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 = kmalloc(sizeof(*control), GFP_KERNEL);
 728        if (control == NULL)
 729                return -ENOMEM; 
 730        if (copy_from_user(control, _control, sizeof(*control))) {
 731                kfree(control);
 732                return -EFAULT;
 733        }
 734        snd_power_lock(card);
 735        result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 736        if (result >= 0)
 737                result = snd_ctl_elem_read(card, control);
 738        snd_power_unlock(card);
 739        if (result >= 0)
 740                if (copy_to_user(_control, control, sizeof(*control)))
 741                        result = -EFAULT;
 742        kfree(control);
 743        return result;
 744}
 745
 746static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 747                              struct snd_ctl_elem_value *control)
 748{
 749        struct snd_kcontrol *kctl;
 750        struct snd_kcontrol_volatile *vd;
 751        unsigned int index_offset;
 752        int result;
 753
 754        down_read(&card->controls_rwsem);
 755        kctl = snd_ctl_find_id(card, &control->id);
 756        if (kctl == NULL) {
 757                result = -ENOENT;
 758        } else {
 759                index_offset = snd_ctl_get_ioff(kctl, &control->id);
 760                vd = &kctl->vd[index_offset];
 761                if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 762                    kctl->put == NULL ||
 763                    (file && vd->owner && vd->owner != file)) {
 764                        result = -EPERM;
 765                } else {
 766                        snd_ctl_build_ioff(&control->id, kctl, index_offset);
 767                        result = kctl->put(kctl, control);
 768                }
 769                if (result > 0) {
 770                        up_read(&card->controls_rwsem);
 771                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 772                                       &control->id);
 773                        return 0;
 774                }
 775        }
 776        up_read(&card->controls_rwsem);
 777        return result;
 778}
 779
 780static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 781                                   struct snd_ctl_elem_value __user *_control)
 782{
 783        struct snd_ctl_elem_value *control;
 784        struct snd_card *card;
 785        int result;
 786
 787        control = kmalloc(sizeof(*control), GFP_KERNEL);
 788        if (control == NULL)
 789                return -ENOMEM; 
 790        if (copy_from_user(control, _control, sizeof(*control))) {
 791                kfree(control);
 792                return -EFAULT;
 793        }
 794        card = file->card;
 795        snd_power_lock(card);
 796        result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 797        if (result >= 0)
 798                result = snd_ctl_elem_write(card, file, control);
 799        snd_power_unlock(card);
 800        if (result >= 0)
 801                if (copy_to_user(_control, control, sizeof(*control)))
 802                        result = -EFAULT;
 803        kfree(control);
 804        return result;
 805}
 806
 807static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 808                             struct snd_ctl_elem_id __user *_id)
 809{
 810        struct snd_card *card = file->card;
 811        struct snd_ctl_elem_id id;
 812        struct snd_kcontrol *kctl;
 813        struct snd_kcontrol_volatile *vd;
 814        int result;
 815        
 816        if (copy_from_user(&id, _id, sizeof(id)))
 817                return -EFAULT;
 818        down_write(&card->controls_rwsem);
 819        kctl = snd_ctl_find_id(card, &id);
 820        if (kctl == NULL) {
 821                result = -ENOENT;
 822        } else {
 823                vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 824                if (vd->owner != NULL)
 825                        result = -EBUSY;
 826                else {
 827                        vd->owner = file;
 828                        vd->owner_pid = current->pid;
 829                        result = 0;
 830                }
 831        }
 832        up_write(&card->controls_rwsem);
 833        return result;
 834}
 835
 836static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 837                               struct snd_ctl_elem_id __user *_id)
 838{
 839        struct snd_card *card = file->card;
 840        struct snd_ctl_elem_id id;
 841        struct snd_kcontrol *kctl;
 842        struct snd_kcontrol_volatile *vd;
 843        int result;
 844        
 845        if (copy_from_user(&id, _id, sizeof(id)))
 846                return -EFAULT;
 847        down_write(&card->controls_rwsem);
 848        kctl = snd_ctl_find_id(card, &id);
 849        if (kctl == NULL) {
 850                result = -ENOENT;
 851        } else {
 852                vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 853                if (vd->owner == NULL)
 854                        result = -EINVAL;
 855                else if (vd->owner != file)
 856                        result = -EPERM;
 857                else {
 858                        vd->owner = NULL;
 859                        vd->owner_pid = 0;
 860                        result = 0;
 861                }
 862        }
 863        up_write(&card->controls_rwsem);
 864        return result;
 865}
 866
 867struct user_element {
 868        struct snd_ctl_elem_info info;
 869        void *elem_data;                /* element data */
 870        unsigned long elem_data_size;   /* size of element data in bytes */
 871        void *tlv_data;                 /* TLV data */
 872        unsigned long tlv_data_size;    /* TLV data size */
 873        void *priv_data;                /* private data (like strings for enumerated type) */
 874        unsigned long priv_data_size;   /* size of private data in bytes */
 875};
 876
 877static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 878                                  struct snd_ctl_elem_info *uinfo)
 879{
 880        struct user_element *ue = kcontrol->private_data;
 881
 882        *uinfo = ue->info;
 883        return 0;
 884}
 885
 886static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
 887                                 struct snd_ctl_elem_value *ucontrol)
 888{
 889        struct user_element *ue = kcontrol->private_data;
 890
 891        memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
 892        return 0;
 893}
 894
 895static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
 896                                 struct snd_ctl_elem_value *ucontrol)
 897{
 898        int change;
 899        struct user_element *ue = kcontrol->private_data;
 900        
 901        change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
 902        if (change)
 903                memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
 904        return change;
 905}
 906
 907static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
 908                                 int op_flag,
 909                                 unsigned int size,
 910                                 unsigned int __user *tlv)
 911{
 912        struct user_element *ue = kcontrol->private_data;
 913        int change = 0;
 914        void *new_data;
 915
 916        if (op_flag > 0) {
 917                if (size > 1024 * 128)  /* sane value */
 918                        return -EINVAL;
 919                new_data = kmalloc(size, GFP_KERNEL);
 920                if (new_data == NULL)
 921                        return -ENOMEM;
 922                if (copy_from_user(new_data, tlv, size)) {
 923                        kfree(new_data);
 924                        return -EFAULT;
 925                }
 926                change = ue->tlv_data_size != size;
 927                if (!change)
 928                        change = memcmp(ue->tlv_data, new_data, size);
 929                kfree(ue->tlv_data);
 930                ue->tlv_data = new_data;
 931                ue->tlv_data_size = size;
 932        } else {
 933                if (! ue->tlv_data_size || ! ue->tlv_data)
 934                        return -ENXIO;
 935                if (size < ue->tlv_data_size)
 936                        return -ENOSPC;
 937                if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
 938                        return -EFAULT;
 939        }
 940        return change;
 941}
 942
 943static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
 944{
 945        struct user_element *ue = kcontrol->private_data;
 946        if (ue->tlv_data)
 947                kfree(ue->tlv_data);
 948        kfree(ue);
 949}
 950
 951static int snd_ctl_elem_add(struct snd_ctl_file *file,
 952                            struct snd_ctl_elem_info *info, int replace)
 953{
 954        struct snd_card *card = file->card;
 955        struct snd_kcontrol kctl, *_kctl;
 956        unsigned int access;
 957        long private_size;
 958        struct user_element *ue;
 959        int idx, err;
 960        
 961        if (card->user_ctl_count >= MAX_USER_CONTROLS)
 962                return -ENOMEM;
 963        if (info->count > 1024)
 964                return -EINVAL;
 965        access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 966                (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 967                                 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 968                                 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
 969        info->id.numid = 0;
 970        memset(&kctl, 0, sizeof(kctl));
 971        down_write(&card->controls_rwsem);
 972        _kctl = snd_ctl_find_id(card, &info->id);
 973        err = 0;
 974        if (_kctl) {
 975                if (replace)
 976                        err = snd_ctl_remove(card, _kctl);
 977                else
 978                        err = -EBUSY;
 979        } else {
 980                if (replace)
 981                        err = -ENOENT;
 982        }
 983        up_write(&card->controls_rwsem);
 984        if (err < 0)
 985                return err;
 986        memcpy(&kctl.id, &info->id, sizeof(info->id));
 987        kctl.count = info->owner ? info->owner : 1;
 988        access |= SNDRV_CTL_ELEM_ACCESS_USER;
 989        kctl.info = snd_ctl_elem_user_info;
 990        if (access & SNDRV_CTL_ELEM_ACCESS_READ)
 991                kctl.get = snd_ctl_elem_user_get;
 992        if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
 993                kctl.put = snd_ctl_elem_user_put;
 994        if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
 995                kctl.tlv.c = snd_ctl_elem_user_tlv;
 996                access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
 997        }
 998        switch (info->type) {
 999        case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1000        case SNDRV_CTL_ELEM_TYPE_INTEGER:
1001                private_size = sizeof(long);
1002                if (info->count > 128)
1003                        return -EINVAL;
1004                break;
1005        case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1006                private_size = sizeof(long long);
1007                if (info->count > 64)
1008                        return -EINVAL;
1009                break;
1010        case SNDRV_CTL_ELEM_TYPE_BYTES:
1011                private_size = sizeof(unsigned char);
1012                if (info->count > 512)
1013                        return -EINVAL;
1014                break;
1015        case SNDRV_CTL_ELEM_TYPE_IEC958:
1016                private_size = sizeof(struct snd_aes_iec958);
1017                if (info->count != 1)
1018                        return -EINVAL;
1019                break;
1020        default:
1021                return -EINVAL;
1022        }
1023        private_size *= info->count;
1024        ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1025        if (ue == NULL)
1026                return -ENOMEM;
1027        ue->info = *info;
1028        ue->info.access = 0;
1029        ue->elem_data = (char *)ue + sizeof(*ue);
1030        ue->elem_data_size = private_size;
1031        kctl.private_free = snd_ctl_elem_user_free;
1032        _kctl = snd_ctl_new(&kctl, access);
1033        if (_kctl == NULL) {
1034                kfree(ue);
1035                return -ENOMEM;
1036        }
1037        _kctl->private_data = ue;
1038        for (idx = 0; idx < _kctl->count; idx++)
1039                _kctl->vd[idx].owner = file;
1040        err = snd_ctl_add(card, _kctl);
1041        if (err < 0)
1042                return err;
1043
1044        down_write(&card->controls_rwsem);
1045        card->user_ctl_count++;
1046        up_write(&card->controls_rwsem);
1047
1048        return 0;
1049}
1050
1051static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1052                                 struct snd_ctl_elem_info __user *_info, int replace)
1053{
1054        struct snd_ctl_elem_info info;
1055        if (copy_from_user(&info, _info, sizeof(info)))
1056                return -EFAULT;
1057        return snd_ctl_elem_add(file, &info, replace);
1058}
1059
1060static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1061                               struct snd_ctl_elem_id __user *_id)
1062{
1063        struct snd_ctl_elem_id id;
1064        int err;
1065
1066        if (copy_from_user(&id, _id, sizeof(id)))
1067                return -EFAULT;
1068        err = snd_ctl_remove_unlocked_id(file, &id);
1069        if (! err) {
1070                struct snd_card *card = file->card;
1071                down_write(&card->controls_rwsem);
1072                card->user_ctl_count--;
1073                up_write(&card->controls_rwsem);
1074        }
1075        return err;
1076}
1077
1078static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1079{
1080        int subscribe;
1081        if (get_user(subscribe, ptr))
1082                return -EFAULT;
1083        if (subscribe < 0) {
1084                subscribe = file->subscribed;
1085                if (put_user(subscribe, ptr))
1086                        return -EFAULT;
1087                return 0;
1088        }
1089        if (subscribe) {
1090                file->subscribed = 1;
1091                return 0;
1092        } else if (file->subscribed) {
1093                snd_ctl_empty_read_queue(file);
1094                file->subscribed = 0;
1095        }
1096        return 0;
1097}
1098
1099static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1100                             struct snd_ctl_tlv __user *_tlv,
1101                             int op_flag)
1102{
1103        struct snd_card *card = file->card;
1104        struct snd_ctl_tlv tlv;
1105        struct snd_kcontrol *kctl;
1106        struct snd_kcontrol_volatile *vd;
1107        unsigned int len;
1108        int err = 0;
1109
1110        if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1111                return -EFAULT;
1112        if (tlv.length < sizeof(unsigned int) * 3)
1113                return -EINVAL;
1114        down_read(&card->controls_rwsem);
1115        kctl = snd_ctl_find_numid(card, tlv.numid);
1116        if (kctl == NULL) {
1117                err = -ENOENT;
1118                goto __kctl_end;
1119        }
1120        if (kctl->tlv.p == NULL) {
1121                err = -ENXIO;
1122                goto __kctl_end;
1123        }
1124        vd = &kctl->vd[tlv.numid - kctl->id.numid];
1125        if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1126            (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1127            (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1128                err = -ENXIO;
1129                goto __kctl_end;
1130        }
1131        if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1132                if (file && vd->owner != NULL && vd->owner != file) {
1133                        err = -EPERM;
1134                        goto __kctl_end;
1135                }
1136                err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1137                if (err > 0) {
1138                        up_read(&card->controls_rwsem);
1139                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1140                        return 0;
1141                }
1142        } else {
1143                if (op_flag) {
1144                        err = -ENXIO;
1145                        goto __kctl_end;
1146                }
1147                len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1148                if (tlv.length < len) {
1149                        err = -ENOMEM;
1150                        goto __kctl_end;
1151                }
1152                if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1153                        err = -EFAULT;
1154        }
1155      __kctl_end:
1156        up_read(&card->controls_rwsem);
1157        return err;
1158}
1159
1160static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1161{
1162        struct snd_ctl_file *ctl;
1163        struct snd_card *card;
1164        struct snd_kctl_ioctl *p;
1165        void __user *argp = (void __user *)arg;
1166        int __user *ip = argp;
1167        int err;
1168
1169        ctl = file->private_data;
1170        card = ctl->card;
1171        if (snd_BUG_ON(!card))
1172                return -ENXIO;
1173        switch (cmd) {
1174        case SNDRV_CTL_IOCTL_PVERSION:
1175                return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1176        case SNDRV_CTL_IOCTL_CARD_INFO:
1177                return snd_ctl_card_info(card, ctl, cmd, argp);
1178        case SNDRV_CTL_IOCTL_ELEM_LIST:
1179                return snd_ctl_elem_list(card, argp);
1180        case SNDRV_CTL_IOCTL_ELEM_INFO:
1181                return snd_ctl_elem_info_user(ctl, argp);
1182        case SNDRV_CTL_IOCTL_ELEM_READ:
1183                return snd_ctl_elem_read_user(card, argp);
1184        case SNDRV_CTL_IOCTL_ELEM_WRITE:
1185                return snd_ctl_elem_write_user(ctl, argp);
1186        case SNDRV_CTL_IOCTL_ELEM_LOCK:
1187                return snd_ctl_elem_lock(ctl, argp);
1188        case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1189                return snd_ctl_elem_unlock(ctl, argp);
1190        case SNDRV_CTL_IOCTL_ELEM_ADD:
1191                return snd_ctl_elem_add_user(ctl, argp, 0);
1192        case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1193                return snd_ctl_elem_add_user(ctl, argp, 1);
1194        case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1195                return snd_ctl_elem_remove(ctl, argp);
1196        case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1197                return snd_ctl_subscribe_events(ctl, ip);
1198        case SNDRV_CTL_IOCTL_TLV_READ:
1199                return snd_ctl_tlv_ioctl(ctl, argp, 0);
1200        case SNDRV_CTL_IOCTL_TLV_WRITE:
1201                return snd_ctl_tlv_ioctl(ctl, argp, 1);
1202        case SNDRV_CTL_IOCTL_TLV_COMMAND:
1203                return snd_ctl_tlv_ioctl(ctl, argp, -1);
1204        case SNDRV_CTL_IOCTL_POWER:
1205                return -ENOPROTOOPT;
1206        case SNDRV_CTL_IOCTL_POWER_STATE:
1207#ifdef CONFIG_PM
1208                return put_user(card->power_state, ip) ? -EFAULT : 0;
1209#else
1210                return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1211#endif
1212        }
1213        down_read(&snd_ioctl_rwsem);
1214        list_for_each_entry(p, &snd_control_ioctls, list) {
1215                err = p->fioctl(card, ctl, cmd, arg);
1216                if (err != -ENOIOCTLCMD) {
1217                        up_read(&snd_ioctl_rwsem);
1218                        return err;
1219                }
1220        }
1221        up_read(&snd_ioctl_rwsem);
1222        snd_printdd("unknown ioctl = 0x%x\n", cmd);
1223        return -ENOTTY;
1224}
1225
1226static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1227                            size_t count, loff_t * offset)
1228{
1229        struct snd_ctl_file *ctl;
1230        int err = 0;
1231        ssize_t result = 0;
1232
1233        ctl = file->private_data;
1234        if (snd_BUG_ON(!ctl || !ctl->card))
1235                return -ENXIO;
1236        if (!ctl->subscribed)
1237                return -EBADFD;
1238        if (count < sizeof(struct snd_ctl_event))
1239                return -EINVAL;
1240        spin_lock_irq(&ctl->read_lock);
1241        while (count >= sizeof(struct snd_ctl_event)) {
1242                struct snd_ctl_event ev;
1243                struct snd_kctl_event *kev;
1244                while (list_empty(&ctl->events)) {
1245                        wait_queue_t wait;
1246                        if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1247                                err = -EAGAIN;
1248                                goto __end_lock;
1249                        }
1250                        init_waitqueue_entry(&wait, current);
1251                        add_wait_queue(&ctl->change_sleep, &wait);
1252                        set_current_state(TASK_INTERRUPTIBLE);
1253                        spin_unlock_irq(&ctl->read_lock);
1254                        schedule();
1255                        remove_wait_queue(&ctl->change_sleep, &wait);
1256                        if (signal_pending(current))
1257                                return -ERESTARTSYS;
1258                        spin_lock_irq(&ctl->read_lock);
1259                }
1260                kev = snd_kctl_event(ctl->events.next);
1261                ev.type = SNDRV_CTL_EVENT_ELEM;
1262                ev.data.elem.mask = kev->mask;
1263                ev.data.elem.id = kev->id;
1264                list_del(&kev->list);
1265                spin_unlock_irq(&ctl->read_lock);
1266                kfree(kev);
1267                if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1268                        err = -EFAULT;
1269                        goto __end;
1270                }
1271                spin_lock_irq(&ctl->read_lock);
1272                buffer += sizeof(struct snd_ctl_event);
1273                count -= sizeof(struct snd_ctl_event);
1274                result += sizeof(struct snd_ctl_event);
1275        }
1276      __end_lock:
1277        spin_unlock_irq(&ctl->read_lock);
1278      __end:
1279        return result > 0 ? result : err;
1280}
1281
1282static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1283{
1284        unsigned int mask;
1285        struct snd_ctl_file *ctl;
1286
1287        ctl = file->private_data;
1288        if (!ctl->subscribed)
1289                return 0;
1290        poll_wait(file, &ctl->change_sleep, wait);
1291
1292        mask = 0;
1293        if (!list_empty(&ctl->events))
1294                mask |= POLLIN | POLLRDNORM;
1295
1296        return mask;
1297}
1298
1299/*
1300 * register the device-specific control-ioctls.
1301 * called from each device manager like pcm.c, hwdep.c, etc.
1302 */
1303static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1304{
1305        struct snd_kctl_ioctl *pn;
1306
1307        pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1308        if (pn == NULL)
1309                return -ENOMEM;
1310        pn->fioctl = fcn;
1311        down_write(&snd_ioctl_rwsem);
1312        list_add_tail(&pn->list, lists);
1313        up_write(&snd_ioctl_rwsem);
1314        return 0;
1315}
1316
1317int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1318{
1319        return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1320}
1321
1322EXPORT_SYMBOL(snd_ctl_register_ioctl);
1323
1324#ifdef CONFIG_COMPAT
1325int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1326{
1327        return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1328}
1329
1330EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1331#endif
1332
1333/*
1334 * de-register the device-specific control-ioctls.
1335 */
1336static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1337                                     struct list_head *lists)
1338{
1339        struct snd_kctl_ioctl *p;
1340
1341        if (snd_BUG_ON(!fcn))
1342                return -EINVAL;
1343        down_write(&snd_ioctl_rwsem);
1344        list_for_each_entry(p, lists, list) {
1345                if (p->fioctl == fcn) {
1346                        list_del(&p->list);
1347                        up_write(&snd_ioctl_rwsem);
1348                        kfree(p);
1349                        return 0;
1350                }
1351        }
1352        up_write(&snd_ioctl_rwsem);
1353        snd_BUG();
1354        return -EINVAL;
1355}
1356
1357int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1358{
1359        return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1360}
1361
1362EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1363
1364#ifdef CONFIG_COMPAT
1365int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1366{
1367        return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1368}
1369
1370EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1371#endif
1372
1373static int snd_ctl_fasync(int fd, struct file * file, int on)
1374{
1375        struct snd_ctl_file *ctl;
1376        int err;
1377        ctl = file->private_data;
1378        err = fasync_helper(fd, file, on, &ctl->fasync);
1379        if (err < 0)
1380                return err;
1381        return 0;
1382}
1383
1384/*
1385 * ioctl32 compat
1386 */
1387#ifdef CONFIG_COMPAT
1388#include "control_compat.c"
1389#else
1390#define snd_ctl_ioctl_compat    NULL
1391#endif
1392
1393/*
1394 *  INIT PART
1395 */
1396
1397static const struct file_operations snd_ctl_f_ops =
1398{
1399        .owner =        THIS_MODULE,
1400        .read =         snd_ctl_read,
1401        .open =         snd_ctl_open,
1402        .release =      snd_ctl_release,
1403        .poll =         snd_ctl_poll,
1404        .unlocked_ioctl =       snd_ctl_ioctl,
1405        .compat_ioctl = snd_ctl_ioctl_compat,
1406        .fasync =       snd_ctl_fasync,
1407};
1408
1409/*
1410 * registration of the control device
1411 */
1412static int snd_ctl_dev_register(struct snd_device *device)
1413{
1414        struct snd_card *card = device->device_data;
1415        int err, cardnum;
1416        char name[16];
1417
1418        if (snd_BUG_ON(!card))
1419                return -ENXIO;
1420        cardnum = card->number;
1421        if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1422                return -ENXIO;
1423        sprintf(name, "controlC%i", cardnum);
1424        if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1425                                       &snd_ctl_f_ops, card, name)) < 0)
1426                return err;
1427        return 0;
1428}
1429
1430/*
1431 * disconnection of the control device
1432 */
1433static int snd_ctl_dev_disconnect(struct snd_device *device)
1434{
1435        struct snd_card *card = device->device_data;
1436        struct snd_ctl_file *ctl;
1437        int err, cardnum;
1438
1439        if (snd_BUG_ON(!card))
1440                return -ENXIO;
1441        cardnum = card->number;
1442        if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1443                return -ENXIO;
1444
1445        read_lock(&card->ctl_files_rwlock);
1446        list_for_each_entry(ctl, &card->ctl_files, list) {
1447                wake_up(&ctl->change_sleep);
1448                kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1449        }
1450        read_unlock(&card->ctl_files_rwlock);
1451
1452        if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1453                                         card, -1)) < 0)
1454                return err;
1455        return 0;
1456}
1457
1458/*
1459 * free all controls
1460 */
1461static int snd_ctl_dev_free(struct snd_device *device)
1462{
1463        struct snd_card *card = device->device_data;
1464        struct snd_kcontrol *control;
1465
1466        down_write(&card->controls_rwsem);
1467        while (!list_empty(&card->controls)) {
1468                control = snd_kcontrol(card->controls.next);
1469                snd_ctl_remove(card, control);
1470        }
1471        up_write(&card->controls_rwsem);
1472        return 0;
1473}
1474
1475/*
1476 * create control core:
1477 * called from init.c
1478 */
1479int snd_ctl_create(struct snd_card *card)
1480{
1481        static struct snd_device_ops ops = {
1482                .dev_free = snd_ctl_dev_free,
1483                .dev_register = snd_ctl_dev_register,
1484                .dev_disconnect = snd_ctl_dev_disconnect,
1485        };
1486
1487        if (snd_BUG_ON(!card))
1488                return -ENXIO;
1489        return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1490}
1491
1492/*
1493 * Frequently used control callbacks
1494 */
1495int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1496                              struct snd_ctl_elem_info *uinfo)
1497{
1498        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1499        uinfo->count = 1;
1500        uinfo->value.integer.min = 0;
1501        uinfo->value.integer.max = 1;
1502        return 0;
1503}
1504
1505EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1506
1507int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1508                                struct snd_ctl_elem_info *uinfo)
1509{
1510        uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1511        uinfo->count = 2;
1512        uinfo->value.integer.min = 0;
1513        uinfo->value.integer.max = 1;
1514        return 0;
1515}
1516
1517EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1518