audio_engine_ops

- audio engine operations vector

Synopsis

#include <sys/audio/audio_driver.h>

Interface Level

Solaris DDI specific (Solaris DDI)

Description

An audio_engine_ops structure defines vectors that an audio driver exports to the Sun audio framework.

One such vector is used for each DMA or PIO engine (sometimes referred to as a “stream”) supported on the device.

The audio framework provides the following synchronization guarantees for audio engines:

• only one thread will be executing an audio engine entry point for a given audio device at any one time

• no threads will be executing any audio engine entry points for a given audio device if that device is suspended. See audio_dev_suspend(9F).

Each entry point receives as its first argument the driver private state that was registered with audio_engine_set_private(9F).

Structure Members

int         audio_engine_version;        /* version number */
int         (*audio_engine_open)();      /* open engine */
void        (*audio_engine_close)();     /* close engine */
int         (*audio_engine_start)();     /* start engine */
void        (*audio_engine_stop)();      /* stop engine */
uint64_t    (*audio_engine_count)();     /* get frame count */
int         (*audio_engine_format)();    /* get format */
int         (*audio_engine_channels)();  /* get num channels */
int         (*audio_engine_rate)();      /* get sample rate */
void        (*audio_engine_sync)();      /* dma cache sync */
uint_t      (*audio_engine_qlen)();      /* get hw fifo len */
void        (*audio_engine_chinfo)();    /* channel cfg info */
uint_t      (*audio_engine_playahead)(); /* play ahead frames */

audio_engine_version

The version of the engine interface. Drivers must supply AUDIO_ENGINE_VERSION.

audio_engine_open

Function entry that opens the engine and initializes hardware and resources.

audio_engine_close

Function entry that closes the engine and possibly releases any resources.

audio_engine_start

Function entry to start audio data transfer.

audio_engine_stop

Function entry to stop audio data transfer.

audio_engine_count

Function entry to return engine's frame count.

audio_engine_format

Function entry to get the format of the engine.

audio_engine_channels

Function entry to get the number of channels of the engine.

audio_engine_rate

Function entry to get the sample rate of the engine.

audio_engine_sync

Function entry to synchronize the DMA cache for the buffer associated with the engine.

audio_engine_qlen

Function entry to determine the on-device FIFO len for the engine.

audio_engine_chinfo

Function entry to determine number and layout channels for device.

audio_engine_playahead

Function entry to determine minimum number of frames that should be queued to the engine.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

attributes(5), audio(7D), audio_engine_channels(9E), audio_engine_chinfo(9E), audio_engine_count(9E), audio_engine_format(9E), audio_engine_open(9E), audio_engine_playahead(9E), audio_engine_qlen(9E), audio_engine_rate(9E), audio_engine_start(9E), audio_engine_sync(9E), audio_dev_add_engine(9F), audio_dev_suspend(9F), audio_engine_alloc(9F), audio_engine_set_private(9F)