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 <sound/driver.h>
  23 #include <linux/threads.h>
  24 #include <linux/interrupt.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
  36 struct snd_kctl_ioctl {
  37         struct list_head list;          /* list of all ioctls */
  38         snd_kctl_ioctl_func_t fioctl;
  39 };
  40
  41 static DECLARE_RWSEM(snd_ioctl_rwsem);
  42 static LIST_HEAD(snd_control_ioctls);
  43 #ifdef CONFIG_COMPAT
  44 static LIST_HEAD(snd_control_compat_ioctls);
  45 #endif
  46
  47 static int snd_ctl_open(struct inode *inode, struct file *file)
  48 {
  49         unsigned long flags;
  50         struct snd_card *card;
  51         struct snd_ctl_file *ctl;
  52         int err;
  53
  54         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  55         if (!card) {
  56                 err = -ENODEV;
  57                 goto __error1;
  58         }
  59         err = snd_card_file_add(card, file);
  60         if (err < 0) {
  61                 err = -ENODEV;
  62                 goto __error1;
  63         }
  64         if (!try_module_get(card->module)) {
  65                 err = -EFAULT;
  66                 goto __error2;
  67         }
  68         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  69         if (ctl == NULL) {
  70                 err = -ENOMEM;
  71                 goto __error;
  72         }
  73         INIT_LIST_HEAD(&ctl->events);
  74         init_waitqueue_head(&ctl->change_sleep);
  75         spin_lock_init(&ctl->read_lock);
  76         ctl->card = card;
  77         ctl->prefer_pcm_subdevice = -1;
  78         ctl->prefer_rawmidi_subdevice = -1;
  79         ctl->pid = current->pid;
  80         file->private_data = ctl;
  81         write_lock_irqsave(&card->ctl_files_rwlock, flags);
  82         list_add_tail(&ctl->list, &card->ctl_files);
  83         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  84         return 0;
  85
  86       __error:
  87         module_put(card->module);
  88       __error2:
  89         snd_card_file_remove(card, file);
  90       __error1:
  91         return err;
  92 }
  93
  94 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  95 {
  96         unsigned long flags;
  97         struct snd_kctl_event *cread;
  98
  99         spin_lock_irqsave(&ctl->read_lock, flags);
 100         while (!list_empty(&ctl->events)) {
 101                 cread = snd_kctl_event(ctl->events.next);
 102                 list_del(&cread->list);
 103                 kfree(cread);
 104         }
 105         spin_unlock_irqrestore(&ctl->read_lock, flags);
 106 }
 107
 108 static int snd_ctl_release(struct inode *inode, struct file *file)
 109 {
 110         unsigned long flags;
 111         struct snd_card *card;
 112         struct snd_ctl_file *ctl;
 113         struct snd_kcontrol *control;
 114         unsigned int idx;
 115
 116         ctl = file->private_data;
 117         fasync_helper(-1, file, 0, &ctl->fasync);
 118         file->private_data = NULL;
 119         card = ctl->card;
 120         write_lock_irqsave(&card->ctl_files_rwlock, flags);
 121         list_del(&ctl->list);
 122         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 123         down_write(&card->controls_rwsem);
 124         list_for_each_entry(control, &card->controls, list)
 125                 for (idx = 0; idx < control->count; idx++)
 126                         if (control->vd[idx].owner == ctl)
 127                                 control->vd[idx].owner = NULL;
 128         up_write(&card->controls_rwsem);
 129         snd_ctl_empty_read_queue(ctl);
 130         kfree(ctl);
 131         module_put(card->module);
 132         snd_card_file_remove(card, file);
 133         return 0;
 134 }
 135
 136 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 137                     struct snd_ctl_elem_id *id)
 138 {
 139         unsigned long flags;
 140         struct snd_ctl_file *ctl;
 141         struct snd_kctl_event *ev;
 142
 143         snd_assert(card != NULL && id != NULL, return);
 144         read_lock(&card->ctl_files_rwlock);
 145 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 146         card->mixer_oss_change_count++;
 147 #endif
 148         list_for_each_entry(ctl, &card->ctl_files, list) {
 149                 if (!ctl->subscribed)
 150                         continue;
 151                 spin_lock_irqsave(&ctl->read_lock, flags);
 152                 list_for_each_entry(ev, &ctl->events, list) {
 153                         if (ev->id.numid == id->numid) {
 154                                 ev->mask |= mask;
 155                                 goto _found;
 156                         }
 157                 }
 158                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 159                 if (ev) {
 160                         ev->id = *id;
 161                         ev->mask = mask;
 162                         list_add_tail(&ev->list, &ctl->events);
 163                 } else {
 164                         snd_printk(KERN_ERR "No memory available to allocate event\n");
 165                 }
 166         _found:
 167                 wake_up(&ctl->change_sleep);
 168                 spin_unlock_irqrestore(&ctl->read_lock, flags);
 169                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 170         }
 171         read_unlock(&card->ctl_files_rwlock);
 172 }
 173
 174 EXPORT_SYMBOL(snd_ctl_notify);
 175
 176 /**
 177  * snd_ctl_new - create a control instance from the template
 178  * @control: the control template
 179  * @access: the default control access
 180  *
 181  * Allocates a new struct snd_kcontrol instance and copies the given template
 182  * to the new instance. It does not copy volatile data (access).
 183  *
 184  * Returns the pointer of the new instance, or NULL on failure.
 185  */
 186 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 187                                         unsigned int access)
 188 {
 189         struct snd_kcontrol *kctl;
 190         unsigned int idx;
 191
 192         snd_assert(control != NULL, return NULL);
 193         snd_assert(control->count > 0, return NULL);
 194         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 195         if (kctl == NULL) {
 196                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
 197                 return NULL;
 198         }
 199         *kctl = *control;
 200         for (idx = 0; idx < kctl->count; idx++)
 201                 kctl->vd[idx].access = access;
 202         return kctl;
 203 }
 204
 205 /**
 206  * snd_ctl_new1 - create a control instance from the template
 207  * @ncontrol: the initialization record
 208  * @private_data: the private data to set
 209  *
 210  * Allocates a new struct snd_kcontrol instance and initialize from the given
 211  * template.  When the access field of ncontrol is 0, it's assumed as
 212  * READWRITE access. When the count field is 0, it's assumes as one.
 213  *
 214  * Returns the pointer of the newly generated instance, or NULL on failure.
 215  */
 216 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 217                                   void *private_data)
 218 {
 219         struct snd_kcontrol kctl;
 220         unsigned int access;
 221
 222         snd_assert(ncontrol != NULL, return NULL);
 223         snd_assert(ncontrol->info != NULL, return NULL);
 224         memset(&kctl, 0, sizeof(kctl));
 225         kctl.id.iface = ncontrol->iface;
 226         kctl.id.device = ncontrol->device;
 227         kctl.id.subdevice = ncontrol->subdevice;
 228         if (ncontrol->name)
 229                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 230         kctl.id.index = ncontrol->index;
 231         kctl.count = ncontrol->count ? ncontrol->count : 1;
 232         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 233                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 234                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 235                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
 236                                       SNDRV_CTL_ELEM_ACCESS_INDIRECT|
 237                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 238                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 239         kctl.info = ncontrol->info;
 240         kctl.get = ncontrol->get;
 241         kctl.put = ncontrol->put;
 242         kctl.tlv.p = ncontrol->tlv.p;
 243         kctl.private_value = ncontrol->private_value;
 244         kctl.private_data = private_data;
 245         return snd_ctl_new(&kctl, access);
 246 }
 247
 248 EXPORT_SYMBOL(snd_ctl_new1);
 249
 250 /**
 251  * snd_ctl_free_one - release the control instance
 252  * @kcontrol: the control instance
 253  *
 254  * Releases the control instance created via snd_ctl_new()
 255  * or snd_ctl_new1().
 256  * Don't call this after the control was added to the card.
 257  */
 258 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 259 {
 260         if (kcontrol) {
 261                 if (kcontrol->private_free)
 262                         kcontrol->private_free(kcontrol);
 263                 kfree(kcontrol);
 264         }
 265 }
 266
 267 EXPORT_SYMBOL(snd_ctl_free_one);
 268
 269 static unsigned int snd_ctl_hole_check(struct snd_card *card,
 270                                        unsigned int count)
 271 {
 272         struct snd_kcontrol *kctl;
 273
 274         list_for_each_entry(kctl, &card->controls, list) {
 275                 if ((kctl->id.numid <= card->last_numid &&
 276                      kctl->id.numid + kctl->count > card->last_numid) ||
 277                     (kctl->id.numid <= card->last_numid + count - 1 &&
 278                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
 279                         return card->last_numid = kctl->id.numid + kctl->count - 1;
 280         }
 281         return card->last_numid;
 282 }
 283
 284 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 285 {
 286         unsigned int last_numid, iter = 100000;
 287
 288         last_numid = card->last_numid;
 289         while (last_numid != snd_ctl_hole_check(card, count)) {
 290                 if (--iter == 0) {
 291                         /* this situation is very unlikely */
 292                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
 293                         return -ENOMEM;
 294                 }
 295                 last_numid = card->last_numid;
 296         }
 297         return 0;
 298 }
 299
 300 /**
 301  * snd_ctl_add - add the control instance to the card
 302  * @card: the card instance
 303  * @kcontrol: the control instance to add
 304  *
 305  * Adds the control instance created via snd_ctl_new() or
 306  * snd_ctl_new1() to the given card. Assigns also an unique
 307  * numid used for fast search.
 308  *
 309  * Returns zero if successful, or a negative error code on failure.
 310  *
 311  * It frees automatically the control which cannot be added.
 312  */
 313 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 314 {
 315         struct snd_ctl_elem_id id;
 316         unsigned int idx;
 317         int err = -EINVAL;
 318
 319         if (! kcontrol)
 320                 return err;
 321         snd_assert(card != NULL, goto error);
 322         snd_assert(kcontrol->info != NULL, goto error);
 323         id = kcontrol->id;
 324         down_write(&card->controls_rwsem);
 325         if (snd_ctl_find_id(card, &id)) {
 326                 up_write(&card->controls_rwsem);
 327                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 328                                         id.iface,
 329                                         id.device,
 330                                         id.subdevice,
 331                                         id.name,
 332                                         id.index);
 333                 err = -EBUSY;
 334                 goto error;
 335         }
 336         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 337                 up_write(&card->controls_rwsem);
 338                 err = -ENOMEM;
 339                 goto error;
 340         }
 341         list_add_tail(&kcontrol->list, &card->controls);
 342         card->controls_count += kcontrol->count;
 343         kcontrol->id.numid = card->last_numid + 1;
 344         card->last_numid += kcontrol->count;
 345         up_write(&card->controls_rwsem);
 346         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 347                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 348         return 0;
 349
 350  error:
 351         snd_ctl_free_one(kcontrol);
 352         return err;
 353 }
 354
 355 EXPORT_SYMBOL(snd_ctl_add);
 356
 357 /**
 358  * snd_ctl_remove - remove the control from the card and release it
 359  * @card: the card instance
 360  * @kcontrol: the control instance to remove
 361  *
 362  * Removes the control from the card and then releases the instance.
 363  * You don't need to call snd_ctl_free_one(). You must be in
 364  * the write lock - down_write(&card->controls_rwsem).
 365  *
 366  * Returns 0 if successful, or a negative error code on failure.
 367  */
 368 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 369 {
 370         struct snd_ctl_elem_id id;
 371         unsigned int idx;
 372
 373         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
 374         list_del(&kcontrol->list);
 375         card->controls_count -= kcontrol->count;
 376         id = kcontrol->id;
 377         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 378                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 379         snd_ctl_free_one(kcontrol);
 380         return 0;
 381 }
 382
 383 EXPORT_SYMBOL(snd_ctl_remove);
 384
 385 /**
 386  * snd_ctl_remove_id - remove the control of the given id and release it
 387  * @card: the card instance
 388  * @id: the control id to remove
 389  *
 390  * Finds the control instance with the given id, removes it from the
 391  * card list and releases it.
 392  *
 393  * Returns 0 if successful, or a negative error code on failure.
 394  */
 395 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 396 {
 397         struct snd_kcontrol *kctl;
 398         int ret;
 399
 400         down_write(&card->controls_rwsem);
 401         kctl = snd_ctl_find_id(card, id);
 402         if (kctl == NULL) {
 403                 up_write(&card->controls_rwsem);
 404                 return -ENOENT;
 405         }
 406         ret = snd_ctl_remove(card, kctl);
 407         up_write(&card->controls_rwsem);
 408         return ret;
 409 }
 410
 411 EXPORT_SYMBOL(snd_ctl_remove_id);
 412
 413 /**
 414  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 415  * @file: active control handle
 416  * @id: the control id to remove
 417  *
 418  * Finds the control instance with the given id, removes it from the
 419  * card list and releases it.
 420  *
 421  * Returns 0 if successful, or a negative error code on failure.
 422  */
 423 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 424                                       struct snd_ctl_elem_id *id)
 425 {
 426         struct snd_card *card = file->card;
 427         struct snd_kcontrol *kctl;
 428         int idx, ret;
 429
 430         down_write(&card->controls_rwsem);
 431         kctl = snd_ctl_find_id(card, id);
 432         if (kctl == NULL) {
 433                 up_write(&card->controls_rwsem);
 434                 return -ENOENT;
 435         }
 436         for (idx = 0; idx < kctl->count; idx++)
 437                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 438                         up_write(&card->controls_rwsem);
 439                         return -EBUSY;
 440                 }
 441         ret = snd_ctl_remove(card, kctl);
 442         up_write(&card->controls_rwsem);
 443         return ret;
 444 }
 445
 446 /**
 447  * snd_ctl_rename_id - replace the id of a control on the card
 448  * @card: the card instance
 449  * @src_id: the old id
 450  * @dst_id: the new id
 451  *
 452  * Finds the control with the old id from the card, and replaces the
 453  * id with the new one.
 454  *
 455  * Returns zero if successful, or a negative error code on failure.
 456  */
 457 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 458                       struct snd_ctl_elem_id *dst_id)
 459 {
 460         struct snd_kcontrol *kctl;
 461
 462         down_write(&card->controls_rwsem);
 463         kctl = snd_ctl_find_id(card, src_id);
 464         if (kctl == NULL) {
 465                 up_write(&card->controls_rwsem);
 466                 return -ENOENT;
 467         }
 468         kctl->id = *dst_id;
 469         kctl->id.numid = card->last_numid + 1;
 470         card->last_numid += kctl->count;
 471         up_write(&card->controls_rwsem);
 472         return 0;
 473 }
 474
 475 EXPORT_SYMBOL(snd_ctl_rename_id);
 476
 477 /**
 478  * snd_ctl_find_numid - find the control instance with the given number-id
 479  * @card: the card instance
 480  * @numid: the number-id to search
 481  *
 482  * Finds the control instance with the given number-id from the card.
 483  *
 484  * Returns the pointer of the instance if found, or NULL if not.
 485  *
 486  * The caller must down card->controls_rwsem before calling this function
 487  * (if the race condition can happen).
 488  */
 489 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 490 {
 491         struct snd_kcontrol *kctl;
 492
 493         snd_assert(card != NULL && numid != 0, return NULL);
 494         list_for_each_entry(kctl, &card->controls, list) {
 495                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 496                         return kctl;
 497         }
 498         return NULL;
 499 }
 500
 501 EXPORT_SYMBOL(snd_ctl_find_numid);
 502
 503 /**
 504  * snd_ctl_find_id - find the control instance with the given id
 505  * @card: the card instance
 506  * @id: the id to search
 507  *
 508  * Finds the control instance with the given id from the card.
 509  *
 510  * Returns the pointer of the instance if found, or NULL if not.
 511  *
 512  * The caller must down card->controls_rwsem before calling this function
 513  * (if the race condition can happen).
 514  */
 515 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 516                                      struct snd_ctl_elem_id *id)
 517 {
 518         struct snd_kcontrol *kctl;
 519
 520         snd_assert(card != NULL && id != NULL, return NULL);
 521         if (id->numid != 0)
 522                 return snd_ctl_find_numid(card, id->numid);
 523         list_for_each_entry(kctl, &card->controls, list) {
 524                 if (kctl->id.iface != id->iface)
 525                         continue;
 526                 if (kctl->id.device != id->device)
 527                         continue;
 528                 if (kctl->id.subdevice != id->subdevice)
 529                         continue;
 530                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 531                         continue;
 532                 if (kctl->id.index > id->index)
 533                         continue;
 534                 if (kctl->id.index + kctl->count <= id->index)
 535                         continue;
 536                 return kctl;
 537         }
 538         return NULL;
 539 }
 540
 541 EXPORT_SYMBOL(snd_ctl_find_id);
 542
 543 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 544                              unsigned int cmd, void __user *arg)
 545 {
 546         struct snd_ctl_card_info *info;
 547
 548         info = kzalloc(sizeof(*info), GFP_KERNEL);
 549         if (! info)
 550                 return -ENOMEM;
 551         down_read(&snd_ioctl_rwsem);
 552         info->card = card->number;
 553         strlcpy(info->id, card->id, sizeof(info->id));
 554         strlcpy(info->driver, card->driver, sizeof(info->driver));
 555         strlcpy(info->name, card->shortname, sizeof(info->name));
 556         strlcpy(info->longname, card->longname, sizeof(info->longname));
 557         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 558         strlcpy(info->components, card->components, sizeof(info->components));
 559         up_read(&snd_ioctl_rwsem);
 560         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 561                 kfree(info);
 562                 return -EFAULT;
 563         }
 564         kfree(info);
 565         return 0;
 566 }
 567
 568 static int snd_ctl_elem_list(struct snd_card *card,
 569                              struct snd_ctl_elem_list __user *_list)
 570 {
 571         struct list_head *plist;
 572         struct snd_ctl_elem_list list;
 573         struct snd_kcontrol *kctl;
 574         struct snd_ctl_elem_id *dst, *id;
 575         unsigned int offset, space, first, jidx;
 576
 577         if (copy_from_user(&list, _list, sizeof(list)))
 578                 return -EFAULT;
 579         offset = list.offset;
 580         space = list.space;
 581         first = 0;
 582         /* try limit maximum space */
 583         if (space > 16384)
 584                 return -ENOMEM;
 585         if (space > 0) {
 586                 /* allocate temporary buffer for atomic operation */
 587                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 588                 if (dst == NULL)
 589                         return -ENOMEM;
 590                 down_read(&card->controls_rwsem);
 591                 list.count = card->controls_count;
 592                 plist = card->controls.next;
 593                 while (plist != &card->controls) {
 594                         if (offset == 0)
 595                                 break;
 596                         kctl = snd_kcontrol(plist);
 597                         if (offset < kctl->count)
 598                                 break;
 599                         offset -= kctl->count;
 600                         plist = plist->next;
 601                 }
 602                 list.used = 0;
 603                 id = dst;
 604                 while (space > 0 && plist != &card->controls) {
 605                         kctl = snd_kcontrol(plist);
 606                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 607                                 snd_ctl_build_ioff(id, kctl, jidx);
 608                                 id++;
 609                                 space--;
 610                                 list.used++;
 611                         }
 612                         plist = plist->next;
 613                         offset = 0;
 614                 }
 615                 up_read(&card->controls_rwsem);
 616                 if (list.used > 0 &&
 617                     copy_to_user(list.pids, dst,
 618                                  list.used * sizeof(struct snd_ctl_elem_id))) {
 619                         vfree(dst);
 620                         return -EFAULT;
 621                 }
 622                 vfree(dst);
 623         } else {
 624                 down_read(&card->controls_rwsem);
 625                 list.count = card->controls_count;
 626                 up_read(&card->controls_rwsem);
 627         }
 628         if (copy_to_user(_list, &list, sizeof(list)))
 629                 return -EFAULT;
 630         return 0;
 631 }
 632
 633 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 634                              struct snd_ctl_elem_info *info)
 635 {
 636         struct snd_card *card = ctl->card;
 637         struct snd_kcontrol *kctl;
 638         struct snd_kcontrol_volatile *vd;
 639         unsigned int index_offset;
 640         int result;
 641
 642         down_read(&card->controls_rwsem);
 643         kctl = snd_ctl_find_id(card, &info->id);
 644         if (kctl == NULL) {
 645                 up_read(&card->controls_rwsem);
 646                 return -ENOENT;
 647         }
 648 #ifdef CONFIG_SND_DEBUG
 649         info->access = 0;
 650 #endif
 651         result = kctl->info(kctl, info);
 652         if (result >= 0) {
 653                 snd_assert(info->access == 0, );
 654                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
 655                 vd = &kctl->vd[index_offset];
 656                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
 657                 info->access = vd->access;
 658                 if (vd->owner) {
 659                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 660                         if (vd->owner == ctl)
 661                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 662                         info->owner = vd->owner_pid;
 663                 } else {
 664                         info->owner = -1;
 665                 }
 666         }
 667         up_read(&card->controls_rwsem);
 668         return result;
 669 }
 670
 671 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 672                                   struct snd_ctl_elem_info __user *_info)
 673 {
 674         struct snd_ctl_elem_info info;
 675         int result;
 676
 677         if (copy_from_user(&info, _info, sizeof(info)))
 678                 return -EFAULT;
 679         snd_power_lock(ctl->card);
 680         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 681         if (result >= 0)
 682                 result = snd_ctl_elem_info(ctl, &info);
 683         snd_power_unlock(ctl->card);
 684         if (result >= 0)
 685                 if (copy_to_user(_info, &info, sizeof(info)))
 686                         return -EFAULT;
 687         return result;
 688 }
 689
 690 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
 691 {
 692         struct snd_kcontrol *kctl;
 693         struct snd_kcontrol_volatile *vd;
 694         unsigned int index_offset;
 695         int result, indirect;
 696
 697         down_read(&card->controls_rwsem);
 698         kctl = snd_ctl_find_id(card, &control->id);
 699         if (kctl == NULL) {
 700                 result = -ENOENT;
 701         } else {
 702                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 703                 vd = &kctl->vd[index_offset];
 704                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 705                 if (control->indirect != indirect) {
 706                         result = -EACCES;
 707                 } else {
 708                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
 709                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 710                                 result = kctl->get(kctl, control);
 711                         } else {
 712                                 result = -EPERM;
 713                         }
 714                 }
 715         }
 716         up_read(&card->controls_rwsem);
 717         return result;
 718 }
 719
 720 static int snd_ctl_elem_read_user(struct snd_card *card,
 721                                   struct snd_ctl_elem_value __user *_control)
 722 {
 723         struct snd_ctl_elem_value *control;
 724         int result;
 725
 726         control = kmalloc(sizeof(*control), GFP_KERNEL);
 727         if (control == NULL)
 728                 return -ENOMEM;
 729         if (copy_from_user(control, _control, sizeof(*control))) {
 730                 kfree(control);
 731                 return -EFAULT;
 732         }
 733         snd_power_lock(card);
 734         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 735         if (result >= 0)
 736                 result = snd_ctl_elem_read(card, control);
 737         snd_power_unlock(card);
 738         if (result >= 0)
 739                 if (copy_to_user(_control, control, sizeof(*control)))
 740                         result = -EFAULT;
 741         kfree(control);
 742         return result;
 743 }
 744
 745 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 746                        struct snd_ctl_elem_value *control)
 747 {
 748         struct snd_kcontrol *kctl;
 749         struct snd_kcontrol_volatile *vd;
 750         unsigned int index_offset;
 751         int result, indirect;
 752
 753         down_read(&card->controls_rwsem);
 754         kctl = snd_ctl_find_id(card, &control->id);
 755         if (kctl == NULL) {
 756                 result = -ENOENT;
 757         } else {
 758                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
 759                 vd = &kctl->vd[index_offset];
 760                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
 761                 if (control->indirect != indirect) {
 762                         result = -EACCES;
 763                 } else {
 764                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 765                             kctl->put == NULL ||
 766                             (file && vd->owner != NULL && vd->owner != file)) {
 767                                 result = -EPERM;
 768                         } else {
 769                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
 770                                 result = kctl->put(kctl, control);
 771                         }
 772                         if (result > 0) {
 773                                 up_read(&card->controls_rwsem);
 774                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
 775                                 return 0;
 776                         }
 777                 }
 778         }
 779         up_read(&card->controls_rwsem);
 780         return result;
 781 }
 782
 783 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 784                                    struct snd_ctl_elem_value __user *_control)
 785 {
 786         struct snd_ctl_elem_value *control;
 787         struct snd_card *card;
 788         int result;
 789
 790         control = kmalloc(sizeof(*control), GFP_KERNEL);
 791         if (control == NULL)
 792                 return -ENOMEM;
 793         if (copy_from_user(control, _control, sizeof(*control))) {
 794                 kfree(control);
 795                 return -EFAULT;
 796         }
 797         card = file->card;
 798         snd_power_lock(card);
 799         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 800         if (result >= 0)
 801                 result = snd_ctl_elem_write(card, file, control);
 802         snd_power_unlock(card);
 803         if (result >= 0)
 804                 if (copy_to_user(_control, control, sizeof(*control)))
 805                         result = -EFAULT;
 806         kfree(control);
 807         return result;
 808 }
 809
 810 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 811                              struct snd_ctl_elem_id __user *_id)
 812 {
 813         struct snd_card *card = file->card;
 814         struct snd_ctl_elem_id id;
 815         struct snd_kcontrol *kctl;
 816         struct snd_kcontrol_volatile *vd;
 817         int result;
 818
 819         if (copy_from_user(&id, _id, sizeof(id)))
 820                 return -EFAULT;
 821         down_write(&card->controls_rwsem);
 822         kctl = snd_ctl_find_id(card, &id);
 823         if (kctl == NULL) {
 824                 result = -ENOENT;
 825         } else {
 826                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 827                 if (vd->owner != NULL)
 828                         result = -EBUSY;
 829                 else {
 830                         vd->owner = file;
 831                         vd->owner_pid = current->pid;
 832                         result = 0;
 833                 }
 834         }
 835         up_write(&card->controls_rwsem);
 836         return result;
 837 }
 838
 839 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 840                                struct snd_ctl_elem_id __user *_id)
 841 {
 842         struct snd_card *card = file->card;
 843         struct snd_ctl_elem_id id;
 844         struct snd_kcontrol *kctl;
 845         struct snd_kcontrol_volatile *vd;
 846         int result;
 847
 848         if (copy_from_user(&id, _id, sizeof(id)))
 849                 return -EFAULT;
 850         down_write(&card->controls_rwsem);
 851         kctl = snd_ctl_find_id(card, &id);
 852         if (kctl == NULL) {
 853                 result = -ENOENT;
 854         } else {
 855                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 856                 if (vd->owner == NULL)
 857                         result = -EINVAL;
 858                 else if (vd->owner != file)
 859                         result = -EPERM;
 860                 else {
 861                         vd->owner = NULL;
 862                         vd->owner_pid = 0;
 863                         result = 0;
 864                 }
 865         }
 866         up_write(&card->controls_rwsem);
 867         return result;
 868 }
 869
 870 struct user_element {
 871         struct snd_ctl_elem_info info;
 872         void *elem_data;                /* element data */
 873         unsigned long elem_data_size;   /* size of element data in bytes */
 874         void *tlv_data;                 /* TLV data */
 875         unsigned long tlv_data_size;    /* TLV data size */
 876         void *priv_data;                /* private data (like strings for enumerated type) */
 877         unsigned long priv_data_size;   /* size of private data in bytes */
 878 };
 879
 880 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 881                                   struct snd_ctl_elem_info *uinfo)
 882 {
 883         struct user_element *ue = kcontrol->private_data;
 884
 885         *uinfo = ue->info;
 886         return 0;
 887 }
 888
 889 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 890                                  struct snd_ctl_elem_value *ucontrol)
 891 {
 892         struct user_element *ue = kcontrol->private_data;
 893
 894         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 895         return 0;
 896 }
 897
 898 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 899                                  struct snd_ctl_elem_value *ucontrol)
 900 {
 901         int change;
 902         struct user_element *ue = kcontrol->private_data;
 903
 904         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 905         if (change)
 906                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 907         return change;
 908 }
 909
 910 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 911                                  int op_flag,
 912                                  unsigned int size,
 913                                  unsigned int __user *tlv)
 914 {
 915         struct user_element *ue = kcontrol->private_data;
 916         int change = 0;
 917         void *new_data;
 918
 919         if (op_flag > 0) {
 920                 if (size > 1024 * 128)  /* sane value */
 921                         return -EINVAL;
 922                 new_data = kmalloc(size, GFP_KERNEL);
 923                 if (new_data == NULL)
 924                         return -ENOMEM;
 925                 if (copy_from_user(new_data, tlv, size)) {
 926                         kfree(new_data);
 927                         return -EFAULT;
 928                 }
 929                 change = ue->tlv_data_size != size;
 930                 if (!change)
 931                         change = memcmp(ue->tlv_data, new_data, size);
 932                 kfree(ue->tlv_data);
 933                 ue->tlv_data = new_data;
 934                 ue->tlv_data_size = size;
 935         } else {
 936                 if (! ue->tlv_data_size || ! ue->tlv_data)
 937                         return -ENXIO;
 938                 if (size < ue->tlv_data_size)
 939                         return -ENOSPC;
 940                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 941                         return -EFAULT;
 942         }
 943         return change;
 944 }
 945
 946 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 947 {
 948         struct user_element *ue = kcontrol->private_data;
 949         if (ue->tlv_data)
 950                 kfree(ue->tlv_data);
 951         kfree(ue);
 952 }
 953
 954 static int snd_ctl_elem_add(struct snd_ctl_file *file,
 955                             struct snd_ctl_elem_info *info, int replace)
 956 {
 957         struct snd_card *card = file->card;
 958         struct snd_kcontrol kctl, *_kctl;
 959         unsigned int access;
 960         long private_size;
 961         struct user_element *ue;
 962         int idx, err;
 963
 964         if (card->user_ctl_count >= MAX_USER_CONTROLS)
 965                 return -ENOMEM;
 966         if (info->count > 1024)
 967                 return -EINVAL;
 968         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 969                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 970                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 971                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 972         info->id.numid = 0;
 973         memset(&kctl, 0, sizeof(kctl));
 974         down_write(&card->controls_rwsem);
 975         _kctl = snd_ctl_find_id(card, &info->id);
 976         err = 0;
 977         if (_kctl) {
 978                 if (replace)
 979                         err = snd_ctl_remove(card, _kctl);
 980                 else
 981                         err = -EBUSY;
 982         } else {
 983                 if (replace)
 984                         err = -ENOENT;
 985         }
 986         up_write(&card->controls_rwsem);
 987         if (err < 0)
 988                 return err;
 989         memcpy(&kctl.id, &info->id, sizeof(info->id));
 990         kctl.count = info->owner ? info->owner : 1;
 991         access |= SNDRV_CTL_ELEM_ACCESS_USER;
 992         kctl.info = snd_ctl_elem_user_info;
 993         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 994                 kctl.get = snd_ctl_elem_user_get;
 995         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 996                 kctl.put = snd_ctl_elem_user_put;
 997         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 998                 kctl.tlv.c = snd_ctl_elem_user_tlv;
 999                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1000         }
1001         switch (info->type) {
1002         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1003         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1004                 private_size = sizeof(long);
1005                 if (info->count > 128)
1006                         return -EINVAL;
1007                 break;
1008         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1009                 private_size = sizeof(long long);
1010                 if (info->count > 64)
1011                         return -EINVAL;
1012                 break;
1013         case SNDRV_CTL_ELEM_TYPE_BYTES:
1014                 private_size = sizeof(unsigned char);
1015                 if (info->count > 512)
1016                         return -EINVAL;
1017                 break;
1018         case SNDRV_CTL_ELEM_TYPE_IEC958:
1019                 private_size = sizeof(struct snd_aes_iec958);
1020                 if (info->count != 1)
1021                         return -EINVAL;
1022                 break;
1023         default:
1024                 return -EINVAL;
1025         }
1026         private_size *= info->count;
1027         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1028         if (ue == NULL)
1029                 return -ENOMEM;
1030         ue->info = *info;
1031         ue->info.access = 0;
1032         ue->elem_data = (char *)ue + sizeof(*ue);
1033         ue->elem_data_size = private_size;
1034         kctl.private_free = snd_ctl_elem_user_free;
1035         _kctl = snd_ctl_new(&kctl, access);
1036         if (_kctl == NULL) {
1037                 kfree(ue);
1038                 return -ENOMEM;
1039         }
1040         _kctl->private_data = ue;
1041         for (idx = 0; idx < _kctl->count; idx++)
1042                 _kctl->vd[idx].owner = file;
1043         err = snd_ctl_add(card, _kctl);
1044         if (err < 0)
1045                 return err;
1046
1047         down_write(&card->controls_rwsem);
1048         card->user_ctl_count++;
1049         up_write(&card->controls_rwsem);
1050
1051         return 0;
1052 }
1053
1054 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1055                                  struct snd_ctl_elem_info __user *_info, int replace)
1056 {
1057         struct snd_ctl_elem_info info;
1058         if (copy_from_user(&info, _info, sizeof(info)))
1059                 return -EFAULT;
1060         return snd_ctl_elem_add(file, &info, replace);
1061 }
1062
1063 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1064                                struct snd_ctl_elem_id __user *_id)
1065 {
1066         struct snd_ctl_elem_id id;
1067         int err;
1068
1069         if (copy_from_user(&id, _id, sizeof(id)))
1070                 return -EFAULT;
1071         err = snd_ctl_remove_unlocked_id(file, &id);
1072         if (! err) {
1073                 struct snd_card *card = file->card;
1074                 down_write(&card->controls_rwsem);
1075                 card->user_ctl_count--;
1076                 up_write(&card->controls_rwsem);
1077         }
1078         return err;
1079 }
1080
1081 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1082 {
1083         int subscribe;
1084         if (get_user(subscribe, ptr))
1085                 return -EFAULT;
1086         if (subscribe < 0) {
1087                 subscribe = file->subscribed;
1088                 if (put_user(subscribe, ptr))
1089                         return -EFAULT;
1090                 return 0;
1091         }
1092         if (subscribe) {
1093                 file->subscribed = 1;
1094                 return 0;
1095         } else if (file->subscribed) {
1096                 snd_ctl_empty_read_queue(file);
1097                 file->subscribed = 0;
1098         }
1099         return 0;
1100 }
1101
1102 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1103                              struct snd_ctl_tlv __user *_tlv,
1104                              int op_flag)
1105 {
1106         struct snd_card *card = file->card;
1107         struct snd_ctl_tlv tlv;
1108         struct snd_kcontrol *kctl;
1109         struct snd_kcontrol_volatile *vd;
1110         unsigned int len;
1111         int err = 0;
1112
1113         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1114                 return -EFAULT;
1115         if (tlv.length < sizeof(unsigned int) * 3)
1116                 return -EINVAL;
1117         down_read(&card->controls_rwsem);
1118         kctl = snd_ctl_find_numid(card, tlv.numid);
1119         if (kctl == NULL) {
1120                 err = -ENOENT;
1121                 goto __kctl_end;
1122         }
1123         if (kctl->tlv.p == NULL) {
1124                 err = -ENXIO;
1125                 goto __kctl_end;
1126         }
1127         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1128         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1129             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1130             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1131                 err = -ENXIO;
1132                 goto __kctl_end;
1133         }
1134         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1135                 if (file && vd->owner != NULL && vd->owner != file) {
1136                         err = -EPERM;
1137                         goto __kctl_end;
1138                 }
1139                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1140                 if (err > 0) {
1141                         up_read(&card->controls_rwsem);
1142                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1143                         return 0;
1144                 }
1145         } else {
1146                 if (op_flag) {
1147                         err = -ENXIO;
1148                         goto __kctl_end;
1149                 }
1150                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1151                 if (tlv.length < len) {
1152                         err = -ENOMEM;
1153                         goto __kctl_end;
1154                 }
1155                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1156                         err = -EFAULT;
1157         }
1158       __kctl_end:
1159         up_read(&card->controls_rwsem);
1160         return err;
1161 }
1162
1163 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1164 {
1165         struct snd_ctl_file *ctl;
1166         struct snd_card *card;
1167         struct snd_kctl_ioctl *p;
1168         void __user *argp = (void __user *)arg;
1169         int __user *ip = argp;
1170         int err;
1171
1172         ctl = file->private_data;
1173         card = ctl->card;
1174         snd_assert(card != NULL, return -ENXIO);
1175         switch (cmd) {
1176         case SNDRV_CTL_IOCTL_PVERSION:
1177                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1178         case SNDRV_CTL_IOCTL_CARD_INFO:
1179                 return snd_ctl_card_info(card, ctl, cmd, argp);
1180         case SNDRV_CTL_IOCTL_ELEM_LIST:
1181                 return snd_ctl_elem_list(card, argp);
1182         case SNDRV_CTL_IOCTL_ELEM_INFO:
1183                 return snd_ctl_elem_info_user(ctl, argp);
1184         case SNDRV_CTL_IOCTL_ELEM_READ:
1185                 return snd_ctl_elem_read_user(card, argp);
1186         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1187                 return snd_ctl_elem_write_user(ctl, argp);
1188         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1189                 return snd_ctl_elem_lock(ctl, argp);
1190         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1191                 return snd_ctl_elem_unlock(ctl, argp);
1192         case SNDRV_CTL_IOCTL_ELEM_ADD:
1193                 return snd_ctl_elem_add_user(ctl, argp, 0);
1194         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1195                 return snd_ctl_elem_add_user(ctl, argp, 1);
1196         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1197                 return snd_ctl_elem_remove(ctl, argp);
1198         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1199                 return snd_ctl_subscribe_events(ctl, ip);
1200         case SNDRV_CTL_IOCTL_TLV_READ:
1201                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1202         case SNDRV_CTL_IOCTL_TLV_WRITE:
1203                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1204         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1205                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1206         case SNDRV_CTL_IOCTL_POWER:
1207                 return -ENOPROTOOPT;
1208         case SNDRV_CTL_IOCTL_POWER_STATE:
1209 #ifdef CONFIG_PM
1210                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1211 #else
1212                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1213 #endif
1214         }
1215         down_read(&snd_ioctl_rwsem);
1216         list_for_each_entry(p, &snd_control_ioctls, list) {
1217                 err = p->fioctl(card, ctl, cmd, arg);
1218                 if (err != -ENOIOCTLCMD) {
1219                         up_read(&snd_ioctl_rwsem);
1220                         return err;
1221                 }
1222         }
1223         up_read(&snd_ioctl_rwsem);
1224         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1225         return -ENOTTY;
1226 }
1227
1228 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1229                             size_t count, loff_t * offset)
1230 {
1231         struct snd_ctl_file *ctl;
1232         int err = 0;
1233         ssize_t result = 0;
1234
1235         ctl = file->private_data;
1236         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1237         if (!ctl->subscribed)
1238                 return -EBADFD;
1239         if (count < sizeof(struct snd_ctl_event))
1240                 return -EINVAL;
1241         spin_lock_irq(&ctl->read_lock);
1242         while (count >= sizeof(struct snd_ctl_event)) {
1243                 struct snd_ctl_event ev;
1244                 struct snd_kctl_event *kev;
1245                 while (list_empty(&ctl->events)) {
1246                         wait_queue_t wait;
1247                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1248                                 err = -EAGAIN;
1249                                 goto __end_lock;
1250                         }
1251                         init_waitqueue_entry(&wait, current);
1252                         add_wait_queue(&ctl->change_sleep, &wait);
1253                         set_current_state(TASK_INTERRUPTIBLE);
1254                         spin_unlock_irq(&ctl->read_lock);
1255                         schedule();
1256                         remove_wait_queue(&ctl->change_sleep, &wait);
1257                         if (signal_pending(current))
1258                                 return -ERESTARTSYS;
1259                         spin_lock_irq(&ctl->read_lock);
1260                 }
1261                 kev = snd_kctl_event(ctl->events.next);
1262                 ev.type = SNDRV_CTL_EVENT_ELEM;
1263                 ev.data.elem.mask = kev->mask;
1264                 ev.data.elem.id = kev->id;
1265                 list_del(&kev->list);
1266                 spin_unlock_irq(&ctl->read_lock);
1267                 kfree(kev);
1268                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1269                         err = -EFAULT;
1270                         goto __end;
1271                 }
1272                 spin_lock_irq(&ctl->read_lock);
1273                 buffer += sizeof(struct snd_ctl_event);
1274                 count -= sizeof(struct snd_ctl_event);
1275                 result += sizeof(struct snd_ctl_event);
1276         }
1277       __end_lock:
1278         spin_unlock_irq(&ctl->read_lock);
1279       __end:
1280         return result > 0 ? result : err;
1281 }
1282
1283 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1284 {
1285         unsigned int mask;
1286         struct snd_ctl_file *ctl;
1287
1288         ctl = file->private_data;
1289         if (!ctl->subscribed)
1290                 return 0;
1291         poll_wait(file, &ctl->change_sleep, wait);
1292
1293         mask = 0;
1294         if (!list_empty(&ctl->events))
1295                 mask |= POLLIN | POLLRDNORM;
1296
1297         return mask;
1298 }
1299
1300 /*
1301  * register the device-specific control-ioctls.
1302  * called from each device manager like pcm.c, hwdep.c, etc.
1303  */
1304 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1305 {
1306         struct snd_kctl_ioctl *pn;
1307
1308         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1309         if (pn == NULL)
1310                 return -ENOMEM;
1311         pn->fioctl = fcn;
1312         down_write(&snd_ioctl_rwsem);
1313         list_add_tail(&pn->list, lists);
1314         up_write(&snd_ioctl_rwsem);
1315         return 0;
1316 }
1317
1318 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1319 {
1320         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1321 }
1322
1323 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1324
1325 #ifdef CONFIG_COMPAT
1326 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1327 {
1328         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1329 }
1330
1331 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1332 #endif
1333
1334 /*
1335  * de-register the device-specific control-ioctls.
1336  */
1337 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1338                                      struct list_head *lists)
1339 {
1340         struct snd_kctl_ioctl *p;
1341
1342         snd_assert(fcn != NULL, return -EINVAL);
1343         down_write(&snd_ioctl_rwsem);
1344         list_for_each_entry(p, lists, list) {
1345                 if (p->fioctl == fcn) {
1346                         list_del(&p->list);
1347                         up_write(&snd_ioctl_rwsem);
1348                         kfree(p);
1349                         return 0;
1350                 }
1351         }
1352         up_write(&snd_ioctl_rwsem);
1353         snd_BUG();
1354         return -EINVAL;
1355 }
1356
1357 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1358 {
1359         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1360 }
1361
1362 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1363
1364 #ifdef CONFIG_COMPAT
1365 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1366 {
1367         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1368 }
1369
1370 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1371 #endif
1372
1373 static int snd_ctl_fasync(int fd, struct file * file, int on)
1374 {
1375         struct snd_ctl_file *ctl;
1376         int err;
1377         ctl = file->private_data;
1378         err = fasync_helper(fd, file, on, &ctl->fasync);
1379         if (err < 0)
1380                 return err;
1381         return 0;
1382 }
1383
1384 /*
1385  * ioctl32 compat
1386  */
1387 #ifdef CONFIG_COMPAT
1388 #include "control_compat.c"
1389 #else
1390 #define snd_ctl_ioctl_compat    NULL
1391 #endif
1392
1393 /*
1394  *  INIT PART
1395  */
1396
1397 static const struct file_operations snd_ctl_f_ops =
1398 {
1399         .owner =        THIS_MODULE,
1400         .read =         snd_ctl_read,
1401         .open =         snd_ctl_open,
1402         .release =      snd_ctl_release,
1403         .poll =         snd_ctl_poll,
1404         .unlocked_ioctl =       snd_ctl_ioctl,
1405         .compat_ioctl = snd_ctl_ioctl_compat,
1406         .fasync =       snd_ctl_fasync,
1407 };
1408
1409 /*
1410  * registration of the control device
1411  */
1412 static int snd_ctl_dev_register(struct snd_device *device)
1413 {
1414         struct snd_card *card = device->device_data;
1415         int err, cardnum;
1416         char name[16];
1417
1418         snd_assert(card != NULL, return -ENXIO);
1419         cardnum = card->number;
1420         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1421         sprintf(name, "controlC%i", cardnum);
1422         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1423                                        &snd_ctl_f_ops, card, name)) < 0)
1424                 return err;
1425         return 0;
1426 }
1427
1428 /*
1429  * disconnection of the control device
1430  */
1431 static int snd_ctl_dev_disconnect(struct snd_device *device)
1432 {
1433         struct snd_card *card = device->device_data;
1434         struct snd_ctl_file *ctl;
1435         int err, cardnum;
1436
1437         snd_assert(card != NULL, return -ENXIO);
1438         cardnum = card->number;
1439         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1440
1441         down_read(&card->controls_rwsem);
1442         list_for_each_entry(ctl, &card->ctl_files, list) {
1443                 wake_up(&ctl->change_sleep);
1444                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1445         }
1446         up_read(&card->controls_rwsem);
1447
1448         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1449                                          card, -1)) < 0)
1450                 return err;
1451         return 0;
1452 }
1453
1454 /*
1455  * free all controls
1456  */
1457 static int snd_ctl_dev_free(struct snd_device *device)
1458 {
1459         struct snd_card *card = device->device_data;
1460         struct snd_kcontrol *control;
1461
1462         down_write(&card->controls_rwsem);
1463         while (!list_empty(&card->controls)) {
1464                 control = snd_kcontrol(card->controls.next);
1465                 snd_ctl_remove(card, control);
1466         }
1467         up_write(&card->controls_rwsem);
1468         return 0;
1469 }
1470
1471 /*
1472  * create control core:
1473  * called from init.c
1474  */
1475 int snd_ctl_create(struct snd_card *card)
1476 {
1477         static struct snd_device_ops ops = {
1478                 .dev_free = snd_ctl_dev_free,
1479                 .dev_register = snd_ctl_dev_register,
1480                 .dev_disconnect = snd_ctl_dev_disconnect,
1481         };
1482
1483         snd_assert(card != NULL, return -ENXIO);
1484         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1485 }
1486
1487 /*
1488  * Frequently used control callbacks
1489  */
1490 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1491                               struct snd_ctl_elem_info *uinfo)
1492 {
1493         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1494         uinfo->count = 1;
1495         uinfo->value.integer.min = 0;
1496         uinfo->value.integer.max = 1;
1497         return 0;
1498 }
1499
1500 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1501
1502 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1503                                 struct snd_ctl_elem_info *uinfo)
1504 {
1505         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1506         uinfo->count = 2;
1507         uinfo->value.integer.min = 0;
1508         uinfo->value.integer.max = 1;
1509         return 0;
1510 }
1511
1512 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);