Linux串口的编程，过程也是配置像停止位、奇偶校验位、波特率和数据位。像打开文件一样打开串口设备，然后配置上面说的几个参数。串口的写用标准的Linux系统调用write，读用read。其中还有一些配置，在代码中在详细阐述，下面直接贴代码：
首先用一个serial.cfg的配置文件来指定串口的参数，后面就直接更改配置文件来修改参数。我们把这个配置文件放置在/etc/下面
DEV=/dev/tq2440_serial2
SPEED=115200
DATABITS=8
STOPBITS=1
PARITY=N
这里的设备文件用已经有的串口驱动生成的设备节点。
定义头文件Serial.h，定义表征串口的结构体
#ifndef SERIAL_PORT_H
#define SERIAL_PORT_H
#define TRUE 1
#define FALSE 0
#define z_U32 unsigned int
#define z_U8 unsigned char
#define SERIAL_NAME_LEN 32
extern int serial_config();
extern int set_speed(int fd);
extern int set_other_parm(int fd);
typedef struct z_Serial_port {
z_U8 serial_name[SERIAL_NAME_LEN];
z_U32 serial_baud;
z_U8 data_bits;
z_U8 stop_bits;
z_U8 parity;
}HI_Serial_port;
extern z_Serial_port get_current_serial();
#endif
接下来当然是serial.c文件咯，实现串口的各个参数的设置
/*
** author: z
** CopyRight: z
** funtion: serial port Interface
** Date: 2014
*/
#include <stdio.h> /**/
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "pthread.h"
#include "serial_port.h"
#define CFG_FILE "/etc/serial.cfg"//放置配置文件的地方
#define DEBUG 1
#define ERROR -1
#define OK 1
/*Serial Port Struct*/
z_Serial_port serial_port ;
int speed_array[] = {B230400, B115200, B57600, B38400, B19200, B9600, B4800,
B2400, B1200, B300, B38400, B19200, B9600, B4800,
B2400, B1200, B300};
int name_array[] = {230400, 115200, 57600, 38400, 19200, 9600, 4800,
2400, 1200, 300, 38400, 19200, 9600, 4800,
2400, 1200, 300};
//得到当前的串口结构体
z_Serial_port get_current_serial(){
z_Serial_port current_serial;
memset(current_serial.serial_name, 0, sizeof(current_serial.serial_name));
strncpy(current_serial.serial_name, serial_port.serial_name, sizeof(current_serial.serial_name));
current_serial.serial_baud = serial_port.serial_baud;
current_serial.data_bits = serial_port.data_bits;
current_serial.stop_bits = serial_port.stop_bits;
current_serial.parity = serial_port.parity;
if(DEBUG){
printf("current_serial.serial_baud = %d\n", current_serial.serial_baud);
printf("current_serial.data_bits = %d\n" , current_serial.data_bits);
printf("current_serial.stop_bits = %d\n", current_serial.stop_bits);
printf("current_serial.parity = %c\n", current_serial.parity);
}
return current_serial;
}
//读取串口的配置文件，并将配置填充到结构体
int serial_config()
{
FILE *serial_fp;
char read_buf[20] = {0};
char temp[20];
char parity;
/*read serial config from file*/
serial_fp = fopen(CFG_FILE, "r");
if(serial_fp == NULL){
printf("Can't open serial config file\n");
return ERROR;
}
memset(serial_port.serial_name, 0 ,sizeof(serial_port.serial_name));
fscanf(serial_fp, "DEV=%s\n", serial_port.serial_name);
fscanf(serial_fp, "SPEED=%s\n", temp);
serial_port.serial_baud = atoi(temp);
fscanf(serial_fp, "DATABITS=%s\n", temp);
serial_port.data_bits = atoi(temp);
fscanf(serial_fp, "STOPBITS=%s\n", temp);
serial_port.stop_bits = atoi(temp);
fscanf(serial_fp, "PARITY=%s\n", temp);
serial_port.parity = temp[0];
if(DEBUG){
printf(" Serial Dev = %s\n", serial_port.serial_name);
printf(" Serial Speed = %d\n", serial_port.serial_baud);
printf(" Serial DataBits = %d\n", serial_port.data_bits);
printf(" Serial StopBite = %d\n ", serial_port.stop_bits);
printf(" Serial Parity = %c\n", serial_port.parity);
}
fclose(serial_fp);
return OK;
}