incubator-nuttx/include/nuttx/audio/audio_null.h

137 lines
4.8 KiB
C

/****************************************************************************
* include/nuttx/audio/audio_null.h
* A do-nothinig audio device driver to simplify testing of audio decoders.
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_AUDIO_AUDIO_NULL_H
#define __INCLUDE_NUTTX_AUDIO_AUDIO_NULL_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdint.h>
#include <stdbool.h>
#include <nuttx/irq.h>
#ifdef CONFIG_AUDIO_NULL
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************
*
* CONFIG_AUDIO_NULL - Enabled NULL audio device support
* CONFIG_AUDIO_NULL_MSG_PRIO - Priority of messages sent to the NULL audio
* device worker thread.
* CONFIG_AUDIO_NULL_BUFFER_SIZE - Preferred buffer size
* CONFIG_AUDIO_NULL_NUM_BUFFERS - Preferred number of buffers
* CONFIG_AUDIO_NULL_WORKER_STACKSIZE - Stack size to use when creating the
* NULL audio device worker thread.
*/
/* Pre-requisites */
#ifndef CONFIG_AUDIO
# error CONFIG_AUDIO is required for audio subsystem support
#endif
/* Default configuration values */
#ifndef CONFIG_AUDIO_NULL_MSG_PRIO
# define CONFIG_AUDIO_NULL_MSG_PRIO 1
#endif
#ifndef CONFIG_AUDIO_NULL_BUFFER_SIZE
# define CONFIG_AUDIO_NULL_BUFFER_SIZE 8192
#endif
#ifndef CONFIG_AUDIO_NULL_NUM_BUFFERS
# define CONFIG_AUDIO_NULL_NUM_BUFFERS 4
#endif
#ifndef CONFIG_AUDIO_NULL_WORKER_STACKSIZE
# define CONFIG_AUDIO_NULL_WORKER_STACKSIZE 768
#endif
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: audio_null_initialize
*
* Description:
* Initialize the null audio device.
*
* Input Parameters:
* i2c - An I2C driver instance
* i2s - An I2S driver instance
* lower - Persistent board configuration data
*
* Returned Value:
* A new lower half audio interface for the NULL audio device is returned
* on success; NULL is returned on failure.
*
****************************************************************************/
struct audio_lowerhalf_s; /* Forward reference. Defined in nuttx/audio/audio.h */
FAR struct audio_lowerhalf_s *audio_null_initialize(void);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_AUDIO_NULL */
#endif /* __INCLUDE_NUTTX_AUDIO_AUDIO_NULL_H */