linux/sound/core/control.c
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   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/slab.h>
  25#include <linux/vmalloc.h>
  26#include <linux/time.h>
  27#include <sound/core.h>
  28#include <sound/minors.h>
  29#include <sound/info.h>
  30#include <sound/control.h>
  31
  32/* max number of user-defined controls */
  33#define MAX_USER_CONTROLS       32
  34
  35struct snd_kctl_ioctl {
  36        struct list_head list;          /* list of all ioctls */
  37        snd_kctl_ioctl_func_t fioctl;
  38};
  39
  40static DECLARE_RWSEM(snd_ioctl_rwsem);
  41static LIST_HEAD(snd_control_ioctls);
  42#ifdef CONFIG_COMPAT
  43static LIST_HEAD(snd_control_compat_ioctls);
  44#endif
  45
  46static int snd_ctl_open(struct inode *inode, struct file *file)
  47{
  48        unsigned long flags;
  49        struct snd_card *card;
  50        struct snd_ctl_file *ctl;
  51        int err;
  52
  53        card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  54        if (!card) {
  55                err = -ENODEV;
  56                goto __error1;
  57        }
  58        err = snd_card_file_add(card, file);
  59        if (err < 0) {
  60                err = -ENODEV;
  61                goto __error1;
  62        }
  63        if (!try_module_get(card->module)) {
  64                err = -EFAULT;
  65                goto __error2;
  66        }
  67        ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  68        if (ctl == NULL) {
  69                err = -ENOMEM;
  70                goto __error;
  71        }
  72        INIT_LIST_HEAD(&ctl->events);
  73        init_waitqueue_head(&ctl->change_sleep);
  74        spin_lock_init(&ctl->read_lock);
  75        ctl->card = card;
  76        ctl->prefer_pcm_subdevice = -1;
  77        ctl->prefer_rawmidi_subdevice = -1;
  78        ctl->pid = current->pid;
  79        file->private_data = ctl;
  80        write_lock_irqsave(&card->ctl_files_rwlock, flags);
  81        list_add_tail(&ctl->list, &card->ctl_files);
  82        write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  83        return 0;
  84
  85      __error:
  86        module_put(card->module);
  87      __error2:
  88        snd_card_file_remove(card, file);
  89      __error1:
  90        return err;
  91}
  92
  93static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
  94{
  95        unsigned long flags;
  96        struct snd_kctl_event *cread;
  97        
  98        spin_lock_irqsave(&ctl->read_lock, flags);
  99        while (!list_empty(&ctl->events)) {
 100                cread = snd_kctl_event(ctl->events.next);
 101                list_del(&cread->list);
 102                kfree(cread);
 103        }
 104        spin_unlock_irqrestore(&ctl->read_lock, flags);
 105}
 106
 107static int snd_ctl_release(struct inode *inode, struct file *file)
 108{
 109        unsigned long flags;
 110        struct snd_card *card;
 111        struct snd_ctl_file *ctl;
 112        struct snd_kcontrol *control;
 113        unsigned int idx;
 114
 115        ctl = file->private_data;
 116        file->private_data = NULL;
 117        card = ctl->card;
 118        write_lock_irqsave(&card->ctl_files_rwlock, flags);
 119        list_del(&ctl->list);
 120        write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 121        down_write(&card->controls_rwsem);
 122        list_for_each_entry(control, &card->controls, list)
 123                for (idx = 0; idx < control->count; idx++)
 124                        if (control->vd[idx].owner == ctl)
 125                                control->vd[idx].owner = NULL;
 126        up_write(&card->controls_rwsem);
 127        snd_ctl_empty_read_queue(ctl);
 128        kfree(ctl);
 129        module_put(card->module);
 130        snd_card_file_remove(card, file);
 131        return 0;
 132}
 133
 134void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 135                    struct snd_ctl_elem_id *id)
 136{
 137        unsigned long flags;
 138        struct snd_ctl_file *ctl;
 139        struct snd_kctl_event *ev;
 140        
 141        if (snd_BUG_ON(!card || !id))
 142                return;
 143        read_lock(&card->ctl_files_rwlock);
 144#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 145        card->mixer_oss_change_count++;
 146#endif
 147        list_for_each_entry(ctl, &card->ctl_files, list) {
 148                if (!ctl->subscribed)
 149                        continue;
 150                spin_lock_irqsave(&ctl->read_lock, flags);
 151                list_for_each_entry(ev, &ctl->events, list) {
 152                        if (ev->id.numid == id->numid) {
 153                                ev->mask |= mask;
 154                                goto _found;
 155                        }
 156                }
 157                ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 158                if (ev) {
 159                        ev->id = *id;
 160                        ev->mask = mask;
 161                        list_add_tail(&ev->list, &ctl->events);
 162                } else {
 163                        snd_printk(KERN_ERR "No memory available to allocate event\n");
 164                }
 165        _found:
 166                wake_up(&ctl->change_sleep);
 167                spin_unlock_irqrestore(&ctl->read_lock, flags);
 168                kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 169        }
 170        read_unlock(&card->ctl_files_rwlock);
 171}
 172
 173EXPORT_SYMBOL(snd_ctl_notify);
 174
 175/**
 176 * snd_ctl_new - create a control instance from the template
 177 * @control: the control template
 178 * @access: the default control access
 179 *
 180 * Allocates a new struct snd_kcontrol instance and copies the given template 
 181 * to the new instance. It does not copy volatile data (access).
 182 *
 183 * Returns the pointer of the new instance, or NULL on failure.
 184 */
 185static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 186                                        unsigned int access)
 187{
 188        struct snd_kcontrol *kctl;
 189        unsigned int idx;
 190        
 191        if (snd_BUG_ON(!control || !control->count))
 192                return NULL;
 193        kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 194        if (kctl == NULL) {
 195                snd_printk(KERN_ERR "Cannot allocate control instance\n");
 196                return NULL;
 197        }
 198        *kctl = *control;
 199        for (idx = 0; idx < kctl->count; idx++)
 200                kctl->vd[idx].access = access;
 201        return kctl;
 202}
 203
 204/**
 205 * snd_ctl_new1 - create a control instance from the template
 206 * @ncontrol: the initialization record
 207 * @private_data: the private data to set
 208 *
 209 * Allocates a new struct snd_kcontrol instance and initialize from the given 
 210 * template.  When the access field of ncontrol is 0, it's assumed as
 211 * READWRITE access. When the count field is 0, it's assumes as one.
 212 *
 213 * Returns the pointer of the newly generated instance, or NULL on failure.
 214 */
 215struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 216                                  void *private_data)
 217{
 218        struct snd_kcontrol kctl;
 219        unsigned int access;
 220        
 221        if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 222                return NULL;
 223        memset(&kctl, 0, sizeof(kctl));
 224        kctl.id.iface = ncontrol->iface;
 225        kctl.id.device = ncontrol->device;
 226        kctl.id.subdevice = ncontrol->subdevice;
 227        if (ncontrol->name) {
 228                strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 229                if (strcmp(ncontrol->name, kctl.id.name) != 0)
 230                        snd_printk(KERN_WARNING
 231                                   "Control name '%s' truncated to '%s'\n",
 232                                   ncontrol->name, kctl.id.name);
 233        }
 234        kctl.id.index = ncontrol->index;
 235        kctl.count = ncontrol->count ? ncontrol->count : 1;
 236        access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 237                 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 238                                      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 239                                      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 240                                      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 241        kctl.info = ncontrol->info;
 242        kctl.get = ncontrol->get;
 243        kctl.put = ncontrol->put;
 244        kctl.tlv.p = ncontrol->tlv.p;
 245        kctl.private_value = ncontrol->private_value;
 246        kctl.private_data = private_data;
 247        return snd_ctl_new(&kctl, access);
 248}
 249
 250EXPORT_SYMBOL(snd_ctl_new1);
 251
 252/**
 253 * snd_ctl_free_one - release the control instance
 254 * @kcontrol: the control instance
 255 *
 256 * Releases the control instance created via snd_ctl_new()
 257 * or snd_ctl_new1().
 258 * Don't call this after the control was added to the card.
 259 */
 260void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 261{
 262        if (kcontrol) {
 263                if (kcontrol->private_free)
 264                        kcontrol->private_free(kcontrol);
 265                kfree(kcontrol);
 266        }
 267}
 268
 269EXPORT_SYMBOL(snd_ctl_free_one);
 270
 271static unsigned int snd_ctl_hole_check(struct snd_card *card,
 272                                       unsigned int count)
 273{
 274        struct snd_kcontrol *kctl;
 275
 276        list_for_each_entry(kctl, &card->controls, list) {
 277                if ((kctl->id.numid <= card->last_numid &&
 278                     kctl->id.numid + kctl->count > card->last_numid) ||
 279                    (kctl->id.numid <= card->last_numid + count - 1 &&
 280                     kctl->id.numid + kctl->count > card->last_numid + count - 1))
 281                        return card->last_numid = kctl->id.numid + kctl->count - 1;
 282        }
 283        return card->last_numid;
 284}
 285
 286static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 287{
 288        unsigned int last_numid, iter = 100000;
 289
 290        last_numid = card->last_numid;
 291        while (last_numid != snd_ctl_hole_check(card, count)) {
 292                if (--iter == 0) {
 293                        /* this situation is very unlikely */
 294                        snd_printk(KERN_ERR "unable to allocate new control numid\n");
 295                        return -ENOMEM;
 296                }
 297                last_numid = card->last_numid;
 298        }
 299        return 0;
 300}
 301
 302/**
 303 * snd_ctl_add - add the control instance to the card
 304 * @card: the card instance
 305 * @kcontrol: the control instance to add
 306 *
 307 * Adds the control instance created via snd_ctl_new() or
 308 * snd_ctl_new1() to the given card. Assigns also an unique
 309 * numid used for fast search.
 310 *
 311 * Returns zero if successful, or a negative error code on failure.
 312 *
 313 * It frees automatically the control which cannot be added.
 314 */
 315int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 316{
 317        struct snd_ctl_elem_id id;
 318        unsigned int idx;
 319        int err = -EINVAL;
 320
 321        if (! kcontrol)
 322                return err;
 323        if (snd_BUG_ON(!card || !kcontrol->info))
 324                goto error;
 325        id = kcontrol->id;
 326        down_write(&card->controls_rwsem);
 327        if (snd_ctl_find_id(card, &id)) {
 328                up_write(&card->controls_rwsem);
 329                snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 330                                        id.iface,
 331                                        id.device,
 332                                        id.subdevice,
 333                                        id.name,
 334                                        id.index);
 335                err = -EBUSY;
 336                goto error;
 337        }
 338        if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 339                up_write(&card->controls_rwsem);
 340                err = -ENOMEM;
 341                goto error;
 342        }
 343        list_add_tail(&kcontrol->list, &card->controls);
 344        card->controls_count += kcontrol->count;
 345        kcontrol->id.numid = card->last_numid + 1;
 346        card->last_numid += kcontrol->count;
 347        up_write(&card->controls_rwsem);
 348        for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 349                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 350        return 0;
 351
 352 error:
 353        snd_ctl_free_one(kcontrol);
 354        return err;
 355}
 356
 357EXPORT_SYMBOL(snd_ctl_add);
 358
 359/**
 360 * snd_ctl_remove - remove the control from the card and release it
 361 * @card: the card instance
 362 * @kcontrol: the control instance to remove
 363 *
 364 * Removes the control from the card and then releases the instance.
 365 * You don't need to call snd_ctl_free_one(). You must be in
 366 * the write lock - down_write(&card->controls_rwsem).
 367 * 
 368 * Returns 0 if successful, or a negative error code on failure.
 369 */
 370int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 371{
 372        struct snd_ctl_elem_id id;
 373        unsigned int idx;
 374
 375        if (snd_BUG_ON(!card || !kcontrol))
 376                return -EINVAL;
 377        list_del(&kcontrol->list);
 378        card->controls_count -= kcontrol->count;
 379        id = kcontrol->id;
 380        for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 381                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 382        snd_ctl_free_one(kcontrol);
 383        return 0;
 384}
 385
 386EXPORT_SYMBOL(snd_ctl_remove);
 387
 388/**
 389 * snd_ctl_remove_id - remove the control of the given id and release it
 390 * @card: the card instance
 391 * @id: the control id to remove
 392 *
 393 * Finds the control instance with the given id, removes it from the
 394 * card list and releases it.
 395 * 
 396 * Returns 0 if successful, or a negative error code on failure.
 397 */
 398int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 399{
 400        struct snd_kcontrol *kctl;
 401        int ret;
 402
 403        down_write(&card->controls_rwsem);
 404        kctl = snd_ctl_find_id(card, id);
 405        if (kctl == NULL) {
 406                up_write(&card->controls_rwsem);
 407                return -ENOENT;
 408        }
 409        ret = snd_ctl_remove(card, kctl);
 410        up_write(&card->controls_rwsem);
 411        return ret;
 412}
 413
 414EXPORT_SYMBOL(snd_ctl_remove_id);
 415
 416/**
 417 * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 418 * @file: active control handle
 419 * @id: the control id to remove
 420 *
 421 * Finds the control instance with the given id, removes it from the
 422 * card list and releases it.
 423 * 
 424 * Returns 0 if successful, or a negative error code on failure.
 425 */
 426static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
 427                                      struct snd_ctl_elem_id *id)
 428{
 429        struct snd_card *card = file->card;
 430        struct snd_kcontrol *kctl;
 431        int idx, ret;
 432
 433        down_write(&card->controls_rwsem);
 434        kctl = snd_ctl_find_id(card, id);
 435        if (kctl == NULL) {
 436                up_write(&card->controls_rwsem);
 437                return -ENOENT;
 438        }
 439        for (idx = 0; idx < kctl->count; idx++)
 440                if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 441                        up_write(&card->controls_rwsem);
 442                        return -EBUSY;
 443                }
 444        ret = snd_ctl_remove(card, kctl);
 445        up_write(&card->controls_rwsem);
 446        return ret;
 447}
 448
 449/**
 450 * snd_ctl_rename_id - replace the id of a control on the card
 451 * @card: the card instance
 452 * @src_id: the old id
 453 * @dst_id: the new id
 454 *
 455 * Finds the control with the old id from the card, and replaces the
 456 * id with the new one.
 457 *
 458 * Returns zero if successful, or a negative error code on failure.
 459 */
 460int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 461                      struct snd_ctl_elem_id *dst_id)
 462{
 463        struct snd_kcontrol *kctl;
 464
 465        down_write(&card->controls_rwsem);
 466        kctl = snd_ctl_find_id(card, src_id);
 467        if (kctl == NULL) {
 468                up_write(&card->controls_rwsem);
 469                return -ENOENT;
 470        }
 471        kctl->id = *dst_id;
 472        kctl->id.numid = card->last_numid + 1;
 473        card->last_numid += kctl->count;
 474        up_write(&card->controls_rwsem);
 475        return 0;
 476}
 477
 478EXPORT_SYMBOL(snd_ctl_rename_id);
 479
 480/**
 481 * snd_ctl_find_numid - find the control instance with the given number-id
 482 * @card: the card instance
 483 * @numid: the number-id to search
 484 *
 485 * Finds the control instance with the given number-id from the card.
 486 *
 487 * Returns the pointer of the instance if found, or NULL if not.
 488 *
 489 * The caller must down card->controls_rwsem before calling this function
 490 * (if the race condition can happen).
 491 */
 492struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 493{
 494        struct snd_kcontrol *kctl;
 495
 496        if (snd_BUG_ON(!card || !numid))
 497                return NULL;
 498        list_for_each_entry(kctl, &card->controls, list) {
 499                if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 500                        return kctl;
 501        }
 502        return NULL;
 503}
 504
 505EXPORT_SYMBOL(snd_ctl_find_numid);
 506
 507/**
 508 * snd_ctl_find_id - find the control instance with the given id
 509 * @card: the card instance
 510 * @id: the id to search
 511 *
 512 * Finds the control instance with the given id from the card.
 513 *
 514 * Returns the pointer of the instance if found, or NULL if not.
 515 *
 516 * The caller must down card->controls_rwsem before calling this function
 517 * (if the race condition can happen).
 518 */
 519struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 520                                     struct snd_ctl_elem_id *id)
 521{
 522        struct snd_kcontrol *kctl;
 523
 524        if (snd_BUG_ON(!card || !id))
 525                return NULL;
 526        if (id->numid != 0)
 527                return snd_ctl_find_numid(card, id->numid);
 528        list_for_each_entry(kctl, &card->controls, list) {
 529                if (kctl->id.iface != id->iface)
 530                        continue;
 531                if (kctl->id.device != id->device)
 532                        continue;
 533                if (kctl->id.subdevice != id->subdevice)
 534                        continue;
 535                if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 536                        continue;
 537                if (kctl->id.index > id->index)
 538                        continue;
 539                if (kctl->id.index + kctl->count <= id->index)
 540                        continue;
 541                return kctl;
 542        }
 543        return NULL;
 544}
 545
 546EXPORT_SYMBOL(snd_ctl_find_id);
 547
 548static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 549                             unsigned int cmd, void __user *arg)
 550{
 551        struct snd_ctl_card_info *info;
 552
 553        info = kzalloc(sizeof(*info), GFP_KERNEL);
 554        if (! info)
 555                return -ENOMEM;
 556        down_read(&snd_ioctl_rwsem);
 557        info->card = card->number;
 558        strlcpy(info->id, card->id, sizeof(info->id));
 559        strlcpy(info->driver, card->driver, sizeof(info->driver));
 560        strlcpy(info->name, card->shortname, sizeof(info->name));
 561        strlcpy(info->longname, card->longname, sizeof(info->longname));
 562        strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 563        strlcpy(info->components, card->components, sizeof(info->components));
 564        up_read(&snd_ioctl_rwsem);
 565        if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 566                kfree(info);
 567                return -EFAULT;
 568        }
 569        kfree(info);
 570        return 0;
 571}
 572
 573static int snd_ctl_elem_list(struct snd_card *card,
 574                             struct snd_ctl_elem_list __user *_list)
 575{
 576        struct list_head *plist;
 577        struct snd_ctl_elem_list list;
 578        struct snd_kcontrol *kctl;
 579        struct snd_ctl_elem_id *dst, *id;
 580        unsigned int offset, space, first, jidx;
 581        
 582        if (copy_from_user(&list, _list, sizeof(list)))
 583                return -EFAULT;
 584        offset = list.offset;
 585        space = list.space;
 586        first = 0;
 587        /* try limit maximum space */
 588        if (space > 16384)
 589                return -ENOMEM;
 590        if (space > 0) {
 591                /* allocate temporary buffer for atomic operation */
 592                dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 593                if (dst == NULL)
 594                        return -ENOMEM;
 595                down_read(&card->controls_rwsem);
 596                list.count = card->controls_count;
 597                plist = card->controls.next;
 598                while (plist != &card->controls) {
 599                        if (offset == 0)
 600                                break;
 601                        kctl = snd_kcontrol(plist);
 602                        if (offset < kctl->count)
 603                                break;
 604                        offset -= kctl->count;
 605                        plist = plist->next;
 606                }
 607                list.used = 0;
 608                id = dst;
 609                while (space > 0 && plist != &card->controls) {
 610                        kctl = snd_kcontrol(plist);
 611                        for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 612                                snd_ctl_build_ioff(id, kctl, jidx);
 613                                id++;
 614                                space--;
 615                                list.used++;
 616                        }
 617                        plist = plist->next;
 618                        offset = 0;
 619                }
 620                up_read(&card->controls_rwsem);
 621                if (list.used > 0 &&
 622                    copy_to_user(list.pids, dst,
 623                                 list.used * sizeof(struct snd_ctl_elem_id))) {
 624                        vfree(dst);
 625                        return -EFAULT;
 626                }
 627                vfree(dst);
 628        } else {
 629                down_read(&card->controls_rwsem);
 630                list.count = card->controls_count;
 631                up_read(&card->controls_rwsem);
 632        }
 633        if (copy_to_user(_list, &list, sizeof(list)))
 634                return -EFAULT;
 635        return 0;
 636}
 637
 638static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 639                             struct snd_ctl_elem_info *info)
 640{
 641        struct snd_card *card = ctl->card;
 642        struct snd_kcontrol *kctl;
 643        struct snd_kcontrol_volatile *vd;
 644        unsigned int index_offset;
 645        int result;
 646        
 647        down_read(&card->controls_rwsem);
 648        kctl = snd_ctl_find_id(card, &info->id);
 649        if (kctl == NULL) {
 650                up_read(&card->controls_rwsem);
 651                return -ENOENT;
 652        }
 653#ifdef CONFIG_SND_DEBUG
 654        info->access = 0;
 655#endif
 656        result = kctl->info(kctl, info);
 657        if (result >= 0) {
 658                snd_BUG_ON(info->access);
 659                index_offset = snd_ctl_get_ioff(kctl, &info->id);
 660                vd = &kctl->vd[index_offset];
 661                snd_ctl_build_ioff(&info->id, kctl, index_offset);
 662                info->access = vd->access;
 663                if (vd->owner) {
 664                        info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 665                        if (vd->owner == ctl)
 666                                info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 667                        info->owner = vd->owner_pid;
 668                } else {
 669                        info->owner = -1;
 670                }
 671        }
 672        up_read(&card->controls_rwsem);
 673        return result;
 674}
 675
 676static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 677                                  struct snd_ctl_elem_info __user *_info)
 678{
 679        struct snd_ctl_elem_info info;
 680        int result;
 681
 682        if (copy_from_user(&info, _info, sizeof(info)))
 683                return -EFAULT;
 684        snd_power_lock(ctl->card);
 685        result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 686        if (result >= 0)
 687                result = snd_ctl_elem_info(ctl, &info);
 688        snd_power_unlock(ctl->card);
 689        if (result >= 0)
 690                if (copy_to_user(_info, &info, sizeof(info)))
 691                        return -EFAULT;
 692        return result;
 693}
 694
 695static int snd_ctl_elem_read(struct snd_card *card,
 696                             struct snd_ctl_elem_value *control)
 697{
 698        struct snd_kcontrol *kctl;
 699        struct snd_kcontrol_volatile *vd;
 700        unsigned int index_offset;
 701        int result;
 702
 703        down_read(&card->controls_rwsem);
 704        kctl = snd_ctl_find_id(card, &control->id);
 705        if (kctl == NULL) {
 706                result = -ENOENT;
 707        } else {
 708                index_offset = snd_ctl_get_ioff(kctl, &control->id);
 709                vd = &kctl->vd[index_offset];
 710                if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 711                    kctl->get != NULL) {
 712                        snd_ctl_build_ioff(&control->id, kctl, index_offset);
 713                        result = kctl->get(kctl, control);
 714                } else
 715                        result = -EPERM;
 716        }
 717        up_read(&card->controls_rwsem);
 718        return result;
 719}
 720
 721static int snd_ctl_elem_read_user(struct snd_card *card,
 722                                  struct snd_ctl_elem_value __user *_control)
 723{
 724        struct snd_ctl_elem_value *control;
 725        int result;
 726
 727        control = memdup_user(_control, sizeof(*control));
 728        if (IS_ERR(control))
 729                return PTR_ERR(control);
 730
 731        snd_power_lock(card);
 732        result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 733        if (result >= 0)
 734                result = snd_ctl_elem_read(card, control);
 735        snd_power_unlock(card);
 736        if (result >= 0)
 737                if (copy_to_user(_control, control, sizeof(*control)))
 738                        result = -EFAULT;
 739        kfree(control);
 740        return result;
 741}
 742
 743static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 744                              struct snd_ctl_elem_value *control)
 745{
 746        struct snd_kcontrol *kctl;
 747        struct snd_kcontrol_volatile *vd;
 748        unsigned int index_offset;
 749        int result;
 750
 751        down_read(&card->controls_rwsem);
 752        kctl = snd_ctl_find_id(card, &control->id);
 753        if (kctl == NULL) {
 754                result = -ENOENT;
 755        } else {
 756                index_offset = snd_ctl_get_ioff(kctl, &control->id);
 757                vd = &kctl->vd[index_offset];
 758                if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 759                    kctl->put == NULL ||
 760                    (file && vd->owner && vd->owner != file)) {
 761                        result = -EPERM;
 762                } else {
 763                        snd_ctl_build_ioff(&control->id, kctl, index_offset);
 764                        result = kctl->put(kctl, control);
 765                }
 766                if (result > 0) {
 767                        up_read(&card->controls_rwsem);
 768                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 769                                       &control->id);
 770                        return 0;
 771                }
 772        }
 773        up_read(&card->controls_rwsem);
 774        return result;
 775}
 776
 777static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 778                                   struct snd_ctl_elem_value __user *_control)
 779{
 780        struct snd_ctl_elem_value *control;
 781        struct snd_card *card;
 782        int result;
 783
 784        control = memdup_user(_control, sizeof(*control));
 785        if (IS_ERR(control))
 786                return PTR_ERR(control);
 787
 788        card = file->card;
 789        snd_power_lock(card);
 790        result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 791        if (result >= 0)
 792                result = snd_ctl_elem_write(card, file, control);
 793        snd_power_unlock(card);
 794        if (result >= 0)
 795                if (copy_to_user(_control, control, sizeof(*control)))
 796                        result = -EFAULT;
 797        kfree(control);
 798        return result;
 799}
 800
 801static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 802                             struct snd_ctl_elem_id __user *_id)
 803{
 804        struct snd_card *card = file->card;
 805        struct snd_ctl_elem_id id;
 806        struct snd_kcontrol *kctl;
 807        struct snd_kcontrol_volatile *vd;
 808        int result;
 809        
 810        if (copy_from_user(&id, _id, sizeof(id)))
 811                return -EFAULT;
 812        down_write(&card->controls_rwsem);
 813        kctl = snd_ctl_find_id(card, &id);
 814        if (kctl == NULL) {
 815                result = -ENOENT;
 816        } else {
 817                vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 818                if (vd->owner != NULL)
 819                        result = -EBUSY;
 820                else {
 821                        vd->owner = file;
 822                        vd->owner_pid = current->pid;
 823                        result = 0;
 824                }
 825        }
 826        up_write(&card->controls_rwsem);
 827        return result;
 828}
 829
 830static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 831                               struct snd_ctl_elem_id __user *_id)
 832{
 833        struct snd_card *card = file->card;
 834        struct snd_ctl_elem_id id;
 835        struct snd_kcontrol *kctl;
 836        struct snd_kcontrol_volatile *vd;
 837        int result;
 838        
 839        if (copy_from_user(&id, _id, sizeof(id)))
 840                return -EFAULT;
 841        down_write(&card->controls_rwsem);
 842        kctl = snd_ctl_find_id(card, &id);
 843        if (kctl == NULL) {
 844                result = -ENOENT;
 845        } else {
 846                vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 847                if (vd->owner == NULL)
 848                        result = -EINVAL;
 849                else if (vd->owner != file)
 850                        result = -EPERM;
 851                else {
 852                        vd->owner = NULL;
 853                        vd->owner_pid = 0;
 854                        result = 0;
 855                }
 856        }
 857        up_write(&card->controls_rwsem);
 858        return result;
 859}
 860
 861struct user_element {
 862        struct snd_ctl_elem_info info;
 863        void *elem_data;                /* element data */
 864        unsigned long elem_data_size;   /* size of element data in bytes */
 865        void *tlv_data;                 /* TLV data */
 866        unsigned long tlv_data_size;    /* TLV data size */
 867        void *priv_data;                /* private data (like strings for enumerated type) */
 868        unsigned long priv_data_size;   /* size of private data in bytes */
 869};
 870
 871static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 872                                  struct snd_ctl_elem_info *uinfo)
 873{
 874        struct user_element *ue = kcontrol->private_data;
 875
 876        *uinfo = ue->info;
 877        return 0;
 878}
 879
 880static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 881                                 struct snd_ctl_elem_value *ucontrol)
 882{
 883        struct user_element *ue = kcontrol->private_data;
 884
 885        memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 886        return 0;
 887}
 888
 889static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 890                                 struct snd_ctl_elem_value *ucontrol)
 891{
 892        int change;
 893        struct user_element *ue = kcontrol->private_data;
 894        
 895        change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 896        if (change)
 897                memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 898        return change;
 899}
 900
 901static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 902                                 int op_flag,
 903                                 unsigned int size,
 904                                 unsigned int __user *tlv)
 905{
 906        struct user_element *ue = kcontrol->private_data;
 907        int change = 0;
 908        void *new_data;
 909
 910        if (op_flag > 0) {
 911                if (size > 1024 * 128)  /* sane value */
 912                        return -EINVAL;
 913
 914                new_data = memdup_user(tlv, size);
 915                if (IS_ERR(new_data))
 916                        return PTR_ERR(new_data);
 917                change = ue->tlv_data_size != size;
 918                if (!change)
 919                        change = memcmp(ue->tlv_data, new_data, size);
 920                kfree(ue->tlv_data);
 921                ue->tlv_data = new_data;
 922                ue->tlv_data_size = size;
 923        } else {
 924                if (! ue->tlv_data_size || ! ue->tlv_data)
 925                        return -ENXIO;
 926                if (size < ue->tlv_data_size)
 927                        return -ENOSPC;
 928                if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 929                        return -EFAULT;
 930        }
 931        return change;
 932}
 933
 934static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 935{
 936        struct user_element *ue = kcontrol->private_data;
 937        if (ue->tlv_data)
 938                kfree(ue->tlv_data);
 939        kfree(ue);
 940}
 941
 942static int snd_ctl_elem_add(struct snd_ctl_file *file,
 943                            struct snd_ctl_elem_info *info, int replace)
 944{
 945        struct snd_card *card = file->card;
 946        struct snd_kcontrol kctl, *_kctl;
 947        unsigned int access;
 948        long private_size;
 949        struct user_element *ue;
 950        int idx, err;
 951        
 952        if (card->user_ctl_count >= MAX_USER_CONTROLS)
 953                return -ENOMEM;
 954        if (info->count > 1024)
 955                return -EINVAL;
 956        access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 957                (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 958                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 959                                 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 960        info->id.numid = 0;
 961        memset(&kctl, 0, sizeof(kctl));
 962        down_write(&card->controls_rwsem);
 963        _kctl = snd_ctl_find_id(card, &info->id);
 964        err = 0;
 965        if (_kctl) {
 966                if (replace)
 967                        err = snd_ctl_remove(card, _kctl);
 968                else
 969                        err = -EBUSY;
 970        } else {
 971                if (replace)
 972                        err = -ENOENT;
 973        }
 974        up_write(&card->controls_rwsem);
 975        if (err < 0)
 976                return err;
 977        memcpy(&kctl.id, &info->id, sizeof(info->id));
 978        kctl.count = info->owner ? info->owner : 1;
 979        access |= SNDRV_CTL_ELEM_ACCESS_USER;
 980        kctl.info = snd_ctl_elem_user_info;
 981        if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 982                kctl.get = snd_ctl_elem_user_get;
 983        if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 984                kctl.put = snd_ctl_elem_user_put;
 985        if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 986                kctl.tlv.c = snd_ctl_elem_user_tlv;
 987                access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 988        }
 989        switch (info->type) {
 990        case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 991        case SNDRV_CTL_ELEM_TYPE_INTEGER:
 992                private_size = sizeof(long);
 993                if (info->count > 128)
 994                        return -EINVAL;
 995                break;
 996        case SNDRV_CTL_ELEM_TYPE_INTEGER64:
 997                private_size = sizeof(long long);
 998                if (info->count > 64)
 999                        return -EINVAL;
1000                break;
1001        case SNDRV_CTL_ELEM_TYPE_BYTES:
1002                private_size = sizeof(unsigned char);
1003                if (info->count > 512)
1004                        return -EINVAL;
1005                break;
1006        case SNDRV_CTL_ELEM_TYPE_IEC958:
1007                private_size = sizeof(struct snd_aes_iec958);
1008                if (info->count != 1)
1009                        return -EINVAL;
1010                break;
1011        default:
1012                return -EINVAL;
1013        }
1014        private_size *= info->count;
1015        ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1016        if (ue == NULL)
1017                return -ENOMEM;
1018        ue->info = *info;
1019        ue->info.access = 0;
1020        ue->elem_data = (char *)ue + sizeof(*ue);
1021        ue->elem_data_size = private_size;
1022        kctl.private_free = snd_ctl_elem_user_free;
1023        _kctl = snd_ctl_new(&kctl, access);
1024        if (_kctl == NULL) {
1025                kfree(ue);
1026                return -ENOMEM;
1027        }
1028        _kctl->private_data = ue;
1029        for (idx = 0; idx < _kctl->count; idx++)
1030                _kctl->vd[idx].owner = file;
1031        err = snd_ctl_add(card, _kctl);
1032        if (err < 0)
1033                return err;
1034
1035        down_write(&card->controls_rwsem);
1036        card->user_ctl_count++;
1037        up_write(&card->controls_rwsem);
1038
1039        return 0;
1040}
1041
1042static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1043                                 struct snd_ctl_elem_info __user *_info, int replace)
1044{
1045        struct snd_ctl_elem_info info;
1046        if (copy_from_user(&info, _info, sizeof(info)))
1047                return -EFAULT;
1048        return snd_ctl_elem_add(file, &info, replace);
1049}
1050
1051static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1052                               struct snd_ctl_elem_id __user *_id)
1053{
1054        struct snd_ctl_elem_id id;
1055        int err;
1056
1057        if (copy_from_user(&id, _id, sizeof(id)))
1058                return -EFAULT;
1059        err = snd_ctl_remove_unlocked_id(file, &id);
1060        if (! err) {
1061                struct snd_card *card = file->card;
1062                down_write(&card->controls_rwsem);
1063                card->user_ctl_count--;
1064                up_write(&card->controls_rwsem);
1065        }
1066        return err;
1067}
1068
1069static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1070{
1071        int subscribe;
1072        if (get_user(subscribe, ptr))
1073                return -EFAULT;
1074        if (subscribe < 0) {
1075                subscribe = file->subscribed;
1076                if (put_user(subscribe, ptr))
1077                        return -EFAULT;
1078                return 0;
1079        }
1080        if (subscribe) {
1081                file->subscribed = 1;
1082                return 0;
1083        } else if (file->subscribed) {
1084                snd_ctl_empty_read_queue(file);
1085                file->subscribed = 0;
1086        }
1087        return 0;
1088}
1089
1090static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1091                             struct snd_ctl_tlv __user *_tlv,
1092                             int op_flag)
1093{
1094        struct snd_card *card = file->card;
1095        struct snd_ctl_tlv tlv;
1096        struct snd_kcontrol *kctl;
1097        struct snd_kcontrol_volatile *vd;
1098        unsigned int len;
1099        int err = 0;
1100
1101        if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1102                return -EFAULT;
1103        if (tlv.length < sizeof(unsigned int) * 3)
1104                return -EINVAL;
1105        down_read(&card->controls_rwsem);
1106        kctl = snd_ctl_find_numid(card, tlv.numid);
1107        if (kctl == NULL) {
1108                err = -ENOENT;
1109                goto __kctl_end;
1110        }
1111        if (kctl->tlv.p == NULL) {
1112                err = -ENXIO;
1113                goto __kctl_end;
1114        }
1115        vd = &kctl->vd[tlv.numid - kctl->id.numid];
1116        if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1117            (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1118            (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1119                err = -ENXIO;
1120                goto __kctl_end;
1121        }
1122        if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1123                if (file && vd->owner != NULL && vd->owner != file) {
1124                        err = -EPERM;
1125                        goto __kctl_end;
1126                }
1127                err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1128                if (err > 0) {
1129                        up_read(&card->controls_rwsem);
1130                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1131                        return 0;
1132                }
1133        } else {
1134                if (op_flag) {
1135                        err = -ENXIO;
1136                        goto __kctl_end;
1137                }
1138                len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1139                if (tlv.length < len) {
1140                        err = -ENOMEM;
1141                        goto __kctl_end;
1142                }
1143                if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1144                        err = -EFAULT;
1145        }
1146      __kctl_end:
1147        up_read(&card->controls_rwsem);
1148        return err;
1149}
1150
1151static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1152{
1153        struct snd_ctl_file *ctl;
1154        struct snd_card *card;
1155        struct snd_kctl_ioctl *p;
1156        void __user *argp = (void __user *)arg;
1157        int __user *ip = argp;
1158        int err;
1159
1160        ctl = file->private_data;
1161        card = ctl->card;
1162        if (snd_BUG_ON(!card))
1163                return -ENXIO;
1164        switch (cmd) {
1165        case SNDRV_CTL_IOCTL_PVERSION:
1166                return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1167        case SNDRV_CTL_IOCTL_CARD_INFO:
1168                return snd_ctl_card_info(card, ctl, cmd, argp);
1169        case SNDRV_CTL_IOCTL_ELEM_LIST:
1170                return snd_ctl_elem_list(card, argp);
1171        case SNDRV_CTL_IOCTL_ELEM_INFO:
1172                return snd_ctl_elem_info_user(ctl, argp);
1173        case SNDRV_CTL_IOCTL_ELEM_READ:
1174                return snd_ctl_elem_read_user(card, argp);
1175        case SNDRV_CTL_IOCTL_ELEM_WRITE:
1176                return snd_ctl_elem_write_user(ctl, argp);
1177        case SNDRV_CTL_IOCTL_ELEM_LOCK:
1178                return snd_ctl_elem_lock(ctl, argp);
1179        case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1180                return snd_ctl_elem_unlock(ctl, argp);
1181        case SNDRV_CTL_IOCTL_ELEM_ADD:
1182                return snd_ctl_elem_add_user(ctl, argp, 0);
1183        case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1184                return snd_ctl_elem_add_user(ctl, argp, 1);
1185        case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1186                return snd_ctl_elem_remove(ctl, argp);
1187        case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1188                return snd_ctl_subscribe_events(ctl, ip);
1189        case SNDRV_CTL_IOCTL_TLV_READ:
1190                return snd_ctl_tlv_ioctl(ctl, argp, 0);
1191        case SNDRV_CTL_IOCTL_TLV_WRITE:
1192                return snd_ctl_tlv_ioctl(ctl, argp, 1);
1193        case SNDRV_CTL_IOCTL_TLV_COMMAND:
1194                return snd_ctl_tlv_ioctl(ctl, argp, -1);
1195        case SNDRV_CTL_IOCTL_POWER:
1196                return -ENOPROTOOPT;
1197        case SNDRV_CTL_IOCTL_POWER_STATE:
1198#ifdef CONFIG_PM
1199                return put_user(card->power_state, ip) ? -EFAULT : 0;
1200#else
1201                return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1202#endif
1203        }
1204        down_read(&snd_ioctl_rwsem);
1205        list_for_each_entry(p, &snd_control_ioctls, list) {
1206                err = p->fioctl(card, ctl, cmd, arg);
1207                if (err != -ENOIOCTLCMD) {
1208                        up_read(&snd_ioctl_rwsem);
1209                        return err;
1210                }
1211        }
1212        up_read(&snd_ioctl_rwsem);
1213        snd_printdd("unknown ioctl = 0x%x\n", cmd);
1214        return -ENOTTY;
1215}
1216
1217static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1218                            size_t count, loff_t * offset)
1219{
1220        struct snd_ctl_file *ctl;
1221        int err = 0;
1222        ssize_t result = 0;
1223
1224        ctl = file->private_data;
1225        if (snd_BUG_ON(!ctl || !ctl->card))
1226                return -ENXIO;
1227        if (!ctl->subscribed)
1228                return -EBADFD;
1229        if (count < sizeof(struct snd_ctl_event))
1230                return -EINVAL;
1231        spin_lock_irq(&ctl->read_lock);
1232        while (count >= sizeof(struct snd_ctl_event)) {
1233                struct snd_ctl_event ev;
1234                struct snd_kctl_event *kev;
1235                while (list_empty(&ctl->events)) {
1236                        wait_queue_t wait;
1237                        if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1238                                err = -EAGAIN;
1239                                goto __end_lock;
1240                        }
1241                        init_waitqueue_entry(&wait, current);
1242                        add_wait_queue(&ctl->change_sleep, &wait);
1243                        set_current_state(TASK_INTERRUPTIBLE);
1244                        spin_unlock_irq(&ctl->read_lock);
1245                        schedule();
1246                        remove_wait_queue(&ctl->change_sleep, &wait);
1247                        if (signal_pending(current))
1248                                return -ERESTARTSYS;
1249                        spin_lock_irq(&ctl->read_lock);
1250                }
1251                kev = snd_kctl_event(ctl->events.next);
1252                ev.type = SNDRV_CTL_EVENT_ELEM;
1253                ev.data.elem.mask = kev->mask;
1254                ev.data.elem.id = kev->id;
1255                list_del(&kev->list);
1256                spin_unlock_irq(&ctl->read_lock);
1257                kfree(kev);
1258                if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1259                        err = -EFAULT;
1260                        goto __end;
1261                }
1262                spin_lock_irq(&ctl->read_lock);
1263                buffer += sizeof(struct snd_ctl_event);
1264                count -= sizeof(struct snd_ctl_event);
1265                result += sizeof(struct snd_ctl_event);
1266        }
1267      __end_lock:
1268        spin_unlock_irq(&ctl->read_lock);
1269      __end:
1270        return result > 0 ? result : err;
1271}
1272
1273static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1274{
1275        unsigned int mask;
1276        struct snd_ctl_file *ctl;
1277
1278        ctl = file->private_data;
1279        if (!ctl->subscribed)
1280                return 0;
1281        poll_wait(file, &ctl->change_sleep, wait);
1282
1283        mask = 0;
1284        if (!list_empty(&ctl->events))
1285                mask |= POLLIN | POLLRDNORM;
1286
1287        return mask;
1288}
1289
1290/*
1291 * register the device-specific control-ioctls.
1292 * called from each device manager like pcm.c, hwdep.c, etc.
1293 */
1294static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1295{
1296        struct snd_kctl_ioctl *pn;
1297
1298        pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1299        if (pn == NULL)
1300                return -ENOMEM;
1301        pn->fioctl = fcn;
1302        down_write(&snd_ioctl_rwsem);
1303        list_add_tail(&pn->list, lists);
1304        up_write(&snd_ioctl_rwsem);
1305        return 0;
1306}
1307
1308int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1309{
1310        return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1311}
1312
1313EXPORT_SYMBOL(snd_ctl_register_ioctl);
1314
1315#ifdef CONFIG_COMPAT
1316int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1317{
1318        return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1319}
1320
1321EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1322#endif
1323
1324/*
1325 * de-register the device-specific control-ioctls.
1326 */
1327static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1328                                     struct list_head *lists)
1329{
1330        struct snd_kctl_ioctl *p;
1331
1332        if (snd_BUG_ON(!fcn))
1333                return -EINVAL;
1334        down_write(&snd_ioctl_rwsem);
1335        list_for_each_entry(p, lists, list) {
1336                if (p->fioctl == fcn) {
1337                        list_del(&p->list);
1338                        up_write(&snd_ioctl_rwsem);
1339                        kfree(p);
1340                        return 0;
1341                }
1342        }
1343        up_write(&snd_ioctl_rwsem);
1344        snd_BUG();
1345        return -EINVAL;
1346}
1347
1348int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1349{
1350        return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1351}
1352
1353EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1354
1355#ifdef CONFIG_COMPAT
1356int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1357{
1358        return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1359}
1360
1361EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1362#endif
1363
1364static int snd_ctl_fasync(int fd, struct file * file, int on)
1365{
1366        struct snd_ctl_file *ctl;
1367
1368        ctl = file->private_data;
1369        return fasync_helper(fd, file, on, &ctl->fasync);
1370}
1371
1372/*
1373 * ioctl32 compat
1374 */
1375#ifdef CONFIG_COMPAT
1376#include "control_compat.c"
1377#else
1378#define snd_ctl_ioctl_compat    NULL
1379#endif
1380
1381/*
1382 *  INIT PART
1383 */
1384
1385static const struct file_operations snd_ctl_f_ops =
1386{
1387        .owner =        THIS_MODULE,
1388        .read =         snd_ctl_read,
1389        .open =         snd_ctl_open,
1390        .release =      snd_ctl_release,
1391        .poll =         snd_ctl_poll,
1392        .unlocked_ioctl =       snd_ctl_ioctl,
1393        .compat_ioctl = snd_ctl_ioctl_compat,
1394        .fasync =       snd_ctl_fasync,
1395};
1396
1397/*
1398 * registration of the control device
1399 */
1400static int snd_ctl_dev_register(struct snd_device *device)
1401{
1402        struct snd_card *card = device->device_data;
1403        int err, cardnum;
1404        char name[16];
1405
1406        if (snd_BUG_ON(!card))
1407                return -ENXIO;
1408        cardnum = card->number;
1409        if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1410                return -ENXIO;
1411        sprintf(name, "controlC%i", cardnum);
1412        if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1413                                       &snd_ctl_f_ops, card, name)) < 0)
1414                return err;
1415        return 0;
1416}
1417
1418/*
1419 * disconnection of the control device
1420 */
1421static int snd_ctl_dev_disconnect(struct snd_device *device)
1422{
1423        struct snd_card *card = device->device_data;
1424        struct snd_ctl_file *ctl;
1425        int err, cardnum;
1426
1427        if (snd_BUG_ON(!card))
1428                return -ENXIO;
1429        cardnum = card->number;
1430        if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1431                return -ENXIO;
1432
1433        read_lock(&card->ctl_files_rwlock);
1434        list_for_each_entry(ctl, &card->ctl_files, list) {
1435                wake_up(&ctl->change_sleep);
1436                kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1437        }
1438        read_unlock(&card->ctl_files_rwlock);
1439
1440        if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1441                                         card, -1)) < 0)
1442                return err;
1443        return 0;
1444}
1445
1446/*
1447 * free all controls
1448 */
1449static int snd_ctl_dev_free(struct snd_device *device)
1450{
1451        struct snd_card *card = device->device_data;
1452        struct snd_kcontrol *control;
1453
1454        down_write(&card->controls_rwsem);
1455        while (!list_empty(&card->controls)) {
1456                control = snd_kcontrol(card->controls.next);
1457                snd_ctl_remove(card, control);
1458        }
1459        up_write(&card->controls_rwsem);
1460        return 0;
1461}
1462
1463/*
1464 * create control core:
1465 * called from init.c
1466 */
1467int snd_ctl_create(struct snd_card *card)
1468{
1469        static struct snd_device_ops ops = {
1470                .dev_free = snd_ctl_dev_free,
1471                .dev_register = snd_ctl_dev_register,
1472                .dev_disconnect = snd_ctl_dev_disconnect,
1473        };
1474
1475        if (snd_BUG_ON(!card))
1476                return -ENXIO;
1477        return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1478}
1479
1480/*
1481 * Frequently used control callbacks
1482 */
1483int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1484                              struct snd_ctl_elem_info *uinfo)
1485{
1486        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1487        uinfo->count = 1;
1488        uinfo->value.integer.min = 0;
1489        uinfo->value.integer.max = 1;
1490        return 0;
1491}
1492
1493EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1494
1495int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1496                                struct snd_ctl_elem_info *uinfo)
1497{
1498        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1499        uinfo->count = 2;
1500        uinfo->value.integer.min = 0;
1501        uinfo->value.integer.max = 1;
1502        return 0;
1503}
1504
1505EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1506
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