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ldc1612_cmake_vscode/Src/i2c.c
2025-09-26 09:02:37 +08:00

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//
// Created by dell on 24-12-20.
//
#include "i2c.h"
/*!
\brief configure the GPIO ports
\param[in] none
\param[out] none
\retval none
*/
void i2c_gpio_config(void) {
/* enable IIC GPIO clock */
rcu_periph_clock_enable(RCU_GPIO_I2C);
/* connect I2C_SCL_PIN to I2C_SCL */
gpio_af_set(I2C_SCL_PORT, I2C_GPIO_AF, I2C_SCL_PIN);
/* connect I2C_SDA_PIN to I2C_SDA */
gpio_af_set(I2C_SDA_PORT, I2C_GPIO_AF, I2C_SDA_PIN);
/* configure GPIO pins of I2C */
gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_AF, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
}
/*!
\brief configure the I2CX interface
\param[in] none
\param[out] none
\retval none
*/
i2c_result_t i2c_config(void) {
/* configure I2C GPIO */
i2c_gpio_config();
/* enable I2C clock */
rcu_periph_clock_enable(RCU_I2C);
/* configure I2C clock */
i2c_clock_config(I2C0, I2C_SPEED, I2C_DTCY_2);
/* configure I2C address */
i2c_mode_addr_config(I2C0, I2C_I2CMODE_ENABLE, I2C_ADDFORMAT_7BITS, 0xA0);
/* enable I2CX */
i2c_enable(I2C0);
/* enable acknowledge */
i2c_ack_config(I2C0, I2C_ACK_ENABLE);
return I2C_RESULT_SUCCESS;
}
/* wait for SCL to go high, return true if successful, false if timeout */
static bool i2c_wait_scl_high(uint16_t max_wait_time) {
while (max_wait_time--) {
if (gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN)) {
return true;
}
delay_10us(1);
}
return false;
}
/* generate one manual SCL pulse; return true if SCL observed high (no stuck/overstretch) */
static bool i2c_generate_scl_pulse(void) {
GPIO_BC(I2C_SCL_PORT) = I2C_SCL_PIN; /* drive SCL low */
delay_10us(1);
GPIO_BOP(I2C_SCL_PORT) = I2C_SCL_PIN; /* release SCL (open-drain -> high via pull-up) */
return i2c_wait_scl_high(200); /* wait up to ~2ms for clock stretching release */
}
/*!
\brief reset I2C bus
\param[in] none
\param[out] none
\retval none
*/
i2c_result_t i2c_bus_reset(void) {
/* 1. Disable & deinit peripheral so pins can be fully controlled */
i2c_disable(I2C0);
i2c_deinit(I2C0);
#ifdef DEBUG_VERBOSE
printf("I2C bus reset\r\n");
#endif
/* 2. Configure SCL/SDA as GPIO open-drain outputs with pull-up and release them */
gpio_mode_set(I2C_SCL_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SCL_PIN);
gpio_mode_set(I2C_SDA_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_PULLUP, I2C_SDA_PIN);
gpio_output_options_set(I2C_SCL_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SCL_PIN);
gpio_output_options_set(I2C_SDA_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_50MHZ, I2C_SDA_PIN);
gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN); /* release SCL */
gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN); /* release SDA */
#ifdef DEBUG_VERBOSE
printf("I2C bus reset: SCL = %d, SDA = %d\r\n", gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN), gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN));
#endif
/* 3. Double sample to confirm bus state */
delay_10us(1);
bool scl_value1 = gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN);
bool sda_value1 = gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN);
delay_10us(1);
bool scl_value2 = gpio_input_bit_get(I2C_SCL_PORT, I2C_SCL_PIN);
bool sda_value2 = gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN);
/* 4. If SCL low -> stuck (cannot proceed) */
if (!scl_value2) {
#ifdef DEBUG_VERBOSE
printf("I2C bus reset: SCL stuck low\r\n");
#endif
return I2C_RECOVERY_SCL_STUCK_LOW;
}
/* 5. Fast path: bus idle */
if (scl_value1 && sda_value1 && scl_value2 && sda_value2) {
i2c_config();
#ifdef DEBUG_VERBOSE
printf("I2C bus reset: bus idle\r\n");
#endif
return I2C_RECOVERY_OK;
}
/* 6. SDA low: attempt to free by generating up to I2C_RECOVERY_CLOCKS pulses */
if (scl_value2 && !sda_value2) {
bool sda_released = false;
#ifdef DEBUG_VERBOSE
printf("I2C bus reset: SCL will try to free SDA\r\n");
#endif
for (uint8_t i = 0; i < I2C_RECOVERY_CLOCKS && !sda_released; i++) {
if (!i2c_generate_scl_pulse()) {
return I2C_RECOVERY_SCL_STUCK_LOW; /* SCL failed to go high */
}
if (gpio_input_bit_get(I2C_SDA_PORT, I2C_SDA_PIN)) {
sda_released = true;
}
}
if (!sda_released) {
return I2C_RECOVERY_SDA_STUCK_LOW;
}
/* 7. Generate a STOP condition to leave bus in idle state */
#ifdef DEBUG_VERBOSE
printf("I2C bus reset: generating STOP condition\r\n");
#endif
gpio_bit_reset(I2C_SDA_PORT, I2C_SDA_PIN); /* SDA low */
delay_10us(1);
gpio_bit_set(I2C_SCL_PORT, I2C_SCL_PIN); /* ensure SCL high */
delay_10us(1);
gpio_bit_set(I2C_SDA_PORT, I2C_SDA_PIN); /* SDA rising while SCL high -> STOP */
delay_10us(1);
}
#ifdef DEBUG_VERBOSE
printf("I2C bus reset: bus recovered\r\n");
#endif
/* 8. Reconfigure & enable peripheral */
i2c_config();
return I2C_RECOVERY_OK;
}
/**
* @brief 扫描I2C总线查找连接的设备
*
* 该函数会扫描I2C总线上的所有地址1到126并尝试与每个地址进行通信。
* 如果在某个地址上发现了设备,则会打印出该设备的地址。
* 最后会打印出找到的设备总数。
*/
void i2c_scan(void) {
uint32_t timeout;
uint8_t address;
int found_devices = 0;
// printf("Scanning I2C bus...\r\n");
const char* msg1 = "Scanning I2C bus...\r\n";
for (uint8_t i = 0; msg1[i] != '\0'; i++) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, msg1[i]);
}
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
for (address = 1; address < 127; address++) {
timeout = 0;
// 生成起始条件
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT))
timeout++;
if (timeout >= I2C_TIME_OUT) {
continue; // 超时,跳过该地址
}
i2c_start_on_bus(I2C0);
timeout = 0;
// 等待起始条件发送完成
while (!i2c_flag_get(I2C0, I2C_FLAG_SBSEND) && (timeout < I2C_TIME_OUT))
timeout++;
if (timeout >= I2C_TIME_OUT) {
continue; // 超时,跳过该地址
}
i2c_master_addressing(I2C0, (address << 1), I2C_TRANSMITTER);
timeout = 0;
// 等待地址发送完成
while (!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND) && (timeout < I2C_TIME_OUT))
timeout++;
if (timeout < I2C_TIME_OUT) {
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
// printf("Found device at 0x%02X\r\n", address);
const char* msg2_prefix = "Found device at 0x";
for (uint8_t i = 0; msg2_prefix[i] != '\0'; i++) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, msg2_prefix[i]);
}
// 发送地址的十六进制表示
uint8_t hex_chars[] = "0123456789ABCDEF";
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, hex_chars[(address >> 4) & 0x0F]);
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, hex_chars[address & 0x0F]);
const char* msg2_suffix = "\r\n";
for (uint8_t i = 0; msg2_suffix[i] != '\0'; i++) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, msg2_suffix[i]);
}
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
found_devices++;
}
// 生成停止条件
i2c_stop_on_bus(I2C0);
timeout = 0;
while (i2c_flag_get(I2C0, I2C_FLAG_STPDET) && (timeout < I2C_TIME_OUT))
timeout++;
}
if (found_devices == 0) {
// printf("No I2C devices found.\r\n");
const char* msg3 = "No I2C devices found.\r\n";
for (uint8_t i = 0; msg3[i] != '\0'; i++) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, msg3[i]);
}
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
} else {
// printf("Total %d I2C devices found.\r\n", found_devices);
const char* msg4_prefix = "Total ";
for (uint8_t i = 0; msg4_prefix[i] != '\0'; i++) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, msg4_prefix[i]);
}
// 发送设备数量
if (found_devices >= 10) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, '0' + (found_devices / 10));
}
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, '0' + (found_devices % 10));
const char* msg4_suffix = " I2C devices found.\r\n";
for (uint8_t i = 0; msg4_suffix[i] != '\0'; i++) {
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TBE) == RESET) {}
usart_data_transmit(I2C_DEBUG_UART, msg4_suffix[i]);
}
while (usart_flag_get(I2C_DEBUG_UART, USART_FLAG_TC) == RESET) {}
}
}
i2c_result_t i2c_write_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t data[2]) {
i2c_state_t state = I2C_STATE_START;
uint16_t timeout = 0;
uint8_t retry_count = 0;
/* parameter validation */
if (data == NULL || slave_addr > 0x7F) {
return I2C_RESULT_INVALID_PARAM;
}
while (retry_count < I2C_MAX_RETRY) {
switch (state) {
case I2C_STATE_START:
timeout = 0;
/* wait for bus to be idle */
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
i2c_start_on_bus(I2C0);
timeout = 0;
state = I2C_STATE_SEND_ADDRESS;
break;
case I2C_STATE_SEND_ADDRESS:
/* wait for start condition to be sent. SBSEND flag */
while((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send slave address */
i2c_master_addressing(I2C0, slave_addr << 1, I2C_TRANSMITTER);
timeout = 0;
state = I2C_STATE_CLEAR_ADDRESS;
break;
case I2C_STATE_CLEAR_ADDRESS:
/* wait for address to be acknowledged.ADDSEND set means i2c slave sends ACK */
while ((!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND)) && (!i2c_flag_get(I2C0, I2C_FLAG_AERR)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
} else if (i2c_flag_get(I2C0, I2C_FLAG_ADDSEND))
{
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
timeout =0;
state = I2C_STATE_TRANSMIT_REG;
break;
} else {
i2c_flag_clear(I2C0, I2C_FLAG_AERR);
timeout =0;
#ifdef DEBUG_VERBOES
printf("IIC write failed for Error Slave Address. \n");
#endif
return I2C_RESULT_NACK;
}
case I2C_STATE_TRANSMIT_REG:
/* wait until the transmit data buffer is empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send register address */
i2c_data_transmit(I2C0, reg_addr);
timeout = 0;
state = I2C_STATE_TRANSMIT_DATA;
break;
case I2C_STATE_TRANSMIT_DATA:
/* wait until the transmit data buffer is empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send register MSB value */
i2c_data_transmit(I2C0, data[0]);
timeout = 0;
/* wait until the transmit data buffer is empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
if (i2c_flag_get(I2C0, I2C_FLAG_AERR)) {
i2c_stop_on_bus(I2C0);
return I2C_RESULT_NACK;
} else if (i2c_flag_get(I2C0, I2C_FLAG_BERR) || i2c_flag_get(I2C0, I2C_FLAG_LOSTARB)) {
// 可按需清标志
i2c_stop_on_bus(I2C0);
return I2C_RESULT_ERROR;
}
/* send register LSB value */
i2c_data_transmit(I2C0, data[1]);
timeout = 0;
/* wait until BTC bit is set */
while (!i2c_flag_get(I2C0, I2C_FLAG_BTC) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
state = I2C_STATE_STOP;
break;
case I2C_STATE_STOP:
/* send a stop condition to I2C bus */
i2c_stop_on_bus(I2C0);
timeout = 0;
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* i2c master sends STOP signal successfully */
/* success */
return I2C_RESULT_SUCCESS;
case I2C_STATE_ERROR:
/* send a stop condition to I2C bus */
i2c_stop_on_bus(I2C0);
timeout = 0;
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
return I2C_RESULT_ERROR;
}
i2c_flag_clear(I2C0, I2C_FLAG_AERR);
i2c_flag_clear(I2C0, I2C_FLAG_BERR);
i2c_flag_clear(I2C0, I2C_FLAG_LOSTARB);
retry_count ++;
if (retry_count >= I2C_MAX_RETRY)
{
#ifdef DEBUG_VERBOES
printf("IIC write failed after %d retries\n", I2C_MAX_RETRY);
#endif
return I2C_RESULT_ERROR;
}
/* reset state machine for retry */
state = I2C_STATE_START;
timeout = 0;
/* small delay before retry */
delay_10us(10);
break;
default:
state = I2C_STATE_START;
break;
}
}
return I2C_RESULT_TIMEOUT;
}
i2c_result_t i2c_read_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data) {
i2c_state_t state = I2C_STATE_START;
uint16_t timeout = 0;
uint8_t retry_count = 0;
bool write_phase = true;
// 参数检查:防止空指针和非法地址
if (data == NULL || slave_addr > 0x7F) {
return I2C_RESULT_INVALID_PARAM;
}
/* enable acknowledge */
i2c_ack_config(I2C0, I2C_ACK_ENABLE);
while (retry_count < (uint8_t)I2C_MAX_RETRY) {
switch (state) {
case I2C_STATE_START:
timeout = 0;
// wait for bus to be idle
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
// send start condition
i2c_start_on_bus(I2C0);
state = I2C_STATE_SEND_ADDRESS;
timeout = 0;
break;
case I2C_STATE_SEND_ADDRESS:
/* wait for start condition to be sent */
while ((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
// send slave address
if (write_phase) {
/* write phase: send address with write bit */
i2c_master_addressing(I2C0, (slave_addr << 1), I2C_TRANSMITTER);
} else {
/* read phase: send address with read bit */
i2c_master_addressing(I2C0, (slave_addr << 1) | 0x01, I2C_RECEIVER);
}
state = I2C_STATE_CLEAR_ADDRESS;
timeout = 0;
break;
case I2C_STATE_CLEAR_ADDRESS:
/* wait for address to be acknowledged */
while ((!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
if (write_phase) {
/* clear address flag (write phase) */
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
state = I2C_STATE_TRANSMIT_DATA;
} else {
/* READ phase for 2 bytes: set POS=NEXT and disable ACK BEFORE clearing ADDR */
i2c_ackpos_config(I2C0, I2C_ACKPOS_NEXT);
i2c_ack_config(I2C0, I2C_ACK_DISABLE);
/* now clear address flag to release SCL and enter data phase */
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
state = I2C_STATE_RECEIVE_DATA;
}
timeout = 0;
break;
case I2C_STATE_TRANSMIT_DATA:
/* wait for transmit buffer to be empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send register address */
i2c_data_transmit(I2C0, reg_addr);
state = I2C_STATE_RESTART;
timeout = 0;
break;
case I2C_STATE_RESTART:
/* wait for byte transfer complete BTC: Bit Transfer Complete */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* generate repeated start condition */
i2c_start_on_bus(I2C0);
/* wait for repeated start condition to be sent */
timeout = 0;
while ((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send slave address with read bit (R/W bit is set by library) */
i2c_master_addressing(I2C0, (slave_addr << 1), I2C_RECEIVER);
/* switch to read phase */
write_phase = false;
state = I2C_STATE_CLEAR_ADDRESS;
timeout = 0;
break;
case I2C_STATE_RECEIVE_DATA:
/* Wait for BTC (both bytes received) */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* Send STOP before reading the last two bytes */
i2c_stop_on_bus(I2C0);
/* Read the two bytes back-to-back */
data[0] = i2c_data_receive(I2C0);
data[1] = i2c_data_receive(I2C0);
state = I2C_STATE_STOP;
break;
case I2C_STATE_STOP:
/* wait for stop condition to complete */
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* i2c master sends STOP signal successfully */
/* success */
return I2C_RESULT_SUCCESS;
case I2C_STATE_ERROR:
/* send stop condition to release bus */
i2c_stop_on_bus(I2C0);
retry_count++;
if (retry_count >= I2C_MAX_RETRY) {
#ifdef DEBUG_VERBOES
printf("IIC read failed after %d retries\n", I2C_RETRY_MAX);
#endif
return I2C_RESULT_ERROR;
}
/* reset state machine for retry */
state = I2C_STATE_START;
write_phase = true;
timeout = 0;
/* small delay before retry */
delay_10us(10);
break;
default:
state = I2C_STATE_START;
break;
}
}
return I2C_RESULT_TIMEOUT;
}
/*!
\brief write data to I2C device with configurable length
\param[in] slave_addr: slave device address (7-bit)
\param[in] reg_addr: register address
\param[in] data: pointer to data buffer
\param[in] length: number of bytes to write (1-255)
\param[out] none
\retval i2c_result_t: operation result
*/
i2c_result_t i2c_write(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data, uint8_t length) {
i2c_state_t state = I2C_STATE_START;
uint16_t timeout = 0;
uint8_t retry_count = 0;
uint8_t data_index = 0;
/* parameter validation */
if (data == NULL || slave_addr > 0x7F || length == 0) {
return I2C_RESULT_INVALID_PARAM;
}
while (retry_count < I2C_MAX_RETRY) {
switch (state) {
case I2C_STATE_START:
timeout = 0;
data_index = 0;
/* wait for bus to be idle */
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
i2c_start_on_bus(I2C0);
timeout = 0;
state = I2C_STATE_SEND_ADDRESS;
break;
case I2C_STATE_SEND_ADDRESS:
/* wait for start condition to be sent. SBSEND flag */
while((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send slave address */
i2c_master_addressing(I2C0, slave_addr << 1, I2C_TRANSMITTER);
timeout = 0;
state = I2C_STATE_CLEAR_ADDRESS;
break;
case I2C_STATE_CLEAR_ADDRESS:
/* wait for address to be acknowledged.ADDSEND set means i2c slave sends ACK */
while ((!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND)) && (!i2c_flag_get(I2C0, I2C_FLAG_AERR)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
} else if (i2c_flag_get(I2C0, I2C_FLAG_ADDSEND)) {
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
timeout = 0;
state = I2C_STATE_TRANSMIT_REG;
break;
} else {
i2c_flag_clear(I2C0, I2C_FLAG_AERR);
timeout = 0;
#ifdef DEBUG_VERBOSE
printf("IIC write failed for Error Slave Address. \n");
#endif
return I2C_RESULT_NACK;
}
case I2C_STATE_TRANSMIT_REG:
/* wait until the transmit data buffer is empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send register address */
i2c_data_transmit(I2C0, reg_addr);
timeout = 0;
state = I2C_STATE_TRANSMIT_DATA;
break;
case I2C_STATE_TRANSMIT_DATA:
/* wait until the transmit data buffer is empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send data byte */
i2c_data_transmit(I2C0, data[data_index]);
data_index++;
/* check for errors */
if (i2c_flag_get(I2C0, I2C_FLAG_AERR)) {
i2c_stop_on_bus(I2C0);
return I2C_RESULT_NACK;
} else if (i2c_flag_get(I2C0, I2C_FLAG_BERR) || i2c_flag_get(I2C0, I2C_FLAG_LOSTARB)) {
i2c_stop_on_bus(I2C0);
return I2C_RESULT_ERROR;
}
/* check if all data has been sent */
if (data_index >= length) {
/* wait until BTC bit is set for last byte */
timeout = 0;
while (!i2c_flag_get(I2C0, I2C_FLAG_BTC) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
state = I2C_STATE_STOP;
}
timeout = 0;
break;
case I2C_STATE_STOP:
/* send a stop condition to I2C bus */
i2c_stop_on_bus(I2C0);
timeout = 0;
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* success */
return I2C_RESULT_SUCCESS;
case I2C_STATE_ERROR:
/* send a stop condition to I2C bus */
i2c_stop_on_bus(I2C0);
timeout = 0;
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
i2c_flag_clear(I2C0, I2C_FLAG_AERR);
i2c_flag_clear(I2C0, I2C_FLAG_BERR);
i2c_flag_clear(I2C0, I2C_FLAG_LOSTARB);
retry_count++;
if (retry_count >= I2C_MAX_RETRY) {
#ifdef DEBUG_VERBOSE
printf("IIC write failed after %d retries\n", I2C_MAX_RETRY);
#endif
return I2C_RESULT_ERROR;
}
/* reset state machine for retry */
state = I2C_STATE_START;
timeout = 0;
/* small delay before retry */
delay_10us(10);
break;
default:
state = I2C_STATE_START;
break;
}
}
return I2C_RESULT_TIMEOUT;
}
/*!
\brief read data from I2C device with configurable length
\param[in] slave_addr: slave device address (7-bit)
\param[in] reg_addr: register address
\param[out] data: pointer to data buffer
\param[in] length: number of bytes to read (1-255)
\retval i2c_result_t: operation result
*/
i2c_result_t i2c_read(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data, uint8_t length) {
i2c_state_t state = I2C_STATE_START;
uint16_t timeout = 0;
uint8_t retry_count = 0;
bool write_phase = true;
uint8_t data_index = 0;
/* parameter validation */
if (data == NULL || slave_addr > 0x7F || length == 0) {
return I2C_RESULT_INVALID_PARAM;
}
/* enable acknowledge */
i2c_ack_config(I2C0, I2C_ACK_ENABLE);
while (retry_count < (uint8_t)I2C_MAX_RETRY) {
switch (state) {
case I2C_STATE_START:
timeout = 0;
data_index = 0;
/* wait for bus to be idle */
while (i2c_flag_get(I2C0, I2C_FLAG_I2CBSY) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send start condition */
i2c_start_on_bus(I2C0);
state = I2C_STATE_SEND_ADDRESS;
timeout = 0;
break;
case I2C_STATE_SEND_ADDRESS:
/* wait for start condition to be sent */
while ((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send slave address */
if (write_phase) {
/* write phase: send address with write bit */
i2c_master_addressing(I2C0, (slave_addr << 1), I2C_TRANSMITTER);
} else {
/* read phase: send address with read bit */
i2c_master_addressing(I2C0, (slave_addr << 1) | 0x01, I2C_RECEIVER);
}
state = I2C_STATE_CLEAR_ADDRESS;
timeout = 0;
break;
case I2C_STATE_CLEAR_ADDRESS:
/* wait for address to be acknowledged */
while ((!i2c_flag_get(I2C0, I2C_FLAG_ADDSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
if (write_phase) {
/* clear address flag (write phase) */
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
state = I2C_STATE_TRANSMIT_DATA;
} else {
/* read phase setup based on length */
if (length == 1) {
/* single byte read: disable ACK before clearing ADDR */
i2c_ack_config(I2C0, I2C_ACK_DISABLE);
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
/* send STOP immediately after clearing ADDR for single byte */
i2c_stop_on_bus(I2C0);
} else if (length == 2) {
/* two bytes read: set POS=NEXT and disable ACK before clearing ADDR */
i2c_ackpos_config(I2C0, I2C_ACKPOS_NEXT);
i2c_ack_config(I2C0, I2C_ACK_DISABLE);
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
} else {
/* multi-byte read: clear ADDR with ACK enabled */
i2c_flag_clear(I2C0, I2C_FLAG_ADDSEND);
}
state = I2C_STATE_RECEIVE_DATA;
}
timeout = 0;
break;
case I2C_STATE_TRANSMIT_DATA:
/* wait for transmit buffer to be empty */
while ((!i2c_flag_get(I2C0, I2C_FLAG_TBE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send register address */
i2c_data_transmit(I2C0, reg_addr);
state = I2C_STATE_RESTART;
timeout = 0;
break;
case I2C_STATE_RESTART:
/* wait for byte transfer complete */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* generate repeated start condition */
i2c_start_on_bus(I2C0);
/* wait for repeated start condition to be sent */
timeout = 0;
while ((!i2c_flag_get(I2C0, I2C_FLAG_SBSEND)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send slave address with read bit */
i2c_master_addressing(I2C0, (slave_addr << 1), I2C_RECEIVER);
/* switch to read phase */
write_phase = false;
state = I2C_STATE_CLEAR_ADDRESS;
timeout = 0;
break;
case I2C_STATE_RECEIVE_DATA:
if (length == 1) {
/* single byte read */
while ((!i2c_flag_get(I2C0, I2C_FLAG_RBNE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
data[0] = i2c_data_receive(I2C0);
state = I2C_STATE_STOP;
} else if (length == 2) {
/* two bytes read */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* send STOP before reading the last two bytes */
i2c_stop_on_bus(I2C0);
/* read the two bytes back-to-back */
data[0] = i2c_data_receive(I2C0);
data[1] = i2c_data_receive(I2C0);
state = I2C_STATE_STOP;
} else {
/* multi-byte read (length > 2) */
while (data_index < length) {
/* wait for RBNE (receive buffer not empty) */
while ((!i2c_flag_get(I2C0, I2C_FLAG_RBNE)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* special handling for last 3 bytes */
if (data_index == length - 3) {
/* wait for BTF (byte transfer finished) before reading N-2 */
while ((!i2c_flag_get(I2C0, I2C_FLAG_BTC)) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* disable ACK for last 2 bytes */
i2c_ack_config(I2C0, I2C_ACK_DISABLE);
}
/* read data byte */
data[data_index] = i2c_data_receive(I2C0);
data_index++;
/* send STOP after reading N-1 byte */
if (data_index == length - 1) {
i2c_stop_on_bus(I2C0);
}
timeout = 0;
}
state = I2C_STATE_STOP;
}
break;
case I2C_STATE_STOP:
/* wait for stop condition to complete */
while ((I2C_CTL0(I2C0) & I2C_CTL0_STOP) && (timeout < I2C_TIME_OUT)) {
timeout++;
}
if (timeout >= I2C_TIME_OUT) {
state = I2C_STATE_ERROR;
break;
}
/* reset ACK configuration for next operation */
i2c_ack_config(I2C0, I2C_ACK_ENABLE);
i2c_ackpos_config(I2C0, I2C_ACKPOS_CURRENT);
/* success */
return I2C_RESULT_SUCCESS;
case I2C_STATE_ERROR:
/* send stop condition to release bus */
i2c_stop_on_bus(I2C0);
/* reset ACK configuration */
i2c_ack_config(I2C0, I2C_ACK_ENABLE);
i2c_ackpos_config(I2C0, I2C_ACKPOS_CURRENT);
retry_count++;
if (retry_count >= I2C_MAX_RETRY) {
#ifdef DEBUG_VERBOSE
printf("I2C read failed after %d retries\n", I2C_MAX_RETRY);
#endif
return I2C_RESULT_ERROR;
}
/* reset state machine for retry */
state = I2C_STATE_START;
write_phase = true;
timeout = 0;
/* small delay before retry */
delay_10us(10);
break;
default:
state = I2C_STATE_START;
break;
}
}
return I2C_RESULT_TIMEOUT;
}
/* convenience functions for common operations */
i2c_result_t i2c_write_8bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t data) {
return i2c_write(slave_addr, reg_addr, &data, 1);
}
i2c_result_t i2c_read_8bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data) {
return i2c_read(slave_addr, reg_addr, data, 1);
}
i2c_result_t i2c_write_32bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t data[4]) {
return i2c_write(slave_addr, reg_addr, data, 4);
}
i2c_result_t i2c_read_32bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data) {
return i2c_read(slave_addr, reg_addr, data, 4);
}
/* 显示面板专用函数 - 支持读取显示界面参数 */
i2c_result_t i2c_read_display_params(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data, uint8_t length) {
/* 针对显示面板的多字节读取支持13字节的完整参数读取 */
if (length > 13) {
return I2C_RESULT_INVALID_PARAM;
}
return i2c_read(slave_addr, reg_addr, data, length);
}
#ifdef DEBUG_VERBOSE
/*!
\brief get status string for debugging
\param[in] status: i2c_status_t value
\param[out] none
\retval const char* status string
*/
const char* i2c_get_status_string(i2c_result_t status) {
switch (status) {
case I2C_RESULT_SUCCESS:
return "SUCCESS";
case I2C_RESULT_TIMEOUT:
return "TIMEOUT";
case I2C_RESULT_NACK:
return "NACK";
case I2C_RESULT_BUS_BUSY:
return "BUS_BUSY";
case I2C_RESULT_ERROR:
return "ERROR";
case I2C_RESULT_INVALID_PARAM:
return "INVALID_PARAM";
default:
return "UNKNOWN";
}
}
#endif