error;
 531         }
 532         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 533                 ret = -EINVAL;
 534                 goto error;
 535         }
 536         for (idx = 0; idx < kctl->count; idx++)
 537                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 538                         ret = -EBUSY;
 539                         goto error;
 540                 }
 541         ret = snd_ctl_remove(card, kctl);
 542         if (ret < 0)
 543                 goto error;
 544         card->user_ctl_count--;
 545 error:
 546         up_write(&card->controls_rwsem);
 547         return ret;
 548 }
 549
 550 /**
 551  * snd_ctl_activate_id - activate/inactivate the control of the given id
 552  * @card: the card instance
 553  * @id: the control id to activate/inactivate
 554  * @active: non-zero to activate
 555  *
 556  * Finds the control instance with the given id, and activate or
 557  * inactivate the control together with notification, if changed.
 558  *
 559  * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
 560  */
 561 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 562                         int active)
 563 {
 564         struct snd_kcontrol *kctl;
 565         struct snd_kcontrol_volatile *vd;
 566         unsigned int index_offset;
 567         int ret;
 568
 569         down_write(&card->controls_rwsem);
 570         kctl = snd_ctl_find_id(card, id);
 571         if (kctl == NULL) {
 572                 ret = -ENOENT;
 573                 goto unlock;
 574         }
 575         index_offset = snd_ctl_get_ioff(kctl, id);
 576         vd = &kctl->vd[index_offset];
 577         ret = 0;
 578         if (active) {
 579                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 580                         goto unlock;
 581                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 582         } else {
 583                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 584                         goto unlock;
 585                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 586         }
 587         ret = 1;
 588  unlock:
 589         up_write(&card->controls_rwsem);
 590         if (ret > 0)
 591                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 592         return ret;
 593 }
 594 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 595
 596 /**
 597  * snd_ctl_rename_id - replace the id of a control on the card
 598  * @card: the card instance
 599  * @src_id: the old id
 600  * @dst_id: the new id
 601  *
 602  * Finds the control with the old id from the card, and replaces the
 603  * id with the new one.
 604  *
 605  * Return: Zero if successful, or a negative error code on failure.
 606  */
 607 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 608                       struct snd_ctl_elem_id *dst_id)
 609 {
 610         struct snd_kcontrol *kctl;
 611
 612         down_write(&card->controls_rwsem);
 613         kctl = snd_ctl_find_id(card, src_id);
 614         if (kctl == NULL) {
 615                 up_write(&card->controls_rwsem);
 616                 return -ENOENT;
 617         }
 618         kctl->id = *dst_id;
 619         kctl->id.numid = card->last_numid + 1;
 620         card->last_numid += kctl->count;
 621         up_write(&card->controls_rwsem);
 622         return 0;
 623 }
 624 EXPORT_SYMBOL(snd_ctl_rename_id);
 625
 626 /**
 627  * snd_ctl_find_numid - find the control instance with the given number-id
 628  * @card: the card instance
 629  * @numid: the number-id to search
 630  *
 631  * Finds the control instance with the given number-id from the card.
 632  *
 633  * The caller must down card->controls_rwsem before calling this function
 634  * (if the race condition can happen).
 635  *
 636  * Return: The pointer of the instance if found, or %NULL if not.
 637  *
 638  */
 639 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 640 {
 641         struct snd_kcontrol *kctl;
 642
 643         if (snd_BUG_ON(!card || !numid))
 644                 return NULL;
 645         list_for_each_entry(kctl, &card->controls, list) {
 646                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 647                         return kctl;
 648         }
 649         return NULL;
 650 }
 651 EXPORT_SYMBOL(snd_ctl_find_numid);
 652
 653 /**
 654  * snd_ctl_find_id - find the control instance with the given id
 655  * @card: the card instance
 656  * @id: the id to search
 657  *
 658  * Finds the control instance with the given id from the card.
 659  *
 660  * The caller must down card->controls_rwsem before calling this function
 661  * (if the race condition can happen).
 662  *
 663  * Return: The pointer of the instance if found, or %NULL if not.
 664  *
 665  */
 666 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 667                                      struct snd_ctl_elem_id *id)
 668 {
 669         struct snd_kcontrol *kctl;
 670
 671         if (snd_BUG_ON(!card || !id))
 672                 return NULL;
 673         if (id->numid != 0)
 674                 return snd_ctl_find_numid(card, id->numid);
 675         list_for_each_entry(kctl, &card->controls, list) {
 676                 if (kctl->id.iface != id->iface)
 677                         continue;
 678                 if (kctl->id.device != id->device)
 679                         continue;
 680                 if (kctl->id.subdevice != id->subdevice)
 681                         continue;
 682                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 683                         continue;
 684                 if (kctl->id.index > id->index)
 685                         continue;
 686                 if (kctl->id.index + kctl->count <= id->index)
 687                         continue;
 688                 return kctl;
 689         }
 690         return NULL;
 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, SNDRV_CTL_TLV_OP_READ);
1411         case SNDRV_CTL_IOCTL_TLV_WRITE:
1412                 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1413         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1414                 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
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         dev_dbg(card->dev, "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 /**
1531  * snd_ctl_register_ioctl - register the device-specific control-ioctls
1532  * @fcn: ioctl callback function
1533  *
1534  * called from each device manager like pcm.c, hwdep.c, etc.
1535  */
1536 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1537 {
1538         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1539 }
1540 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1541
1542 #ifdef CONFIG_COMPAT
1543 /**
1544  * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1545  * control-ioctls
1546  * @fcn: ioctl callback function
1547  */
1548 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1549 {
1550         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1551 }
1552 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1553 #endif
1554
1555 /*
1556  * de-register the device-specific control-ioctls.
1557  */
1558 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1559                                      struct list_head *lists)
1560 {
1561         struct snd_kctl_ioctl *p;
1562
1563         if (snd_BUG_ON(!fcn))
1564                 return -EINVAL;
1565         down_write(&snd_ioctl_rwsem);
1566         list_for_each_entry(p, lists, list) {
1567                 if (p->fioctl == fcn) {
1568                         list_del(&p->list);
1569                         up_write(&snd_ioctl_rwsem);
1570                         kfree(p);
1571                         return 0;
1572                 }
1573         }
1574         up_write(&snd_ioctl_rwsem);
1575         snd_BUG();
1576         return -EINVAL;
1577 }
1578
1579 /**
1580  * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1581  * @fcn: ioctl callback function to unregister
1582  */
1583 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1584 {
1585         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1586 }
1587 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1588
1589 #ifdef CONFIG_COMPAT
1590 /**
1591  * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1592  * control-ioctls
1593  * @fcn: ioctl callback function to unregister
1594  */
1595 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1596 {
1597         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1598 }
1599 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1600 #endif
1601
1602 static int snd_ctl_fasync(int fd, struct file * file, int on)
1603 {
1604         struct snd_ctl_file *ctl;
1605
1606         ctl = file->private_data;
1607         return fasync_helper(fd, file, on, &ctl->fasync);
1608 }
1609
1610 /*
1611  * ioctl32 compat
1612  */
1613 #ifdef CONFIG_COMPAT
1614 #include "control_compat.c"
1615 #else
1616 #define snd_ctl_ioctl_compat    NULL
1617 #endif
1618
1619 /*
1620  *  INIT PART
1621  */
1622
1623 static const struct file_operations snd_ctl_f_ops =
1624 {
1625         .owner =        THIS_MODULE,
1626         .read =         snd_ctl_read,
1627         .open =         snd_ctl_open,
1628         .release =      snd_ctl_release,
1629         .llseek =       no_llseek,
1630         .poll =         snd_ctl_poll,
1631         .unlocked_ioctl =       snd_ctl_ioctl,
1632         .compat_ioctl = snd_ctl_ioctl_compat,
1633         .fasync =       snd_ctl_fasync,
1634 };
1635
1636 /*
1637  * registration of the control device
1638  */
1639 static int snd_ctl_dev_register(struct snd_device *device)
1640 {
1641         struct snd_card *card = device->device_data;
1642         int err, cardnum;
1643         char name[16];
1644
1645         if (snd_BUG_ON(!card))
1646                 return -ENXIO;
1647         cardnum = card->number;
1648         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1649                 return -ENXIO;
1650         sprintf(name, "controlC%i", cardnum);
1651         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1652                                        &snd_ctl_f_ops, card, name)) < 0)
1653                 return err;
1654         return 0;
1655 }
1656
1657 /*
1658  * disconnection of the control device
1659  */
1660 static int snd_ctl_dev_disconnect(struct snd_device *device)
1661 {
1662         struct snd_card *card = device->device_data;
1663         struct snd_ctl_file *ctl;
1664         int err, cardnum;
1665
1666         if (snd_BUG_ON(!card))
1667                 return -ENXIO;
1668         cardnum = card->number;
1669         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1670                 return -ENXIO;
1671
1672         read_lock(&card->ctl_files_rwlock);
1673         list_for_each_entry(ctl, &card->ctl_files, list) {
1674                 wake_up(&ctl->change_sleep);
1675                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1676         }
1677         read_unlock(&card->ctl_files_rwlock);
1678
1679         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1680                                          card, -1)) < 0)
1681                 return err;
1682         return 0;
1683 }
1684
1685 /*
1686  * free all controls
1687  */
1688 static int snd_ctl_dev_free(struct snd_device *device)
1689 {
1690         struct snd_card *card = device->device_data;
1691         struct snd_kcontrol *control;
1692
1693         down_write(&card->controls_rwsem);
1694         while (!list_empty(&card->controls)) {
1695                 control = snd_kcontrol(card->controls.next);
1696                 snd_ctl_remove(card, control);
1697         }
1698         up_write(&card->controls_rwsem);
1699         return 0;
1700 }
1701
1702 /*
1703  * create control core:
1704  * called from init.c
1705  */
1706 int snd_ctl_create(struct snd_card *card)
1707 {
1708         static struct snd_device_ops ops = {
1709                 .dev_free = snd_ctl_dev_free,
1710                 .dev_register = snd_ctl_dev_register,
1711                 .dev_disconnect = snd_ctl_dev_disconnect,
1712         };
1713
1714         if (snd_BUG_ON(!card))
1715                 return -ENXIO;
1716         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1717 }
1718
1719 /*
1720  * Frequently used control callbacks/helpers
1721  */
1722
1723 /**
1724  * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1725  * callback with a mono channel
1726  * @kcontrol: the kcontrol instance
1727  * @uinfo: info to store
1728  *
1729  * This is a function that can be used as info callback for a standard
1730  * boolean control with a single mono channel.
1731  */
1732 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1733                               struct snd_ctl_elem_info *uinfo)
1734 {
1735         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1736         uinfo->count = 1;
1737         uinfo->value.integer.min = 0;
1738         uinfo->value.integer.max = 1;
1739         return 0;
1740 }
1741 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1742
1743 /**
1744  * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1745  * callback with stereo two channels
1746  * @kcontrol: the kcontrol instance
1747  * @uinfo: info to store
1748  *
1749  * This is a function that can be used as info callback for a standard
1750  * boolean control with stereo two channels.
1751  */
1752 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1753                                 struct snd_ctl_elem_info *uinfo)
1754 {
1755         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1756         uinfo->count = 2;
1757         uinfo->value.integer.min = 0;
1758         uinfo->value.integer.max = 1;
1759         return 0;
1760 }
1761 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1762
1763 /**
1764  * snd_ctl_enum_info - fills the info structure for an enumerated control
1765  * @info: the structure to be filled
1766  * @channels: the number of the control's channels; often one
1767  * @items: the number of control values; also the size of @names
1768  * @names: an array containing the names of all control values
1769  *
1770  * Sets all required fields in @info to their appropriate values.
1771  * If the control's accessibility is not the default (readable and writable),
1772  * the caller has to fill @info->access.
1773  *
1774  * Return: Zero.
1775  */
1776 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1777                       unsigned int items, const char *const names[])
1778 {
1779         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1780         info->count = channels;
1781         info->value.enumerated.items = items;
1782         if (!items)
1783                 return 0;
1784         if (info->value.enumerated.item >= items)
1785                 info->value.enumerated.item = items - 1;
1786         WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1787              "ALSA: too long item name '%s'\n",
1788              names[info->value.enumerated.item]);
1789         strlcpy(info->value.enumerated.name,
1790                 names[info->value.enumerated.item],
1791                 sizeof(info->value.enumerated.name));
1792         return 0;
1793 }
1794 EXPORT_SYMBOL(snd_ctl_enum_info);