linux/sound/core/init.c
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   1/*
   2 *  Initialization routines
   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/init.h>
  23#include <linux/sched.h>
  24#include <linux/file.h>
  25#include <linux/slab.h>
  26#include <linux/time.h>
  27#include <linux/ctype.h>
  28#include <linux/pm.h>
  29
  30#include <sound/core.h>
  31#include <sound/control.h>
  32#include <sound/info.h>
  33
  34static DEFINE_SPINLOCK(shutdown_lock);
  35static LIST_HEAD(shutdown_files);
  36
  37static const struct file_operations snd_shutdown_f_ops;
  38
  39static unsigned int snd_cards_lock;     /* locked for registering/using */
  40struct snd_card *snd_cards[SNDRV_CARDS];
  41EXPORT_SYMBOL(snd_cards);
  42
  43static DEFINE_MUTEX(snd_card_mutex);
  44
  45static char *slots[SNDRV_CARDS];
  46module_param_array(slots, charp, NULL, 0444);
  47MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
  48
  49/* return non-zero if the given index is reserved for the given
  50 * module via slots option
  51 */
  52static int module_slot_match(struct module *module, int idx)
  53{
  54        int match = 1;
  55#ifdef MODULE
  56        const char *s1, *s2;
  57
  58        if (!module || !module->name || !slots[idx])
  59                return 0;
  60
  61        s1 = module->name;
  62        s2 = slots[idx];
  63        if (*s2 == '!') {
  64                match = 0; /* negative match */
  65                s2++;
  66        }
  67        /* compare module name strings
  68         * hyphens are handled as equivalent with underscore
  69         */
  70        for (;;) {
  71                char c1 = *s1++;
  72                char c2 = *s2++;
  73                if (c1 == '-')
  74                        c1 = '_';
  75                if (c2 == '-')
  76                        c2 = '_';
  77                if (c1 != c2)
  78                        return !match;
  79                if (!c1)
  80                        break;
  81        }
  82#endif /* MODULE */
  83        return match;
  84}
  85
  86#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  87int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
  88EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
  89#endif
  90
  91#ifdef CONFIG_PROC_FS
  92static void snd_card_id_read(struct snd_info_entry *entry,
  93                             struct snd_info_buffer *buffer)
  94{
  95        snd_iprintf(buffer, "%s\n", entry->card->id);
  96}
  97
  98static inline int init_info_for_card(struct snd_card *card)
  99{
 100        int err;
 101        struct snd_info_entry *entry;
 102
 103        if ((err = snd_info_card_register(card)) < 0) {
 104                snd_printd("unable to create card info\n");
 105                return err;
 106        }
 107        if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
 108                snd_printd("unable to create card entry\n");
 109                return err;
 110        }
 111        entry->c.text.read = snd_card_id_read;
 112        if (snd_info_register(entry) < 0) {
 113                snd_info_free_entry(entry);
 114                entry = NULL;
 115        }
 116        card->proc_id = entry;
 117        return 0;
 118}
 119#else /* !CONFIG_PROC_FS */
 120#define init_info_for_card(card)
 121#endif
 122
 123/**
 124 *  snd_card_new - create and initialize a soundcard structure
 125 *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
 126 *  @xid: card identification (ASCII string)
 127 *  @module: top level module for locking
 128 *  @extra_size: allocate this extra size after the main soundcard structure
 129 *
 130 *  Creates and initializes a soundcard structure.
 131 *
 132 *  Returns kmallocated snd_card structure. Creates the ALSA control interface
 133 *  (which is blocked until snd_card_register function is called).
 134 */
 135struct snd_card *snd_card_new(int idx, const char *xid,
 136                         struct module *module, int extra_size)
 137{
 138        struct snd_card *card;
 139        int err, idx2;
 140
 141        if (extra_size < 0)
 142                extra_size = 0;
 143        card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
 144        if (card == NULL)
 145                return NULL;
 146        if (xid) {
 147                if (!snd_info_check_reserved_words(xid))
 148                        goto __error;
 149                strlcpy(card->id, xid, sizeof(card->id));
 150        }
 151        err = 0;
 152        mutex_lock(&snd_card_mutex);
 153        if (idx < 0) {
 154                for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 155                        /* idx == -1 == 0xffff means: take any free slot */
 156                        if (~snd_cards_lock & idx & 1<<idx2) {
 157                                if (module_slot_match(module, idx2)) {
 158                                        idx = idx2;
 159                                        break;
 160                                }
 161                        }
 162        }
 163        if (idx < 0) {
 164                for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
 165                        /* idx == -1 == 0xffff means: take any free slot */
 166                        if (~snd_cards_lock & idx & 1<<idx2) {
 167                                if (!slots[idx2] || !*slots[idx2]) {
 168                                        idx = idx2;
 169                                        break;
 170                                }
 171                        }
 172        }
 173        if (idx < 0)
 174                err = -ENODEV;
 175        else if (idx < snd_ecards_limit) {
 176                if (snd_cards_lock & (1 << idx))
 177                        err = -EBUSY;   /* invalid */
 178        } else if (idx >= SNDRV_CARDS)
 179                err = -ENODEV;
 180        if (err < 0) {
 181                mutex_unlock(&snd_card_mutex);
 182                snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
 183                         idx, snd_ecards_limit - 1, err);
 184                goto __error;
 185        }
 186        snd_cards_lock |= 1 << idx;             /* lock it */
 187        if (idx >= snd_ecards_limit)
 188                snd_ecards_limit = idx + 1; /* increase the limit */
 189        mutex_unlock(&snd_card_mutex);
 190        card->number = idx;
 191        card->module = module;
 192        INIT_LIST_HEAD(&card->devices);
 193        init_rwsem(&card->controls_rwsem);
 194        rwlock_init(&card->ctl_files_rwlock);
 195        INIT_LIST_HEAD(&card->controls);
 196        INIT_LIST_HEAD(&card->ctl_files);
 197        spin_lock_init(&card->files_lock);
 198        init_waitqueue_head(&card->shutdown_sleep);
 199#ifdef CONFIG_PM
 200        mutex_init(&card->power_lock);
 201        init_waitqueue_head(&card->power_sleep);
 202#endif
 203        /* the control interface cannot be accessed from the user space until */
 204        /* snd_cards_bitmask and snd_cards are set with snd_card_register */
 205        if ((err = snd_ctl_create(card)) < 0) {
 206                snd_printd("unable to register control minors\n");
 207                goto __error;
 208        }
 209        if ((err = snd_info_card_create(card)) < 0) {
 210                snd_printd("unable to create card info\n");
 211                goto __error_ctl;
 212        }
 213        if (extra_size > 0)
 214                card->private_data = (char *)card + sizeof(struct snd_card);
 215        return card;
 216
 217      __error_ctl:
 218        snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
 219      __error:
 220        kfree(card);
 221        return NULL;
 222}
 223
 224EXPORT_SYMBOL(snd_card_new);
 225
 226/* return non-zero if a card is already locked */
 227int snd_card_locked(int card)
 228{
 229        int locked;
 230
 231        mutex_lock(&snd_card_mutex);
 232        locked = snd_cards_lock & (1 << card);
 233        mutex_unlock(&snd_card_mutex);
 234        return locked;
 235}
 236
 237static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
 238{
 239        return -ENODEV;
 240}
 241
 242static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
 243                                   size_t count, loff_t *offset)
 244{
 245        return -ENODEV;
 246}
 247
 248static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
 249                                    size_t count, loff_t *offset)
 250{
 251        return -ENODEV;
 252}
 253
 254static int snd_disconnect_release(struct inode *inode, struct file *file)
 255{
 256        struct snd_monitor_file *df = NULL, *_df;
 257
 258        spin_lock(&shutdown_lock);
 259        list_for_each_entry(_df, &shutdown_files, shutdown_list) {
 260                if (_df->file == file) {
 261                        df = _df;
 262                        break;
 263                }
 264        }
 265        spin_unlock(&shutdown_lock);
 266
 267        if (likely(df)) {
 268                if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
 269                        df->disconnected_f_op->fasync(-1, file, 0);
 270                return df->disconnected_f_op->release(inode, file);
 271        }
 272
 273        panic("%s(%p, %p) failed!", __func__, inode, file);
 274}
 275
 276static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
 277{
 278        return POLLERR | POLLNVAL;
 279}
 280
 281static long snd_disconnect_ioctl(struct file *file,
 282                                 unsigned int cmd, unsigned long arg)
 283{
 284        return -ENODEV;
 285}
 286
 287static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
 288{
 289        return -ENODEV;
 290}
 291
 292static int snd_disconnect_fasync(int fd, struct file *file, int on)
 293{
 294        return -ENODEV;
 295}
 296
 297static const struct file_operations snd_shutdown_f_ops =
 298{
 299        .owner =        THIS_MODULE,
 300        .llseek =       snd_disconnect_llseek,
 301        .read =         snd_disconnect_read,
 302        .write =        snd_disconnect_write,
 303        .release =      snd_disconnect_release,
 304        .poll =         snd_disconnect_poll,
 305        .unlocked_ioctl = snd_disconnect_ioctl,
 306#ifdef CONFIG_COMPAT
 307        .compat_ioctl = snd_disconnect_ioctl,
 308#endif
 309        .mmap =         snd_disconnect_mmap,
 310        .fasync =       snd_disconnect_fasync
 311};
 312
 313/**
 314 *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
 315 *  @card: soundcard structure
 316 *
 317 *  Disconnects all APIs from the file-operations (user space).
 318 *
 319 *  Returns zero, otherwise a negative error code.
 320 *
 321 *  Note: The current implementation replaces all active file->f_op with special
 322 *        dummy file operations (they do nothing except release).
 323 */
 324int snd_card_disconnect(struct snd_card *card)
 325{
 326        struct snd_monitor_file *mfile;
 327        struct file *file;
 328        int err;
 329
 330        if (!card)
 331                return -EINVAL;
 332
 333        spin_lock(&card->files_lock);
 334        if (card->shutdown) {
 335                spin_unlock(&card->files_lock);
 336                return 0;
 337        }
 338        card->shutdown = 1;
 339        spin_unlock(&card->files_lock);
 340
 341        /* phase 1: disable fops (user space) operations for ALSA API */
 342        mutex_lock(&snd_card_mutex);
 343        snd_cards[card->number] = NULL;
 344        snd_cards_lock &= ~(1 << card->number);
 345        mutex_unlock(&snd_card_mutex);
 346        
 347        /* phase 2: replace file->f_op with special dummy operations */
 348        
 349        spin_lock(&card->files_lock);
 350        mfile = card->files;
 351        while (mfile) {
 352                file = mfile->file;
 353
 354                /* it's critical part, use endless loop */
 355                /* we have no room to fail */
 356                mfile->disconnected_f_op = mfile->file->f_op;
 357
 358                spin_lock(&shutdown_lock);
 359                list_add(&mfile->shutdown_list, &shutdown_files);
 360                spin_unlock(&shutdown_lock);
 361
 362                mfile->file->f_op = &snd_shutdown_f_ops;
 363                fops_get(mfile->file->f_op);
 364                
 365                mfile = mfile->next;
 366        }
 367        spin_unlock(&card->files_lock); 
 368
 369        /* phase 3: notify all connected devices about disconnection */
 370        /* at this point, they cannot respond to any calls except release() */
 371
 372#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 373        if (snd_mixer_oss_notify_callback)
 374                snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
 375#endif
 376
 377        /* notify all devices that we are disconnected */
 378        err = snd_device_disconnect_all(card);
 379        if (err < 0)
 380                snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
 381
 382        snd_info_card_disconnect(card);
 383#ifndef CONFIG_SYSFS_DEPRECATED
 384        if (card->card_dev) {
 385                device_unregister(card->card_dev);
 386                card->card_dev = NULL;
 387        }
 388#endif
 389#ifdef CONFIG_PM
 390        wake_up(&card->power_sleep);
 391#endif
 392        return 0;       
 393}
 394
 395EXPORT_SYMBOL(snd_card_disconnect);
 396
 397/**
 398 *  snd_card_free - frees given soundcard structure
 399 *  @card: soundcard structure
 400 *
 401 *  This function releases the soundcard structure and the all assigned
 402 *  devices automatically.  That is, you don't have to release the devices
 403 *  by yourself.
 404 *
 405 *  Returns zero. Frees all associated devices and frees the control
 406 *  interface associated to given soundcard.
 407 */
 408static int snd_card_do_free(struct snd_card *card)
 409{
 410#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 411        if (snd_mixer_oss_notify_callback)
 412                snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
 413#endif
 414        if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
 415                snd_printk(KERN_ERR "unable to free all devices (pre)\n");
 416                /* Fatal, but this situation should never occur */
 417        }
 418        if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
 419                snd_printk(KERN_ERR "unable to free all devices (normal)\n");
 420                /* Fatal, but this situation should never occur */
 421        }
 422        if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
 423                snd_printk(KERN_ERR "unable to free all devices (post)\n");
 424                /* Fatal, but this situation should never occur */
 425        }
 426        if (card->private_free)
 427                card->private_free(card);
 428        snd_info_free_entry(card->proc_id);
 429        if (snd_info_card_free(card) < 0) {
 430                snd_printk(KERN_WARNING "unable to free card info\n");
 431                /* Not fatal error */
 432        }
 433        kfree(card);
 434        return 0;
 435}
 436
 437int snd_card_free_when_closed(struct snd_card *card)
 438{
 439        int free_now = 0;
 440        int ret = snd_card_disconnect(card);
 441        if (ret)
 442                return ret;
 443
 444        spin_lock(&card->files_lock);
 445        if (card->files == NULL)
 446                free_now = 1;
 447        else
 448                card->free_on_last_close = 1;
 449        spin_unlock(&card->files_lock);
 450
 451        if (free_now)
 452                snd_card_do_free(card);
 453        return 0;
 454}
 455
 456EXPORT_SYMBOL(snd_card_free_when_closed);
 457
 458int snd_card_free(struct snd_card *card)
 459{
 460        int ret = snd_card_disconnect(card);
 461        if (ret)
 462                return ret;
 463
 464        /* wait, until all devices are ready for the free operation */
 465        wait_event(card->shutdown_sleep, card->files == NULL);
 466        snd_card_do_free(card);
 467        return 0;
 468}
 469
 470EXPORT_SYMBOL(snd_card_free);
 471
 472static void choose_default_id(struct snd_card *card)
 473{
 474        int i, len, idx_flag = 0, loops = SNDRV_CARDS;
 475        char *id, *spos;
 476        
 477        id = spos = card->shortname;    
 478        while (*id != '\0') {
 479                if (*id == ' ')
 480                        spos = id + 1;
 481                id++;
 482        }
 483        id = card->id;
 484        while (*spos != '\0' && !isalnum(*spos))
 485                spos++;
 486        if (isdigit(*spos))
 487                *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
 488        while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
 489                if (isalnum(*spos))
 490                        *id++ = *spos;
 491                spos++;
 492        }
 493        *id = '\0';
 494
 495        id = card->id;
 496        
 497        if (*id == '\0')
 498                strcpy(id, "default");
 499
 500        while (1) {
 501                if (loops-- == 0) {
 502                        snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
 503                        strcpy(card->id, card->proc_root->name);
 504                        return;
 505                }
 506                if (!snd_info_check_reserved_words(id))
 507                        goto __change;
 508                for (i = 0; i < snd_ecards_limit; i++) {
 509                        if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
 510                                goto __change;
 511                }
 512                break;
 513
 514              __change:
 515                len = strlen(id);
 516                if (idx_flag) {
 517                        if (id[len-1] != '9')
 518                                id[len-1]++;
 519                        else
 520                                id[len-1] = 'A';
 521                } else if ((size_t)len <= sizeof(card->id) - 3) {
 522                        strcat(id, "_1");
 523                        idx_flag++;
 524                } else {
 525                        spos = id + len - 2;
 526                        if ((size_t)len <= sizeof(card->id) - 2)
 527                                spos++;
 528                        *spos++ = '_';
 529                        *spos++ = '1';
 530                        *spos++ = '\0';
 531                        idx_flag++;
 532                }
 533        }
 534}
 535
 536#ifndef CONFIG_SYSFS_DEPRECATED
 537static ssize_t
 538card_id_show_attr(struct device *dev,
 539                  struct device_attribute *attr, char *buf)
 540{
 541        struct snd_card *card = dev_get_drvdata(dev);
 542        return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)");
 543}
 544
 545static ssize_t
 546card_id_store_attr(struct device *dev, struct device_attribute *attr,
 547                   const char *buf, size_t count)
 548{
 549        struct snd_card *card = dev_get_drvdata(dev);
 550        char buf1[sizeof(card->id)];
 551        size_t copy = count > sizeof(card->id) - 1 ?
 552                                        sizeof(card->id) - 1 : count;
 553        size_t idx;
 554        int c;
 555
 556        for (idx = 0; idx < copy; idx++) {
 557                c = buf[idx];
 558                if (!isalnum(c) && c != '_' && c != '-')
 559                        return -EINVAL;
 560        }
 561        memcpy(buf1, buf, copy);
 562        buf1[copy] = '\0';
 563        mutex_lock(&snd_card_mutex);
 564        if (!snd_info_check_reserved_words(buf1)) {
 565             __exist:
 566                mutex_unlock(&snd_card_mutex);
 567                return -EEXIST;
 568        }
 569        for (idx = 0; idx < snd_ecards_limit; idx++) {
 570                if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1))
 571                        goto __exist;
 572        }
 573        strcpy(card->id, buf1);
 574        snd_info_card_id_change(card);
 575        mutex_unlock(&snd_card_mutex);
 576
 577        return count;
 578}
 579
 580static struct device_attribute card_id_attrs =
 581        __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
 582
 583static ssize_t
 584card_number_show_attr(struct device *dev,
 585                     struct device_attribute *attr, char *buf)
 586{
 587        struct snd_card *card = dev_get_drvdata(dev);
 588        return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1);
 589}
 590
 591static struct device_attribute card_number_attrs =
 592        __ATTR(number, S_IRUGO, card_number_show_attr, NULL);
 593#endif /* CONFIG_SYSFS_DEPRECATED */
 594
 595/**
 596 *  snd_card_register - register the soundcard
 597 *  @card: soundcard structure
 598 *
 599 *  This function registers all the devices assigned to the soundcard.
 600 *  Until calling this, the ALSA control interface is blocked from the
 601 *  external accesses.  Thus, you should call this function at the end
 602 *  of the initialization of the card.
 603 *
 604 *  Returns zero otherwise a negative error code if the registrain failed.
 605 */
 606int snd_card_register(struct snd_card *card)
 607{
 608        int err;
 609
 610        if (snd_BUG_ON(!card))
 611                return -EINVAL;
 612#ifndef CONFIG_SYSFS_DEPRECATED
 613        if (!card->card_dev) {
 614                card->card_dev = device_create(sound_class, card->dev,
 615                                               MKDEV(0, 0), card,
 616                                               "card%i", card->number);
 617                if (IS_ERR(card->card_dev))
 618                        card->card_dev = NULL;
 619        }
 620#endif
 621        if ((err = snd_device_register_all(card)) < 0)
 622                return err;
 623        mutex_lock(&snd_card_mutex);
 624        if (snd_cards[card->number]) {
 625                /* already registered */
 626                mutex_unlock(&snd_card_mutex);
 627                return 0;
 628        }
 629        if (card->id[0] == '\0')
 630                choose_default_id(card);
 631        snd_cards[card->number] = card;
 632        mutex_unlock(&snd_card_mutex);
 633        init_info_for_card(card);
 634#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 635        if (snd_mixer_oss_notify_callback)
 636                snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
 637#endif
 638#ifndef CONFIG_SYSFS_DEPRECATED
 639        if (card->card_dev) {
 640                err = device_create_file(card->card_dev, &card_id_attrs);
 641                if (err < 0)
 642                        return err;
 643                err = device_create_file(card->card_dev, &card_number_attrs);
 644                if (err < 0)
 645                        return err;
 646        }
 647#endif
 648        return 0;
 649}
 650
 651EXPORT_SYMBOL(snd_card_register);
 652
 653#ifdef CONFIG_PROC_FS
 654static struct snd_info_entry *snd_card_info_entry;
 655
 656static void snd_card_info_read(struct snd_info_entry *entry,
 657                               struct snd_info_buffer *buffer)
 658{
 659        int idx, count;
 660        struct snd_card *card;
 661
 662        for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 663                mutex_lock(&snd_card_mutex);
 664                if ((card = snd_cards[idx]) != NULL) {
 665                        count++;
 666                        snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
 667                                        idx,
 668                                        card->id,
 669                                        card->driver,
 670                                        card->shortname);
 671                        snd_iprintf(buffer, "                      %s\n",
 672                                        card->longname);
 673                }
 674                mutex_unlock(&snd_card_mutex);
 675        }
 676        if (!count)
 677                snd_iprintf(buffer, "--- no soundcards ---\n");
 678}
 679
 680#ifdef CONFIG_SND_OSSEMUL
 681
 682void snd_card_info_read_oss(struct snd_info_buffer *buffer)
 683{
 684        int idx, count;
 685        struct snd_card *card;
 686
 687        for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
 688                mutex_lock(&snd_card_mutex);
 689                if ((card = snd_cards[idx]) != NULL) {
 690                        count++;
 691                        snd_iprintf(buffer, "%s\n", card->longname);
 692                }
 693                mutex_unlock(&snd_card_mutex);
 694        }
 695        if (!count) {
 696                snd_iprintf(buffer, "--- no soundcards ---\n");
 697        }
 698}
 699
 700#endif
 701
 702#ifdef MODULE
 703static struct snd_info_entry *snd_card_module_info_entry;
 704static void snd_card_module_info_read(struct snd_info_entry *entry,
 705                                      struct snd_info_buffer *buffer)
 706{
 707        int idx;
 708        struct snd_card *card;
 709
 710        for (idx = 0; idx < SNDRV_CARDS; idx++) {
 711                mutex_lock(&snd_card_mutex);
 712                if ((card = snd_cards[idx]) != NULL)
 713                        snd_iprintf(buffer, "%2i %s\n",
 714                                    idx, card->module->name);
 715                mutex_unlock(&snd_card_mutex);
 716        }
 717}
 718#endif
 719
 720int __init snd_card_info_init(void)
 721{
 722        struct snd_info_entry *entry;
 723
 724        entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
 725        if (! entry)
 726                return -ENOMEM;
 727        entry->c.text.read = snd_card_info_read;
 728        if (snd_info_register(entry) < 0) {
 729                snd_info_free_entry(entry);
 730                return -ENOMEM;
 731        }
 732        snd_card_info_entry = entry;
 733
 734#ifdef MODULE
 735        entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
 736        if (entry) {
 737                entry->c.text.read = snd_card_module_info_read;
 738                if (snd_info_register(entry) < 0)
 739                        snd_info_free_entry(entry);
 740                else
 741                        snd_card_module_info_entry = entry;
 742        }
 743#endif
 744
 745        return 0;
 746}
 747
 748int __exit snd_card_info_done(void)
 749{
 750        snd_info_free_entry(snd_card_info_entry);
 751#ifdef MODULE
 752        snd_info_free_entry(snd_card_module_info_entry);
 753#endif
 754        return 0;
 755}
 756
 757#endif /* CONFIG_PROC_FS */
 758
 759/**
 760 *  snd_component_add - add a component string
 761 *  @card: soundcard structure
 762 *  @component: the component id string
 763 *
 764 *  This function adds the component id string to the supported list.
 765 *  The component can be referred from the alsa-lib.
 766 *
 767 *  Returns zero otherwise a negative error code.
 768 */
 769  
 770int snd_component_add(struct snd_card *card, const char *component)
 771{
 772        char *ptr;
 773        int len = strlen(component);
 774
 775        ptr = strstr(card->components, component);
 776        if (ptr != NULL) {
 777                if (ptr[len] == '\0' || ptr[len] == ' ')        /* already there */
 778                        return 1;
 779        }
 780        if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
 781                snd_BUG();
 782                return -ENOMEM;
 783        }
 784        if (card->components[0] != '\0')
 785                strcat(card->components, " ");
 786        strcat(card->components, component);
 787        return 0;
 788}
 789
 790EXPORT_SYMBOL(snd_component_add);
 791
 792/**
 793 *  snd_card_file_add - add the file to the file list of the card
 794 *  @card: soundcard structure
 795 *  @file: file pointer
 796 *
 797 *  This function adds the file to the file linked-list of the card.
 798 *  This linked-list is used to keep tracking the connection state,
 799 *  and to avoid the release of busy resources by hotplug.
 800 *
 801 *  Returns zero or a negative error code.
 802 */
 803int snd_card_file_add(struct snd_card *card, struct file *file)
 804{
 805        struct snd_monitor_file *mfile;
 806
 807        mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
 808        if (mfile == NULL)
 809                return -ENOMEM;
 810        mfile->file = file;
 811        mfile->disconnected_f_op = NULL;
 812        mfile->next = NULL;
 813        spin_lock(&card->files_lock);
 814        if (card->shutdown) {
 815                spin_unlock(&card->files_lock);
 816                kfree(mfile);
 817                return -ENODEV;
 818        }
 819        mfile->next = card->files;
 820        card->files = mfile;
 821        spin_unlock(&card->files_lock);
 822        return 0;
 823}
 824
 825EXPORT_SYMBOL(snd_card_file_add);
 826
 827/**
 828 *  snd_card_file_remove - remove the file from the file list
 829 *  @card: soundcard structure
 830 *  @file: file pointer
 831 *
 832 *  This function removes the file formerly added to the card via
 833 *  snd_card_file_add() function.
 834 *  If all files are removed and snd_card_free_when_closed() was
 835 *  called beforehand, it processes the pending release of
 836 *  resources.
 837 *
 838 *  Returns zero or a negative error code.
 839 */
 840int snd_card_file_remove(struct snd_card *card, struct file *file)
 841{
 842        struct snd_monitor_file *mfile, *pfile = NULL;
 843        int last_close = 0;
 844
 845        spin_lock(&card->files_lock);
 846        mfile = card->files;
 847        while (mfile) {
 848                if (mfile->file == file) {
 849                        if (pfile)
 850                                pfile->next = mfile->next;
 851                        else
 852                                card->files = mfile->next;
 853                        break;
 854                }
 855                pfile = mfile;
 856                mfile = mfile->next;
 857        }
 858        if (mfile && mfile->disconnected_f_op) {
 859                fops_put(mfile->disconnected_f_op);
 860                spin_lock(&shutdown_lock);
 861                list_del(&mfile->shutdown_list);
 862                spin_unlock(&shutdown_lock);
 863        }
 864        if (card->files == NULL)
 865                last_close = 1;
 866        spin_unlock(&card->files_lock);
 867        if (last_close) {
 868                wake_up(&card->shutdown_sleep);
 869                if (card->free_on_last_close)
 870                        snd_card_do_free(card);
 871        }
 872        if (!mfile) {
 873                snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
 874                return -ENOENT;
 875        }
 876        kfree(mfile);
 877        return 0;
 878}
 879
 880EXPORT_SYMBOL(snd_card_file_remove);
 881
 882#ifdef CONFIG_PM
 883/**
 884 *  snd_power_wait - wait until the power-state is changed.
 885 *  @card: soundcard structure
 886 *  @power_state: expected power state
 887 *
 888 *  Waits until the power-state is changed.
 889 *
 890 *  Note: the power lock must be active before call.
 891 */
 892int snd_power_wait(struct snd_card *card, unsigned int power_state)
 893{
 894        wait_queue_t wait;
 895        int result = 0;
 896
 897        /* fastpath */
 898        if (snd_power_get_state(card) == power_state)
 899                return 0;
 900        init_waitqueue_entry(&wait, current);
 901        add_wait_queue(&card->power_sleep, &wait);
 902        while (1) {
 903                if (card->shutdown) {
 904                        result = -ENODEV;
 905                        break;
 906                }
 907                if (snd_power_get_state(card) == power_state)
 908                        break;
 909                set_current_state(TASK_UNINTERRUPTIBLE);
 910                snd_power_unlock(card);
 911                schedule_timeout(30 * HZ);
 912                snd_power_lock(card);
 913        }
 914        remove_wait_queue(&card->power_sleep, &wait);
 915        return result;
 916}
 917
 918EXPORT_SYMBOL(snd_power_wait);
 919#endif /* CONFIG_PM */
 920