Note

This is the documentation for the latest development branch and may refer to features that are not available in released versions. If you are looking for the documentation for a specific release, use the drop-down menu on the left and select the desired version.

I2C HAL Interface Documentation

Hardware Introduction

The K230 has a total of 5 I2C channels. The I2C module supports master and slave modes, supports 7/10-bit addressing, supports interrupts, and the I2C module transfer rates support 100k/400k/1M/3.4M.

---

Data Structure Description

drv_i2c_inst_t

Description: I2C master instance structure, containing I2C configuration and status information.

i2c_msg_t

Description: I2C message structure.

• addr: device address

• flags: transfer flags (read/write, 10-bit address, etc.)

• len: data length

• buf: data buffer pointer

drv_i2c_slave_inst_t

Description: I2C slave instance structure.

I2C Transfer Flags

• DRV_I2C_WR: write operation

• DRV_I2C_RD: read operation

• DRV_I2C_ADDR_10BIT: 10-bit address mode

• DRV_I2C_NO_START: do not send start signal

• DRV_I2C_IGNORE_NACK: ignore NACK

• DRV_I2C_NO_READ_ACK: do not send ACK during read

• DRV_I2C_NO_STOP: do not send stop signal

---

I2C Host Mode Interface

int drv_i2c_inst_create(int id, uint32_t freq, uint32_t timeout_ms, uint8_t scl, uint8_t sda, drv_i2c_inst_t** inst);

Function: Create an I2C host instance.

Parameters:

• id: I2C number, 0-4 for hardware I2C, greater than 4 for software I2C

• freq: I2C clock frequency (Hz)

• timeout_ms: Timeout duration (milliseconds)

• scl: SCL pin number (valid for software I2C, must be less than 64)

• sda: SDA pin number (valid for software I2C, must be less than 64)

• inst: Pointer used to store the created I2C instance pointer

Return Value:

• 0: Success

• -1: Failure

---

void drv_i2c_inst_destroy(drv_i2c_inst_t** inst);

Function: Destroy the I2C host instance and release resources.

Parameters:

• inst: Pointer to the I2C instance pointer

---

int drv_i2c_set_7b_addr(drv_i2c_inst_t* inst);

Function: Set I2C to 7-bit address mode.

Parameters:

• inst: I2C instance pointer

Return Value:

• 0: Success

• -1: Failure

---

int drv_i2c_set_10b_addr(drv_i2c_inst_t* inst);

Function: Set I2C to 10-bit address mode.

Parameters:

• inst: I2C instance pointer

Return Value:

• 0: Success

• -1: Failure

---

int drv_i2c_set_freq(drv_i2c_inst_t* inst, uint32_t freq);

Function: Set the I2C clock frequency.

Parameters:

• inst: I2C instance pointer

• freq: Clock frequency (Hz)

Return Value:

• 0: Success

• -1: Failure

---

int drv_i2c_set_timeout(drv_i2c_inst_t* inst, uint32_t timeout_ms);

Function: Set the I2C timeout duration.

Parameters:

• inst: I2C instance pointer

• timeout_ms: Timeout duration (milliseconds)

Return Value:

• 0: Success

• -1: Failure

---

int drv_i2c_transfer(drv_i2c_inst_t* inst, i2c_msg_t* msgs, int msg_cnt);

Function: Perform an I2C transfer operation.

Parameters:

• inst: I2C instance pointer

• msgs: Message array

• msg_cnt: Number of messages

Return Value:

• 0: Success

• -1: Failure

---

I2C Host Attribute Getter Functions

The following functions are used to retrieve various attributes of the I2C host instance:

• uint32_t drv_i2c_master_get_type(drv_i2c_inst_t* inst); - Get the I2C type (hardware/software)

• int drv_i2c_master_get_id(drv_i2c_inst_t* inst); - Get the I2C number

• int drv_i2c_master_get_fd(drv_i2c_inst_t* inst); - Get the file descriptor

• uint32_t drv_i2c_master_get_freq(drv_i2c_inst_t* inst); - Get the clock frequency

• uint32_t drv_i2c_master_get_timeout_ms(drv_i2c_inst_t* inst); - Get the timeout duration

• uint8_t drv_i2c_master_get_pin_scl(drv_i2c_inst_t* inst); - Get the SCL pin number

• uint8_t drv_i2c_master_get_pin_sda(drv_i2c_inst_t* inst); - Get the SDA pin number

---

I2C Slave Mode Interface

int drv_i2c_slave_inst_create(int id, uint32_t buffer_size, uint16_t slave_address, uint8_t scl, uint8_t sda, drv_i2c_slave_inst_t** inst);

Function: Creates an I2C slave instance.

Parameters:

• id: I2C number

• buffer_size: Buffer size

• slave_address: Slave address

• scl: SCL pin number

• sda: SDA pin number

• inst: Used to store the created slave instance pointer

Return Value:

• 0: Success

• -1: Failure

---

I2C Slave Attribute Getter Functions

• int drv_i2c_slave_get_id(drv_i2c_slave_inst_t* inst); - Get I2C number

• int drv_i2c_slave_get_fd(drv_i2c_slave_inst_t* inst); - Get file descriptor

• uint8_t drv_i2c_slave_get_pin_scl(drv_i2c_slave_inst_t* inst); - Get SCL pin number

• uint8_t drv_i2c_slave_get_pin_sda(drv_i2c_slave_inst_t* inst); - Get SDA pin number

• uint32_t drv_i2c_slave_get_buffer_size(drv_i2c_slave_inst_t* inst); - Get buffer size

• uint16_t drv_i2c_slave_get_slave_address(drv_i2c_slave_inst_t* inst); - Get slave address

---

Usage Example

Please refer to src/rtsmart/libs/testcases/rtsmart_hal/test_i2c_ssd1306.c

Notes:

1. Before using hardware I2C, the corresponding pin functions need to be configured through FPIOA