I2S

概述

I2S(Inter-IC Sound Bus) 是为数字音频设备之间的音频数据传输而指定的一种总线标准，广泛应用于各种多媒体系统。I2S 主要有以下 3 种信号：

• 串行时钟信号 BCK：每一位串行数据都有一个BCK脉冲对应。

• 声道选择信号 WS：用于指示左右声道的数据。WS为 "0" 默认表示正在传输的是左声道数据，为 "1" 表示正在传输的是右声道数据。

• 串行数据信号 SDATA：实际音频数据。

WQ7036 有 2 个 I2S 模块，可以工作在不同的时钟频率。

功能特性

I2S 模块支持：

• 支持 2 个 I2S，包括 2 个 Tx, 2 个 Rx

• 支持每个 Tx/Rx 最大8 channel 数据

• 支持双通道/单通道的 16 bit，24 bit，32 bit 数据格式

• 支持 标准 Philips 和非 Philips 模式(左右对齐)

Standard Philips 格式：数据信号与 WS 信号相比有一个位的位移。WS 信号的占空比为 50%

Left justified 格式：与 Standard Philips 格式基本相同，但其数据没有位移。

Right justified 格式：数据有一个位的位移，同时 WS 信号变成脉冲，持续一个 BCLK 周期。

• 支持 TX/RX 分别配置成 master 或者 slave 模式

• I2S 收发数据过程支持 DMA 传输

• 支持最高 49.152 MHz Bclk

• 支持 WS 脉冲形式， 1 slot 模式， 50% 占空比模式

• 支持 STANDARD/TDM/PCM 模式

• 支持 4 条数据线同时工作

• 支持外部时钟或多种内部时钟选择

• 支持 16 k， 24 k， 32 k， 48 k， 62.5 k， 96 k， 125 k， 128 k， 192 k， 256 k 等多种采样率配置 (需选择不同 AUDIO 时钟源)

• 最大支持上行 16 路channel、下行 8 channel 同时工作

内部时钟源选择：XTAL_CLK, APLL_CLK

• XTAL_CLK: 32 MHz

• APLL_CLK: 主要为307.2 MHz

数据流

I2S 收发数据流如下图所示。

I2S 收发数据流

API 介绍

This section introduces the I2S module's enum, structure, functions and how to use this driver.

struct i2s_tx_irq_cfg

Public Members

WQ_I2S_LINE_ID tx_data_line_id

I2s TX dataline id

WQ_I2S_TX_CHANNEL tx_ch

I2s TX channel select

WQ_I2S_INTC_TYPE intc_type

I2s TX interrupt type

struct i2s_rx_irq_cfg

Public Members

WQ_I2S_LINE_ID rx_data_line_id

I2s RX dataline id

WQ_I2S_RX_CHANNEL rx_ch

I2s RX channel select

WQ_I2S_INTC_TYPE intc_type

I2s RX interrupt type

struct i2s_tdm_mode_config

Public Members

WQ_I2S_TDM_WORK_MODE tdm_mode

I2s work mode

uint8_t chn_num

the number of channels used by I2S

struct i2s_gpio_config

Public Members

WQ_GPIO_ID ws

I2S ws GPIO ID

WQ_GPIO_ID bck

I2S bck GPIO ID

WQ_GPIO_ID data[WQ_I2S_LINE_ID_MAX]

I2S dataline GPIO ID

WQ_GPIO_ID mclk

I2S mclk GPIO ID

struct mclk_src_config

Public Members

bool mclk_en

I2S mclk enable

bool mclk_out

i2s mclk trans direction, true is out, false is in, effective when mclk_en is true

WQ_I2S_MCLK_SRC mclk_src

I2S mclk source

struct i2s_tx_line_config

Public Members

bool line_enable[WQ_I2S_LINE_ID_MAX]

I2S dataline enable state

WQ_I2S_TX_CHANNEL tx_channel[WQ_I2S_LINE_ID_MAX]

I2S all dataline cahnnel state

WQ_I2S_TX_DATA_SRC tx_data_src

data source of I2S tx

struct i2s_rx_line_config

Public Members

bool line_enable[WQ_I2S_LINE_ID_MAX]

I2S dataline enable state

WQ_I2S_RX_CHANNEL rx_channel[WQ_I2S_LINE_ID_MAX]

I2S all dataline cahnnel state

WQ_I2S_RX_DATA_DST rx_data_dst

data destination of I2S rx

union i2s_data_line_config

Public Members

i2s_tx_line_config_t tx_line_config

I2S tx dataline config

i2s_rx_line_config_t rx_line_config

I2S rx dataline config

struct i2s_tx_register_irq

Public Members

wq_i2s_data_intc_hook tx_cb

I2S tx irq callback

i2s_tx_irq_cfg_t tx_irq_cfg

I2S tx irq config

struct i2s_rx_register_irq

Public Members

wq_i2s_data_intc_hook rx_cb

I2S rx irq callback

i2s_rx_irq_cfg_t rx_irq_cfg

I2S rx irq config

union i2s_register_irq

Public Members

i2s_tx_register_irq_t tx_register_irq

information related to tx interrupts

i2s_rx_register_irq_t rx_register_irq

information related to rx interrupts

struct wq_i2s_config

Public Members

i2s_gpio_cfg_t gpio

I2S pin info

mclk_src_config_t mclk_cfg

I2S mclk info

i2s_data_line_config_u data_line

I2S dataline config info

i2s_tdm_mode_config_t tdm_mode_config

I2S work mode config info

i2s_register_irq_u register_irq

register I2S tx or rx irq

WQ_I2S_SAMPLE_RATE freq

config I2S sample rate

WQ_I2S_MODE trans_mode

config I2S transmode, such as master_tx、master_rx...

WQ_I2S_WORK_MODE word_mode

config I2S data alignment mode

WQ_I2S_DATA_FORMAT format

config I2S data format

WQ_I2S_MODULE i2s_module

the hardware module to which I2S belongs

WQ_I2S_TRIGGER_SRC trigger

trigger source of I2S

bool right_first

config transmit or receive right-channel data first

bool single_ch

I2S single channel transmit and receive enable

bool pcm_mode

ws clk use pcm or i2s mode

struct wq_i2s_start_cfg

Public Members

WQ_I2S_MODULE i2s_module

the hardware module to which I2S belongs

Typedefs

typedef enum _WQ_I2S_TRANS_MODE WQ_I2S_TRANS_MODE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_MODULE WQ_I2S_MODULE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_TX_DATA_SRC WQ_I2S_TX_DATA_SRC

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_INTC_TYPE WQ_I2S_INTC_TYPE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_TX_CHANNEL WQ_I2S_TX_CHANNEL

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_RX_CHANNEL WQ_I2S_RX_CHANNEL

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_MCLK_SRC WQ_I2S_MCLK_SRC

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_LINE_ID WQ_I2S_LINE_ID

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_WORK_MODE WQ_I2S_WORK_MODE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_TDM_WORK_MODE WQ_I2S_TDM_WORK_MODE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_MODE WQ_I2S_MODE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_DATA_FORMAT WQ_I2S_DATA_FORMAT

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_RX_DATA_DST WQ_I2S_RX_DATA_DST

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_TRIGGER_SRC WQ_I2S_TRIGGER_SRC

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef enum _WQ_I2S_SAMPLE_RATE WQ_I2S_SAMPLE_RATE

For specific definitions, please refer to the header file wq_audio_resource.h.

typedef uint8_t (*wq_i2s_data_intc_hook)(uint32_t id)

This is the i2s interrupt callback function.

备注

When i2s is in tx mode and its data comes from txfifo, it is possible to register a txfifo empty interrupt and continue to package in the interrupt callback;When i2s is in rx mode and rxfifo receives data from i2s, it can register a rxfifo full interrupt and continue to package in the interrupt callback

typedef struct i2s_tx_irq_cfg i2s_tx_irq_cfg_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_rx_irq_cfg i2s_rx_irq_cfg_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_tdm_mode_config i2s_tdm_mode_config_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_gpio_config i2s_gpio_cfg_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct mclk_src_config mclk_src_config_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_tx_line_config i2s_tx_line_config_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_rx_line_config i2s_rx_line_config_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef union i2s_data_line_config i2s_data_line_config_u

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_tx_register_irq i2s_tx_register_irq_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct i2s_rx_register_irq i2s_rx_register_irq_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef union i2s_register_irq i2s_register_irq_u

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct wq_i2s_config wq_i2s_config_t

For specific definitions, please refer to the header file wq_i2s.h.

typedef struct wq_i2s_start_cfg wq_i2s_start_cfg_t

For specific definitions, please refer to the header file wq_i2s.h.

Functions

WQ_RET wq_i2s_init(WQ_I2S_TRANS_MODE mode)

This function is to init i2s.

参数:

mode -- i2s trans mode tx or rx

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_deinit(WQ_I2S_TRANS_MODE mode)

This function is to deinit i2s.

参数:

mode -- i2s trans mode tx or rx

返回:

uint8_t WQ_RET_OK for success else error.

void wq_i2s_start_all_trigger(void)

This function is to start i2s by sync mode.

void wq_i2s_stop_all_trigger(void)

This function is to stop i2s by sync mode.

WQ_RET wq_i2s_start(const wq_i2s_start_cfg_t *cfg)

This function is to start i2s module.

参数:

cfg -- config i2s start parameter

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_stop(WQ_I2S_MODULE module)

This function is to stop i2s module.

参数:

module -- i2s module, e.g: WQ_I2S_MODULE_RX0,WQ_I2S_MODULE_TX0

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_open(const wq_i2s_config_t *i2s_config)

This function is to open i2s, mainly complete hardware pin functions, transmission data format, sampling rate and other configurations.

参数:

i2s_config -- the config to open i2s

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_close(const wq_i2s_config_t *i2s_config)

This function is to close i2s, mainly responsible for clearing hardware pin functions, transmission data formats, sampling rates, and other configurations, which is opposite to the function of wq_i2s_open.

参数:

i2s_config -- the config to close i2s

返回:

uint8_t WQ_RET_OK for success else error.

int8_t wq_i2s_get_start_cnt(WQ_I2S_MODULE module)

get i2s open refcounter

参数:

module -- i2s module, e.g: WQ_I2S_MODULE_TX0

返回:

open refcounter

WQ_RET wq_i2s_ext_pa_on(WQ_I2S_MODULE module, uint8_t chn)

i2s external PA open

参数:

• module -- i2s module, e.g: WQ_I2S_MODULE_TX0

• chn -- 0:left,1:right,2:dual channel

返回:

WQ_RET for success else error.

WQ_RET wq_i2s_ext_pa_off(WQ_I2S_MODULE module, uint8_t chn)

i2s external PA close

参数:

• module -- i2s module, e.g: WQ_I2S_MODULE_TX0

• chn -- 0:left,1:right,2:dual channel

返回:

WQ_RET for success else error.

WQ_RET wq_i2s_ext_pa_set(uint8_t channels, bool on) __attribute__((weak))

weak function, Invoked when i2s tx data running by trigger

参数:

• channels -- i2s data channel number

• on -- true is external PA on,false is external PA off

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_ext_pa_mute(uint8_t channels) __attribute__((weak))

weak function, mute pa digital gain

参数:

channels -- i2s data channel number

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_ext_pa_unmute(uint8_t channels) __attribute__((weak))

weak function, unmute pa digital gain

参数:

channels -- i2s data channel number

返回:

uint8_t WQ_RET_OK for success else error.

WQ_RET wq_i2s_ext_pa_set_volume(uint8_t channels, float db) __attribute__((weak))

weak function, set pa digital gain volume

参数:

• channels -- i2s data channel number

• db -- volume unit is dB

返回:

uint8_t WQ_RET_OK for success else error.

float wq_i2s_ext_pa_get_volume(uint8_t channels) __attribute__((weak))

weak function, get pa digital gain volume

参数:

channels -- i2s data channel number

返回:

int16_t unit is dB