添加IIC多字节读写,以应对不同环境

This commit is contained in:
2025-08-25 09:43:20 +08:00
parent 233576fd9a
commit 75ea93cd53
3 changed files with 1064 additions and 0 deletions

975
Src/iic_new.c Normal file
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@@ -0,0 +1,975 @@
// ...existing code...
/*!
\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 (only if not already sent) */
if (length > 2) {
/* for multi-byte reads, STOP was already sent */
/* just wait for the STOP bit to clear */
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;
}
/* compatibility functions for legacy code */
i2c_result_t i2c_write_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t data[2]) {
return i2c_write(slave_addr, reg_addr, data, 2);
}
i2c_result_t i2c_read_16bits(uint8_t slave_addr, uint8_t reg_addr, uint8_t *data) {
return i2c_read(slave_addr, reg_addr, data, 2);
}
/* 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);
}
// ...existing code...
// ...existing code...
/*!
\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);
}
// ...existing code...