I2C API指南¶
I2C API¶
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。
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¶
structhosal_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
structhosal_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