s3c2410.c

一个经典的串口调试程序

/*
		文件名：S3C2410串口1调试.c
		编写  ：bingnan
		时间  ：写串口操作初次便测试成功，读测试由于在PC利用串口工具发
		        送数据时未加'\n'，直到2006-05-19日测试成功
		功能  ：测试S3C2410串口1的读操作和写操作，包括串口参数设置函数
		说明  ：串口读写操作时，读写函数在遇到'\n'时才返回，因此务必在
		        写串口时，在单位数据后加上回车换行符
		使用  ：编译命令：arm-linux-gcc comtest.c -o comtest
		        写操作运行：./comtest write
		        读操作运行：./comtest read
*/
#include <unistd.h> 
#include <fcntl.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#define TRUE  1
#define FALSE 0
int speed_arr[] = { B921600, B460800, B230400, B115200, B57600,  
	                  B38400, B19200, B9600, B4800, B2400, B1200, B300, B110};
int  name_arr[] = {921600  ,460800  ,230400  ,115200,  57600,  
	                 38400,  19200,  9600, 4800, 2400, 1200,  300, 110};

/**********************************************************************
*		function :	the com param set
***********************************************************************/
void set_speed(int fd, int speed)
{
	int   i;
	int   status;
	struct termios   Opt;
	tcgetattr(fd, &Opt);
	for( i= 0;  i < sizeof(speed_arr) / sizeof(int);  i++)
	{
	if(speed == name_arr[i])
	{
		tcflush(fd, TCIOFLUSH);
		cfsetispeed(&Opt, speed_arr[i]);
		cfsetospeed(&Opt, speed_arr[i]);
		status = tcsetattr(fd, TCSANOW, &Opt);
		if  (status != 0)
		perror("tcsetattr fd1");
		return;
	}
	tcflush(fd,TCIOFLUSH);
	}
}
/**********************************************************************
*		stop data verify
***********************************************************************/
int set_Parity(int fd,int databits,int stopbits,int parity)
{
	struct termios options;
	if( tcgetattr( fd,&options) !=  0)
	{
		perror("SetupSerial 1");
		return(FALSE);
	}
	options.c_cflag &= ~CSIZE;
	switch (databits)
	{
		case 7:
			options.c_cflag |= CS7;
			break;
		case 8:
			options.c_cflag |= CS8;
			break;
		default:
			fprintf(stderr,"Unsupported data size\n");
			return (FALSE);
	}
	switch (parity)
	{
		case 'n':
		case 'N':
			options.c_cflag &= ~PARENB;    /* Clear parity enable */
			options.c_iflag &= ~INPCK;     /* Enable parity checking */
			break;
		case 'o':
		case 'O':
			options.c_cflag |= (PARODD | PARENB);  /* ????Ч?*/
			options.c_iflag |= INPCK;              /* Disnable parity checking */
			break;
		case 'e':
		case 'E':
			options.c_cflag |= PARENB;      /* Enable parity */
			options.c_cflag &= ~PARODD;     /* ?????Ч?*/
			options.c_iflag |= INPCK;       /* Disnable parity checking */
			break;
		case 'S':
		case 's':  /*as no parity*/
			options.c_cflag &= ~PARENB;
			options.c_cflag &= ~CSTOPB;
			break;
		default:
			fprintf(stderr,"Unsupported parity\n");
			return (FALSE);
		}
	/* ????λ*/
	switch (stopbits)
	{
		case 1:
			options.c_cflag &= ~CSTOPB;
			break;
		case 2:
			options.c_cflag |= CSTOPB;
			break;
		default:
			fprintf(stderr,"Unsupported stop bits\n");
			return (FALSE);
	}
	/* Set input parity option */
	if (parity != 'n')
	options.c_iflag |= INPCK;
	options.c_cc[VTIME] = 150; // 15 seconds
	options.c_cc[VMIN] = 0;
	
	tcflush(fd,TCIFLUSH); /* Update the options and do it NOW */
	if (tcsetattr(fd,TCSANOW,&options) != 0)
	{
		perror("SetupSerial 3");
		return (FALSE);
	}
	return (TRUE);
}

int main(int argc,char *argv[])
{
	int loop = 0;
	char buff[1024];
	int fd;
	int nread;
	char *dev = "/dev/ttyS1";
	if(argc != 2)
	{
		printf("parameter error\n");
		return -1;
	}
	fd = open(dev,O_RDWR);// | O_NONBLOCK
	if(fd == -1)
	{
		printf("/dev/ttyS1 open error\n");
		return -1;
	}
	printf("device is opened\n");
	set_speed(fd,19200);
	printf("set the device baude rate\n");
	if(set_Parity(fd,8,1,'N') == FALSE)
	printf("set the /dev/ttyS1 attr error\n");
	if(!strcmp(argv[1],"read"))
	{
		printf("dev/tty1 read test\n");
		while(loop < 1000)
		{
			loop ++;
			//当读到换行符后read函数返回
			if((nread = read(fd,buff,1024))>0)
			{
					buff[nread] = '\0';
	        printf("%s\n",buff);
	    }
      //usleep(100000);
		}
	}
	else if(!strcmp(argv[1],"write"))
	{
		printf("dev/ttys1 write test\n");
		while(loop < 1000)
		{
			loop ++;
			sprintf(buff,"write %d times\n",loop);
      printf(buff);
			write(fd,buff,16);
      usleep(100000);
		}
	}
	else
	{
		printf("the second paramter is wrong\n");
	}
  return 0;	
}