/*
   *  Device management 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/slab.h>
  #include <linux/time.h>

  #include <linux/export.h>

  #include <linux/errno.h>
  #include <sound/core.h>
  
  /**
   * snd_device_new - create an ALSA device component
   * @card: the card instance

   * @type: the device type, SNDRV_DEV_XXX

   * @device_data: the data pointer of this device
   * @ops: the operator table
   *
   * Creates a new device component for the given data pointer.
   * The device will be assigned to the card and managed together
   * by the card.
   *
   * The data pointer plays a role as the identifier, too, so the
   * pointer address must be unique and unchanged.
   *
   * Returns zero if successful, or a negative error code on failure.
   */

  int snd_device_new(struct snd_card *card, snd_device_type_t type,
  		   void *device_data, struct snd_device_ops *ops)

  {

  	struct snd_device *dev;

  	if (snd_BUG_ON(!card || !device_data || !ops))
  		return -ENXIO;

  	dev = kzalloc(sizeof(*dev), GFP_KERNEL);

  	if (dev == NULL) {
  		snd_printk(KERN_ERR "Cannot allocate device
  ");

  		return -ENOMEM;

  	}

  	dev->card = card;
  	dev->type = type;
  	dev->state = SNDRV_DEV_BUILD;
  	dev->device_data = device_data;
  	dev->ops = ops;
  	list_add(&dev->list, &card->devices);	/* add to the head of list */
  	return 0;
  }

  EXPORT_SYMBOL(snd_device_new);

  /**
   * snd_device_free - release the device from the card
   * @card: the card instance
   * @device_data: the data pointer to release
   *
   * Removes the device from the list on the card and invokes the

   * callbacks, dev_disconnect and dev_free, corresponding to the state.

   * Then release the device.
   *
   * Returns zero if successful, or a negative error code on failure or if the
   * device not found.
   */

  int snd_device_free(struct snd_card *card, void *device_data)

  {

  	struct snd_device *dev;

  	if (snd_BUG_ON(!card || !device_data))
  		return -ENXIO;

  	list_for_each_entry(dev, &card->devices, list) {

  		if (dev->device_data != device_data)
  			continue;
  		/* unlink */
  		list_del(&dev->list);

  		if (dev->state == SNDRV_DEV_REGISTERED &&
  		    dev->ops->dev_disconnect)
  			if (dev->ops->dev_disconnect(dev))
  				snd_printk(KERN_ERR
  					   "device disconnect failure
  ");
  		if (dev->ops->dev_free) {
  			if (dev->ops->dev_free(dev))
  				snd_printk(KERN_ERR "device free failure
  ");

  		}
  		kfree(dev);
  		return 0;
  	}

  	snd_printd("device free %p (from %pF), not found
  ", device_data,

  		   __builtin_return_address(0));

  	return -ENXIO;
  }

  EXPORT_SYMBOL(snd_device_free);

  /**

   * snd_device_disconnect - disconnect the device

   * @card: the card instance
   * @device_data: the data pointer to disconnect
   *
   * Turns the device into the disconnection state, invoking
   * dev_disconnect callback, if the device was already registered.
   *
   * Usually called from snd_card_disconnect().
   *
   * Returns zero if successful, or a negative error code on failure or if the
   * device not found.
   */

  int snd_device_disconnect(struct snd_card *card, void *device_data)

  {

  	struct snd_device *dev;

  	if (snd_BUG_ON(!card || !device_data))
  		return -ENXIO;

  	list_for_each_entry(dev, &card->devices, list) {

  		if (dev->device_data != device_data)
  			continue;

  		if (dev->state == SNDRV_DEV_REGISTERED &&
  		    dev->ops->dev_disconnect) {

  			if (dev->ops->dev_disconnect(dev))
  				snd_printk(KERN_ERR "device disconnect failure
  ");
  			dev->state = SNDRV_DEV_DISCONNECTED;
  		}
  		return 0;
  	}

  	snd_printd("device disconnect %p (from %pF), not found
  ", device_data,

  		   __builtin_return_address(0));

  	return -ENXIO;
  }
  
  /**
   * snd_device_register - register the device
   * @card: the card instance
   * @device_data: the data pointer to register
   *
   * Registers the device which was already created via
   * snd_device_new().  Usually this is called from snd_card_register(),
   * but it can be called later if any new devices are created after
   * invocation of snd_card_register().
   *
   * Returns zero if successful, or a negative error code on failure or if the
   * device not found.
   */

  int snd_device_register(struct snd_card *card, void *device_data)

  {

  	struct snd_device *dev;

  	int err;

  	if (snd_BUG_ON(!card || !device_data))
  		return -ENXIO;

  	list_for_each_entry(dev, &card->devices, list) {

  		if (dev->device_data != device_data)
  			continue;
  		if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
  			if ((err = dev->ops->dev_register(dev)) < 0)
  				return err;
  			dev->state = SNDRV_DEV_REGISTERED;
  			return 0;
  		}

  		snd_printd("snd_device_register busy
  ");

  		return -EBUSY;
  	}
  	snd_BUG();
  	return -ENXIO;
  }

  EXPORT_SYMBOL(snd_device_register);

  /*
   * register all the devices on the card.
   * called from init.c
   */

  int snd_device_register_all(struct snd_card *card)

  {

  	struct snd_device *dev;

  	int err;
  	

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

  	list_for_each_entry(dev, &card->devices, list) {

  		if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
  			if ((err = dev->ops->dev_register(dev)) < 0)
  				return err;
  			dev->state = SNDRV_DEV_REGISTERED;
  		}
  	}
  	return 0;
  }
  
  /*
   * disconnect all the devices on the card.
   * called from init.c
   */

  int snd_device_disconnect_all(struct snd_card *card)

  {

  	struct snd_device *dev;

  	int err = 0;

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

  	list_for_each_entry(dev, &card->devices, list) {

  		if (snd_device_disconnect(card, dev->device_data) < 0)
  			err = -ENXIO;
  	}
  	return err;
  }
  
  /*
   * release all the devices on the card.
   * called from init.c
   */

  int snd_device_free_all(struct snd_card *card, snd_device_cmd_t cmd)

  {

  	struct snd_device *dev;

  	int err;

  	unsigned int range_low, range_high, type;

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

  	range_low = (__force unsigned int)cmd * SNDRV_DEV_TYPE_RANGE_SIZE;

  	range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
        __again:

  	list_for_each_entry(dev, &card->devices, list) {

  		type = (__force unsigned int)dev->type;
  		if (type >= range_low && type <= range_high) {

  			if ((err = snd_device_free(card, dev->device_data)) < 0)
  				return err;
  			goto __again;
  		}
  	}
  	return 0;
  }