linux/sound/core/control.c
<<
>>
Prefs
   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
  37struct snd_kctl_ioctl {
  38        struct list_head list;          /* list of all ioctls */
  39        snd_kctl_ioctl_func_t fioctl;
  40};
  41
  42static DECLARE_RWSEM(snd_ioctl_rwsem);
  43static LIST_HEAD(snd_control_ioctls);
  44#ifdef CONFIG_COMPAT
  45static LIST_HEAD(snd_control_compat_ioctls);
  46#endif
  47
  48static 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        return 0;
  90
  91      __error:
  92        module_put(card->module);
  93      __error2:
  94        snd_card_file_remove(card, file);
  95      __error1:
  96        return err;
  97}
  98
  99static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
 100{
 101        unsigned long flags;
 102        struct snd_kctl_event *cread;
 103        
 104        spin_lock_irqsave(&ctl->read_lock, flags);
 105        while (!list_empty(&ctl->events)) {
 106                cread = snd_kctl_event(ctl->events.next);
 107                list_del(&cread->list);
 108                kfree(cread);
 109        }
 110        spin_unlock_irqrestore(&ctl->read_lock, flags);
 111}
 112
 113static int snd_ctl_release(struct inode *inode, struct file *file)
 114{
 115        unsigned long flags;
 116        struct snd_card *card;
 117        struct snd_ctl_file *ctl;
 118        struct snd_kcontrol *control;
 119        unsigned int idx;
 120
 121        ctl = file->private_data;
 122        file->private_data = NULL;
 123        card = ctl->card;
 124        write_lock_irqsave(&card->ctl_files_rwlock, flags);
 125        list_del(&ctl->list);
 126        write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 127        down_write(&card->controls_rwsem);
 128        list_for_each_entry(control, &card->controls, list)
 129                for (idx = 0; idx < control->count; idx++)
 130                        if (control->vd[idx].owner == ctl)
 131                                control->vd[idx].owner = NULL;
 132        up_write(&card->controls_rwsem);
 133        snd_ctl_empty_read_queue(ctl);
 134        put_pid(ctl->pid);
 135        kfree(ctl);
 136        module_put(card->module);
 137        snd_card_file_remove(card, file);
 138        return 0;
 139}
 140
 141void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 142                    struct snd_ctl_elem_id *id)
 143{
 144        unsigned long flags;
 145        struct snd_ctl_file *ctl;
 146        struct snd_kctl_event *ev;
 147        
 148        if (snd_BUG_ON(!card || !id))
 149                return;
 150        read_lock(&card->ctl_files_rwlock);
 151#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 152        card->mixer_oss_change_count++;
 153#endif
 154        list_for_each_entry(ctl, &card->ctl_files, list) {
 155                if (!ctl->subscribed)
 156                        continue;
 157                spin_lock_irqsave(&ctl->read_lock, flags);
 158                list_for_each_entry(ev, &ctl->events, list) {
 159                        if (ev->id.numid == id->numid) {
 160                                ev->mask |= mask;
 161                                goto _found;
 162                        }
 163                }
 164                ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 165                if (ev) {
 166                        ev->id = *id;
 167                        ev->mask = mask;
 168                        list_add_tail(&ev->list, &ctl->events);
 169                } else {
 170                        snd_printk(KERN_ERR "No memory available to allocate event\n");
 171                }
 172        _found:
 173                wake_up(&ctl->change_sleep);
 174                spin_unlock_irqrestore(&ctl->read_lock, flags);
 175                kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 176        }
 177        read_unlock(&card->ctl_files_rwlock);
 178}
 179
 180EXPORT_SYMBOL(snd_ctl_notify);
 181
 182/**
 183 * snd_ctl_new - create a control instance from the template
 184 * @control: the control template
 185 * @access: the default control access
 186 *
 187 * Allocates a new struct snd_kcontrol instance and copies the given template 
 188 * to the new instance. It does not copy volatile data (access).
 189 *
 190 * Returns the pointer of the new instance, or NULL on failure.
 191 */
 192static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 193                                        unsigned int access)
 194{
 195        struct snd_kcontrol *kctl;
 196        unsigned int idx;
 197        
 198        if (snd_BUG_ON(!control || !control->count))
 199                return NULL;
 200
 201        if (control->count > MAX_CONTROL_COUNT)
 202                return NULL;
 203
 204        kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 205        if (kctl == NULL) {
 206                snd_printk(KERN_ERR "Cannot allocate control instance\n");
 207                return NULL;
 208        }
 209        *kctl = *control;
 210        for (idx = 0; idx < kctl->count; idx++)
 211                kctl->vd[idx].access = access;
 212        return kctl;
 213}
 214
 215/**
 216 * snd_ctl_new1 - create a control instance from the template
 217 * @ncontrol: the initialization record
 218 * @private_data: the private data to set
 219 *
 220 * Allocates a new struct snd_kcontrol instance and initialize from the given 
 221 * template.  When the access field of ncontrol is 0, it's assumed as
 222 * READWRITE access. When the count field is 0, it's assumes as one.
 223 *
 224 * Returns the pointer of the newly generated instance, or NULL on failure.
 225 */
 226struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 227                                  void *private_data)
 228{
 229        struct snd_kcontrol kctl;
 230        unsigned int access;
 231        
 232        if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 233                return NULL;
 234        memset(&kctl, 0, sizeof(kctl));
 235        kctl.id.iface = ncontrol->iface;
 236        kctl.id.device = ncontrol->device;
 237        kctl.id.subdevice = ncontrol->subdevice;
 238        if (ncontrol->name) {
 239                strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 240                if (strcmp(ncontrol->name, kctl.id.name) != 0)
 241                        snd_printk(KERN_WARNING
 242                                   "Control name '%s' truncated to '%s'\n",
 243                                   ncontrol->name, kctl.id.name);
 244        }
 245        kctl.id.index = ncontrol->index;
 246        kctl.count = ncontrol->count ? ncontrol->count : 1;
 247        access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 248                 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 249                                      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 250                                      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 251                                      SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 252                                      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 253        kctl.info = ncontrol->info;
 254        kctl.get = ncontrol->get;
 255        kctl.put = ncontrol->put;
 256        kctl.tlv.p = ncontrol->tlv.p;
 257        kctl.private_value = ncontrol->private_value;
 258        kctl.private_data = private_data;
 259        return snd_ctl_new(&kctl, access);
 260}
 261
 262EXPORT_SYMBOL(snd_ctl_new1);
 263
 264/**
 265 * snd_ctl_free_one - release the control instance
 266 * @kcontrol: the control instance
 267 *
 268 * Releases the control instance created via snd_ctl_new()
 269 * or snd_ctl_new1().
 270 * Don't call this after the control was added to the card.
 271 */
 272void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 273{
 274        if (kcontrol) {
 275                if (kcontrol->private_free)
 276                        kcontrol->private_free(kcontrol);
 277                kfree(kcontrol);
 278        }
 279}
 280
 281EXPORT_SYMBOL(snd_ctl_free_one);
 282
 283static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 284                                          unsigned int count)
 285{
 286        struct snd_kcontrol *kctl;
 287
 288        list_for_each_entry(kctl, &card->controls, list) {
 289                if (kctl->id.numid < card->last_numid + 1 + count &&
 290                    kctl->id.numid + kctl->count > card->last_numid + 1) {
 291                        card->last_numid = kctl->id.numid + kctl->count - 1;
 292                        return true;
 293                }
 294        }
 295        return false;
 296}
 297
 298static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 299{
 300        unsigned int iter = 100000;
 301
 302        while (snd_ctl_remove_numid_conflict(card, count)) {
 303                if (--iter == 0) {
 304                        /* this situation is very unlikely */
 305                        snd_printk(KERN_ERR "unable to allocate new control numid\n");
 306                        return -ENOMEM;
 307                }
 308        }
 309        return 0;
 310}
 311
 312/**
 313 * snd_ctl_add - add the control instance to the card
 314 * @card: the card instance
 315 * @kcontrol: the control instance to add
 316 *
 317 * Adds the control instance created via snd_ctl_new() or
 318 * snd_ctl_new1() to the given card. Assigns also an unique
 319 * numid used for fast search.
 320 *
 321 * Returns zero if successful, or a negative error code on failure.
 322 *
 323 * It frees automatically the control which cannot be added.
 324 */
 325int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 326{
 327        struct snd_ctl_elem_id id;
 328        unsigned int idx;
 329        int err = -EINVAL;
 330
 331        if (! kcontrol)
 332                return err;
 333        if (snd_BUG_ON(!card || !kcontrol->info))
 334                goto error;
 335        id = kcontrol->id;
 336        down_write(&card->controls_rwsem);
 337        if (snd_ctl_find_id(card, &id)) {
 338                up_write(&card->controls_rwsem);
 339                snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 340                                        id.iface,
 341                                        id.device,
 342                                        id.subdevice,
 343                                        id.name,
 344                                        id.index);
 345                err = -EBUSY;
 346                goto error;
 347        }
 348        if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 349                up_write(&card->controls_rwsem);
 350                err = -ENOMEM;
 351                goto error;
 352        }
 353        list_add_tail(&kcontrol->list, &card->controls);
 354        card->controls_count += kcontrol->count;
 355        kcontrol->id.numid = card->last_numid + 1;
 356        card->last_numid += kcontrol->count;
 357        up_write(&card->controls_rwsem);
 358        for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 359                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 360        return 0;
 361
 362 error:
 363        snd_ctl_free_one(kcontrol);
 364        return err;
 365}
 366
 367EXPORT_SYMBOL(snd_ctl_add);
 368
 369/**
 370 * snd_ctl_replace - replace the control instance of the card
 371 * @card: the card instance
 372 * @kcontrol: the control instance to replace
 373 * @add_on_replace: add the control if not already added
 374 *
 375 * Replaces the given control.  If the given control does not exist
 376 * and the add_on_replace flag is set, the control is added.  If the
 377 * control exists, it is destroyed first.
 378 *
 379 * Returns zero if successful, or a negative error code on failure.
 380 *
 381 * It frees automatically the control which cannot be added or replaced.
 382 */
 383int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 384                    bool add_on_replace)
 385{
 386        struct snd_ctl_elem_id id;
 387        unsigned int idx;
 388        struct snd_kcontrol *old;
 389        int ret;
 390
 391        if (!kcontrol)
 392                return -EINVAL;
 393        if (snd_BUG_ON(!card || !kcontrol->info)) {
 394                ret = -EINVAL;
 395                goto error;
 396        }
 397        id = kcontrol->id;
 398        down_write(&card->controls_rwsem);
 399        old = snd_ctl_find_id(card, &id);
 400        if (!old) {
 401                if (add_on_replace)
 402                        goto add;
 403                up_write(&card->controls_rwsem);
 404                ret = -EINVAL;
 405                goto error;
 406        }
 407        ret = snd_ctl_remove(card, old);
 408        if (ret < 0) {
 409                up_write(&card->controls_rwsem);
 410                goto error;
 411        }
 412add:
 413        if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 414                up_write(&card->controls_rwsem);
 415                ret = -ENOMEM;
 416                goto error;
 417        }
 418        list_add_tail(&kcontrol->list, &card->controls);
 419        card->controls_count += kcontrol->count;
 420        kcontrol->id.numid = card->last_numid + 1;
 421        card->last_numid += kcontrol->count;
 422        up_write(&card->controls_rwsem);
 423        for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 424                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 425        return 0;
 426
 427error:
 428        snd_ctl_free_one(kcontrol);
 429        return ret;
 430}
 431EXPORT_SYMBOL(snd_ctl_replace);
 432
 433/**
 434 * snd_ctl_remove - remove the control from the card and release it
 435 * @card: the card instance
 436 * @kcontrol: the control instance to remove
 437 *
 438 * Removes the control from the card and then releases the instance.
 439 * You don't need to call snd_ctl_free_one(). You must be in
 440 * the write lock - down_write(&card->controls_rwsem).
 441 * 
 442 * Returns 0 if successful, or a negative error code on failure.
 443 */
 444int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 445{
 446        struct snd_ctl_elem_id id;
 447        unsigned int idx;
 448
 449        if (snd_BUG_ON(!card || !kcontrol))
 450                return -EINVAL;
 451        list_del(&kcontrol->list);
 452        card->controls_count -= kcontrol->count;
 453        id = kcontrol->id;
 454        for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 455                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 456        snd_ctl_free_one(kcontrol);
 457        return 0;
 458}
 459
 460EXPORT_SYMBOL(snd_ctl_remove);
 461
 462/**
 463 * snd_ctl_remove_id - remove the control of the given id and release it
 464 * @card: the card instance
 465 * @id: the control id to remove
 466 *
 467 * Finds the control instance with the given id, removes it from the
 468 * card list and releases it.
 469 * 
 470 * Returns 0 if successful, or a negative error code on failure.
 471 */
 472int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 473{
 474        struct snd_kcontrol *kctl;
 475        int ret;
 476
 477        down_write(&card->controls_rwsem);
 478        kctl = snd_ctl_find_id(card, id);
 479        if (kctl == NULL) {
 480                up_write(&card->controls_rwsem);
 481                return -ENOENT;
 482        }
 483        ret = snd_ctl_remove(card, kctl);
 484        up_write(&card->controls_rwsem);
 485        return ret;
 486}
 487
 488EXPORT_SYMBOL(snd_ctl_remove_id);
 489
 490/**
 491 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 492 * @file: active control handle
 493 * @id: the control id to remove
 494 *
 495 * Finds the control instance with the given id, removes it from the
 496 * card list and releases it.
 497 * 
 498 * Returns 0 if successful, or a negative error code on failure.
 499 */
 500static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 501                                   struct snd_ctl_elem_id *id)
 502{
 503        struct snd_card *card = file->card;
 504        struct snd_kcontrol *kctl;
 505        int idx, ret;
 506
 507        down_write(&card->controls_rwsem);
 508        kctl = snd_ctl_find_id(card, id);
 509        if (kctl == NULL) {
 510                ret = -ENOENT;
 511                goto error;
 512        }
 513        if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 514                ret = -EINVAL;
 515                goto error;
 516        }
 517        for (idx = 0; idx < kctl->count; idx++)
 518                if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 519                        ret = -EBUSY;
 520                        goto error;
 521                }
 522        ret = snd_ctl_remove(card, kctl);
 523        if (ret < 0)
 524                goto error;
 525        card->user_ctl_count--;
 526error:
 527        up_write(&card->controls_rwsem);
 528        return ret;
 529}
 530
 531/**
 532 * snd_ctl_activate_id - activate/inactivate the control of the given id
 533 * @card: the card instance
 534 * @id: the control id to activate/inactivate
 535 * @active: non-zero to activate
 536 *
 537 * Finds the control instance with the given id, and activate or
 538 * inactivate the control together with notification, if changed.
 539 *
 540 * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 541 */
 542int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 543                        int active)
 544{
 545        struct snd_kcontrol *kctl;
 546        struct snd_kcontrol_volatile *vd;
 547        unsigned int index_offset;
 548        int ret;
 549
 550        down_write(&card->controls_rwsem);
 551        kctl = snd_ctl_find_id(card, id);
 552        if (kctl == NULL) {
 553                ret = -ENOENT;
 554                goto unlock;
 555        }
 556        index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 557        vd = &kctl->vd[index_offset];
 558        ret = 0;
 559        if (active) {
 560                if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 561                        goto unlock;
 562                vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 563        } else {
 564                if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 565                        goto unlock;
 566                vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 567        }
 568        ret = 1;
 569 unlock:
 570        up_write(&card->controls_rwsem);
 571        if (ret > 0)
 572                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 573        return ret;
 574}
 575EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 576
 577/**
 578 * snd_ctl_rename_id - replace the id of a control on the card
 579 * @card: the card instance
 580 * @src_id: the old id
 581 * @dst_id: the new id
 582 *
 583 * Finds the control with the old id from the card, and replaces the
 584 * id with the new one.
 585 *
 586 * Returns zero if successful, or a negative error code on failure.
 587 */
 588int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 589                      struct snd_ctl_elem_id *dst_id)
 590{
 591        struct snd_kcontrol *kctl;
 592
 593        down_write(&card->controls_rwsem);
 594        kctl = snd_ctl_find_id(card, src_id);
 595        if (kctl == NULL) {
 596                up_write(&card->controls_rwsem);
 597                return -ENOENT;
 598        }
 599        kctl->id = *dst_id;
 600        kctl->id.numid = card->last_numid + 1;
 601        card->last_numid += kctl->count;
 602        up_write(&card->controls_rwsem);
 603        return 0;
 604}
 605
 606EXPORT_SYMBOL(snd_ctl_rename_id);
 607
 608/**
 609 * snd_ctl_find_numid - find the control instance with the given number-id
 610 * @card: the card instance
 611 * @numid: the number-id to search
 612 *
 613 * Finds the control instance with the given number-id from the card.
 614 *
 615 * Returns the pointer of the instance if found, or NULL if not.
 616 *
 617 * The caller must down card->controls_rwsem before calling this function
 618 * (if the race condition can happen).
 619 */
 620struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 621{
 622        struct snd_kcontrol *kctl;
 623
 624        if (snd_BUG_ON(!card || !numid))
 625                return NULL;
 626        list_for_each_entry(kctl, &card->controls, list) {
 627                if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 628                        return kctl;
 629        }
 630        return NULL;
 631}
 632
 633EXPORT_SYMBOL(snd_ctl_find_numid);
 634
 635/**
 636 * snd_ctl_find_id - find the control instance with the given id
 637 * @card: the card instance
 638 * @id: the id to search
 639 *
 640 * Finds the control instance with the given id from the card.
 641 *
 642 * Returns the pointer of the instance if found, or NULL if not.
 643 *
 644 * The caller must down card->controls_rwsem before calling this function
 645 * (if the race condition can happen).
 646 */
 647struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 648                                     struct snd_ctl_elem_id *id)
 649{
 650        struct snd_kcontrol *kctl;
 651
 652        if (snd_BUG_ON(!card || !id))
 653                return NULL;
 654        if (id->numid != 0)
 655                return snd_ctl_find_numid(card, id->numid);
 656        list_for_each_entry(kctl, &card->controls, list) {
 657                if (kctl->id.iface != id->iface)
 658                        continue;
 659                if (kctl->id.device != id->device)
 660                        continue;
 661                if (kctl->id.subdevice != id->subdevice)
 662                        continue;
 663                if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 664                        continue;
 665                if (kctl->id.index > id->index)
 666                        continue;
 667                if (kctl->id.index + kctl->count <= id->index)
 668                        continue;
 669                return kctl;
 670        }
 671        return NULL;
 672}
 673
 674EXPORT_SYMBOL(snd_ctl_find_id);
 675
 676static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 677                             unsigned int cmd, void __user *arg)
 678{
 679        struct snd_ctl_card_info *info;
 680
 681        info = kzalloc(sizeof(*info), GFP_KERNEL);
 682        if (! info)
 683                return -ENOMEM;
 684        down_read(&snd_ioctl_rwsem);
 685        info->card = card->number;
 686        strlcpy(info->id, card->id, sizeof(info->id));
 687        strlcpy(info->driver, card->driver, sizeof(info->driver));
 688        strlcpy(info->name, card->shortname, sizeof(info->name));
 689        strlcpy(info->longname, card->longname, sizeof(info->longname));
 690        strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 691        strlcpy(info->components, card->components, sizeof(info->components));
 692        up_read(&snd_ioctl_rwsem);
 693        if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 694                kfree(info);
 695                return -EFAULT;
 696        }
 697        kfree(info);
 698        return 0;
 699}
 700
 701static int snd_ctl_elem_list(struct snd_card *card,
 702                             struct snd_ctl_elem_list __user *_list)
 703{
 704        struct list_head *plist;
 705        struct snd_ctl_elem_list list;
 706        struct snd_kcontrol *kctl;
 707        struct snd_ctl_elem_id *dst, *id;
 708        unsigned int offset, space, jidx;
 709        
 710        if (copy_from_user(&list, _list, sizeof(list)))
 711                return -EFAULT;
 712        offset = list.offset;
 713        space = list.space;
 714        /* try limit maximum space */
 715        if (space > 16384)
 716                return -ENOMEM;
 717        if (space > 0) {
 718                /* allocate temporary buffer for atomic operation */
 719                dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 720                if (dst == NULL)
 721                        return -ENOMEM;
 722                down_read(&card->controls_rwsem);
 723                list.count = card->controls_count;
 724                plist = card->controls.next;
 725                while (plist != &card->controls) {
 726                        if (offset == 0)
 727                                break;
 728                        kctl = snd_kcontrol(plist);
 729                        if (offset < kctl->count)
 730                                break;
 731                        offset -= kctl->count;
 732                        plist = plist->next;
 733                }
 734                list.used = 0;
 735                id = dst;
 736                while (space > 0 && plist != &card->controls) {
 737                        kctl = snd_kcontrol(plist);
 738                        for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 739                                snd_ctl_build_ioff(id, kctl, jidx);
 740                                id++;
 741                                space--;
 742                                list.used++;
 743                        }
 744                        plist = plist->next;
 745                        offset = 0;
 746                }
 747                up_read(&card->controls_rwsem);
 748                if (list.used > 0 &&
 749                    copy_to_user(list.pids, dst,
 750                                 list.used * sizeof(struct snd_ctl_elem_id))) {
 751                        vfree(dst);
 752                        return -EFAULT;
 753                }
 754                vfree(dst);
 755        } else {
 756                down_read(&card->controls_rwsem);
 757                list.count = card->controls_count;
 758                up_read(&card->controls_rwsem);
 759        }
 760        if (copy_to_user(_list, &list, sizeof(list)))
 761                return -EFAULT;
 762        return 0;
 763}
 764
 765static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 766                             struct snd_ctl_elem_info *info)
 767{
 768        struct snd_card *card = ctl->card;
 769        struct snd_kcontrol *kctl;
 770        struct snd_kcontrol_volatile *vd;
 771        unsigned int index_offset;
 772        int result;
 773        
 774        down_read(&card->controls_rwsem);
 775        kctl = snd_ctl_find_id(card, &info->id);
 776        if (kctl == NULL) {
 777                up_read(&card->controls_rwsem);
 778                return -ENOENT;
 779        }
 780#ifdef CONFIG_SND_DEBUG
 781        info->access = 0;
 782#endif
 783        result = kctl->info(kctl, info);
 784        if (result >= 0) {
 785                snd_BUG_ON(info->access);
 786                index_offset = snd_ctl_get_ioff(kctl, &info->id);
 787                vd = &kctl->vd[index_offset];
 788                snd_ctl_build_ioff(&info->id, kctl, index_offset);
 789                info->access = vd->access;
 790                if (vd->owner) {
 791                        info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 792                        if (vd->owner == ctl)
 793                                info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 794                        info->owner = pid_vnr(vd->owner->pid);
 795                } else {
 796                        info->owner = -1;
 797                }
 798        }
 799        up_read(&card->controls_rwsem);
 800        return result;
 801}
 802
 803static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 804                                  struct snd_ctl_elem_info __user *_info)
 805{
 806        struct snd_ctl_elem_info info;
 807        int result;
 808
 809        if (copy_from_user(&info, _info, sizeof(info)))
 810                return -EFAULT;
 811        snd_power_lock(ctl->card);
 812        result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 813        if (result >= 0)
 814                result = snd_ctl_elem_info(ctl, &info);
 815        snd_power_unlock(ctl->card);
 816        if (result >= 0)
 817                if (copy_to_user(_info, &info, sizeof(info)))
 818                        return -EFAULT;
 819        return result;
 820}
 821
 822static int snd_ctl_elem_read(struct snd_card *card,
 823                             struct snd_ctl_elem_value *control)
 824{
 825        struct snd_kcontrol *kctl;
 826        struct snd_kcontrol_volatile *vd;
 827        unsigned int index_offset;
 828        int result;
 829
 830        down_read(&card->controls_rwsem);
 831        kctl = snd_ctl_find_id(card, &control->id);
 832        if (kctl == NULL) {
 833                result = -ENOENT;
 834        } else {
 835                index_offset = snd_ctl_get_ioff(kctl, &control->id);
 836                vd = &kctl->vd[index_offset];
 837                if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 838                    kctl->get != NULL) {
 839                        snd_ctl_build_ioff(&control->id, kctl, index_offset);
 840                        result = kctl->get(kctl, control);
 841                } else
 842                        result = -EPERM;
 843        }
 844        up_read(&card->controls_rwsem);
 845        return result;
 846}
 847
 848static int snd_ctl_elem_read_user(struct snd_card *card,
 849                                  struct snd_ctl_elem_value __user *_control)
 850{
 851        struct snd_ctl_elem_value *control;
 852        int result;
 853
 854        control = memdup_user(_control, sizeof(*control));
 855        if (IS_ERR(control))
 856                return PTR_ERR(control);
 857
 858        snd_power_lock(card);
 859        result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 860        if (result >= 0)
 861                result = snd_ctl_elem_read(card, control);
 862        snd_power_unlock(card);
 863        if (result >= 0)
 864                if (copy_to_user(_control, control, sizeof(*control)))
 865                        result = -EFAULT;
 866        kfree(control);
 867        return result;
 868}
 869
 870static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 871                              struct snd_ctl_elem_value *control)
 872{
 873        struct snd_kcontrol *kctl;
 874        struct snd_kcontrol_volatile *vd;
 875        unsigned int index_offset;
 876        int result;
 877
 878        down_read(&card->controls_rwsem);
 879        kctl = snd_ctl_find_id(card, &control->id);
 880        if (kctl == NULL) {
 881                result = -ENOENT;
 882        } else {
 883                index_offset = snd_ctl_get_ioff(kctl, &control->id);
 884                vd = &kctl->vd[index_offset];
 885                if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 886                    kctl->put == NULL ||
 887                    (file && vd->owner && vd->owner != file)) {
 888                        result = -EPERM;
 889                } else {
 890                        snd_ctl_build_ioff(&control->id, kctl, index_offset);
 891                        result = kctl->put(kctl, control);
 892                }
 893                if (result > 0) {
 894                        up_read(&card->controls_rwsem);
 895                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 896                                       &control->id);
 897                        return 0;
 898                }
 899        }
 900        up_read(&card->controls_rwsem);
 901        return result;
 902}
 903
 904static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 905                                   struct snd_ctl_elem_value __user *_control)
 906{
 907        struct snd_ctl_elem_value *control;
 908        struct snd_card *card;
 909        int result;
 910
 911        control = memdup_user(_control, sizeof(*control));
 912        if (IS_ERR(control))
 913                return PTR_ERR(control);
 914
 915        card = file->card;
 916        snd_power_lock(card);
 917        result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 918        if (result >= 0)
 919                result = snd_ctl_elem_write(card, file, control);
 920        snd_power_unlock(card);
 921        if (result >= 0)
 922                if (copy_to_user(_control, control, sizeof(*control)))
 923                        result = -EFAULT;
 924        kfree(control);
 925        return result;
 926}
 927
 928static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 929                             struct snd_ctl_elem_id __user *_id)
 930{
 931        struct snd_card *card = file->card;
 932        struct snd_ctl_elem_id id;
 933        struct snd_kcontrol *kctl;
 934        struct snd_kcontrol_volatile *vd;
 935        int result;
 936        
 937        if (copy_from_user(&id, _id, sizeof(id)))
 938                return -EFAULT;
 939        down_write(&card->controls_rwsem);
 940        kctl = snd_ctl_find_id(card, &id);
 941        if (kctl == NULL) {
 942                result = -ENOENT;
 943        } else {
 944                vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 945                if (vd->owner != NULL)
 946                        result = -EBUSY;
 947                else {
 948                        vd->owner = file;
 949                        result = 0;
 950                }
 951        }
 952        up_write(&card->controls_rwsem);
 953        return result;
 954}
 955
 956static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 957                               struct snd_ctl_elem_id __user *_id)
 958{
 959        struct snd_card *card = file->card;
 960        struct snd_ctl_elem_id id;
 961        struct snd_kcontrol *kctl;
 962        struct snd_kcontrol_volatile *vd;
 963        int result;
 964        
 965        if (copy_from_user(&id, _id, sizeof(id)))
 966                return -EFAULT;
 967        down_write(&card->controls_rwsem);
 968        kctl = snd_ctl_find_id(card, &id);
 969        if (kctl == NULL) {
 970                result = -ENOENT;
 971        } else {
 972                vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 973                if (vd->owner == NULL)
 974                        result = -EINVAL;
 975                else if (vd->owner != file)
 976                        result = -EPERM;
 977                else {
 978                        vd->owner = NULL;
 979                        result = 0;
 980                }
 981        }
 982        up_write(&card->controls_rwsem);
 983        return result;
 984}
 985
 986struct user_element {
 987        struct snd_ctl_elem_info info;
 988        void *elem_data;                /* element data */
 989        unsigned long elem_data_size;   /* size of element data in bytes */
 990        void *tlv_data;                 /* TLV data */
 991        unsigned long tlv_data_size;    /* TLV data size */
 992        void *priv_data;                /* private data (like strings for enumerated type) */
 993};
 994
 995static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 996                                  struct snd_ctl_elem_info *uinfo)
 997{
 998        struct user_element *ue = kcontrol->private_data;
 999
1000        *uinfo = ue->info;
1001        return 0;
1002}
1003
1004static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1005                                       struct snd_ctl_elem_info *uinfo)
1006{
1007        struct user_element *ue = kcontrol->private_data;
1008        const char *names;
1009        unsigned int item;
1010
1011        item = uinfo->value.enumerated.item;
1012
1013        *uinfo = ue->info;
1014
1015        item = min(item, uinfo->value.enumerated.items - 1);
1016        uinfo->value.enumerated.item = item;
1017
1018        names = ue->priv_data;
1019        for (; item > 0; --item)
1020                names += strlen(names) + 1;
1021        strcpy(uinfo->value.enumerated.name, names);
1022
1023        return 0;
1024}
1025
1026static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1027                                 struct snd_ctl_elem_value *ucontrol)
1028{
1029        struct user_element *ue = kcontrol->private_data;
1030
1031        memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1032        return 0;
1033}
1034
1035static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1036                                 struct snd_ctl_elem_value *ucontrol)
1037{
1038        int change;
1039        struct user_element *ue = kcontrol->private_data;
1040        
1041        change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1042        if (change)
1043                memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1044        return change;
1045}
1046
1047static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1048                                 int op_flag,
1049                                 unsigned int size,
1050                                 unsigned int __user *tlv)
1051{
1052        struct user_element *ue = kcontrol->private_data;
1053        int change = 0;
1054        void *new_data;
1055
1056        if (op_flag > 0) {
1057                if (size > 1024 * 128)  /* sane value */
1058                        return -EINVAL;
1059
1060                new_data = memdup_user(tlv, size);
1061                if (IS_ERR(new_data))
1062                        return PTR_ERR(new_data);
1063                change = ue->tlv_data_size != size;
1064                if (!change)
1065                        change = memcmp(ue->tlv_data, new_data, size);
1066                kfree(ue->tlv_data);
1067                ue->tlv_data = new_data;
1068                ue->tlv_data_size = size;
1069        } else {
1070                if (! ue->tlv_data_size || ! ue->tlv_data)
1071                        return -ENXIO;
1072                if (size < ue->tlv_data_size)
1073                        return -ENOSPC;
1074                if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1075                        return -EFAULT;
1076        }
1077        return change;
1078}
1079
1080static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1081{
1082        char *names, *p;
1083        size_t buf_len, name_len;
1084        unsigned int i;
1085        const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1086
1087        if (ue->info.value.enumerated.names_length > 64 * 1024)
1088                return -EINVAL;
1089
1090        names = memdup_user((const void __user *)user_ptrval,
1091                ue->info.value.enumerated.names_length);
1092        if (IS_ERR(names))
1093                return PTR_ERR(names);
1094
1095        /* check that there are enough valid names */
1096        buf_len = ue->info.value.enumerated.names_length;
1097        p = names;
1098        for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1099                name_len = strnlen(p, buf_len);
1100                if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1101                        kfree(names);
1102                        return -EINVAL;
1103                }
1104                p += name_len + 1;
1105                buf_len -= name_len + 1;
1106        }
1107
1108        ue->priv_data = names;
1109        ue->info.value.enumerated.names_ptr = 0;
1110
1111        return 0;
1112}
1113
1114static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1115{
1116        struct user_element *ue = kcontrol->private_data;
1117
1118        kfree(ue->tlv_data);
1119        kfree(ue->priv_data);
1120        kfree(ue);
1121}
1122
1123static int snd_ctl_elem_add(struct snd_ctl_file *file,
1124                            struct snd_ctl_elem_info *info, int replace)
1125{
1126        struct snd_card *card = file->card;
1127        struct snd_kcontrol kctl, *_kctl;
1128        unsigned int access;
1129        long private_size;
1130        struct user_element *ue;
1131        int idx, err;
1132
1133        if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1134                return -ENOMEM;
1135        if (info->count < 1)
1136                return -EINVAL;
1137        access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1138                (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1139                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1140                                 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1141        info->id.numid = 0;
1142        memset(&kctl, 0, sizeof(kctl));
1143        down_write(&card->controls_rwsem);
1144        _kctl = snd_ctl_find_id(card, &info->id);
1145        err = 0;
1146        if (_kctl) {
1147                if (replace)
1148                        err = snd_ctl_remove(card, _kctl);
1149                else
1150                        err = -EBUSY;
1151        } else {
1152                if (replace)
1153                        err = -ENOENT;
1154        }
1155        up_write(&card->controls_rwsem);
1156        if (err < 0)
1157                return err;
1158        memcpy(&kctl.id, &info->id, sizeof(info->id));
1159        kctl.count = info->owner ? info->owner : 1;
1160        access |= SNDRV_CTL_ELEM_ACCESS_USER;
1161        if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1162                kctl.info = snd_ctl_elem_user_enum_info;
1163        else
1164                kctl.info = snd_ctl_elem_user_info;
1165        if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1166                kctl.get = snd_ctl_elem_user_get;
1167        if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1168                kctl.put = snd_ctl_elem_user_put;
1169        if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1170                kctl.tlv.c = snd_ctl_elem_user_tlv;
1171                access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1172        }
1173        switch (info->type) {
1174        case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1175        case SNDRV_CTL_ELEM_TYPE_INTEGER:
1176                private_size = sizeof(long);
1177                if (info->count > 128)
1178                        return -EINVAL;
1179                break;
1180        case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1181                private_size = sizeof(long long);
1182                if (info->count > 64)
1183                        return -EINVAL;
1184                break;
1185        case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1186                private_size = sizeof(unsigned int);
1187                if (info->count > 128 || info->value.enumerated.items == 0)
1188                        return -EINVAL;
1189                break;
1190        case SNDRV_CTL_ELEM_TYPE_BYTES:
1191                private_size = sizeof(unsigned char);
1192                if (info->count > 512)
1193                        return -EINVAL;
1194                break;
1195        case SNDRV_CTL_ELEM_TYPE_IEC958:
1196                private_size = sizeof(struct snd_aes_iec958);
1197                if (info->count != 1)
1198                        return -EINVAL;
1199                break;
1200        default:
1201                return -EINVAL;
1202        }
1203        private_size *= info->count;
1204        ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1205        if (ue == NULL)
1206                return -ENOMEM;
1207        ue->info = *info;
1208        ue->info.access = 0;
1209        ue->elem_data = (char *)ue + sizeof(*ue);
1210        ue->elem_data_size = private_size;
1211        if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1212                err = snd_ctl_elem_init_enum_names(ue);
1213                if (err < 0) {
1214                        kfree(ue);
1215                        return err;
1216                }
1217        }
1218        kctl.private_free = snd_ctl_elem_user_free;
1219        _kctl = snd_ctl_new(&kctl, access);
1220        if (_kctl == NULL) {
1221                kfree(ue->priv_data);
1222                kfree(ue);
1223                return -ENOMEM;
1224        }
1225        _kctl->private_data = ue;
1226        for (idx = 0; idx < _kctl->count; idx++)
1227                _kctl->vd[idx].owner = file;
1228        err = snd_ctl_add(card, _kctl);
1229        if (err < 0)
1230                return err;
1231
1232        down_write(&card->controls_rwsem);
1233        card->user_ctl_count++;
1234        up_write(&card->controls_rwsem);
1235
1236        return 0;
1237}
1238
1239static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1240                                 struct snd_ctl_elem_info __user *_info, int replace)
1241{
1242        struct snd_ctl_elem_info info;
1243        if (copy_from_user(&info, _info, sizeof(info)))
1244                return -EFAULT;
1245        return snd_ctl_elem_add(file, &info, replace);
1246}
1247
1248static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1249                               struct snd_ctl_elem_id __user *_id)
1250{
1251        struct snd_ctl_elem_id id;
1252
1253        if (copy_from_user(&id, _id, sizeof(id)))
1254                return -EFAULT;
1255        return snd_ctl_remove_user_ctl(file, &id);
1256}
1257
1258static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1259{
1260        int subscribe;
1261        if (get_user(subscribe, ptr))
1262                return -EFAULT;
1263        if (subscribe < 0) {
1264                subscribe = file->subscribed;
1265                if (put_user(subscribe, ptr))
1266                        return -EFAULT;
1267                return 0;
1268        }
1269        if (subscribe) {
1270                file->subscribed = 1;
1271                return 0;
1272        } else if (file->subscribed) {
1273                snd_ctl_empty_read_queue(file);
1274                file->subscribed = 0;
1275        }
1276        return 0;
1277}
1278
1279static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1280                             struct snd_ctl_tlv __user *_tlv,
1281                             int op_flag)
1282{
1283        struct snd_card *card = file->card;
1284        struct snd_ctl_tlv tlv;
1285        struct snd_kcontrol *kctl;
1286        struct snd_kcontrol_volatile *vd;
1287        unsigned int len;
1288        int err = 0;
1289
1290        if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1291                return -EFAULT;
1292        if (tlv.length < sizeof(unsigned int) * 2)
1293                return -EINVAL;
1294        down_read(&card->controls_rwsem);
1295        kctl = snd_ctl_find_numid(card, tlv.numid);
1296        if (kctl == NULL) {
1297                err = -ENOENT;
1298                goto __kctl_end;
1299        }
1300        if (kctl->tlv.p == NULL) {
1301                err = -ENXIO;
1302                goto __kctl_end;
1303        }
1304        vd = &kctl->vd[tlv.numid - kctl->id.numid];
1305        if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1306            (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1307            (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1308                err = -ENXIO;
1309                goto __kctl_end;
1310        }
1311        if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1312                if (vd->owner != NULL && vd->owner != file) {
1313                        err = -EPERM;
1314                        goto __kctl_end;
1315                }
1316                err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1317                if (err > 0) {
1318                        up_read(&card->controls_rwsem);
1319                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1320                        return 0;
1321                }
1322        } else {
1323                if (op_flag) {
1324                        err = -ENXIO;
1325                        goto __kctl_end;
1326                }
1327                len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1328                if (tlv.length < len) {
1329                        err = -ENOMEM;
1330                        goto __kctl_end;
1331                }
1332                if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1333                        err = -EFAULT;
1334        }
1335      __kctl_end:
1336        up_read(&card->controls_rwsem);
1337        return err;
1338}
1339
1340static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1341{
1342        struct snd_ctl_file *ctl;
1343        struct snd_card *card;
1344        struct snd_kctl_ioctl *p;
1345        void __user *argp = (void __user *)arg;
1346        int __user *ip = argp;
1347        int err;
1348
1349        ctl = file->private_data;
1350        card = ctl->card;
1351        if (snd_BUG_ON(!card))
1352                return -ENXIO;
1353        switch (cmd) {
1354        case SNDRV_CTL_IOCTL_PVERSION:
1355                return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1356        case SNDRV_CTL_IOCTL_CARD_INFO:
1357                return snd_ctl_card_info(card, ctl, cmd, argp);
1358        case SNDRV_CTL_IOCTL_ELEM_LIST:
1359                return snd_ctl_elem_list(card, argp);
1360        case SNDRV_CTL_IOCTL_ELEM_INFO:
1361                return snd_ctl_elem_info_user(ctl, argp);
1362        case SNDRV_CTL_IOCTL_ELEM_READ:
1363                return snd_ctl_elem_read_user(card, argp);
1364        case SNDRV_CTL_IOCTL_ELEM_WRITE:
1365                return snd_ctl_elem_write_user(ctl, argp);
1366        case SNDRV_CTL_IOCTL_ELEM_LOCK:
1367                return snd_ctl_elem_lock(ctl, argp);
1368        case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1369                return snd_ctl_elem_unlock(ctl, argp);
1370        case SNDRV_CTL_IOCTL_ELEM_ADD:
1371                return snd_ctl_elem_add_user(ctl, argp, 0);
1372        case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1373                return snd_ctl_elem_add_user(ctl, argp, 1);
1374        case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1375                return snd_ctl_elem_remove(ctl, argp);
1376        case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1377                return snd_ctl_subscribe_events(ctl, ip);
1378        case SNDRV_CTL_IOCTL_TLV_READ:
1379                return snd_ctl_tlv_ioctl(ctl, argp, 0);
1380        case SNDRV_CTL_IOCTL_TLV_WRITE:
1381                return snd_ctl_tlv_ioctl(ctl, argp, 1);
1382        case SNDRV_CTL_IOCTL_TLV_COMMAND:
1383                return snd_ctl_tlv_ioctl(ctl, argp, -1);
1384        case SNDRV_CTL_IOCTL_POWER:
1385                return -ENOPROTOOPT;
1386        case SNDRV_CTL_IOCTL_POWER_STATE:
1387#ifdef CONFIG_PM
1388                return put_user(card->power_state, ip) ? -EFAULT : 0;
1389#else
1390                return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1391#endif
1392        }
1393        down_read(&snd_ioctl_rwsem);
1394        list_for_each_entry(p, &snd_control_ioctls, list) {
1395                err = p->fioctl(card, ctl, cmd, arg);
1396                if (err != -ENOIOCTLCMD) {
1397                        up_read(&snd_ioctl_rwsem);
1398                        return err;
1399                }
1400        }
1401        up_read(&snd_ioctl_rwsem);
1402        snd_printdd("unknown ioctl = 0x%x\n", cmd);
1403        return -ENOTTY;
1404}
1405
1406static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1407                            size_t count, loff_t * offset)
1408{
1409        struct snd_ctl_file *ctl;
1410        int err = 0;
1411        ssize_t result = 0;
1412
1413        ctl = file->private_data;
1414        if (snd_BUG_ON(!ctl || !ctl->card))
1415                return -ENXIO;
1416        if (!ctl->subscribed)
1417                return -EBADFD;
1418        if (count < sizeof(struct snd_ctl_event))
1419                return -EINVAL;
1420        spin_lock_irq(&ctl->read_lock);
1421        while (count >= sizeof(struct snd_ctl_event)) {
1422                struct snd_ctl_event ev;
1423                struct snd_kctl_event *kev;
1424                while (list_empty(&ctl->events)) {
1425                        wait_queue_t wait;
1426                        if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1427                                err = -EAGAIN;
1428                                goto __end_lock;
1429                        }
1430                        init_waitqueue_entry(&wait, current);
1431                        add_wait_queue(&ctl->change_sleep, &wait);
1432                        set_current_state(TASK_INTERRUPTIBLE);
1433                        spin_unlock_irq(&ctl->read_lock);
1434                        schedule();
1435                        remove_wait_queue(&ctl->change_sleep, &wait);
1436                        if (signal_pending(current))
1437                                return -ERESTARTSYS;
1438                        spin_lock_irq(&ctl->read_lock);
1439                }
1440                kev = snd_kctl_event(ctl->events.next);
1441                ev.type = SNDRV_CTL_EVENT_ELEM;
1442                ev.data.elem.mask = kev->mask;
1443                ev.data.elem.id = kev->id;
1444                list_del(&kev->list);
1445                spin_unlock_irq(&ctl->read_lock);
1446                kfree(kev);
1447                if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1448                        err = -EFAULT;
1449                        goto __end;
1450                }
1451                spin_lock_irq(&ctl->read_lock);
1452                buffer += sizeof(struct snd_ctl_event);
1453                count -= sizeof(struct snd_ctl_event);
1454                result += sizeof(struct snd_ctl_event);
1455        }
1456      __end_lock:
1457        spin_unlock_irq(&ctl->read_lock);
1458      __end:
1459        return result > 0 ? result : err;
1460}
1461
1462static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1463{
1464        unsigned int mask;
1465        struct snd_ctl_file *ctl;
1466
1467        ctl = file->private_data;
1468        if (!ctl->subscribed)
1469                return 0;
1470        poll_wait(file, &ctl->change_sleep, wait);
1471
1472        mask = 0;
1473        if (!list_empty(&ctl->events))
1474                mask |= POLLIN | POLLRDNORM;
1475
1476        return mask;
1477}
1478
1479/*
1480 * register the device-specific control-ioctls.
1481 * called from each device manager like pcm.c, hwdep.c, etc.
1482 */
1483static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1484{
1485        struct snd_kctl_ioctl *pn;
1486
1487        pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1488        if (pn == NULL)
1489                return -ENOMEM;
1490        pn->fioctl = fcn;
1491        down_write(&snd_ioctl_rwsem);
1492        list_add_tail(&pn->list, lists);
1493        up_write(&snd_ioctl_rwsem);
1494        return 0;
1495}
1496
1497int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1498{
1499        return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1500}
1501
1502EXPORT_SYMBOL(snd_ctl_register_ioctl);
1503
1504#ifdef CONFIG_COMPAT
1505int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1506{
1507        return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1508}
1509
1510EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1511#endif
1512
1513/*
1514 * de-register the device-specific control-ioctls.
1515 */
1516static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1517                                     struct list_head *lists)
1518{
1519        struct snd_kctl_ioctl *p;
1520
1521        if (snd_BUG_ON(!fcn))
1522                return -EINVAL;
1523        down_write(&snd_ioctl_rwsem);
1524        list_for_each_entry(p, lists, list) {
1525                if (p->fioctl == fcn) {
1526                        list_del(&p->list);
1527                        up_write(&snd_ioctl_rwsem);
1528                        kfree(p);
1529                        return 0;
1530                }
1531        }
1532        up_write(&snd_ioctl_rwsem);
1533        snd_BUG();
1534        return -EINVAL;
1535}
1536
1537int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1538{
1539        return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1540}
1541
1542EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1543
1544#ifdef CONFIG_COMPAT
1545int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1546{
1547        return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1548}
1549
1550EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1551#endif
1552
1553static int snd_ctl_fasync(int fd, struct file * file, int on)
1554{
1555        struct snd_ctl_file *ctl;
1556
1557        ctl = file->private_data;
1558        return fasync_helper(fd, file, on, &ctl->fasync);
1559}
1560
1561/*
1562 * ioctl32 compat
1563 */
1564#ifdef CONFIG_COMPAT
1565#include "control_compat.c"
1566#else
1567#define snd_ctl_ioctl_compat    NULL
1568#endif
1569
1570/*
1571 *  INIT PART
1572 */
1573
1574static const struct file_operations snd_ctl_f_ops =
1575{
1576        .owner =        THIS_MODULE,
1577        .read =         snd_ctl_read,
1578        .open =         snd_ctl_open,
1579        .release =      snd_ctl_release,
1580        .llseek =       no_llseek,
1581        .poll =         snd_ctl_poll,
1582        .unlocked_ioctl =       snd_ctl_ioctl,
1583        .compat_ioctl = snd_ctl_ioctl_compat,
1584        .fasync =       snd_ctl_fasync,
1585};
1586
1587/*
1588 * registration of the control device
1589 */
1590static int snd_ctl_dev_register(struct snd_device *device)
1591{
1592        struct snd_card *card = device->device_data;
1593        int err, cardnum;
1594        char name[16];
1595
1596        if (snd_BUG_ON(!card))
1597                return -ENXIO;
1598        cardnum = card->number;
1599        if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1600                return -ENXIO;
1601        sprintf(name, "controlC%i", cardnum);
1602        if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1603                                       &snd_ctl_f_ops, card, name)) < 0)
1604                return err;
1605        return 0;
1606}
1607
1608/*
1609 * disconnection of the control device
1610 */
1611static int snd_ctl_dev_disconnect(struct snd_device *device)
1612{
1613        struct snd_card *card = device->device_data;
1614        struct snd_ctl_file *ctl;
1615        int err, cardnum;
1616
1617        if (snd_BUG_ON(!card))
1618                return -ENXIO;
1619        cardnum = card->number;
1620        if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1621                return -ENXIO;
1622
1623        read_lock(&card->ctl_files_rwlock);
1624        list_for_each_entry(ctl, &card->ctl_files, list) {
1625                wake_up(&ctl->change_sleep);
1626                kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1627        }
1628        read_unlock(&card->ctl_files_rwlock);
1629
1630        if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1631                                         card, -1)) < 0)
1632                return err;
1633        return 0;
1634}
1635
1636/*
1637 * free all controls
1638 */
1639static int snd_ctl_dev_free(struct snd_device *device)
1640{
1641        struct snd_card *card = device->device_data;
1642        struct snd_kcontrol *control;
1643
1644        down_write(&card->controls_rwsem);
1645        while (!list_empty(&card->controls)) {
1646                control = snd_kcontrol(card->controls.next);
1647                snd_ctl_remove(card, control);
1648        }
1649        up_write(&card->controls_rwsem);
1650        return 0;
1651}
1652
1653/*
1654 * create control core:
1655 * called from init.c
1656 */
1657int snd_ctl_create(struct snd_card *card)
1658{
1659        static struct snd_device_ops ops = {
1660                .dev_free = snd_ctl_dev_free,
1661                .dev_register = snd_ctl_dev_register,
1662                .dev_disconnect = snd_ctl_dev_disconnect,
1663        };
1664
1665        if (snd_BUG_ON(!card))
1666                return -ENXIO;
1667        return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1668}
1669
1670/*
1671 * Frequently used control callbacks/helpers
1672 */
1673int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1674                              struct snd_ctl_elem_info *uinfo)
1675{
1676        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1677        uinfo->count = 1;
1678        uinfo->value.integer.min = 0;
1679        uinfo->value.integer.max = 1;
1680        return 0;
1681}
1682
1683EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1684
1685int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1686                                struct snd_ctl_elem_info *uinfo)
1687{
1688        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1689        uinfo->count = 2;
1690        uinfo->value.integer.min = 0;
1691        uinfo->value.integer.max = 1;
1692        return 0;
1693}
1694
1695EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1696
1697/**
1698 * snd_ctl_enum_info - fills the info structure for an enumerated control
1699 * @info: the structure to be filled
1700 * @channels: the number of the control's channels; often one
1701 * @items: the number of control values; also the size of @names
1702 * @names: an array containing the names of all control values
1703 *
1704 * Sets all required fields in @info to their appropriate values.
1705 * If the control's accessibility is not the default (readable and writable),
1706 * the caller has to fill @info->access.
1707 */
1708int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1709                      unsigned int items, const char *const names[])
1710{
1711        info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1712        info->count = channels;
1713        info->value.enumerated.items = items;
1714        if (info->value.enumerated.item >= items)
1715                info->value.enumerated.item = items - 1;
1716        strlcpy(info->value.enumerated.name,
1717                names[info->value.enumerated.item],
1718                sizeof(info->value.enumerated.name));
1719        return 0;
1720}
1721EXPORT_SYMBOL(snd_ctl_enum_info);
1722
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.