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// SPDX-License-Identifier: GPL-2.0
/*
* ALSA Virtual Soundcard
*
* alsa.h - Top level ALSA interface
*
* Copyright (C) 2010-2018 Fiberdyne Systems Pty Ltd
*/
#ifndef __AVIRT_ALSA_H__
#define __AVIRT_ALSA_H__
#include <linux/platform_device.h>
#define MAX_NAME_LEN 32
#define PRINT_ERR(errno, errmsg, ...) \
pr_err("[%s()] %s [ERRNO:%d]", __func__, errmsg, ##__VA_ARGS__, errno);
#define CHK_ERR(errno) \
do { \
if (errno < 0) \
return errno; \
} while (0)
#define CHK_ERR_V(errno, errmsg, ...) \
do { \
if (errno < 0) { \
PRINT_ERR(errno, errmsg, ##__VA_ARGS__) \
return errno; \
} \
} while (0)
#define CHK_NULL(x) \
do { \
if (!x) \
return -EFAULT; \
} while (0)
#define CHK_NULL_V(x, errmsg, ...) \
do { \
if (!x) { \
PRINT_ERR(EFAULT, errmsg, ##__VA_ARGS__) \
return -EFAULT; \
} \
} while (0)
/*
* Substream device configuration
*/
struct avirt_alsa_dev_config {
const char devicename[MAX_NAME_LEN];
int channels;
};
/**
* Stream maintainance
*/
struct avirt_alsa_stream {
int hw_frame_idx;
struct snd_pcm_substream *substream;
};
/**
* Collection of devices
*/
struct avirt_alsa_dev_group {
struct avirt_alsa_dev_config *config;
struct avirt_alsa_stream *streams;
int devices;
int buffersize;
};
/**
* ALSA driver data
*/
struct avirt_alsa_driver {
struct snd_card *card;
struct avirt_alsa_dev_group playback;
struct avirt_alsa_dev_group capture;
};
/**
* avirt_alsa_init - Initializes the ALSA driver
* @return: 0 on success or error code otherwise
*/
int avirt_alsa_init(void);
/**
* avirt_alsa_configure_pcm- Configure the PCM device
* @config: Device configuration structure array
* @direction: Direction of PCM (SNDRV_PCM_STREAM_XXX)
* @numdevices: Number of devices (array length)
* @return: 0 on success or error code otherwise
*/
int avirt_alsa_configure_pcm(struct avirt_alsa_dev_config *config,
int direction, unsigned numdevices);
/**
* avirt_alsa_register - Registers the ALSA driver
* @devptr: Platform driver device
* @return: 0 on success or error code otherwise
*/
int avirt_alsa_register(struct platform_device *devptr);
/**
* avirt_alsa_deregister - Deregisters the ALSA driver
* @devptr: Platform driver device
* @return: 0 on success or error code otherwise
*/
int avirt_alsa_deregister(void);
/**
* avirt_alsa_get_dev_group - Gets the device group for the specified direction
* @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
* @return: Either the playback or capture device group on success,
* or NULL otherwise
*/
struct avirt_alsa_dev_group *avirt_alsa_get_dev_group(int direction);
/**
* pcm_buff_complete_cb - PCM buffer complete callback
* @substream: pointer to ALSA PCM substream
* @return 0 on success or error code otherwise
*
* This should be called from a child Audio Path once it has finished processing
* the PCM buffer
*/
int pcm_buff_complete_cb(struct snd_pcm_substream *substream);
#endif // __AVIRT_ALSA_H__
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