src/control/control.c

/**
 * \file control/control.c
 * \brief CTL interface - primitive controls
 * \author Abramo Bagnara <abramo@alsa-project.org>
 * \date 2000
 *
 * CTL interface is designed to access primitive controls.
 * See \ref control page for more details.
 */
/*
 *  Control Interface - main file
 *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
 *
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as
 *   published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

/*! \page control Control interface

<P>Control interface is designed to access primitive controls. There is
also interface notifying about control and structure changes.

\section control_general_overview General overview

The primitive controls can be integer, boolean, enumerators, bytes
and IEC958 structure.

*/

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/poll.h>
#include "control_local.h"

/**
 * \brief get identifier of CTL handle
 * \param ctl CTL handle
 * \return ascii identifier of CTL handle
 *
 * Returns the ASCII identifier of given CTL handle. It's the same
 * identifier specified in snd_ctl_open().
 */
const char *snd_ctl_name(snd_ctl_t *ctl)
{
	assert(ctl);
	return ctl->name;
}

/**
 * \brief get type of CTL handle
 * \param ctl CTL handle
 * \return type of CTL handle
 *
 * Returns the type #snd_ctl_type_t of given CTL handle.
 */
snd_ctl_type_t snd_ctl_type(snd_ctl_t *ctl)
{
	assert(ctl);
	return ctl->type;
}

/**
 * \brief close CTL handle
 * \param ctl CTL handle
 * \return 0 on success otherwise a negative error code
 *
 * Closes the specified CTL handle and frees all associated
 * resources.
 */
int snd_ctl_close(snd_ctl_t *ctl)
{
	int err;
	while (!list_empty(&ctl->async_handlers)) {
		snd_async_handler_t *h = list_entry(&ctl->async_handlers.next, snd_async_handler_t, hlist);
		snd_async_del_handler(h);
	}
	err = ctl->ops->close(ctl);
	free(ctl->name);
	snd_dlobj_cache_put(ctl->open_func);
	free(ctl);
	return err;
}

/**
 * \brief set nonblock mode
 * \param ctl CTL handle
 * \param nonblock 0 = block, 1 = nonblock mode, 2 = abort
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_nonblock(snd_ctl_t *ctl, int nonblock)
{
	int err;
	assert(ctl);
	err = ctl->ops->nonblock(ctl, nonblock);
	if (err < 0)
		return err;
	ctl->nonblock = nonblock;
	return 0;
}

#ifndef DOC_HIDDEN
int snd_ctl_new(snd_ctl_t **ctlp, snd_ctl_type_t type, const char *name)
{
	snd_ctl_t *ctl;
	ctl = calloc(1, sizeof(*ctl));
	if (!ctl)
		return -ENOMEM;
	ctl->type = type;
	if (name)
		ctl->name = strdup(name);
	INIT_LIST_HEAD(&ctl->async_handlers);
	*ctlp = ctl;
	return 0;
}
	

/**
 * \brief set async mode
 * \param ctl CTL handle
 * \param sig Signal to raise: < 0 disable, 0 default (SIGIO)
 * \param pid Process ID to signal: 0 current
 * \return 0 on success otherwise a negative error code
 *
 * A signal is raised when a change happens.
 */
int snd_ctl_async(snd_ctl_t *ctl, int sig, pid_t pid)
{
	assert(ctl);
	if (sig == 0)
		sig = SIGIO;
	if (pid == 0)
		pid = getpid();
	return ctl->ops->async(ctl, sig, pid);
}
#endif

/**
 * \brief get count of poll descriptors for CTL handle
 * \param ctl CTL handle
 * \return count of poll descriptors
 */
int snd_ctl_poll_descriptors_count(snd_ctl_t *ctl)
{
	assert(ctl);
	if (ctl->ops->poll_descriptors_count)
		return ctl->ops->poll_descriptors_count(ctl);
	if (ctl->poll_fd < 0)
		return 0;
	return 1;
}

/**
 * \brief get poll descriptors
 * \param ctl CTL handle
 * \param pfds array of poll descriptors
 * \param space space in the poll descriptor array
 * \return count of filled descriptors
 */
int snd_ctl_poll_descriptors(snd_ctl_t *ctl, struct pollfd *pfds, unsigned int space)
{
	assert(ctl && pfds);
	if (ctl->ops->poll_descriptors)
		return ctl->ops->poll_descriptors(ctl, pfds, space);
	if (ctl->poll_fd < 0)
		return 0;
	if (space > 0) {
		pfds->fd = ctl->poll_fd;
		pfds->events = POLLIN|POLLERR|POLLNVAL;
		return 1;
	}
	return 0;
}

/**
 * \brief get returned events from poll descriptors
 * \param ctl CTL handle
 * \param pfds array of poll descriptors
 * \param nfds count of poll descriptors
 * \param revents returned events
 * \return zero if success, otherwise a negative error code
 */
int snd_ctl_poll_descriptors_revents(snd_ctl_t *ctl, struct pollfd *pfds, unsigned int nfds, unsigned short *revents)
{
	assert(ctl && pfds && revents);
	if (ctl->ops->poll_revents)
		return ctl->ops->poll_revents(ctl, pfds, nfds, revents);
	if (nfds == 1) {
		*revents = pfds->revents;
                return 0;
	}
	return -EINVAL;
}

/**
 * \brief Ask to be informed about events (poll, #snd_async_add_ctl_handler, #snd_ctl_read)
 * \param ctl CTL handle
 * \param subscribe 0 = unsubscribe, 1 = subscribe, -1 = check subscribe or not
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_subscribe_events(snd_ctl_t *ctl, int subscribe)
{
	assert(ctl);
	return ctl->ops->subscribe_events(ctl, subscribe);
}


/**
 * \brief Get card related information
 * \param ctl CTL handle
 * \param info Card info pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_card_info(snd_ctl_t *ctl, snd_ctl_card_info_t *info)
{
	assert(ctl && info);
	return ctl->ops->card_info(ctl, info);
}

/**
 * \brief Get a list of element identifiers
 * \param ctl CTL handle
 * \param list CTL element identifiers list pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_list(snd_ctl_t *ctl, snd_ctl_elem_list_t *list)
{
	assert(ctl && list);
	assert(list->space == 0 || list->pids);
	return ctl->ops->element_list(ctl, list);
}

/**
 * \brief Get CTL element information
 * \param ctl CTL handle
 * \param info CTL element id/information pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_info(snd_ctl_t *ctl, snd_ctl_elem_info_t *info)
{
	assert(ctl && info && (info->id.name[0] || info->id.numid));
	return ctl->ops->element_info(ctl, info);
}

/**
 * \brief Create and add an user INTEGER CTL element
 * \param ctl CTL handle
 * \param id CTL element id to add
 * \param count number of elements
 * \param min minimum value
 * \param max maximum value
 * \param step value step
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_add_integer(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
			     unsigned int count, long min, long max, long step)
{
	snd_ctl_elem_info_t *info;
	snd_ctl_elem_value_t *val;
	unsigned int i;
	int err;

	assert(ctl && id && id->name[0]);
	snd_ctl_elem_info_alloca(&info);
	info->id = *id;
	info->type = SND_CTL_ELEM_TYPE_INTEGER;
	info->access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
		SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE;
	info->count = count;
	info->value.integer.min = min;
	info->value.integer.max = max;
	info->value.integer.step = step;
	err = ctl->ops->element_add(ctl, info);
	if (err < 0)
		return err;
	snd_ctl_elem_value_alloca(&val);
	val->id = *id;
	for (i = 0; i < count; i++)
		val->value.integer.value[i] = min;
	err = ctl->ops->element_write(ctl, val);
	return err;
}

/**
 * \brief Create and add an user INTEGER64 CTL element
 * \param ctl CTL handle
 * \param id CTL element id to add
 * \param count number of elements
 * \param min minimum value
 * \param max maximum value
 * \param step value step
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_add_integer64(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
			       unsigned int count, long long min, long long max,
			       long long step)
{
	snd_ctl_elem_info_t *info;
	snd_ctl_elem_value_t *val;
	unsigned int i;
	int err;

	assert(ctl && id && id->name[0]);
	snd_ctl_elem_info_alloca(&info);
	info->id = *id;
	info->type = SND_CTL_ELEM_TYPE_INTEGER64;
	info->count = count;
	info->value.integer64.min = min;
	info->value.integer64.max = max;
	info->value.integer64.step = step;
	err = ctl->ops->element_add(ctl, info);
	if (err < 0)
		return err;
	snd_ctl_elem_value_alloca(&val);
	val->id = *id;
	for (i = 0; i < count; i++)
		val->value.integer64.value[i] = min;
	err = ctl->ops->element_write(ctl, val);
	return err;
}

/**
 * \brief Create and add an user BOOLEAN CTL element
 * \param ctl CTL handle
 * \param id CTL element id to add
 * \param count number of elements
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_add_boolean(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
			     unsigned int count)
{
	snd_ctl_elem_info_t *info;

	assert(ctl && id && id->name[0]);
	snd_ctl_elem_info_alloca(&info);
	info->id = *id;
	info->type = SND_CTL_ELEM_TYPE_BOOLEAN;
	info->count = count;
	info->value.integer.min = 0;
	info->value.integer.max = 1;
	return ctl->ops->element_add(ctl, info);
}

/**
 * \brief Create and add a user-defined control element of type enumerated.
 * \param[in] ctl Control device handle.
 * \param[in] id ID of the new control element.
 * \param[in] count Number of element values.
 * \param[in] items Range of possible values (0 ... \a items - 1).
 * \param[in] names An array containing \a items strings.
 * \return Zero on success, otherwise a negative error code.
 *
 * This function creates a user element, i.e., a control element that is not
 * controlled by the control device's driver but that is just stored together
 * with the other elements of \a ctl.
 *
 * The fields of \a id, except numid, must be set to unique values that
 * identify the new element.
 *
 * The new element is locked; its value is initialized as zero.
 *
 * \par Errors:
 * <dl>
 * <dt>-EBUSY<dd>A control element with ID \a id already exists.
 * <dt>-EINVAL<dd>\a count is not at least one or greater than 128, or \a items
 * 	is not at least one, or a string in \a names is empty or longer than 63
 * 	bytes, or the strings in \a names require more than 64 KB storage.
 * <dt>-ENOMEM<dd>Out of memory, or there are too many user control elements.
 * <dt>-ENXIO<dd>This driver does not support (enumerated) user controls.
 * <dt>-ENODEV<dd>Device unplugged.
 * </dl>
 *
 * \par Compatibility:
 * snd_ctl_elem_add_enumerated() was introduced in ALSA 1.0.25.
 */
int snd_ctl_elem_add_enumerated(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
				unsigned int count, unsigned int items,
				const char *const names[])
{
	snd_ctl_elem_info_t *info;
	unsigned int i, bytes;
	char *buf, *p;
	int err;

	assert(ctl && id && id->name[0] && names);

	snd_ctl_elem_info_alloca(&info);
	info->id = *id;
	info->type = SND_CTL_ELEM_TYPE_ENUMERATED;
	info->count = count;
	info->value.enumerated.items = items;

	bytes = 0;
	for (i = 0; i < items; ++i)
		bytes += strlen(names[i]) + 1;
	buf = malloc(bytes);
	if (!buf)
		return -ENOMEM;
	info->value.enumerated.names_ptr = (uintptr_t)buf;
	info->value.enumerated.names_length = bytes;
	p = buf;
	for (i = 0; i < items; ++i) {
		strcpy(p, names[i]);
		p += strlen(names[i]) + 1;
	}

	err = ctl->ops->element_add(ctl, info);

	free(buf);

	return err;
}

/**
 * \brief Create and add an user IEC958 CTL element
 * \param ctl CTL handle
 * \param id CTL element info to add
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_add_iec958(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id)
{
	snd_ctl_elem_info_t *info;

	assert(ctl && id && id->name[0]);
	snd_ctl_elem_info_alloca(&info);
	info->id = *id;
	info->type = SND_CTL_ELEM_TYPE_IEC958;
	info->count = 1;
	return ctl->ops->element_add(ctl, info);
}

/**
 * \brief Remove an user CTL element
 * \param ctl CTL handle
 * \param id CTL element identification
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_remove(snd_ctl_t *ctl, snd_ctl_elem_id_t *id)
{
	assert(ctl && id && (id->name[0] || id->numid));
	return ctl->ops->element_remove(ctl, id);
}

/**
 * \brief Get CTL element value
 * \param ctl CTL handle
 * \param control CTL element id/value pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_read(snd_ctl_t *ctl, snd_ctl_elem_value_t *control)
{
	assert(ctl && control && (control->id.name[0] || control->id.numid));
	return ctl->ops->element_read(ctl, control);
}

/**
 * \brief Set CTL element value
 * \param ctl CTL handle
 * \param control CTL element id/value pointer
 * \retval 0 on success
 * \retval >0 on success when value was changed
 * \retval <0 a negative error code
 */
int snd_ctl_elem_write(snd_ctl_t *ctl, snd_ctl_elem_value_t *control)
{
	assert(ctl && control && (control->id.name[0] || control->id.numid));
	return ctl->ops->element_write(ctl, control);
}

static int snd_ctl_tlv_do(snd_ctl_t *ctl, int op_flag,
			  const snd_ctl_elem_id_t *id,
		          unsigned int *tlv, unsigned int tlv_size)
{
	snd_ctl_elem_info_t *info = NULL;
	int err;

	if (id->numid == 0) {
		info = calloc(1, sizeof(*info));
		if (info == NULL)
			return -ENOMEM;
		info->id = *id;
		id = &info->id;
		err = snd_ctl_elem_info(ctl, info);
		if (err < 0)
			goto __err;
		if (id->numid == 0) {
			err = -ENOENT;
			goto __err;
		}
	}
	err = ctl->ops->element_tlv(ctl, op_flag, id->numid, tlv, tlv_size);
      __err:
      	if (info)
      		free(info);
	return err;
}



/**
 * \brief Get CTL element TLV value
 * \param ctl CTL handle
 * \param id CTL element id pointer
 * \param tlv TLV array pointer to store 
 * \param tlv_size TLV array size in bytes
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_tlv_read(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
			  unsigned int *tlv, unsigned int tlv_size)
{
	int err;
	assert(ctl && id && (id->name[0] || id->numid) && tlv);
	if (tlv_size < 2 * sizeof(int))
		return -EINVAL;
	/* 1.0.12 driver doesn't return the error even if the user TLV
	 * is empty.  So, initialize TLV here with an invalid type
	 * and compare the returned value after ioctl for checking
	 * the validity of TLV.
	 */
	tlv[0] = -1;
	tlv[1] = 0;
	err = snd_ctl_tlv_do(ctl, 0, id, tlv, tlv_size);
	if (err >= 0 && tlv[0] == (unsigned int)-1)
		err = -ENXIO;
	return err;
}

/**
 * \brief Set CTL element TLV value
 * \param ctl CTL handle
 * \param id CTL element id pointer
 * \param tlv TLV array pointer to store 
 * \retval 0 on success
 * \retval >0 on success when value was changed
 * \retval <0 a negative error code
 */
int snd_ctl_elem_tlv_write(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
			   const unsigned int *tlv)
{
	assert(ctl && id && (id->name[0] || id->numid) && tlv);
	return snd_ctl_tlv_do(ctl, 1, id, (unsigned int *)tlv, tlv[1] + 2 * sizeof(unsigned int));
}

/**
 * \brief Process CTL element TLV command
 * \param ctl CTL handle
 * \param id CTL element id pointer
 * \param tlv TLV array pointer to process
 * \retval 0 on success
 * \retval >0 on success when value was changed
 * \retval <0 a negative error code
 */
int snd_ctl_elem_tlv_command(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
			     const unsigned int *tlv)
{
	assert(ctl && id && (id->name[0] || id->numid) && tlv);
	return snd_ctl_tlv_do(ctl, -1, id, (unsigned int *)tlv, tlv[1] + 2 * sizeof(unsigned int));
}

/**
 * \brief Lock CTL element
 * \param ctl CTL handle
 * \param id CTL element id pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_lock(snd_ctl_t *ctl, snd_ctl_elem_id_t *id)
{
	assert(ctl && id);
	return ctl->ops->element_lock(ctl, id);
}

/**
 * \brief Unlock CTL element
 * \param ctl CTL handle
 * \param id CTL element id pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_unlock(snd_ctl_t *ctl, snd_ctl_elem_id_t *id)
{
	assert(ctl && id);
	return ctl->ops->element_unlock(ctl, id);
}

/**
 * \brief Get next hardware dependent device number
 * \param ctl CTL handle
 * \param device current device on entry and next device on return
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_hwdep_next_device(snd_ctl_t *ctl, int *device)
{
	assert(ctl && device);
	return ctl->ops->hwdep_next_device(ctl, device);
}

/**
 * \brief Get info about a hardware dependent device
 * \param ctl CTL handle
 * \param info Hardware dependent device id/info pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_hwdep_info(snd_ctl_t *ctl, snd_hwdep_info_t * info)
{
	assert(ctl && info);
	return ctl->ops->hwdep_info(ctl, info);
}

/**
 * \brief Get next PCM device number
 * \param ctl CTL handle
 * \param device current device on entry and next device on return
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_pcm_next_device(snd_ctl_t *ctl, int * device)
{
	assert(ctl && device);
	return ctl->ops->pcm_next_device(ctl, device);
}

/**
 * \brief Get info about a PCM device
 * \param ctl CTL handle
 * \param info PCM device id/info pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_pcm_info(snd_ctl_t *ctl, snd_pcm_info_t * info)
{
	assert(ctl && info);
	return ctl->ops->pcm_info(ctl, info);
}

/**
 * \brief Set preferred PCM subdevice number of successive PCM open
 * \param ctl CTL handle
 * \param subdev Preferred PCM subdevice number
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_pcm_prefer_subdevice(snd_ctl_t *ctl, int subdev)
{
	assert(ctl);
	return ctl->ops->pcm_prefer_subdevice(ctl, subdev);
}

/**
 * \brief Get next RawMidi device number
 * \param ctl CTL handle
 * \param device current device on entry and next device on return
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_rawmidi_next_device(snd_ctl_t *ctl, int * device)
{
	assert(ctl && device);
	return ctl->ops->rawmidi_next_device(ctl, device);
}

/**
 * \brief Get info about a RawMidi device
 * \param ctl CTL handle
 * \param info RawMidi device id/info pointer
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_rawmidi_info(snd_ctl_t *ctl, snd_rawmidi_info_t * info)
{
	assert(ctl && info);
	return ctl->ops->rawmidi_info(ctl, info);
}

/**
 * \brief Set preferred RawMidi subdevice number of successive RawMidi open
 * \param ctl CTL handle
 * \param subdev Preferred RawMidi subdevice number
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_rawmidi_prefer_subdevice(snd_ctl_t *ctl, int subdev)
{
	assert(ctl);
	return ctl->ops->rawmidi_prefer_subdevice(ctl, subdev);
}

/**
 * \brief Set Power State to given SND_CTL_POWER_* value and do the power management
 * \param ctl CTL handle
 * \param state Desired Power State
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_set_power_state(snd_ctl_t *ctl, unsigned int state)
{
	assert(ctl);
	if (ctl->ops->set_power_state)
		return ctl->ops->set_power_state(ctl, state);
	return -ENXIO;
}

/**
 * \brief Get actual Power State
 * \param ctl CTL handle
 * \param state Destination value
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_get_power_state(snd_ctl_t *ctl, unsigned int *state)
{
	assert(ctl);
	if (ctl->ops->get_power_state)
		return ctl->ops->get_power_state(ctl, state);
	return -ENXIO;
}

/**
 * \brief Read an event
 * \param ctl CTL handle
 * \param event Event pointer
 * \return number of events read otherwise a negative error code on failure
 */
int snd_ctl_read(snd_ctl_t *ctl, snd_ctl_event_t *event)
{
	assert(ctl && event);
	return (ctl->ops->read)(ctl, event);
}

/**
 * \brief Wait for a CTL to become ready (i.e. at least one event pending)
 * \param ctl CTL handle
 * \param timeout maximum time in milliseconds to wait
 * \return 0 otherwise a negative error code on failure
 */
int snd_ctl_wait(snd_ctl_t *ctl, int timeout)
{
	struct pollfd *pfd;
	unsigned short revents;
	int npfds, err, err_poll;

	npfds = snd_ctl_poll_descriptors_count(ctl);
	if (npfds <= 0 || npfds >= 16) {
		SNDERR("Invalid poll_fds %d\n", npfds);
		return -EIO;
	}
	pfd = alloca(sizeof(*pfd) * npfds);
	err = snd_ctl_poll_descriptors(ctl, pfd, npfds);
	if (err < 0)
		return err;
	if (err != npfds) {
		SNDMSG("invalid poll descriptors %d\n", err);
		return -EIO;
	}
	for (;;) {
		err_poll = poll(pfd, npfds, timeout);
		if (err_poll < 0)
			return -errno;
		if (! err_poll)
			return 0;
		err = snd_ctl_poll_descriptors_revents(ctl, pfd, npfds, &revents);
		if (err < 0)
			return err;
		if (revents & (POLLERR | POLLNVAL))
			return -EIO;
		if (revents & (POLLIN | POLLOUT))
			return 1;
	}
}

/**
 * \brief Add an async handler for a CTL
 * \param handler Returned handler handle
 * \param ctl CTL handle
 * \param callback Callback function
 * \param private_data Callback private data
 * \return 0 otherwise a negative error code on failure
 */
int snd_async_add_ctl_handler(snd_async_handler_t **handler, snd_ctl_t *ctl, 
			      snd_async_callback_t callback, void *private_data)
{
	int err;
	int was_empty;
	snd_async_handler_t *h;
	err = snd_async_add_handler(&h, _snd_ctl_async_descriptor(ctl),
				    callback, private_data);
	if (err < 0)
		return err;
	h->type = SND_ASYNC_HANDLER_CTL;
	h->u.ctl = ctl;
	was_empty = list_empty(&ctl->async_handlers);
	list_add_tail(&h->hlist, &ctl->async_handlers);
	if (was_empty) {
		err = snd_ctl_async(ctl, snd_async_handler_get_signo(h), getpid());
		if (err < 0) {
			snd_async_del_handler(h);
			return err;
		}
	}
	*handler = h;
	return 0;
}

/**
 * \brief Return CTL handle related to an async handler
 * \param handler Async handler handle
 * \return CTL handle
 */
snd_ctl_t *snd_async_handler_get_ctl(snd_async_handler_t *handler)
{
	assert(handler->type == SND_ASYNC_HANDLER_CTL);
	return handler->u.ctl;
}

static const char *const build_in_ctls[] = {
	"hw", "shm", NULL
};

static int snd_ctl_open_conf(snd_ctl_t **ctlp, const char *name,
			     snd_config_t *ctl_root, snd_config_t *ctl_conf, int mode)
{
	const char *str;
	char *buf = NULL, *buf1 = NULL;
	int err;
	snd_config_t *conf, *type_conf = NULL;
	snd_config_iterator_t i, next;
	const char *lib = NULL, *open_name = NULL;
	const char *id;
	int (*open_func)(snd_ctl_t **, const char *, snd_config_t *, snd_config_t *, int) = NULL;
#ifndef PIC
	extern void *snd_control_open_symbols(void);
#endif
	if (snd_config_get_type(ctl_conf) != SND_CONFIG_TYPE_COMPOUND) {
		if (name)
			SNDERR("Invalid type for CTL %s definition", name);
		else
			SNDERR("Invalid type for CTL definition");
		return -EINVAL;
	}
	err = snd_config_search(ctl_conf, "type", &conf);
	if (err < 0) {
		SNDERR("type is not defined");
		return err;
	}
	err = snd_config_get_id(conf, &id);
	if (err < 0) {
		SNDERR("unable to get id");
		return err;
	}
	err = snd_config_get_string(conf, &str);
	if (err < 0) {
		SNDERR("Invalid type for %s", id);
		return err;
	}
	err = snd_config_search_definition(ctl_root, "ctl_type", str, &type_conf);
	if (err >= 0) {
		if (snd_config_get_type(type_conf) != SND_CONFIG_TYPE_COMPOUND) {
			SNDERR("Invalid type for CTL type %s definition", str);
			err = -EINVAL;
			goto _err;
		}
		snd_config_for_each(i, next, type_conf) {
			snd_config_t *n = snd_config_iterator_entry(i);
			const char *id;
			if (snd_config_get_id(n, &id) < 0)
				continue;
			if (strcmp(id, "comment") == 0)
				continue;
			if (strcmp(id, "lib") == 0) {
				err = snd_config_get_string(n, &lib);
				if (err < 0) {
					SNDERR("Invalid type for %s", id);
					goto _err;
				}
				continue;
			}
			if (strcmp(id, "open") == 0) {
				err = snd_config_get_string(n, &open_name);
				if (err < 0) {
					SNDERR("Invalid type for %s", id);
					goto _err;
				}
				continue;
			}
			SNDERR("Unknown field %s", id);
			err = -EINVAL;
			goto _err;
		}
	}
	if (!open_name) {
		buf = malloc(strlen(str) + 32);
		if (buf == NULL) {
			err = -ENOMEM;
			goto _err;
		}
		open_name = buf;
		sprintf(buf, "_snd_ctl_%s_open", str);
	}
	if (!lib) {
		const char *const *build_in = build_in_ctls;
		while (*build_in) {
			if (!strcmp(*build_in, str))
				break;
			build_in++;
		}
		if (*build_in == NULL) {
			buf1 = malloc(strlen(str) + sizeof(ALSA_PLUGIN_DIR) + 32);
			if (buf1 == NULL) {
				err = -ENOMEM;
				goto _err;
			}
			lib = buf1;
			sprintf(buf1, "%s/libasound_module_ctl_%s.so", ALSA_PLUGIN_DIR, str);
		}
	}
#ifndef PIC
	snd_control_open_symbols();
#endif
	open_func = snd_dlobj_cache_get(lib, open_name,
			SND_DLSYM_VERSION(SND_CONTROL_DLSYM_VERSION), 1);
	if (open_func) {
		err = open_func(ctlp, name, ctl_root, ctl_conf, mode);
		if (err >= 0) {
			(*ctlp)->open_func = open_func;
			err = 0;
		} else {
			snd_dlobj_cache_put(open_func);
		}
	} else {
		err = -ENXIO;
	}
       _err:
	if (type_conf)
		snd_config_delete(type_conf);
	free(buf);
	free(buf1);
	return err;
}

static int snd_ctl_open_noupdate(snd_ctl_t **ctlp, snd_config_t *root, const char *name, int mode)
{
	int err;
	snd_config_t *ctl_conf;
	err = snd_config_search_definition(root, "ctl", name, &ctl_conf);
	if (err < 0) {
		SNDERR("Invalid CTL %s", name);
		return err;
	}
	err = snd_ctl_open_conf(ctlp, name, root, ctl_conf, mode);
	snd_config_delete(ctl_conf);
	return err;
}

/**
 * \brief Opens a CTL
 * \param ctlp Returned CTL handle
 * \param name ASCII identifier of the CTL handle
 * \param mode Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC)
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_open(snd_ctl_t **ctlp, const char *name, int mode)
{
	int err;
	assert(ctlp && name);
	err = snd_config_update();
	if (err < 0)
		return err;
	return snd_ctl_open_noupdate(ctlp, snd_config, name, mode);
}

/**
 * \brief Opens a CTL using local configuration
 * \param ctlp Returned CTL handle
 * \param name ASCII identifier of the CTL handle
 * \param mode Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC)
 * \param lconf Local configuration
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_open_lconf(snd_ctl_t **ctlp, const char *name,
		       int mode, snd_config_t *lconf)
{
	assert(ctlp && name && lconf);
	return snd_ctl_open_noupdate(ctlp, lconf, name, mode);
}

/**
 * \brief Opens a fallback CTL
 * \param ctlp Returned CTL handle
 * \param root Configuration root
 * \param name ASCII identifier of the CTL handle used as fallback
 * \param orig_name The original ASCII name
 * \param mode Open mode (see #SND_CTL_NONBLOCK, #SND_CTL_ASYNC)
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_open_fallback(snd_ctl_t **ctlp, snd_config_t *root,
			  const char *name, const char *orig_name, int mode)
{
	int err;
	assert(ctlp && name && root);
	err = snd_ctl_open_noupdate(ctlp, root, name, mode);
	if (err >= 0) {
		free((*ctlp)->name);
		(*ctlp)->name = orig_name ? strdup(orig_name) : NULL;
	}
	return err;
}

#ifndef DOC_HIDDEN
#define TYPE(v) [SND_CTL_ELEM_TYPE_##v] = #v
#define IFACE(v) [SND_CTL_ELEM_IFACE_##v] = #v
#define IFACE1(v, n) [SND_CTL_ELEM_IFACE_##v] = #n
#define EVENT(v) [SND_CTL_EVENT_##v] = #v

static const char *const snd_ctl_elem_type_names[] = {
	TYPE(NONE),
	TYPE(BOOLEAN),
	TYPE(INTEGER),
	TYPE(ENUMERATED),
	TYPE(BYTES),
	TYPE(IEC958),
	TYPE(INTEGER64),
};

static const char *const snd_ctl_elem_iface_names[] = {
	IFACE(CARD),
	IFACE(HWDEP),
	IFACE(MIXER),
	IFACE(PCM),
	IFACE(RAWMIDI),
	IFACE(TIMER),
	IFACE(SEQUENCER),
};

static const char *const snd_ctl_event_type_names[] = {
	EVENT(ELEM),
};
#endif

/**
 * \brief get name of a CTL element type
 * \param type CTL element type
 * \return ascii name of CTL element type
 */
const char *snd_ctl_elem_type_name(snd_ctl_elem_type_t type)
{
	assert(type <= SND_CTL_ELEM_TYPE_LAST);
	return snd_ctl_elem_type_names[type];
}

/**
 * \brief get name of a CTL element related interface
 * \param iface CTL element related interface
 * \return ascii name of CTL element related interface
 */
const char *snd_ctl_elem_iface_name(snd_ctl_elem_iface_t iface)
{
	assert(iface <= SND_CTL_ELEM_IFACE_LAST);
	return snd_ctl_elem_iface_names[iface];
}

/**
 * \brief get name of a CTL event type
 * \param type CTL event type
 * \return ascii name of CTL event type
 */
const char *snd_ctl_event_type_name(snd_ctl_event_type_t type)
{
	assert(type <= SND_CTL_EVENT_LAST);
	return snd_ctl_event_type_names[type];
}

/**
 * \brief allocate space for CTL element identifiers list
 * \param obj CTL element identifiers list
 * \param entries Entries to allocate
 * \return 0 on success otherwise a negative error code
 */
int snd_ctl_elem_list_alloc_space(snd_ctl_elem_list_t *obj, unsigned int entries)
{
	free(obj->pids);
	obj->pids = calloc(entries, sizeof(*obj->pids));
	if (!obj->pids) {
		obj->space = 0;
		return -ENOMEM;
	}
	obj->space = entries;
	return 0;
}  

/**
 * \brief free previously allocated space for CTL element identifiers list
 * \param obj CTL element identifiers list
 */
void snd_ctl_elem_list_free_space(snd_ctl_elem_list_t *obj)
{
	free(obj->pids);
	obj->pids = NULL;
	obj->space = 0;
}

/**
 * \brief Get event mask for an element related event
 * \param obj CTL event
 * \return event mask for element related event
 */
unsigned int snd_ctl_event_elem_get_mask(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return obj->data.elem.mask;
}

/**
 * \brief Get CTL element identifier for an element related event
 * \param obj CTL event
 * \param ptr Pointer to returned CTL element identifier
 */
void snd_ctl_event_elem_get_id(const snd_ctl_event_t *obj, snd_ctl_elem_id_t *ptr)
{
	assert(obj && ptr);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	*ptr = obj->data.elem.id;
}

/**
 * \brief Get element numeric identifier for an element related event
 * \param obj CTL event
 * \return element numeric identifier
 */
unsigned int snd_ctl_event_elem_get_numid(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return obj->data.elem.id.numid;
}

/**
 * \brief Get interface part of CTL element identifier for an element related event
 * \param obj CTL event
 * \return interface part of element identifier
 */
snd_ctl_elem_iface_t snd_ctl_event_elem_get_interface(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return obj->data.elem.id.iface;
}

/**
 * \brief Get device part of CTL element identifier for an element related event
 * \param obj CTL event
 * \return device part of element identifier
 */
unsigned int snd_ctl_event_elem_get_device(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return obj->data.elem.id.device;
}

/**
 * \brief Get subdevice part of CTL element identifier for an element related event
 * \param obj CTL event
 * \return subdevice part of element identifier
 */
unsigned int snd_ctl_event_elem_get_subdevice(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return obj->data.elem.id.subdevice;
}

/**
 * \brief Get name part of CTL element identifier for an element related event
 * \param obj CTL event
 * \return name part of element identifier
 */
const char *snd_ctl_event_elem_get_name(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return (const char *)obj->data.elem.id.name;
}

/**
 * \brief Get index part of CTL element identifier for an element related event
 * \param obj CTL event
 * \return index part of element identifier
 */
unsigned int snd_ctl_event_elem_get_index(const snd_ctl_event_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_EVENT_ELEM);
	return obj->data.elem.id.index;
}

#ifndef DOC_HIDDEN
int _snd_ctl_poll_descriptor(snd_ctl_t *ctl)
{
	assert(ctl);
	return ctl->poll_fd;
}
#endif

/**
 * \brief get size of #snd_ctl_elem_id_t
 * \return size in bytes
 */
size_t snd_ctl_elem_id_sizeof()
{
	return sizeof(snd_ctl_elem_id_t);
}

/**
 * \brief allocate an invalid #snd_ctl_elem_id_t using standard malloc
 * \param ptr returned pointer
 * \return 0 on success otherwise negative error code
 */
int snd_ctl_elem_id_malloc(snd_ctl_elem_id_t **ptr)
{
	assert(ptr);
	*ptr = calloc(1, sizeof(snd_ctl_elem_id_t));
	if (!*ptr)
		return -ENOMEM;
	return 0;
}

/**
 * \brief frees a previously allocated #snd_ctl_elem_id_t
 * \param obj pointer to object to free
 */
void snd_ctl_elem_id_free(snd_ctl_elem_id_t *obj)
{
	free(obj);
}

/**
 * \brief clear given #snd_ctl_elem_id_t object
 * \param obj pointer to object to clear
 */
void snd_ctl_elem_id_clear(snd_ctl_elem_id_t *obj)
{
	memset(obj, 0, sizeof(snd_ctl_elem_id_t));
}

/**
 * \brief copy one #snd_ctl_elem_id_t to another
 * \param dst pointer to destination
 * \param src pointer to source
 */
void snd_ctl_elem_id_copy(snd_ctl_elem_id_t *dst, const snd_ctl_elem_id_t *src)
{
	assert(dst && src);
	*dst = *src;
}

/**
 * \brief Get numeric identifier from a CTL element identifier
 * \param obj CTL element identifier
 * \return CTL element numeric identifier
 */
unsigned int snd_ctl_elem_id_get_numid(const snd_ctl_elem_id_t *obj)
{
	assert(obj);
	return obj->numid;
}

/**
 * \brief Get interface part of a CTL element identifier
 * \param obj CTL element identifier
 * \return CTL element related interface
 */
snd_ctl_elem_iface_t snd_ctl_elem_id_get_interface(const snd_ctl_elem_id_t *obj)
{
	assert(obj);
	return obj->iface;
}

/**
 * \brief Get device part of a CTL element identifier
 * \param obj CTL element identifier
 * \return CTL element related device
 */
unsigned int snd_ctl_elem_id_get_device(const snd_ctl_elem_id_t *obj)
{
	assert(obj);
	return obj->device;
}

/**
 * \brief Get subdevice part of a CTL element identifier
 * \param obj CTL element identifier
 * \return CTL element related subdevice
 */
unsigned int snd_ctl_elem_id_get_subdevice(const snd_ctl_elem_id_t *obj)
{
	assert(obj);
	return obj->subdevice;
}

/**
 * \brief Get name part of a CTL element identifier
 * \param obj CTL element identifier
 * \return CTL element name
 */
const char *snd_ctl_elem_id_get_name(const snd_ctl_elem_id_t *obj)
{
	assert(obj);
	return (const char *)obj->name;
}

/**
 * \brief Get index part of a CTL element identifier
 * \param obj CTL element identifier
 * \return CTL element index
 */
unsigned int snd_ctl_elem_id_get_index(const snd_ctl_elem_id_t *obj)
{
	assert(obj);
	return obj->index;
}

/**
 * \brief Set numeric identifier for a CTL element identifier
 * \param obj CTL element identifier
 * \param val CTL element numeric identifier
 */
void snd_ctl_elem_id_set_numid(snd_ctl_elem_id_t *obj, unsigned int val)
{
	assert(obj);
	obj->numid = val;
}

/**
 * \brief Set interface part for a CTL element identifier
 * \param obj CTL element identifier
 * \param val CTL element related interface
 */
void snd_ctl_elem_id_set_interface(snd_ctl_elem_id_t *obj, snd_ctl_elem_iface_t val)
{
	assert(obj);
	obj->iface = val;
}

/**
 * \brief Set device part for a CTL element identifier
 * \param obj CTL element identifier
 * \param val CTL element related device
 */
void snd_ctl_elem_id_set_device(snd_ctl_elem_id_t *obj, unsigned int val)
{
	assert(obj);
	obj->device = val;
}

/**
 * \brief Set subdevice part for a CTL element identifier
 * \param obj CTL element identifier
 * \param val CTL element related subdevice
 */
void snd_ctl_elem_id_set_subdevice(snd_ctl_elem_id_t *obj, unsigned int val)
{
	assert(obj);
	obj->subdevice = val;
}

/**
 * \brief Set name part for a CTL element identifier
 * \param obj CTL element identifier
 * \param val CTL element name
 */
void snd_ctl_elem_id_set_name(snd_ctl_elem_id_t *obj, const char *val)
{
	assert(obj);
	strncpy((char *)obj->name, val, sizeof(obj->name));
}

/**
 * \brief Set index part for a CTL element identifier
 * \param obj CTL element identifier
 * \param val CTL element index
 */
void snd_ctl_elem_id_set_index(snd_ctl_elem_id_t *obj, unsigned int val)
{
	assert(obj);
	obj->index = val;
}

/**
 * \brief get size of #snd_ctl_card_info_t
 * \return size in bytes
 */
size_t snd_ctl_card_info_sizeof()
{
	return sizeof(snd_ctl_card_info_t);
}

/**
 * \brief allocate an invalid #snd_ctl_card_info_t using standard malloc
 * \param ptr returned pointer
 * \return 0 on success otherwise negative error code
 */
int snd_ctl_card_info_malloc(snd_ctl_card_info_t **ptr)
{
	assert(ptr);
	*ptr = calloc(1, sizeof(snd_ctl_card_info_t));
	if (!*ptr)
		return -ENOMEM;
	return 0;
}

/**
 * \brief frees a previously allocated #snd_ctl_card_info_t
 * \param obj pointer to object to free
 */
void snd_ctl_card_info_free(snd_ctl_card_info_t *obj)
{
	free(obj);
}

/**
 * \brief clear given #snd_ctl_card_info_t object
 * \param obj pointer to object to clear
 */
void snd_ctl_card_info_clear(snd_ctl_card_info_t *obj)
{
	memset(obj, 0, sizeof(snd_ctl_card_info_t));
}

/**
 * \brief copy one #snd_ctl_card_info_t to another
 * \param dst pointer to destination
 * \param src pointer to source
 */
void snd_ctl_card_info_copy(snd_ctl_card_info_t *dst, const snd_ctl_card_info_t *src)
{
	assert(dst && src);
	*dst = *src;
}

/**
 * \brief Get card number from a CTL card info
 * \param obj CTL card info
 * \return card number
 */
int snd_ctl_card_info_get_card(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return obj->card;
}

/**
 * \brief Get card identifier from a CTL card info
 * \param obj CTL card info
 * \return card identifier
 */
const char *snd_ctl_card_info_get_id(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return (const char *)obj->id;
}

/**
 * \brief Get card driver name from a CTL card info
 * \param obj CTL card info
 * \return card driver name
 */
const char *snd_ctl_card_info_get_driver(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return (const char *)obj->driver;
}

/**
 * \brief Get card name from a CTL card info
 * \param obj CTL card info
 * \return card name
 */
const char *snd_ctl_card_info_get_name(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return (const char *)obj->name;
}

/**
 * \brief Get card long name from a CTL card info
 * \param obj CTL card info
 * \return card long name
 */
const char *snd_ctl_card_info_get_longname(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return (const char *)obj->longname;
}

/**
 * \brief Get card mixer name from a CTL card info
 * \param obj CTL card info
 * \return card mixer name
 */
const char *snd_ctl_card_info_get_mixername(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return (const char *)obj->mixername;
}

/**
 * \brief Get card component list from a CTL card info
 * \param obj CTL card info
 * \return card mixer identifier
 */
const char *snd_ctl_card_info_get_components(const snd_ctl_card_info_t *obj)
{
	assert(obj);
	return (const char *)obj->components;
}

/**
 * \brief get size of #snd_ctl_event_t
 * \return size in bytes
 */
size_t snd_ctl_event_sizeof()
{
	return sizeof(snd_ctl_event_t);
}

/**
 * \brief allocate an invalid #snd_ctl_event_t using standard malloc
 * \param ptr returned pointer
 * \return 0 on success otherwise negative error code
 */
int snd_ctl_event_malloc(snd_ctl_event_t **ptr)
{
	assert(ptr);
	*ptr = calloc(1, sizeof(snd_ctl_event_t));
	if (!*ptr)
		return -ENOMEM;
	return 0;
}

/**
 * \brief frees a previously allocated #snd_ctl_event_t
 * \param obj pointer to object to free
 */
void snd_ctl_event_free(snd_ctl_event_t *obj)
{
	free(obj);
}

/**
 * \brief clear given #snd_ctl_event_t object
 * \param obj pointer to object to clear
 */
void snd_ctl_event_clear(snd_ctl_event_t *obj)
{
	memset(obj, 0, sizeof(snd_ctl_event_t));
}

/**
 * \brief copy one #snd_ctl_event_t to another
 * \param dst pointer to destination
 * \param src pointer to source
 */
void snd_ctl_event_copy(snd_ctl_event_t *dst, const snd_ctl_event_t *src)
{
	assert(dst && src);
	*dst = *src;
}

/**
 * \brief Get type of a CTL event
 * \param obj CTL event
 * \return CTL event type
 */
snd_ctl_event_type_t snd_ctl_event_get_type(const snd_ctl_event_t *obj)
{
	assert(obj);
	return obj->type;
}

/**
 * \brief get size of #snd_ctl_elem_list_t
 * \return size in bytes
 */
size_t snd_ctl_elem_list_sizeof()
{
	return sizeof(snd_ctl_elem_list_t);
}

/**
 * \brief allocate an invalid #snd_ctl_elem_list_t using standard malloc
 * \param ptr returned pointer
 * \return 0 on success otherwise negative error code
 */
int snd_ctl_elem_list_malloc(snd_ctl_elem_list_t **ptr)
{
	assert(ptr);
	*ptr = calloc(1, sizeof(snd_ctl_elem_list_t));
	if (!*ptr)
		return -ENOMEM;
	return 0;
}

/**
 * \brief frees a previously allocated #snd_ctl_elem_list_t
 * \param obj pointer to object to free
 */
void snd_ctl_elem_list_free(snd_ctl_elem_list_t *obj)
{
	free(obj);
}

/**
 * \brief clear given #snd_ctl_elem_list_t object
 * \param obj pointer to object to clear
 */
void snd_ctl_elem_list_clear(snd_ctl_elem_list_t *obj)
{
	memset(obj, 0, sizeof(snd_ctl_elem_list_t));
}

/**
 * \brief copy one #snd_ctl_elem_list_t to another
 * \param dst pointer to destination
 * \param src pointer to source
 */
void snd_ctl_elem_list_copy(snd_ctl_elem_list_t *dst, const snd_ctl_elem_list_t *src)
{
	assert(dst && src);
	*dst = *src;
}

/**
 * \brief Set index of first wanted CTL element identifier in a CTL element identifiers list
 * \param obj CTL element identifiers list
 * \param val index of CTL element to put at position 0 of list
 */
void snd_ctl_elem_list_set_offset(snd_ctl_elem_list_t *obj, unsigned int val)
{
	assert(obj);
	obj->offset = val;
}

/**
 * \brief Get number of used entries in CTL element identifiers list
 * \param obj CTL element identifier list
 * \return number of used entries
 */
unsigned int snd_ctl_elem_list_get_used(const snd_ctl_elem_list_t *obj)
{
	assert(obj);
	return obj->used;
}

/**
 * \brief Get total count of elements present in CTL device (information present in every filled CTL element identifiers list)
 * \param obj CTL element identifier list
 * \return total number of elements
 */
unsigned int snd_ctl_elem_list_get_count(const snd_ctl_elem_list_t *obj)
{
	assert(obj);
	return obj->count;
}

/**
 * \brief Get CTL element identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \param ptr Pointer to returned CTL element identifier
 */
void snd_ctl_elem_list_get_id(const snd_ctl_elem_list_t *obj, unsigned int idx, snd_ctl_elem_id_t *ptr)
{
	assert(obj && ptr);
	assert(idx < obj->used);
	*ptr = obj->pids[idx];
}

/**
 * \brief Get CTL element numeric identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \return CTL element numeric identifier
 */
unsigned int snd_ctl_elem_list_get_numid(const snd_ctl_elem_list_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < obj->used);
	return obj->pids[idx].numid;
}

/**
 * \brief Get interface part of CTL element identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \return CTL element related interface
 */
snd_ctl_elem_iface_t snd_ctl_elem_list_get_interface(const snd_ctl_elem_list_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < obj->used);
	return obj->pids[idx].iface;
}

/**
 * \brief Get device part of CTL element identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \return CTL element related device
 */
unsigned int snd_ctl_elem_list_get_device(const snd_ctl_elem_list_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < obj->used);
	return obj->pids[idx].device;
}

/**
 * \brief Get subdevice part of CTL element identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \return CTL element related subdevice
 */
unsigned int snd_ctl_elem_list_get_subdevice(const snd_ctl_elem_list_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < obj->used);
	return obj->pids[idx].subdevice;
}

/**
 * \brief Get name part of CTL element identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \return CTL element name
 */
const char *snd_ctl_elem_list_get_name(const snd_ctl_elem_list_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < obj->used);
	return (const char *)obj->pids[idx].name;
}

/**
 * \brief Get index part of CTL element identifier for an entry of a CTL element identifiers list
 * \param obj CTL element identifier list
 * \param idx Index of entry
 * \return CTL element index
 */
unsigned int snd_ctl_elem_list_get_index(const snd_ctl_elem_list_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < obj->used);
	return obj->pids[idx].index;
}

/**
 * \brief get size of #snd_ctl_elem_info_t
 * \return size in bytes
 */
size_t snd_ctl_elem_info_sizeof()
{
	return sizeof(snd_ctl_elem_info_t);
}

/**
 * \brief allocate an invalid #snd_ctl_elem_info_t using standard malloc
 * \param ptr returned pointer
 * \return 0 on success otherwise negative error code
 */
int snd_ctl_elem_info_malloc(snd_ctl_elem_info_t **ptr)
{
	assert(ptr);
	*ptr = calloc(1, sizeof(snd_ctl_elem_info_t));
	if (!*ptr)
		return -ENOMEM;
	return 0;
}

/**
 * \brief frees a previously allocated #snd_ctl_elem_info_t
 * \param obj pointer to object to free
 */
void snd_ctl_elem_info_free(snd_ctl_elem_info_t *obj)
{
	free(obj);
}

/**
 * \brief clear given #snd_ctl_elem_info_t object
 * \param obj pointer to object to clear
 */
void snd_ctl_elem_info_clear(snd_ctl_elem_info_t *obj)
{
	memset(obj, 0, sizeof(snd_ctl_elem_info_t));
}

/**
 * \brief copy one #snd_ctl_elem_info_t to another
 * \param dst pointer to destination
 * \param src pointer to source
 */
void snd_ctl_elem_info_copy(snd_ctl_elem_info_t *dst, const snd_ctl_elem_info_t *src)
{
	assert(dst && src);
	*dst = *src;
}

/**
 * \brief Get type from a CTL element id/info
 * \param obj CTL element id/info
 * \return CTL element content type
 */
snd_ctl_elem_type_t snd_ctl_elem_info_get_type(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->type;
}

/**
 * \brief Get info about readability from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if element is not readable, 1 if element is readable
 */
int snd_ctl_elem_info_is_readable(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_READ);
}

/**
 * \brief Get info about writability from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if element is not writable, 1 if element is not writable
 */
int snd_ctl_elem_info_is_writable(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_WRITE);
}

/**
 * \brief Get info about notification feasibility from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if all element value changes are notified to subscribed applications, 1 otherwise
 */
int snd_ctl_elem_info_is_volatile(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_VOLATILE);
}

/**
 * \brief Get info about status from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if element value is not active, 1 if is active
 */
int snd_ctl_elem_info_is_inactive(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE);
}

/**
 * \brief Get info whether an element is locked
 * \param obj CTL element id/info
 * \return 0 if element value is currently changeable, 1 if it's locked by another application
 */
int snd_ctl_elem_info_is_locked(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_LOCK);
}

/**
 * \brief Get info if I own an element
 * \param obj CTL element id/info
 * \return 0 if element value is currently changeable, 1 if it's locked by another application
 */
int snd_ctl_elem_info_is_owner(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_OWNER);
}

/**
 * \brief Get info if it's a user element
 * \param obj CTL element id/info
 * \return 0 if element value is a system element, 1 if it's a user-created element
 */
int snd_ctl_elem_info_is_user(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_USER);
}

/**
 * \brief Get info about TLV readability from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if element's TLV is not readable, 1 if element's TLV is readable
 */
int snd_ctl_elem_info_is_tlv_readable(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ);
}

/**
 * \brief Get info about TLV writeability from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if element's TLV is not writable, 1 if element's TLV is writable
 */
int snd_ctl_elem_info_is_tlv_writable(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
}

/**
 * \brief Get info about TLV command possibility from a CTL element id/info
 * \param obj CTL element id/info
 * \return 0 if element's TLV command is not possible, 1 if element's TLV command is supported
 */
int snd_ctl_elem_info_is_tlv_commandable(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return !!(obj->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND);
}

/**
 * \brief (DEPRECATED) Get info about values passing policy from a CTL element value
 * \param obj CTL element id/info
 * \return 0 if element value need to be passed by contents, 1 if need to be passed with a pointer
 */
int snd_ctl_elem_info_is_indirect(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return 0;
}
link_warning(snd_ctl_elem_info_is_indirect, "Warning: snd_ctl_elem_info_is_indirect is deprecated, do not use it");

/**
 * \brief Get owner of a locked element
 * \param obj CTL element id/info
 * \return value entries count
 */
pid_t snd_ctl_elem_info_get_owner(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->owner;
}

/**
 * \brief Get number of value entries from a CTL element id/info
 * \param obj CTL element id/info
 * \return value entries count
 */
unsigned int snd_ctl_elem_info_get_count(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->count;
}

/**
 * \brief Get minimum value from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info
 * \param obj CTL element id/info
 * \return Minimum value
 */
long snd_ctl_elem_info_get_min(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_INTEGER);
	return obj->value.integer.min;
}

/**
 * \brief Get maximum value from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info
 * \param obj CTL element id/info
 * \return Maximum value
 */
long snd_ctl_elem_info_get_max(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_INTEGER);
	return obj->value.integer.max;
}

/**
 * \brief Get value step from a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/info
 * \param obj CTL element id/info
 * \return Step
 */
long snd_ctl_elem_info_get_step(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_INTEGER);
	return obj->value.integer.step;
}

/**
 * \brief Get minimum value from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info
 * \param obj CTL element id/info
 * \return Minimum value
 */
long long snd_ctl_elem_info_get_min64(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_INTEGER64);
	return obj->value.integer64.min;
}

/**
 * \brief Get maximum value from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info
 * \param obj CTL element id/info
 * \return Maximum value
 */
long long snd_ctl_elem_info_get_max64(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_INTEGER64);
	return obj->value.integer64.max;
}

/**
 * \brief Get value step from a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/info
 * \param obj CTL element id/info
 * \return Step
 */
long long snd_ctl_elem_info_get_step64(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_INTEGER64);
	return obj->value.integer64.step;
}

/**
 * \brief Get number of items available from a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info
 * \param obj CTL element id/info
 * \return items count
 */
unsigned int snd_ctl_elem_info_get_items(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_ENUMERATED);
	return obj->value.enumerated.items;
}

/**
 * \brief Select item in a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info
 * \param obj CTL element id/info
 * \param val item number
 */
void snd_ctl_elem_info_set_item(snd_ctl_elem_info_t *obj, unsigned int val)
{
	assert(obj);
	obj->value.enumerated.item = val;
}

/**
 * \brief Get name for selected item in a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/info
 * \param obj CTL element id/info
 * \return name of chosen item
 */
const char *snd_ctl_elem_info_get_item_name(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	assert(obj->type == SND_CTL_ELEM_TYPE_ENUMERATED);
	return obj->value.enumerated.name;
}

/**
 * \brief Get count of dimensions for given element
 * \param obj CTL element id/info
 * \return zero value if no dimensions are defined, otherwise positive value with count of dimensions
 */
#ifndef DOXYGEN
int INTERNAL(snd_ctl_elem_info_get_dimensions)(const snd_ctl_elem_info_t *obj)
#else
int snd_ctl_elem_info_get_dimensions(const snd_ctl_elem_info_t *obj)
#endif
{
	int i;

	assert(obj);
	for (i = 3; i >= 0; i--)
		if (obj->dimen.d[i])
			break;
	return i + 1;
}
use_default_symbol_version(__snd_ctl_elem_info_get_dimensions, snd_ctl_elem_info_get_dimensions, ALSA_0.9.3);

/**
 * \brief Get specified of dimension width for given element
 * \param obj CTL element id/info
 * \param idx The dimension index
 * \return zero value if no dimension width is defined, otherwise positive value with with of specified dimension
 */
#ifndef DOXYGEN
int INTERNAL(snd_ctl_elem_info_get_dimension)(const snd_ctl_elem_info_t *obj, unsigned int idx)
#else
int snd_ctl_elem_info_get_dimension(const snd_ctl_elem_info_t *obj, unsigned int idx)
#endif
{
	assert(obj);
	if (idx >= 3)
		return 0;
	return obj->dimen.d[idx];
}
use_default_symbol_version(__snd_ctl_elem_info_get_dimension, snd_ctl_elem_info_get_dimension, ALSA_0.9.3);

/**
 * \brief Get CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param ptr Pointer to returned CTL element identifier
 */
void snd_ctl_elem_info_get_id(const snd_ctl_elem_info_t *obj, snd_ctl_elem_id_t *ptr)
{
	assert(obj && ptr);
	*ptr = obj->id;
}

/**
 * \brief Get element numeric identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \return element numeric identifier
 */
unsigned int snd_ctl_elem_info_get_numid(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->id.numid;
}

/**
 * \brief Get interface part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \return interface part of element identifier
 */
snd_ctl_elem_iface_t snd_ctl_elem_info_get_interface(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->id.iface;
}

/**
 * \brief Get device part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \return device part of element identifier
 */
unsigned int snd_ctl_elem_info_get_device(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->id.device;
}

/**
 * \brief Get subdevice part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \return subdevice part of element identifier
 */
unsigned int snd_ctl_elem_info_get_subdevice(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->id.subdevice;
}

/**
 * \brief Get name part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \return name part of element identifier
 */
const char *snd_ctl_elem_info_get_name(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return (const char *)obj->id.name;
}

/**
 * \brief Get index part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \return index part of element identifier
 */
unsigned int snd_ctl_elem_info_get_index(const snd_ctl_elem_info_t *obj)
{
	assert(obj);
	return obj->id.index;
}

/**
 * \brief Set CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param ptr CTL element identifier
 */
void snd_ctl_elem_info_set_id(snd_ctl_elem_info_t *obj, const snd_ctl_elem_id_t *ptr)
{
	assert(obj && ptr);
	obj->id = *ptr;
}

/**
 * \brief Set element numeric identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param val element numeric identifier
 */
void snd_ctl_elem_info_set_numid(snd_ctl_elem_info_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.numid = val;
}

/**
 * \brief Set interface part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param val interface part of element identifier
 */
void snd_ctl_elem_info_set_interface(snd_ctl_elem_info_t *obj, snd_ctl_elem_iface_t val)
{
	assert(obj);
	obj->id.iface = val;
}

/**
 * \brief Set device part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param val device part of element identifier
 */
void snd_ctl_elem_info_set_device(snd_ctl_elem_info_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.device = val;
}

/**
 * \brief Set subdevice part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param val subdevice part of element identifier
 */
void snd_ctl_elem_info_set_subdevice(snd_ctl_elem_info_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.subdevice = val;
}

/**
 * \brief Set name part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param val name part of element identifier
 */
void snd_ctl_elem_info_set_name(snd_ctl_elem_info_t *obj, const char *val)
{
	assert(obj);
	strncpy((char *)obj->id.name, val, sizeof(obj->id.name));
}

/**
 * \brief Set index part of CTL element identifier of a CTL element id/info
 * \param obj CTL element id/info
 * \param val index part of element identifier
 */
void snd_ctl_elem_info_set_index(snd_ctl_elem_info_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.index = val;
}

/**
 * \brief get size of #snd_ctl_elem_value_t
 * \return size in bytes
 */
size_t snd_ctl_elem_value_sizeof()
{
	return sizeof(snd_ctl_elem_value_t);
}

/**
 * \brief allocate an invalid #snd_ctl_elem_value_t using standard malloc
 * \param ptr returned pointer
 * \return 0 on success otherwise negative error code
 */
int snd_ctl_elem_value_malloc(snd_ctl_elem_value_t **ptr)
{
	assert(ptr);
	*ptr = calloc(1, sizeof(snd_ctl_elem_value_t));
	if (!*ptr)
		return -ENOMEM;
	return 0;
}

/**
 * \brief frees a previously allocated #snd_ctl_elem_value_t
 * \param obj pointer to object to free
 */
void snd_ctl_elem_value_free(snd_ctl_elem_value_t *obj)
{
	free(obj);
}

/**
 * \brief clear given #snd_ctl_elem_value_t object
 * \param obj pointer to object to clear
 */
void snd_ctl_elem_value_clear(snd_ctl_elem_value_t *obj)
{
	memset(obj, 0, sizeof(snd_ctl_elem_value_t));
}

/**
 * \brief copy one #snd_ctl_elem_value_t to another
 * \param dst pointer to destination
 * \param src pointer to source
 */
void snd_ctl_elem_value_copy(snd_ctl_elem_value_t *dst, const snd_ctl_elem_value_t *src)
{
	assert(dst && src);
	*dst = *src;
}

/**
 * \brief compare one #snd_ctl_elem_value_t to another
 * \param left pointer to first value
 * \param right pointer to second value
 * \return 0 on match, less than or greater than otherwise, see memcmp
 */
int snd_ctl_elem_value_compare(snd_ctl_elem_value_t *left, const snd_ctl_elem_value_t *right)
{
	assert(left && right);
	return memcmp(left, right, sizeof(*left));
}

/**
 * \brief Get CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param ptr Pointer to returned CTL element identifier
 */
void snd_ctl_elem_value_get_id(const snd_ctl_elem_value_t *obj, snd_ctl_elem_id_t *ptr)
{
	assert(obj && ptr);
	*ptr = obj->id;
}

/**
 * \brief Get element numeric identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \return element numeric identifier
 */
unsigned int snd_ctl_elem_value_get_numid(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return obj->id.numid;
}

/**
 * \brief Get interface part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \return interface part of element identifier
 */
snd_ctl_elem_iface_t snd_ctl_elem_value_get_interface(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return obj->id.iface;
}

/**
 * \brief Get device part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \return device part of element identifier
 */
unsigned int snd_ctl_elem_value_get_device(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return obj->id.device;
}

/**
 * \brief Get subdevice part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \return subdevice part of element identifier
 */
unsigned int snd_ctl_elem_value_get_subdevice(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return obj->id.subdevice;
}

/**
 * \brief Get name part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \return name part of element identifier
 */
const char *snd_ctl_elem_value_get_name(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return (const char *)obj->id.name;
}

/**
 * \brief Get index part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \return index part of element identifier
 */
unsigned int snd_ctl_elem_value_get_index(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return obj->id.index;
}

/**
 * \brief Set CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param ptr CTL element identifier
 */
void snd_ctl_elem_value_set_id(snd_ctl_elem_value_t *obj, const snd_ctl_elem_id_t *ptr)
{
	assert(obj && ptr);
	obj->id = *ptr;
}

/**
 * \brief Set element numeric identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param val element numeric identifier
 */
void snd_ctl_elem_value_set_numid(snd_ctl_elem_value_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.numid = val;
}

/**
 * \brief Set interface part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param val interface part of element identifier
 */
void snd_ctl_elem_value_set_interface(snd_ctl_elem_value_t *obj, snd_ctl_elem_iface_t val)
{
	assert(obj);
	obj->id.iface = val;
}

/**
 * \brief Set device part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param val device part of element identifier
 */
void snd_ctl_elem_value_set_device(snd_ctl_elem_value_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.device = val;
}

/**
 * \brief Set subdevice part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param val subdevice part of element identifier
 */
void snd_ctl_elem_value_set_subdevice(snd_ctl_elem_value_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.subdevice = val;
}

/**
 * \brief Set name part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param val name part of element identifier
 */
void snd_ctl_elem_value_set_name(snd_ctl_elem_value_t *obj, const char *val)
{
	assert(obj);
	strncpy((char *)obj->id.name, val, sizeof(obj->id.name));
}

/**
 * \brief Set index part of CTL element identifier of a CTL element id/value
 * \param obj CTL element id/value
 * \param val index part of element identifier
 */
void snd_ctl_elem_value_set_index(snd_ctl_elem_value_t *obj, unsigned int val)
{
	assert(obj);
	obj->id.index = val;
}

/**
 * \brief Get value for an entry of a #SND_CTL_ELEM_TYPE_BOOLEAN CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \return value for the entry
 */ 
int snd_ctl_elem_value_get_boolean(const snd_ctl_elem_value_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < sizeof(obj->value.integer.value) / sizeof(obj->value.integer.value[0]));
	return obj->value.integer.value[idx];
}

/**
 * \brief Get value for an entry of a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \return value for the entry
 */ 
long snd_ctl_elem_value_get_integer(const snd_ctl_elem_value_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < sizeof(obj->value.integer.value) / sizeof(obj->value.integer.value[0]));
	return obj->value.integer.value[idx];
}

/**
 * \brief Get value for an entry of a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \return value for the entry
 */ 
long long snd_ctl_elem_value_get_integer64(const snd_ctl_elem_value_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < sizeof(obj->value.integer64.value) / sizeof(obj->value.integer64.value[0]));
	return obj->value.integer64.value[idx];
}

/**
 * \brief Get value for an entry of a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \return value for the entry
 */ 
unsigned int snd_ctl_elem_value_get_enumerated(const snd_ctl_elem_value_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < sizeof(obj->value.enumerated.item) / sizeof(obj->value.enumerated.item[0]));
	return obj->value.enumerated.item[idx];
}

/**
 * \brief Get value for an entry of a #SND_CTL_ELEM_TYPE_BYTES CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \return value for the entry
 */ 
unsigned char snd_ctl_elem_value_get_byte(const snd_ctl_elem_value_t *obj, unsigned int idx)
{
	assert(obj);
	assert(idx < sizeof(obj->value.bytes.data));
	return obj->value.bytes.data[idx];
}

/**
 * \brief Set value for an entry of a #SND_CTL_ELEM_TYPE_BOOLEAN CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \param val value for the entry
 */ 
void snd_ctl_elem_value_set_boolean(snd_ctl_elem_value_t *obj, unsigned int idx, long val)
{
	assert(obj);
	obj->value.integer.value[idx] = val;
}

/**
 * \brief Set value for an entry of a #SND_CTL_ELEM_TYPE_INTEGER CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \param val value for the entry
 */ 
void snd_ctl_elem_value_set_integer(snd_ctl_elem_value_t *obj, unsigned int idx, long val)
{
	assert(obj);
	obj->value.integer.value[idx] = val;
}

/**
 * \brief Set value for an entry of a #SND_CTL_ELEM_TYPE_INTEGER64 CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \param val value for the entry
 */ 
void snd_ctl_elem_value_set_integer64(snd_ctl_elem_value_t *obj, unsigned int idx, long long val)
{
	assert(obj);
	obj->value.integer64.value[idx] = val;
}

/**
 * \brief Set value for an entry of a #SND_CTL_ELEM_TYPE_ENUMERATED CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \param val value for the entry
 */ 
void snd_ctl_elem_value_set_enumerated(snd_ctl_elem_value_t *obj, unsigned int idx, unsigned int val)
{
	assert(obj);
	obj->value.enumerated.item[idx] = val;
}

/**
 * \brief Set value for an entry of a #SND_CTL_ELEM_TYPE_BYTES CTL element id/value 
 * \param obj CTL element id/value
 * \param idx Entry index
 * \param val value for the entry
 */ 
void snd_ctl_elem_value_set_byte(snd_ctl_elem_value_t *obj, unsigned int idx, unsigned char val)
{
	assert(obj);
	obj->value.bytes.data[idx] = val;
}

/**
 * \brief Set CTL element #SND_CTL_ELEM_TYPE_BYTES value
 * \param obj CTL handle
 * \param data Bytes value
 * \param size Size in bytes
 */
void snd_ctl_elem_set_bytes(snd_ctl_elem_value_t *obj, void *data, size_t size)
{
	assert(obj);
	if (size >= sizeof(obj->value.bytes.data)) {
		assert(0);
		return;
	}
	memcpy(obj->value.bytes.data, data, size);
}

/**
 * \brief Get value for a #SND_CTL_ELEM_TYPE_BYTES CTL element id/value 
 * \param obj CTL element id/value
 * \return Pointer to CTL element value
 */ 
const void * snd_ctl_elem_value_get_bytes(const snd_ctl_elem_value_t *obj)
{
	assert(obj);
	return obj->value.bytes.data;
}

/**
 * \brief Get value for a #SND_CTL_ELEM_TYPE_IEC958 CTL element id/value 
 * \param obj CTL element id/value
 * \param ptr Pointer to returned CTL element value
 */ 
void snd_ctl_elem_value_get_iec958(const snd_ctl_elem_value_t *obj, snd_aes_iec958_t *ptr)
{
	assert(obj && ptr);
	memcpy(ptr, &obj->value.iec958, sizeof(*ptr));
}

/**
 * \brief Set value for a #SND_CTL_ELEM_TYPE_IEC958 CTL element id/value 
 * \param obj CTL element id/value
 * \param ptr Pointer to CTL element value
 */ 
void snd_ctl_elem_value_set_iec958(snd_ctl_elem_value_t *obj, const snd_aes_iec958_t *ptr)
{
	assert(obj && ptr);
	memcpy(&obj->value.iec958, ptr, sizeof(obj->value.iec958));
}