I2C

概述

I2C (Inter-Intergrated Circuit)是一种串行通讯总线，使用多主从架构，用来连接低速外围装置。 每个器件都有一个唯一的识别地址，并且都可以作为一个发送器或接收器。 如果有两个或多个主机同时初始化，数据传输可以通过冲突检测和仲裁防止数据被破坏。 BL602/BL604包含一个I2C控制器主机，可灵活配置slaveAddr、subAddr以及传输数据，方便与从设备通信，提供2个word深度的fifo，提供中断功能，可搭配DMA使用提高效率，可灵活调整时钟频率。

注解

i2c更多资料请参考 BL602参考手册 。

应用实例

i2c实例： customer_app/peripheral/demo_i2c 。

API参考

Header File

  • components/platform/hosal/include/hosal_i2c.h

Functions

int hosal_i2c_init(hosal_i2c_dev_t *i2c)

Initialises an I2C interface.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the device for which the i2c port should be initialised

int hosal_i2c_master_send(hosal_i2c_dev_t *i2c, uint16_t dev_addr, const uint8_t *data, uint16_t size, uint32_t timeout)

I2c master send.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the i2c device
  • dev_addr: device address
  • data: i2c send data
  • size: i2c send data size
  • timeout: timeout in milisecond, set this value to HAL_WAIT_FOREVER if you want to wait forever

int hosal_i2c_master_recv(hosal_i2c_dev_t *i2c, uint16_t dev_addr, uint8_t *data, uint16_t size, uint32_t timeout)

I2c master recv.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the i2c device
  • dev_addr: device address
  • data: i2c receive data
  • size: i2c receive data size
  • timeout: timeout in milisecond, set this value to HAL_WAIT_FOREVER if you want to wait forever

int hosal_i2c_slave_send(hosal_i2c_dev_t *i2c, const uint8_t *data, uint16_t size, uint32_t timeout)

I2c slave send.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the i2c device
  • data: i2c slave send data
  • size: i2c slave send data size
  • timeout: timeout in milisecond, set this value to HAL_WAIT_FOREVER if you want to wait forever

int hosal_i2c_slave_recv(hosal_i2c_dev_t *i2c, uint8_t *data, uint16_t size, uint32_t timeout)

I2c slave receive.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: tthe i2c device
  • data: i2c slave receive data
  • size: i2c slave receive data size
  • timeout: timeout in milisecond, set this value to HAL_WAIT_FOREVER if you want to wait forever

int hosal_i2c_mem_write(hosal_i2c_dev_t *i2c, uint16_t dev_addr, uint32_t mem_addr, uint16_t mem_addr_size, const uint8_t *data, uint16_t size, uint32_t timeout)

I2c mem write.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the i2c device
  • dev_addr: device address
  • mem_addr: mem address
  • mem_addr_size: mem address
  • data: i2c master send data
  • size: i2c master send data size
  • timeout: timeout in milisecond, set this value to HAL_WAIT_FOREVER if you want to wait forever

int hosal_i2c_mem_read(hosal_i2c_dev_t *i2c, uint16_t dev_addr, uint32_t mem_addr, uint16_t mem_addr_size, uint8_t *data, uint16_t size, uint32_t timeout)

I2c master mem read.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the i2c device
  • dev_addr: device address
  • mem_addr: mem address
  • mem_addr_size: mem address
  • data: i2c master send data
  • size: i2c master send data size
  • timeout: timeout in milisecond, set this value to HAL_WAIT_FOREVER if you want to wait forever

int hosal_i2c_finalize(hosal_i2c_dev_t *i2c)

Deinitialises an I2C device.

Return
  • 0 on success
  • EIO if an error occurred with any step
Parameters
  • i2c: the i2c device

Structures

struct hosal_i2c_config_t

I2C configuration.

Public Members

uint32_t address_width

Addressing mode: 7 bit or 10 bit.

uint32_t freq

CLK freq.

uint8_t scl

i2c clk pin

uint8_t sda

i2c data pin

uint8_t mode

master or slave mode

struct hosal_i2c_dev_t

I2C device type.

Public Members

uint8_t port

i2c port

hosal_i2c_config_t config

i2c config

void *priv

priv data

Macros

HOSAL_WAIT_FOREVER

Define the wait forever timeout macro.

HOSAL_I2C_MODE_MASTER

i2c communication is master mode

HOSAL_I2C_MODE_SLAVE

i2c communication is slave mode

HOSAL_I2C_MEM_ADDR_SIZE_8BIT

i2c memory address size 8bit

HOSAL_I2C_MEM_ADDR_SIZE_16BIT

i2c memory address size 16bit

HOSAL_I2C_MEM_ADDR_SIZE_24BIT

i2c memory address size 24bit

HOSAL_I2C_MEM_ADDR_SIZE_32BIT

i2c memory address size 32bit

HOSAL_I2C_ADDRESS_WIDTH_7BIT

7 bit mode

HOSAL_I2C_ADDRESS_WIDTH_10BIT

10 bit mode