/*
   *  Initialization routines

   *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>

   *
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *   GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   */

  #include <linux/init.h>
  #include <linux/sched.h>

  #include <linux/module.h>

  #include <linux/file.h>
  #include <linux/slab.h>
  #include <linux/time.h>
  #include <linux/ctype.h>

  #include <linux/pm.h>

  #include <sound/core.h>
  #include <sound/control.h>
  #include <sound/info.h>

  /* monitor files for graceful shutdown (hotplug) */
  struct snd_monitor_file {
  	struct file *file;
  	const struct file_operations *disconnected_f_op;
  	struct list_head shutdown_list;	/* still need to shutdown */
  	struct list_head list;	/* link of monitor files */
  };

  static DEFINE_SPINLOCK(shutdown_lock);
  static LIST_HEAD(shutdown_files);

  static const struct file_operations snd_shutdown_f_ops;

  static unsigned int snd_cards_lock;	/* locked for registering/using */
  struct snd_card *snd_cards[SNDRV_CARDS];

  EXPORT_SYMBOL(snd_cards);

  static DEFINE_MUTEX(snd_card_mutex);

  static char *slots[SNDRV_CARDS];
  module_param_array(slots, charp, NULL, 0444);
  MODULE_PARM_DESC(slots, "Module names assigned to the slots.");

  /* return non-zero if the given index is reserved for the given

   * module via slots option
   */

  static int module_slot_match(struct module *module, int idx)

  {

  	int match = 1;

  #ifdef MODULE

  	const char *s1, *s2;

  	if (!module || !module->name || !slots[idx])
  		return 0;

  
  	s1 = module->name;
  	s2 = slots[idx];
  	if (*s2 == '!') {
  		match = 0; /* negative match */
  		s2++;
  	}

  	/* compare module name strings
  	 * hyphens are handled as equivalent with underscore
  	 */
  	for (;;) {
  		char c1 = *s1++;
  		char c2 = *s2++;
  		if (c1 == '-')
  			c1 = '_';
  		if (c2 == '-')
  			c2 = '_';
  		if (c1 != c2)

  			return !match;

  		if (!c1)
  			break;
  	}

  #endif /* MODULE */
  	return match;

  }

  #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)

  int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);

  EXPORT_SYMBOL(snd_mixer_oss_notify_callback);

  #endif

  #ifdef CONFIG_PROC_FS

  static void snd_card_id_read(struct snd_info_entry *entry,
  			     struct snd_info_buffer *buffer)

  {
  	snd_iprintf(buffer, "%s
  ", entry->card->id);
  }

  static inline int init_info_for_card(struct snd_card *card)
  {
  	int err;
  	struct snd_info_entry *entry;
  
  	if ((err = snd_info_card_register(card)) < 0) {
  		snd_printd("unable to create card info
  ");
  		return err;
  	}
  	if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
  		snd_printd("unable to create card entry
  ");
  		return err;
  	}

  	entry->c.text.read = snd_card_id_read;
  	if (snd_info_register(entry) < 0) {
  		snd_info_free_entry(entry);
  		entry = NULL;
  	}
  	card->proc_id = entry;
  	return 0;
  }
  #else /* !CONFIG_PROC_FS */
  #define init_info_for_card(card)
  #endif

  /**

   *  snd_card_create - create and initialize a soundcard structure

   *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
   *  @xid: card identification (ASCII string)
   *  @module: top level module for locking
   *  @extra_size: allocate this extra size after the main soundcard structure

   *  @card_ret: the pointer to store the created card instance

   *
   *  Creates and initializes a soundcard structure.
   *

   *  The function allocates snd_card instance via kzalloc with the given
   *  space for the driver to use freely.  The allocated struct is stored
   *  in the given card_ret pointer.
   *
   *  Returns zero if successful or a negative error code.

   */

  int snd_card_create(int idx, const char *xid,
  		    struct module *module, int extra_size,
  		    struct snd_card **card_ret)

  {

  	struct snd_card *card;

  	int err, idx2;

  	if (snd_BUG_ON(!card_ret))
  		return -EINVAL;
  	*card_ret = NULL;

  	if (extra_size < 0)
  		extra_size = 0;

  	card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);

  	if (!card)
  		return -ENOMEM;

  	if (xid)

  		strlcpy(card->id, xid, sizeof(card->id));

  	err = 0;

  	mutex_lock(&snd_card_mutex);

  	if (idx < 0) {

  		for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)

  			/* idx == -1 == 0xffff means: take any free slot */

  			if (~snd_cards_lock & idx & 1<<idx2) {

  				if (module_slot_match(module, idx2)) {
  					idx = idx2;
  					break;
  				}
  			}
  	}
  	if (idx < 0) {
  		for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
  			/* idx == -1 == 0xffff means: take any free slot */
  			if (~snd_cards_lock & idx & 1<<idx2) {
  				if (!slots[idx2] || !*slots[idx2]) {
  					idx = idx2;
  					break;
  				}

  			}

  	}

  	if (idx < 0)
  		err = -ENODEV;
  	else if (idx < snd_ecards_limit) {
  		if (snd_cards_lock & (1 << idx))
  			err = -EBUSY;	/* invalid */
  	} else if (idx >= SNDRV_CARDS)
  		err = -ENODEV;
  	if (err < 0) {

  		mutex_unlock(&snd_card_mutex);

  		snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d
  ",
  			 idx, snd_ecards_limit - 1, err);

  		goto __error;
  	}
  	snd_cards_lock |= 1 << idx;		/* lock it */

  	if (idx >= snd_ecards_limit)
  		snd_ecards_limit = idx + 1; /* increase the limit */

  	mutex_unlock(&snd_card_mutex);

  	card->number = idx;
  	card->module = module;
  	INIT_LIST_HEAD(&card->devices);
  	init_rwsem(&card->controls_rwsem);
  	rwlock_init(&card->ctl_files_rwlock);
  	INIT_LIST_HEAD(&card->controls);
  	INIT_LIST_HEAD(&card->ctl_files);
  	spin_lock_init(&card->files_lock);

  	INIT_LIST_HEAD(&card->files_list);

  	init_waitqueue_head(&card->shutdown_sleep);

  #ifdef CONFIG_PM

  	mutex_init(&card->power_lock);

  	init_waitqueue_head(&card->power_sleep);
  #endif
  	/* the control interface cannot be accessed from the user space until */
  	/* snd_cards_bitmask and snd_cards are set with snd_card_register */

  	err = snd_ctl_create(card);
  	if (err < 0) {
  		snd_printk(KERN_ERR "unable to register control minors
  ");

  		goto __error;
  	}

  	err = snd_info_card_create(card);
  	if (err < 0) {
  		snd_printk(KERN_ERR "unable to create card info
  ");

  		goto __error_ctl;
  	}
  	if (extra_size > 0)

  		card->private_data = (char *)card + sizeof(struct snd_card);

  	*card_ret = card;
  	return 0;

  
        __error_ctl:
  	snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
        __error:
  	kfree(card);

    	return err;

  }

  EXPORT_SYMBOL(snd_card_create);

  /* return non-zero if a card is already locked */
  int snd_card_locked(int card)
  {
  	int locked;
  
  	mutex_lock(&snd_card_mutex);
  	locked = snd_cards_lock & (1 << card);
  	mutex_unlock(&snd_card_mutex);
  	return locked;
  }

  static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
  {
  	return -ENODEV;
  }
  
  static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
  				   size_t count, loff_t *offset)
  {
  	return -ENODEV;
  }
  
  static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
  				    size_t count, loff_t *offset)
  {
  	return -ENODEV;
  }

  static int snd_disconnect_release(struct inode *inode, struct file *file)
  {
  	struct snd_monitor_file *df = NULL, *_df;
  
  	spin_lock(&shutdown_lock);
  	list_for_each_entry(_df, &shutdown_files, shutdown_list) {
  		if (_df->file == file) {
  			df = _df;

  			list_del_init(&df->shutdown_list);

  			break;
  		}
  	}
  	spin_unlock(&shutdown_lock);

  	if (likely(df)) {
  		if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
  			df->disconnected_f_op->fasync(-1, file, 0);

  		return df->disconnected_f_op->release(inode, file);

  	}

  	panic("%s(%p, %p) failed!", __func__, inode, file);

  }

  static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
  {
  	return POLLERR | POLLNVAL;
  }

  static long snd_disconnect_ioctl(struct file *file,
  				 unsigned int cmd, unsigned long arg)
  {
  	return -ENODEV;
  }
  
  static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
  {
  	return -ENODEV;
  }
  
  static int snd_disconnect_fasync(int fd, struct file *file, int on)
  {
  	return -ENODEV;
  }

  static const struct file_operations snd_shutdown_f_ops =

  {
  	.owner = 	THIS_MODULE,
  	.llseek =	snd_disconnect_llseek,
  	.read = 	snd_disconnect_read,
  	.write =	snd_disconnect_write,
  	.release =	snd_disconnect_release,
  	.poll =		snd_disconnect_poll,
  	.unlocked_ioctl = snd_disconnect_ioctl,
  #ifdef CONFIG_COMPAT
  	.compat_ioctl = snd_disconnect_ioctl,
  #endif
  	.mmap =		snd_disconnect_mmap,
  	.fasync =	snd_disconnect_fasync
  };

  /**
   *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
   *  @card: soundcard structure
   *
   *  Disconnects all APIs from the file-operations (user space).
   *
   *  Returns zero, otherwise a negative error code.
   *
   *  Note: The current implementation replaces all active file->f_op with special
   *        dummy file operations (they do nothing except release).
   */

  int snd_card_disconnect(struct snd_card *card)

  {
  	struct snd_monitor_file *mfile;

  	int err;

  	if (!card)
  		return -EINVAL;

  	spin_lock(&card->files_lock);
  	if (card->shutdown) {
  		spin_unlock(&card->files_lock);
  		return 0;
  	}
  	card->shutdown = 1;
  	spin_unlock(&card->files_lock);
  
  	/* phase 1: disable fops (user space) operations for ALSA API */

  	mutex_lock(&snd_card_mutex);

  	snd_cards[card->number] = NULL;

  	snd_cards_lock &= ~(1 << card->number);

  	mutex_unlock(&snd_card_mutex);

  	
  	/* phase 2: replace file->f_op with special dummy operations */
  	
  	spin_lock(&card->files_lock);

  	list_for_each_entry(mfile, &card->files_list, list) {

  		/* it's critical part, use endless loop */
  		/* we have no room to fail */

  		mfile->disconnected_f_op = mfile->file->f_op;

  		spin_lock(&shutdown_lock);
  		list_add(&mfile->shutdown_list, &shutdown_files);
  		spin_unlock(&shutdown_lock);

  		mfile->file->f_op = &snd_shutdown_f_ops;

  		fops_get(mfile->file->f_op);

  	}
  	spin_unlock(&card->files_lock);	
  
  	/* phase 3: notify all connected devices about disconnection */
  	/* at this point, they cannot respond to any calls except release() */
  
  #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  	if (snd_mixer_oss_notify_callback)
  		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
  #endif
  
  	/* notify all devices that we are disconnected */
  	err = snd_device_disconnect_all(card);
  	if (err < 0)
  		snd_printk(KERN_ERR "not all devices for card %i can be disconnected
  ", card->number);

  	snd_info_card_disconnect(card);

  	if (card->card_dev) {
  		device_unregister(card->card_dev);
  		card->card_dev = NULL;
  	}

  #ifdef CONFIG_PM
  	wake_up(&card->power_sleep);
  #endif

  	return 0;	
  }

  EXPORT_SYMBOL(snd_card_disconnect);

  /**
   *  snd_card_free - frees given soundcard structure
   *  @card: soundcard structure
   *
   *  This function releases the soundcard structure and the all assigned
   *  devices automatically.  That is, you don't have to release the devices
   *  by yourself.
   *
   *  Returns zero. Frees all associated devices and frees the control
   *  interface associated to given soundcard.
   */

  static int snd_card_do_free(struct snd_card *card)

  {

  #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  	if (snd_mixer_oss_notify_callback)
  		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
  #endif
  	if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
  		snd_printk(KERN_ERR "unable to free all devices (pre)
  ");
  		/* Fatal, but this situation should never occur */
  	}
  	if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
  		snd_printk(KERN_ERR "unable to free all devices (normal)
  ");
  		/* Fatal, but this situation should never occur */
  	}
  	if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
  		snd_printk(KERN_ERR "unable to free all devices (post)
  ");
  		/* Fatal, but this situation should never occur */
  	}
  	if (card->private_free)
  		card->private_free(card);

  	snd_info_free_entry(card->proc_id);

  	if (snd_info_card_free(card) < 0) {
  		snd_printk(KERN_WARNING "unable to free card info
  ");
  		/* Not fatal error */
  	}

  	kfree(card);
  	return 0;
  }

  int snd_card_free_when_closed(struct snd_card *card)
  {
  	int free_now = 0;

  	int ret = snd_card_disconnect(card);

  	if (ret)
  		return ret;
  
  	spin_lock(&card->files_lock);

  	if (list_empty(&card->files_list))

  		free_now = 1;
  	else
  		card->free_on_last_close = 1;
  	spin_unlock(&card->files_lock);
  
  	if (free_now)
  		snd_card_do_free(card);
  	return 0;
  }
  
  EXPORT_SYMBOL(snd_card_free_when_closed);
  
  int snd_card_free(struct snd_card *card)
  {

  	int ret = snd_card_disconnect(card);

  	if (ret)
  		return ret;
  
  	/* wait, until all devices are ready for the free operation */

  	wait_event(card->shutdown_sleep, list_empty(&card->files_list));

  	snd_card_do_free(card);

  	return 0;
  }

  EXPORT_SYMBOL(snd_card_free);

  static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)

  {

  	int i, len, idx_flag = 0, loops = SNDRV_CARDS;

  	const char *spos, *src;
  	char *id;

  	if (nid == NULL) {
  		id = card->shortname;
  		spos = src = id;
  		while (*id != '\0') {
  			if (*id == ' ')
  				spos = id + 1;
  			id++;
  		}
  	} else {
  		spos = src = nid;

  	}
  	id = card->id;
  	while (*spos != '\0' && !isalnum(*spos))
  		spos++;
  	if (isdigit(*spos))

  		*id++ = isalpha(src[0]) ? src[0] : 'D';

  	while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
  		if (isalnum(*spos))
  			*id++ = *spos;
  		spos++;
  	}
  	*id = '\0';
  
  	id = card->id;
  	
  	if (*id == '\0')

  		strcpy(id, "Default");

  
  	while (1) {
  	      	if (loops-- == 0) {

  			snd_printk(KERN_ERR "unable to set card id (%s)
  ", id);

        			strcpy(card->id, card->proc_root->name);
        			return;
        		}
  	      	if (!snd_info_check_reserved_words(id))
        			goto __change;
  		for (i = 0; i < snd_ecards_limit; i++) {

  			if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))

  				goto __change;
  		}
  		break;
  
  	      __change:
  		len = strlen(id);

  		if (idx_flag) {
  			if (id[len-1] != '9')
  				id[len-1]++;
  			else
  				id[len-1] = 'A';
  		} else if ((size_t)len <= sizeof(card->id) - 3) {

  			strcat(id, "_1");
  			idx_flag++;
  		} else {
  			spos = id + len - 2;
  			if ((size_t)len <= sizeof(card->id) - 2)
  				spos++;

  			*(char *)spos++ = '_';
  			*(char *)spos++ = '1';
  			*(char *)spos++ = '\0';

  			idx_flag++;
  		}
  	}
  }

  /**
   *  snd_card_set_id - set card identification name
   *  @card: soundcard structure
   *  @nid: new identification string
   *
   *  This function sets the card identification and checks for name
   *  collisions.
   */
  void snd_card_set_id(struct snd_card *card, const char *nid)
  {

  	/* check if user specified own card->id */
  	if (card->id[0] != '\0')
  		return;
  	mutex_lock(&snd_card_mutex);
  	snd_card_set_id_no_lock(card, nid);
  	mutex_unlock(&snd_card_mutex);

  }

  EXPORT_SYMBOL(snd_card_set_id);

  static ssize_t
  card_id_show_attr(struct device *dev,
  		  struct device_attribute *attr, char *buf)
  {
  	struct snd_card *card = dev_get_drvdata(dev);
  	return snprintf(buf, PAGE_SIZE, "%s
  ", card ? card->id : "(null)");
  }
  
  static ssize_t
  card_id_store_attr(struct device *dev, struct device_attribute *attr,
  		   const char *buf, size_t count)
  {
  	struct snd_card *card = dev_get_drvdata(dev);
  	char buf1[sizeof(card->id)];
  	size_t copy = count > sizeof(card->id) - 1 ?
  					sizeof(card->id) - 1 : count;
  	size_t idx;
  	int c;
  
  	for (idx = 0; idx < copy; idx++) {
  		c = buf[idx];
  		if (!isalnum(c) && c != '_' && c != '-')
  			return -EINVAL;
  	}
  	memcpy(buf1, buf, copy);
  	buf1[copy] = '\0';
  	mutex_lock(&snd_card_mutex);
  	if (!snd_info_check_reserved_words(buf1)) {
  	     __exist:
  		mutex_unlock(&snd_card_mutex);
  		return -EEXIST;
  	}
  	for (idx = 0; idx < snd_ecards_limit; idx++) {

  		if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) {
  			if (card == snd_cards[idx])
  				goto __ok;
  			else
  				goto __exist;
  		}

  	}
  	strcpy(card->id, buf1);

  	snd_info_card_id_change(card);

  __ok:

  	mutex_unlock(&snd_card_mutex);
  
  	return count;
  }
  
  static struct device_attribute card_id_attrs =
  	__ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr);
  
  static ssize_t
  card_number_show_attr(struct device *dev,
  		     struct device_attribute *attr, char *buf)
  {
  	struct snd_card *card = dev_get_drvdata(dev);
  	return snprintf(buf, PAGE_SIZE, "%i
  ", card ? card->number : -1);
  }
  
  static struct device_attribute card_number_attrs =
  	__ATTR(number, S_IRUGO, card_number_show_attr, NULL);

  /**
   *  snd_card_register - register the soundcard
   *  @card: soundcard structure
   *
   *  This function registers all the devices assigned to the soundcard.
   *  Until calling this, the ALSA control interface is blocked from the
   *  external accesses.  Thus, you should call this function at the end
   *  of the initialization of the card.
   *

   *  Returns zero otherwise a negative error code if the registration failed.

   */

  int snd_card_register(struct snd_card *card)

  {
  	int err;

  	if (snd_BUG_ON(!card))
  		return -EINVAL;

  	if (!card->card_dev) {

  		card->card_dev = device_create(sound_class, card->dev,

  					       MKDEV(0, 0), card,

  					       "card%i", card->number);

  		if (IS_ERR(card->card_dev))
  			card->card_dev = NULL;

  	}

  	if ((err = snd_device_register_all(card)) < 0)
  		return err;

  	mutex_lock(&snd_card_mutex);

  	if (snd_cards[card->number]) {
  		/* already registered */

  		mutex_unlock(&snd_card_mutex);

  		return 0;
  	}

  	snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id);

  	snd_cards[card->number] = card;

  	mutex_unlock(&snd_card_mutex);

  	init_info_for_card(card);

  #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
  	if (snd_mixer_oss_notify_callback)
  		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
  #endif

  	if (card->card_dev) {

  		err = device_create_file(card->card_dev, &card_id_attrs);
  		if (err < 0)
  			return err;
  		err = device_create_file(card->card_dev, &card_number_attrs);
  		if (err < 0)
  			return err;

  	}

  	return 0;
  }

  EXPORT_SYMBOL(snd_card_register);

  #ifdef CONFIG_PROC_FS

  static struct snd_info_entry *snd_card_info_entry;

  static void snd_card_info_read(struct snd_info_entry *entry,
  			       struct snd_info_buffer *buffer)

  {
  	int idx, count;

  	struct snd_card *card;

  
  	for (idx = count = 0; idx < SNDRV_CARDS; idx++) {

  		mutex_lock(&snd_card_mutex);

  		if ((card = snd_cards[idx]) != NULL) {
  			count++;

  			snd_iprintf(buffer, "%2i [%-15s]: %s - %s
  ",

  					idx,
  					card->id,
  					card->driver,
  					card->shortname);

  			snd_iprintf(buffer, "                      %s
  ",

  					card->longname);
  		}

  		mutex_unlock(&snd_card_mutex);

  	}
  	if (!count)
  		snd_iprintf(buffer, "--- no soundcards ---
  ");
  }

  #ifdef CONFIG_SND_OSSEMUL

  void snd_card_info_read_oss(struct snd_info_buffer *buffer)

  {
  	int idx, count;

  	struct snd_card *card;

  
  	for (idx = count = 0; idx < SNDRV_CARDS; idx++) {

  		mutex_lock(&snd_card_mutex);

  		if ((card = snd_cards[idx]) != NULL) {
  			count++;
  			snd_iprintf(buffer, "%s
  ", card->longname);
  		}

  		mutex_unlock(&snd_card_mutex);

  	}
  	if (!count) {
  		snd_iprintf(buffer, "--- no soundcards ---
  ");
  	}
  }
  
  #endif
  
  #ifdef MODULE

  static struct snd_info_entry *snd_card_module_info_entry;
  static void snd_card_module_info_read(struct snd_info_entry *entry,
  				      struct snd_info_buffer *buffer)

  {
  	int idx;

  	struct snd_card *card;

  
  	for (idx = 0; idx < SNDRV_CARDS; idx++) {

  		mutex_lock(&snd_card_mutex);

  		if ((card = snd_cards[idx]) != NULL)

  			snd_iprintf(buffer, "%2i %s
  ",
  				    idx, card->module->name);

  		mutex_unlock(&snd_card_mutex);

  	}
  }
  #endif
  
  int __init snd_card_info_init(void)
  {

  	struct snd_info_entry *entry;

  
  	entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);

  	if (! entry)
  		return -ENOMEM;

  	entry->c.text.read = snd_card_info_read;
  	if (snd_info_register(entry) < 0) {
  		snd_info_free_entry(entry);
  		return -ENOMEM;
  	}
  	snd_card_info_entry = entry;
  
  #ifdef MODULE
  	entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
  	if (entry) {

  		entry->c.text.read = snd_card_module_info_read;
  		if (snd_info_register(entry) < 0)
  			snd_info_free_entry(entry);
  		else
  			snd_card_module_info_entry = entry;
  	}
  #endif
  
  	return 0;
  }
  
  int __exit snd_card_info_done(void)
  {

  	snd_info_free_entry(snd_card_info_entry);

  #ifdef MODULE

  	snd_info_free_entry(snd_card_module_info_entry);

  #endif
  	return 0;
  }

  #endif /* CONFIG_PROC_FS */

  /**
   *  snd_component_add - add a component string
   *  @card: soundcard structure
   *  @component: the component id string
   *
   *  This function adds the component id string to the supported list.
   *  The component can be referred from the alsa-lib.
   *
   *  Returns zero otherwise a negative error code.
   */
    

  int snd_component_add(struct snd_card *card, const char *component)

  {
  	char *ptr;
  	int len = strlen(component);
  
  	ptr = strstr(card->components, component);
  	if (ptr != NULL) {
  		if (ptr[len] == '\0' || ptr[len] == ' ')	/* already there */
  			return 1;
  	}
  	if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
  		snd_BUG();
  		return -ENOMEM;
  	}
  	if (card->components[0] != '\0')
  		strcat(card->components, " ");
  	strcat(card->components, component);
  	return 0;
  }

  EXPORT_SYMBOL(snd_component_add);

  /**
   *  snd_card_file_add - add the file to the file list of the card
   *  @card: soundcard structure
   *  @file: file pointer
   *
   *  This function adds the file to the file linked-list of the card.
   *  This linked-list is used to keep tracking the connection state,
   *  and to avoid the release of busy resources by hotplug.
   *
   *  Returns zero or a negative error code.
   */

  int snd_card_file_add(struct snd_card *card, struct file *file)

  {
  	struct snd_monitor_file *mfile;
  
  	mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
  	if (mfile == NULL)
  		return -ENOMEM;
  	mfile->file = file;

  	mfile->disconnected_f_op = NULL;

  	INIT_LIST_HEAD(&mfile->shutdown_list);

  	spin_lock(&card->files_lock);
  	if (card->shutdown) {
  		spin_unlock(&card->files_lock);
  		kfree(mfile);
  		return -ENODEV;
  	}

  	list_add(&mfile->list, &card->files_list);

  	spin_unlock(&card->files_lock);
  	return 0;
  }

  EXPORT_SYMBOL(snd_card_file_add);

  /**
   *  snd_card_file_remove - remove the file from the file list
   *  @card: soundcard structure
   *  @file: file pointer
   *
   *  This function removes the file formerly added to the card via
   *  snd_card_file_add() function.

   *  If all files are removed and snd_card_free_when_closed() was
   *  called beforehand, it processes the pending release of
   *  resources.

   *
   *  Returns zero or a negative error code.
   */

  int snd_card_file_remove(struct snd_card *card, struct file *file)

  {

  	struct snd_monitor_file *mfile, *found = NULL;

  	int last_close = 0;

  
  	spin_lock(&card->files_lock);

  	list_for_each_entry(mfile, &card->files_list, list) {

  		if (mfile->file == file) {

  			list_del(&mfile->list);

  			spin_lock(&shutdown_lock);
  			list_del(&mfile->shutdown_list);
  			spin_unlock(&shutdown_lock);

  			if (mfile->disconnected_f_op)
  				fops_put(mfile->disconnected_f_op);
  			found = mfile;

  			break;
  		}

  	}

  	if (list_empty(&card->files_list))

  		last_close = 1;
  	spin_unlock(&card->files_lock);
  	if (last_close) {

  		wake_up(&card->shutdown_sleep);

  		if (card->free_on_last_close)
  			snd_card_do_free(card);
  	}

  	if (!found) {

  		snd_printk(KERN_ERR "ALSA card file remove problem (%p)
  ", file);
  		return -ENOENT;
  	}

  	kfree(found);

  	return 0;
  }

  EXPORT_SYMBOL(snd_card_file_remove);

  #ifdef CONFIG_PM
  /**
   *  snd_power_wait - wait until the power-state is changed.
   *  @card: soundcard structure
   *  @power_state: expected power state

   *
   *  Waits until the power-state is changed.
   *
   *  Note: the power lock must be active before call.
   */

  int snd_power_wait(struct snd_card *card, unsigned int power_state)

  {
  	wait_queue_t wait;
  	int result = 0;
  
  	/* fastpath */
  	if (snd_power_get_state(card) == power_state)
  		return 0;
  	init_waitqueue_entry(&wait, current);
  	add_wait_queue(&card->power_sleep, &wait);
  	while (1) {
  		if (card->shutdown) {
  			result = -ENODEV;
  			break;
  		}
  		if (snd_power_get_state(card) == power_state)
  			break;

  		set_current_state(TASK_UNINTERRUPTIBLE);
  		snd_power_unlock(card);
  		schedule_timeout(30 * HZ);
  		snd_power_lock(card);
  	}
  	remove_wait_queue(&card->power_sleep, &wait);
  	return result;
  }

  EXPORT_SYMBOL(snd_power_wait);

  #endif /* CONFIG_PM */