为什么i2c_smbus函数不可用？(I2C -嵌入式Linux)

#include <stdio.h>
#include <stdlib.h>
#include <linux/i2c-dev.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>

int main() {
    int file;
    char filename[20];
    int adapter_nr = 1; /* 或者根据实际情况修改 */
    snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
    file = open(filename, O_RDWR);
    if (file < 0) {
        perror("Error opening I2C bus");
        return 1;
    }

    if (ioctl(file, I2C_SLAVE, 0x50) < 0) { /* 0x50 是I2C设备的地址 */
        perror("Error setting I2C device address");
        return 1;
    }

    // 写操作
    if (i2c_smbus_write_byte_data(file, 0x01, 0xAA) < 0) {
        perror("Error writing to I2C device");
    }

    // 读操作
    int val = i2c_smbus_read_byte_data(file, 0x01);
    if (val < 0) {
        perror("Error reading from I2C device");
    } else {
        printf("Read value: 0x%02X\n", val);
    }

    close(file);
    return 0;
}