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walnux/include/nuttx/audio/audio.h
Alin Jerpelea 231b8518b7 NuttX: Ken Pettit: update licenses to Apache 
Ken Pettit has submitted the ICLA and we can migrate the licenses
 to Apache.

Sebastien Lorquet has submitted the ICLA and we can migrate the licenses
 to Apache.

Gregory Nutt has submitted the SGA and we can migrate the licenses
 to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-04-10 06:42:19 -05:00

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/****************************************************************************
* include/nuttx/audio/audio.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_AUDIO_AUDIO_H
#define __INCLUDE_NUTTX_AUDIO_AUDIO_H
/* For the purposes of this driver, an Audio device is any device that
* generates, records, mixes, or otherwise modifies audio data in any format,
* such as PCM, MP3, AAC, etc.
*
* The Audio driver is split into two parts:
*
* 1) An "upper half", generic driver that provides the common Audio
* interface to application level code, and
* 2) A "lower half", platform-specific driver that implements the
* low-level controls to configure and communicate with the audio
* device(s).
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <nuttx/fs/ioctl.h>
#include <nuttx/semaphore.h>
#include <nuttx/spi/spi.h>
#include <queue.h>
#ifdef CONFIG_AUDIO
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* CONFIG_AUDIO - Enables Audio driver support
* CONFIG_DEBUG_AUDIO - If enabled (with CONFIG_DEBUG_FEATURES and,
* optionally, CONFIG_DEBUG_INFO), this will generate output that can
* be used to debug Audio drivers.
*/
/* IOCTL Commands ***********************************************************/
/* The Audio module uses a standard character driver framework. However, a
* lot of the Audio driver functionality is configured via a device control
* interface, such as sampling rate, volume, data format, etc.
* The Audio ioctl commands are listed below:
*
* AUDIOIOC_GETCAPS - Get the Audio Device Capabilities
*
* ioctl argument: Pointer to the audio_caps_s structure to receive the
* capabilities info. The "len" and "type" fields should
* be filled in prior to calling this ioctl. To get
* overall capabilities, specify the type as
* AUDIO_TYPE_QUERY, otherwise specify any type that was
* reported by the device during the QUERY.
*
* AUDIOIOC_CONFIGURE - Configure device for the specified mode
*
* ioctl argument: Pointer to the audio_caps_s structure which identifies
* the capabilities to configure for.
*
* AUDIOIOC_SHUTDOWN - Shutdown the device.
*
* ioctl argument: None
*
* AUDIOIOC_START - Start Audio streaming
*
* ioctl argument: None
*
* AUDIOIOC_STOP - Stop Audio streaming
*
* ioctl argument: None
*/
#define AUDIOIOC_GETCAPS _AUDIOIOC(1)
#define AUDIOIOC_RESERVE _AUDIOIOC(2)
#define AUDIOIOC_RELEASE _AUDIOIOC(3)
#define AUDIOIOC_CONFIGURE _AUDIOIOC(4)
#define AUDIOIOC_SHUTDOWN _AUDIOIOC(5)
#define AUDIOIOC_START _AUDIOIOC(6)
#define AUDIOIOC_STOP _AUDIOIOC(7)
#define AUDIOIOC_PAUSE _AUDIOIOC(8)
#define AUDIOIOC_RESUME _AUDIOIOC(9)
#define AUDIOIOC_GETBUFFERINFO _AUDIOIOC(10)
#define AUDIOIOC_ALLOCBUFFER _AUDIOIOC(11)
#define AUDIOIOC_FREEBUFFER _AUDIOIOC(12)
#define AUDIOIOC_ENQUEUEBUFFER _AUDIOIOC(13)
#define AUDIOIOC_REGISTERMQ _AUDIOIOC(14)
#define AUDIOIOC_UNREGISTERMQ _AUDIOIOC(15)
#define AUDIOIOC_HWRESET _AUDIOIOC(16)
#define AUDIOIOC_SETBUFFERINFO _AUDIOIOC(17)
/* Audio Device Types *******************************************************/
/* The NuttX audio interface support different types of audio devices for
* input, output, synthesis, and manipulation of audio data. A given driver/
* device could support a combination of these device type. The following
* is a list of bit-field definitions for defining the device type.
*/
#define AUDIO_TYPE_QUERY 0x00
#define AUDIO_TYPE_INPUT 0x01
#define AUDIO_TYPE_OUTPUT 0x02
#define AUDIO_TYPE_MIXER 0x04
#define AUDIO_TYPE_SELECTOR 0x08
#define AUDIO_TYPE_FEATURE 0x10
#define AUDIO_TYPE_EFFECT 0x20
#define AUDIO_TYPE_PROCESSING 0x40
#define AUDIO_TYPE_EXTENSION 0x80
/* Audio Format Types *******************************************************/
/* The following defines the audio data format types in NuttX. During a
* format query, these will be converted to bit positions within the
* ac_format field, meaning we currently only support up to 16 formats. To
* support more than that, we will use the FMT_OTHER entry, and the
* interfacing software can perform a second query to get the other formats.
*/
#define AUDIO_FMT_UNDEF 0x00
#define AUDIO_FMT_OTHER 0x01
#define AUDIO_FMT_MPEG 0x02
#define AUDIO_FMT_AC3 0x03
#define AUDIO_FMT_WMA 0x04
#define AUDIO_FMT_DTS 0x05
#define AUDIO_FMT_PCM 0x06
#define AUDIO_FMT_WAV 0x07
#define AUDIO_FMT_MP3 0x08
#define AUDIO_FMT_MIDI 0x09
#define AUDIO_FMT_OGG_VORBIS 0x0a
#define AUDIO_FMT_FLAC 0x0b
/* Audio Sub-Format Types ***************************************************/
#define AUDIO_SUBFMT_END 0x00
#define AUDIO_SUBFMT_PCM_MP1 0x01
#define AUDIO_SUBFMT_PCM_MP2 0x02
#define AUDIO_SUBFMT_PCM_MP3 0x03
#define AUDIO_SUBFMT_PCM_MU_LAW 0x04
#define AUDIO_SUBFMT_PCM_A_LAW 0x05
#define AUDIO_SUBFMT_PCM_U8 0x06
#define AUDIO_SUBFMT_PCM_S8 0x07
#define AUDIO_SUBFMT_PCM_U16_LE 0x08
#define AUDIO_SUBFMT_PCM_S16_BE 0x09
#define AUDIO_SUBFMT_PCM_S16_LE 0x0a
#define AUDIO_SUBFMT_PCM_U16_BE 0x0b
#define AUDIO_SUBFMT_MIDI_0 0x0c
#define AUDIO_SUBFMT_MIDI_1 0x0d
#define AUDIO_SUBFMT_MIDI_2 0x0e
/* Audio Hardware-Format Types **********************************************/
#define AUDIO_HWFMT_I2S (1 << 0)
#define AUDIO_HWFMT_RIGHT_J (2 << 0)
#define AUDIO_HWFMT_LEFT_J (3 << 0)
#define AUDIO_HWFMT_DSP_A (4 << 0)
#define AUDIO_HWFMT_DSP_B (5 << 0)
#define AUDIO_HWFMT_AC97 (6 << 0)
#define AUDIO_HWFMT_PDM (7 << 0)
#define AUDIO_HWFMT_NB_NF (0 << 8)
#define AUDIO_HWFMT_NB_IF (2 << 8)
#define AUDIO_HWFMT_IB_NF (3 << 8)
#define AUDIO_HWFMT_IB_IF (4 << 8)
#define AUDIO_HWFMT_CBM_CFM (1 << 12)
#define AUDIO_HWFMT_CBS_CFM (2 << 12)
#define AUDIO_HWFMT_CBM_CFS (3 << 12)
#define AUDIO_HWFMT_CBS_CFS (4 << 12)
#define AUDIO_HWFMT_FORMAT_MASK 0x000f
#define AUDIO_HWFMT_CLOCK_MASK 0x00f0
#define AUDIO_HWFMT_INV_MASK 0x0f00
#define AUDIO_HWFMT_MASTER_MASK 0xf000
/* Supported Sampling Rates *************************************************/
#define AUDIO_SAMP_RATE_8K 0x0001
#define AUDIO_SAMP_RATE_11K 0x0002
#define AUDIO_SAMP_RATE_16K 0x0004
#define AUDIO_SAMP_RATE_22K 0x0008
#define AUDIO_SAMP_RATE_32K 0x0010
#define AUDIO_SAMP_RATE_44K 0x0020
#define AUDIO_SAMP_RATE_48K 0x0040
#define AUDIO_SAMP_RATE_96K 0x0080
#define AUDIO_SAMP_RATE_128K 0x0100
#define AUDIO_SAMP_RATE_160K 0x0200
#define AUDIO_SAMP_RATE_172K 0x0400
#define AUDIO_SAMP_RATE_192K 0x0800
/* Audio Sub-sampling Ratios ***********************************************/
#define AUDIO_SUBSAMPLE_NONE 0
#define AUDIO_SUBSAMPLE_2X 2
#define AUDIO_SUBSAMPLE_4X 4
#define AUDIO_SUBSAMPLE_8X 8
#define AUDIO_SUBSAMPLE_16X 16
#define AUDIO_SUBSAMPLE_MIN AUDIO_SUBSAMPLE_2X
#define AUDIO_SUBSAMPLE_MAX AUDIO_SUBSAMPLE_16X
/* Supported Bit Rates ******************************************************/
#define AUDIO_BIT_RATE_22K 0x01
#define AUDIO_BIT_RATE_44K 0x02
#define AUDIO_BIT_RATE_48K 0x04
#define AUDIO_BIT_RATE_96K 0x08
#define AUDIO_BIT_RATE_128K 0x10
#define AUDIO_BIT_RATE_160K 0x20
#define AUDIO_BIT_RATE_172K 0x40
#define AUDIO_BIT_RATE_192K 0x80
/* Supported Feature Units controls *****************************************/
#define AUDIO_FU_UNDEF 0x0000
#define AUDIO_FU_MUTE 0x0001
#define AUDIO_FU_VOLUME 0x0002
#define AUDIO_FU_BASS 0x0004
#define AUDIO_FU_MID 0x0008
#define AUDIO_FU_TREBLE 0x0010
#define AUDIO_FU_EQUALIZER 0x0020
#define AUDIO_FU_AGC 0x0040
#define AUDIO_FU_DELAY 0x0080
#define AUDIO_FU_BASS_BOOST 0x0100
#define AUDIO_FU_LOUDNESS 0x0200
#define AUDIO_FU_INP_GAIN 0x0400
#define AUDIO_FU_BALANCE 0x0800
#define AUDIO_FU_PHASE_INVERT 0x1000
#define AUDIO_FU_UNDERFLOW 0x2000
#define AUDIO_FU_OVERFLOW 0x4000
#define AUDIO_FU_LATENCY 0x8000
/* Processing Unit controls *************************************************/
#define AUDIO_PU_UNDEF 0x00
#define AUDIO_PU_UPDOWNMIX 0x01
#define AUDIO_PU_DOLBY_PROLOGIC 0x02
#define AUDIO_PU_STEREO_EXTENDER 0x03
#define AUDIO_PU_SUBSAMPLE_FORWARD 0x04
#define AUDIO_PU_SUBSAMPLE_REWIND 0x05
/* Stereo Extender PU Controls **********************************************/
#define AUDIO_STEXT_UNDEF 0x00
#define AUDIO_STEXT_ENABLE 0x01
#define AUDIO_STEXT_WIDTH 0x02
#define AUDIO_STEXT_UNDERFLOW 0x03
#define AUDIO_STEXT_OVERFLOW 0x04
#define AUDIO_STEXT_LATENCY 0x05
/* Extension Unit controls **************************************************/
#define AUDIO_EU_HW_FORMAT 0x0001
#define AUDIO_EU_LOAD_MODULE 0x0002
/* Audio Callback Reasons ***************************************************/
#define AUDIO_CALLBACK_UNDEF 0x00
#define AUDIO_CALLBACK_DEQUEUE 0x01
#define AUDIO_CALLBACK_IOERR 0x02
#define AUDIO_CALLBACK_COMPLETE 0x03
#define AUDIO_CALLBACK_MESSAGE 0x04
/* Audio Pipeline Buffer (AP Buffer) flags **********************************/
#define AUDIO_ABP_ALIGNMENT 0x000f /* Mask to define buffer alignment */
#define AUDIO_ABP_CANDMA 0x0010 /* Set if the data is DMA'able */
#define AUDIO_ABP_STATIC 0x0020 /* Set if statically allocated */
#define AUDIO_ABP_ACTIVE 0x0040 /* Set if this buffer is still active.
* A buffer could become inactive
* if it is processed by an output
* device or a processing device
* that replaces it with an alternate
* buffer as a result of some DSP
* operation, etc.
*/
/* Standard Audio Message Queue message IDs */
#define AUDIO_MSG_NONE 0
#define AUDIO_MSG_DEQUEUE 1
#define AUDIO_MSG_START 2
#define AUDIO_MSG_STOP 3
#define AUDIO_MSG_PAUSE 4
#define AUDIO_MSG_RESUME 5
#define AUDIO_MSG_DATA_REQUEST 6
#define AUDIO_MSG_ENQUEUE 7
#define AUDIO_MSG_COMPLETE 8
#define AUDIO_MSG_WAKEUP 9
#define AUDIO_MSG_COMMAND 10
#define AUDIO_MSG_SLIENCE 11
#define AUDIO_MSG_USER 64
/* Audio Pipeline Buffer flags */
#define AUDIO_APB_OUTPUT_ENQUEUED (1 << 0)
#define AUDIO_APB_OUTPUT_PROCESS (1 << 1)
#define AUDIO_APB_DEQUEUED (1 << 2)
#define AUDIO_APB_FINAL (1 << 3) /* Last buffer in the stream */
/****************************************************************************
* Public Types
****************************************************************************/
/* Define the size of AP Buffer sample count base on CONFIG */
#ifdef CONFIG_AUDIO_LARGE_BUFFERS
typedef uint32_t apb_samp_t;
#else
typedef uint16_t apb_samp_t;
#endif
/* This structure is used to describe the audio device capabilities */
struct audio_caps_s
{
uint8_t ac_len; /* Length of the structure */
uint8_t ac_type; /* Capabilities (device) type */
uint8_t ac_subtype; /* Capabilities sub-type, if needed */
uint8_t ac_channels; /* Number of channels (1, 2, 3, ... 8) */
uint8_t ac_chmap; /* Channel map, each ch for each bit,
* zero means don't care */
uint8_t reserved; /* Reserved for future use */
/* Audio data format(s) for this device */
union
{
uint8_t b[2];
uint16_t hw;
} ac_format;
/* Specific controls for AUDIO_DEVICE_QUERY
* this field reports the device type supported
* by this lower-half driver.
*/
union
{
uint8_t b[4];
uint16_t hw[2];
uint32_t w;
#ifdef CONFIG_HAVE_LONG_LONG
uint64_t qw;
#endif
} ac_controls;
};
struct audio_caps_desc_s
{
#ifdef CONFIG_AUDIO_MULTI_SESSION
FAR void *session; /* Associated session */
#endif
struct audio_caps_s caps; /* The capabilities struct */
};
/* This structure describes the characteristics of the Audio samples */
struct audio_info_s
{
uint8_t samplerate; /* Sample Rate of the audio data */
uint8_t channels; /* Number of channels (1, 2, 5, 7) */
uint8_t format; /* Audio data format */
uint8_t subformat; /* Audio subformat
* (maybe should be combined with format?
*/
};
/* This structure describes the preferred number and size of
* audio pipeline buffers for the audio device. Each device
* may have unique needs regarding size and qty of buffers,
* so this info is queried from the lower-half driver.
*/
struct ap_buffer_info_s
{
apb_samp_t nbuffers; /* Preferred qty of buffers */
apb_samp_t buffer_size; /* Preferred size of the buffers */
};
/* This structure describes an Audio Pipeline Buffer */
struct ap_buffer_s
{
struct dq_entry_s dq_entry; /* Double linked queue entry */
struct audio_info_s i; /* The info for samples in this buffer */
#ifdef CONFIG_AUDIO_MULTI_SESSION
FAR void *session; /* Associated session */
#endif
apb_samp_t nmaxbytes; /* The maximum number of bytes */
apb_samp_t nbytes; /* The number of bytes used */
apb_samp_t curbyte; /* Next byte to be processed */
sem_t sem; /* Reference locking semaphore */
uint16_t flags; /* Buffer flags */
uint16_t crefs; /* Number of reference counts */
FAR uint8_t *samp; /* Offset of the first sample */
};
/* Structure defining the messages passed to a listening audio thread
* for dequeuing buffers and other operations. Also used to allocate
* and enqueue buffers via the AUDIOIOC_ALLOCBUFFER, AUDIOIOC_FREEBUFFER,
* and AUDIOIOC_ENQUEUEBUFFER ioctls.
*/
struct audio_msg_s
{
#ifdef CONFIG_AUDIO_MULTI_SESSION
FAR void *session; /* Associated channel */
#endif
uint16_t msg_id; /* Message ID */
union
{
FAR void *ptr; /* Buffer being dequeued */
uint32_t data; /* Message data */
} u;
};
/* Structure defining the built-in sounds */
#ifdef CONFIG_AUDIO_BUILTIN_SOUNDS
struct audio_sound_s
{
const char *name; /* Name of the sound */
uint32_t id; /* ID of the sound */
uint32_t type; /* Type of sound */
uint32_t size; /* Number of bytes in the sound */
const uint8_t *data; /* Pointer to the data */
};
#endif
/* Structure for allocating, freeing and enqueueing audio pipeline
* buffers via the AUDIOIOC_ALLOCBUFFER, AUDIOIOC_FREEBUFFER,
* and AUDIOIOC_ENQUEUEBUFFER ioctls.
*/
struct audio_buf_desc_s
{
#ifdef CONFIG_AUDIO_MULTI_SESSION
FAR void *session; /* Associated channel */
#endif
uint16_t numbytes; /* Number of bytes to allocate */
union
{
FAR struct ap_buffer_s *buffer; /* Buffer to free / enqueue */
FAR struct ap_buffer_s **pbuffer; /* Pointer to receive allocated buffer */
} u;
};
/* Typedef for lower-level to upper-level callback for buffer dequeuing */
#ifdef CONFIG_AUDIO_MULTI_SESSION
typedef CODE void (*audio_callback_t)(FAR void *priv, uint16_t reason,
FAR struct ap_buffer_s *apb, uint16_t status, FAR void *session);
#else
typedef CODE void (*audio_callback_t)(FAR void *priv, uint16_t reason,
FAR struct ap_buffer_s *apb, uint16_t status);
#endif
/* This structure is a set a callback functions used to call from the upper-
* half, generic Audo driver into lower-half, platform-specific logic that
* supports the low-level functionality.
*/
struct audio_lowerhalf_s;
struct audio_ops_s
{
/* This method is called to retrieve the lower-half device capabilities.
* It will be called with device type AUDIO_TYPE_QUERY to request the
* overall capabilities, such as to determine the types of devices
* supported audio formats supported, etc.
* Then it may be called once or more with reported supported device types
* to determine the specific capabilities of that device type
* (such as MP3 encoder, WMA encoder, PCM output, etc.).
*/
CODE int (*getcaps)(FAR struct audio_lowerhalf_s *dev, int type,
FAR struct audio_caps_s *caps);
/* This method is called to bind the lower-level driver to the upper-level
* driver and to configure the driver for a specific mode of
* operation defined by the parameters selected in supplied device caps
* structure. The lower-level device should perform any initialization
* needed to prepare for operations in the specified mode. It should not,
* however, process any audio data until the start method is called.
*/
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*configure)(FAR struct audio_lowerhalf_s *dev,
FAR void *session, FAR const struct audio_caps_s *caps);
#else
CODE int (*configure)(FAR struct audio_lowerhalf_s *dev,
FAR const struct audio_caps_s *caps);
#endif
/* This method is called when the driver is closed. The lower half driver
* should stop processing audio data, including terminating any active
* output generation. It should also disable the audio hardware and put
* it into the lowest possible power usage state.
*
* Any enqueued Audio Pipeline Buffers that have not been
* processed / dequeued should be dequeued by this function.
*/
CODE int (*shutdown)(FAR struct audio_lowerhalf_s *dev);
/* Start audio streaming in the configured mode. For input and synthesis
* devices, this means it should begin sending streaming audio data.
* For output or processing type device, it means it should begin
* processing of any enqueued Audio Pipeline Buffers.
*/
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*start)(FAR struct audio_lowerhalf_s *dev, FAR void *session);
#else
CODE int (*start)(FAR struct audio_lowerhalf_s *dev);
#endif
/* Stop audio streaming and/or processing of enqueued
* Audio Pipeline Buffers
*/
#ifndef CONFIG_AUDIO_EXCLUDE_STOP
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*stop)(FAR struct audio_lowerhalf_s *dev, FAR void *session);
#else
CODE int (*stop)(FAR struct audio_lowerhalf_s *dev);
#endif
#endif
/* Pause the audio stream.
* Should keep current playback context active in case a resume is issued.
* Could be called and then followed by a stop.
*/
#ifndef CONFIG_AUDIO_EXCLUDE_PAUSE_RESUME
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*pause)(FAR struct audio_lowerhalf_s *dev, FAR void *session);
#else
CODE int (*pause)(FAR struct audio_lowerhalf_s *dev);
#endif
/* Resumes audio streaming after a pause */
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*resume)(FAR struct audio_lowerhalf_s *dev, FAR void *session);
#else
CODE int (*resume)(FAR struct audio_lowerhalf_s *dev);
#endif
#endif /* CONFIG_AUDIO_EXCLUDE_PAUSE_RESUME */
/* Allocate an audio pipeline buffer. This routine provides the
* lower-half driver with the opportunity to perform special buffer
* allocation if needed, such as allocating from a specific memory
* region (DMA-able, etc.). If not supplied, then the top-half
* driver will perform a standard kumm_malloc using normal user-space
* memory region.
*/
CODE int (*allocbuffer)(FAR struct audio_lowerhalf_s *dev,
FAR struct audio_buf_desc_s *apb);
/* Free an audio pipeline buffer. If the lower-level driver
* provides an allocbuffer routine, it should also provide the
* freebuffer routine to perform the free operation.
*/
CODE int (*freebuffer)(FAR struct audio_lowerhalf_s *dev,
FAR struct audio_buf_desc_s *apb);
/* Enqueue a buffer for processing.
* This is a non-blocking enqueue operation.
* If the lower-half driver's buffer queue is full, then it should return
* an error code of -ENOMEM, and the upper-half driver can decide to either
* block the calling thread or deal with it in a non-blocking manner.
* For each call to enqueuebuffer, the lower-half driver must call
* audio_dequeuebuffer when it is finished processing the bufferr, passing
* the previously enqueued apb and a dequeue status so that the upper-half
* driver can decide if a waiting thread needs to be release, if the
* dequeued buffer should be passed to the next block in the
* Audio Pipeline, etc.
*/
CODE int (*enqueuebuffer)(FAR struct audio_lowerhalf_s *dev,
FAR struct ap_buffer_s *apb);
/* Cancel a previously enqueued buffer. */
CODE int (*cancelbuffer)(FAR struct audio_lowerhalf_s *dev,
FAR struct ap_buffer_s *apb);
/* Lower-half logic may support platform-specific ioctl commands */
CODE int (*ioctl)(FAR struct audio_lowerhalf_s *dev,
int cmd, unsigned long arg);
/* Lower-half logic may support platform-specific read commands */
CODE int (*read)(FAR struct audio_lowerhalf_s *dev,
FAR char *buffer, size_t buflen);
/* Lower-half logic may support platform-specific write commands */
CODE int (*write)(FAR struct audio_lowerhalf_s *dev,
FAR const char *buffer, size_t buflen);
/* Reserve a session (may only be one per device or may be multiple) for
* use by a client. Client software can open audio devices and issue
* AUDIOIOC_GETCAPS calls freely, but other operations require a
* reservation. A session reservation will assign a context that must
* be passed with
*/
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*reserve)(FAR struct audio_lowerhalf_s *dev,
FAR void **psession);
#else
CODE int (*reserve)(FAR struct audio_lowerhalf_s *dev);
#endif
/* Release a session. */
#ifdef CONFIG_AUDIO_MULTI_SESSION
CODE int (*release)(FAR struct audio_lowerhalf_s *dev,
FAR void *session);
#else
CODE int (*release)(FAR struct audio_lowerhalf_s *dev);
#endif
};
/* This structure is the generic form of state structure used by lower half
* Audio driver. This state structure is passed to the Audio driver when the
* driver is initialized. Then, on subsequent callbacks into the lower half
* Audio logic, this structure is provided so that the Audio logic can
* maintain state information.
*
* Normally that Audio logic will have its own, custom state structure
* that is simply cast to struct audio_lowerhalf_s. In order to perform such
* casts, the initial fields of the custom state structure match the initial
* fields of the following generic Audio state structure.
*/
struct audio_lowerhalf_s
{
/* The first field of this state structure must be a pointer to the Audio
* callback structure:
*/
FAR const struct audio_ops_s *ops;
/* The bind data to the upper-half driver used for callbacks of dequeuing
* buffer, reporting asynchronous event, reporting errors, etc.
*/
FAR audio_callback_t upper;
/* The private opaque pointer to be passed to upper-layer during
* callbacks
*/
FAR void *priv;
/* The custom Audio device state structure may include additional fields
* after the pointer to the Audio callback structure.
*/
};
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* "Upper-Half" Audio Driver Interfaces
****************************************************************************/
/****************************************************************************
* Name: audio_register
*
* Description:
* This function binds an instance of a "lower half" Audio driver with the
* "upper half" Audio device and registers that device so that can be used
* by application code.
*
* When this function is called, the "lower half" driver should be in the
* reset state (as if the shutdown() method had already been called).
*
* Input Parameters:
* name - The name of the audio device. This name will be used to generate
* a full path to the driver in the format "/dev/audio/[name]" in the
* NuttX filesystem (i.e. the path "/dev/audio" will be prepended to the
* supplied device name. The recommended convention is to name Audio
* drivers based on the type of functionality they provide, such as
* "/dev/audio/pcm0", "/dev/audio/midi0", "/dev/audio/mp30, etc.
* dev - A pointer to an instance of lower half audio driver. This instance
* is bound to the Audio driver and must persists as long as the driver
* persists.
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int audio_register(FAR const char *name, FAR struct audio_lowerhalf_s *dev);
/****************************************************************************
* Name: abp_alloc
*
* Description:
* Allocated an AP Buffer and prepares it for use.
* This allocates a dynamically allocated buffer that has no special
* DMA capabilities.
*
* Input Parameters:
* bufdesc: Pointer to a buffer descriptor
*
* Returned Value:
* Pointer to the allocated buffer or NULL if no memory.
*
****************************************************************************/
int apb_alloc(FAR struct audio_buf_desc_s *bufdesc);
/****************************************************************************
* Name: apb_free
*
* Free's a previously allocated or referenced Audio Pipeline Buffer
*
****************************************************************************/
void apb_free(FAR struct ap_buffer_s *apb);
/****************************************************************************
* Name: apb_reference
*
* Claim a reference to an Audio Pipeline Buffer. Each call to apb_reference
* will increment the reference count and must have a matching apb_free
* call. When the refcount decrements to zero, the buffer will be freed.
*
****************************************************************************/
void apb_reference(FAR struct ap_buffer_s *apb);
/****************************************************************************
* Platform-Dependent "Lower-Half" Audio Driver Interfaces
****************************************************************************/
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_AUDIO */
#endif /* __INCLUDE_NUTTX_AUDIO_AUDIO_H */
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