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// SPDX-License-Identifier: GPL-2.0
/*
* ALSA Virtual Soundcard
*
* core.h - System-level header for virtual ALSA card
*
* Copyright (C) 2010-2018 Fiberdyne Systems Pty Ltd
*/
#ifndef __AVIRT_CORE_H__
#define __AVIRT_CORE_H__
#include <sound/pcm.h>
#include <linux/configfs.h>
#define MAX_STREAMS 16
#define MAX_NAME_LEN 80
#define DINFO(logname, fmt, args...) \
printk(KERN_INFO "[AVIRT][%s]: " fmt "\n", logname, ##args)
#define DERROR(logname, fmt, args...) \
printk(KERN_ERR "[AVIRT][%s]: %d:%s " fmt "\n", logname, __LINE__, \
__func__, ##args)
#define DDEBUG(logname, fmt, args...) \
printk(KERN_DEBUG "[AVIRT][%s]: %d:%s " fmt "\n", logname, __LINE__, \
__func__, ##args)
/**
* AVIRT Audio Path configure function type
* Each Audio Path registers this at avirt_audiopath_register time.
* It is then called by the core once AVIRT has been configured
*/
typedef int (*avirt_audiopath_configure)(struct config_group *stream_group,
unsigned int stream_count);
/**
* AVIRT Audio Path info
*/
struct avirt_audiopath {
const char *uid; /* Unique identifier */
const char *name; /* Pretty name */
unsigned int version[3]; /* Version - Major.Minor.Ext */
const struct snd_pcm_hardware *hw; /* ALSA PCM HW conf */
const struct snd_pcm_ops *pcm_ops; /* ALSA PCM op table */
avirt_audiopath_configure configure; /* Configure callback function */
void *context;
};
/*
* Audio stream configuration
*/
struct avirt_stream {
char name[MAX_NAME_LEN]; /* Stream name */
char map[MAX_NAME_LEN]; /* Stream Audio Path mapping */
unsigned int channels; /* Stream channel count */
unsigned int device; /* Stream PCM device no. */
unsigned int direction; /* Stream direction */
struct config_item item; /* configfs item reference */
};
/**
* AVIRT core info
*/
struct avirt_coreinfo {
unsigned int version[3];
};
/**
* avirt_audiopath_register - register Audio Path with ALSA virtual driver
* @audiopath: Audio Path to be registered
* @core: ALSA virtual driver core info
* @return: 0 on success or error code otherwise
*/
int avirt_audiopath_register(struct avirt_audiopath *audiopath,
struct avirt_coreinfo **coreinfo);
/**
* avirt_audiopath_deregister - deregister Audio Path with ALSA virtual driver
* @audiopath: Audio Path to be deregistered
* @return: 0 on success or error code otherwise
*/
int avirt_audiopath_deregister(struct avirt_audiopath *audiopath);
/**
* avirt_audiopath_get - retrieves the Audio Path by it's UID
* @uid: Unique ID for the Audio Path
* @return: Corresponding Audio Path
*/
struct avirt_audiopath *avirt_audiopath_get(const char *uid);
/**
* avirt_stream_count - get the stream count for the given direction
* @direction: The direction to get the stream count for
* @return: The stream count
*/
int avirt_stream_count(unsigned int direction);
/**
* avirt_stream_from_config_item - Convert a config_item to an avirt_stream
* @item: The config_item to convert from
* @return: The item's avirt_stream if successful, NULL otherwise
*/
static inline struct avirt_stream *
avirt_stream_from_config_item(struct config_item *item)
{
return item ? container_of(item, struct avirt_stream, item) : NULL;
}
/**
* avirt_pcm_period_elapsed - PCM buffer complete callback
* @substream: pointer to ALSA PCM substream
*
* This should be called from a child Audio Path once it has finished processing
* the PCM buffer
*/
void avirt_pcm_period_elapsed(struct snd_pcm_substream *substream);
#endif // __AVIRT_CORE_H__
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