test-uart.c

s3c2410上的串口通信例子

/*********************************************************************
* File：	test-uart.c
* Author：	Embest
* Desc：		
* History：	
*			Program modify, 2005.06.05 Embest R.X.Huang <[e-mail]> 
*********************************************************************/

#include <stdio.h>
#include <fcntl.h> 
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/io.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <termios.h>
#include <sys/time.h>
#include <errno.h>
   
int uart_open(char *Port, int Baud);

#define  TIMEOUT     30
#define  UART_DEBUG

/* Uart open and setting fuction */
int uart_open(char *Port, int Baud)
{
	struct termio SerialPara;
	int i, fd;

	/* We want to open the port in nodelay mode */
	if ((fd = open (Port, O_RDWR)) == -1) {
		#ifdef UART_DEBUG
		fprintf (stderr, "uart_open: Cannot open port %s\n", Port);
		#endif
		return -1;
	}

	/* Now change the rest of the parameters - non-canonical input, etc. */
	if (ioctl (fd, TCGETA, &SerialPara) == -1) {
		#ifdef UART_DEBUG
		fprintf (stderr, "uart_open: Cannot ioctl(TCGETA) on port %s. Errno = %d\n", Port, errno);
		#endif
		return -1;
	}

	SerialPara.c_cflag = Baud | CS8 | CLOCAL | CREAD | HUPCL;
	SerialPara.c_lflag &= ~ICANON;

	SerialPara.c_lflag = 0;
	SerialPara.c_oflag = 0;
	SerialPara.c_iflag = IGNBRK | IGNPAR;
	for (i = 0; i < NCC; i++)
		SerialPara.c_cc[i] = (unsigned char) 0;
	SerialPara.c_cc[VMIN]  = (unsigned char) 0;
	SerialPara.c_cc[VTIME] = (unsigned char) TIMEOUT;

	if(ioctl (fd, TCSETA, &SerialPara) == -1) {
		#ifdef UART_DEBUG
		fprintf (stderr, "uart_open: Cannot ioctl(TCSETA) on port %s. Errno = %d\n", Port, errno);
		#endif
		return -1;
	}

	return fd;
}

/* Main test program */
int main(void)
{

	int i,err,fd,ret;
	unsigned char ch;
	char buf[] = "Write Something to Test...\n";
	struct timeval timeout;
	fd_set new_fd_set;
	static char *driver = "/dev/ttyS0";
 
	printf("UARTx test example base on Linux. \n");

	timeout.tv_sec = 0;
	timeout.tv_usec = 0;

	fd = uart_open(driver,B115200);
	/* print something to UARTx */   
	write(fd,buf,strlen(buf));

	/* Wait input through UART0, or press Crtl+C or Enter to Exit */   
	while(!((ch==3)|(ch==0xd))){
		FD_ZERO (&new_fd_set);
		if (fd >= 0)
			FD_SET (fd, &new_fd_set);
		err = select (fd + 1, &new_fd_set, NULL, NULL, &timeout);
		if (err > 0){
			if (fd >= 0 && FD_ISSET (fd, &new_fd_set)){
				FD_CLR(fd, &new_fd_set);
				read(fd,&ch,1);
				printf("ch = %c\n",ch);
			}
		}
	}
	printf("end.\n");
	
    return 0;

#if 0 // simply test
	/* open ttyS0 device file --- UART0 */
	fd = open(driver, O_RDWR|O_NOCTTY|O_NDELAY);
	if(fd == -1)
	{
		printf("Fail to open /dev/ttyS0\n");
		return -1;
	}
	else
		fcntl(fd, F_SETFL, 0);
	
	/* write data to UART0 */
	if(write(fd, buf, strlen(buf) != strlen(buf))
	{
		printf("Fail to open /dev/ttyS0\n");
		return -1;
	}
	/* close ttyS0 */
	close(fd);
    return 0;
    
#endif

}