tty.c

该段代码实现了在arm2410的平台下使用gprs模块实现收发短消息

/************************************************
 *  TTY SERIAL ROUTES 
 *  use ttyS1 to ctrol GPRS
 *  by Zou jian guo <[e-mail]>   
 *  2004-11-02
 *  
 *  edited by wbin <[e-mail]>
 *  2005-01-19
 *  
*************************************************/
//#include <termios.h>
//#include <stdio.h>
//#include <unistd.h>
//#include <fcntl.h>
//#include <sys/signal.h>
//#include <pthread.h>
//#include "tty.h"

#include <sys/types.h>                                                  
#include <sys/stat.h>                                                      
#include <fcntl.h>                                                       
#include <termios.h>                                                    
#include <stdio.h>    

#define BAUDRATE B19200
#define COM1 "/dev/ttyS0"
#define COM2 "/dev/ttyS2"

static int fd;
static struct termios oldtio,newtio;

//==============================================================
int tty_end()
{
  	tcsetattr(fd,TCSANOW,&oldtio);	 	/* restore old modem setings */
//  	tcsetattr(0,TCSANOW,&oldstdtio); 	/* restore old tty setings */
  	close(fd);
}
//==============================================================
/*static void do_exit()
{
	tty_end();
	exit(1);
}*/
//==============================================================
int tty_read(char *buf,int nbytes)
{
	return read(fd,buf,nbytes);
}
//==============================================================
int tty_write(char *buf,int nbytes)
{
	int i;
	for(i=0; i<nbytes; i++) {
		write(fd,&buf[i],1);
		usleep(100);
	}
	return tcdrain(fd);
}

//==============================================================
int tty_writecmd(char *buf,int nbytes)
{
	int i;
	for(i=0; i<nbytes; i++) {
		write(fd,&buf[i],1);
		usleep(100);
	}
	write(fd,"\r",1);
	usleep(300000);
	return tcdrain(fd);
}

//==============================================================
/*int tty_writebyte(char *buf)
{
	write(fd,&buf[0],1);
	usleep(10);
//	write(fd,buf,nbytes);
	return tcdrain(fd);
}*/
//==============================================================
int tty_init()
{
	fd = open(COM2, O_RDWR ); //| O_NONBLOCK);//
	if (fd <0) {
	    	perror(COM2);
	    	exit(-1);
  	}
	
//  	tcgetattr(0,&oldstdtio);
  	tcgetattr(fd,&oldtio); /* save current modem settings */
//  	tcgetattr(fd,&newstdtio); /* get working stdtio */
	bzero(&newtio, sizeof(newtio)); 

//	newtio.c_cflag = oldstdtio.c_cflag;
//	newtio.c_iflag = oldstdtio.c_iflag;
//	newtio.c_oflag = oldstdtio.c_oflag;
// 	newtio.c_lflag = oldstdtio.c_lflag;

	newtio.c_cflag = BAUDRATE | /*CRTSCTS |*/ CS8 /*| CLOCAL | CREAD */;
	newtio.c_iflag = IGNPAR | ICRNL; 
	newtio.c_oflag = 0; 
	newtio.c_lflag = ICANON;

	 newtio.c_cc[VINTR]    = 0;     /* Ctrl-c */  
	 newtio.c_cc[VQUIT]    = 0;     /* Ctrl-\ */ 
	 newtio.c_cc[VERASE]   = 0;     /* del */ 
	 newtio.c_cc[VKILL]    = 0;     /* @ */ 
	 newtio.c_cc[VEOF]     = 4;     /* Ctrl-d */ 
	 newtio.c_cc[VTIME]    = 0;     /* 不使用分割字元组的计时器 */ 
	 newtio.c_cc[VMIN]     = 1;     /* 在读取到 1 个字元前先停止 */ 
	 newtio.c_cc[VSWTC]    = 0;     /* '\0' */ 
	 newtio.c_cc[VSTART]   = 0;     /* Ctrl-q */  
	 newtio.c_cc[VSTOP]    = 0;     /* Ctrl-s */ 
	 newtio.c_cc[VSUSP]    = 0;     /* Ctrl-z */ 
	 newtio.c_cc[VEOL]     = 0;     /* '\0' */ 
	 newtio.c_cc[VREPRINT] = 0;     /* Ctrl-r */ 
	 newtio.c_cc[VDISCARD] = 0;     /* Ctrl-u */ 
	 newtio.c_cc[VWERASE]  = 0;     /* Ctrl-w */ 
	 newtio.c_cc[VLNEXT]   = 0;     /* Ctrl-v */ 
	 newtio.c_cc[VEOL2]    = 0;     /* '\0' */ 


//	newtio.c_lflag  &= ~(ICANON | ECHO | ECHOE | ISIG);  /*Input*/
//	newtio.c_oflag  &= ~OPOST;   /*Output*/
 	tcflush(fd, TCIFLUSH);
	tcsetattr(fd,TCSANOW,&newtio);/*set attrib	  */

#if 0	
	newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;/*ctrol flag*/
	newtio.c_iflag = IGNPAR; /*input flag*/
	newtio.c_oflag = 0;		/*output flag*/
 	newtio.c_lflag = 0;
 	newtio.c_cc[VMIN]=1;
	newtio.c_cc[VTIME]=0;
//#else	
	newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;/*ctrol flag*/
//	newtio.c_iflag = IGNPAR; /*input flag*/
	newtio.c_iflag &= ~(ICRNL|IGNCR | INLCR |IGNBRK |BRKINT ); //input flag
	newtio.c_oflag &= ~OPOST;		/*output flag*/
 	newtio.c_lflag = ECHO |NOFLSH;
 	newtio.c_cc[VMIN]=1;
	newtio.c_cc[VTIME]=0;
#endif


/* now clean the modem line and activate the settings for modem */
// 	tcflush(fd, TCIFLUSH);
//	tcsetattr(fd,TCSANOW,&newtio);/*set attrib	  */
//	signal(SIGTERM,do_exit);
//	signal(SIGQUIT,do_exit);
//	signal(SIGINT,do_exit);
	return 0;
}