Mity CPU Platforms » MityDSP-L138 (ARM9 Based Platforms)

#include <linux/serial.h>

#include <stdio.h>

#include <stdlib.h>

#include <fcntl.h>

#include <termios.h>

#include <unistd.h>

#include <string.h>

/* Driver-specific ioctls: */

#define TIOCGRS485 0x542E

#define TIOCSRS485 0x542F

/* new defines in linux/serial.h of CL provided kernel */

#ifndef SER_RS485_USE_GPIO

#define SER_RS485_USE_GPIO (1<<4)

#define gpio_pin padding[0]

#endif

#define GPIO0_9 (9)

#define USE2

/*

 * Test program for 485 control

 */

int main(int argc, char* argv[])

{

	struct serial_rs485 rs485conf;

	char buffer2[21];

	int i, rv, opt;

	struct termios my_termios, new_termios, stdio;

	int fd2 = open("/dev/ttyS2", O_RDWR | O_NOCTTY | O_NDELAY);

	rs485conf.flags = SER_RS485_ENABLED;

	rs485conf.flags |= SER_RS485_USE_GPIO;

	rs485conf.delay_rts_before_send = 0;

	rs485conf.gpio_pin = GPIO0_9;

	rv = ioctl (fd2, TIOCSRS485, &rs485conf);

	if (rv) {

		perror("unable to set IOCTL:");

	}

	tcgetattr(fd2, &my_termios);

	my_termios.c_iflag &= ~(IGNBRK | BRKINT | ICRNL | INLCR | PARMRK | INPCK | ISTRIP | IXON);

	my_termios.c_oflag &= ~(OCRNL | ONLCR | ONLRET | ONOCR | OFILL | OLCUC | OPOST);

	my_termios.c_lflag &= ~(ECHO | ECHOE | ECHOKE | ECHONL | ICANON | IEXTEN | ISIG | ECHOK | ECHOCTL | ECHOPRT);

	my_termios.c_cflag &= ~(CSIZE | PARENB);

	my_termios.c_cflag &= ~CRTSCTS;

	my_termios.c_cflag |= CS8 | CLOCAL | CREAD;

	my_termios.c_cflag &= ~CBAUD;

	my_termios.c_cflag |= B19200;

	my_termios.c_cc[VMIN] = 1;

	my_termios.c_cc[VTIME] = 5;

	rv = tcsetattr(fd2, TCSANOW, &my_termios);

	tcgetattr(fd2, &new_termios);

	fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);

	printf("Reading (hit q, return to quit)...\n");

	while(1)

	{

		if(read(fd2, buffer2, 1) > 0) write(STDOUT_FILENO, buffer2, 1);

		if(read(STDIN_FILENO, buffer2, 1) > 0) {

			if (buffer2[0]='q') {

				break;

			}

		}

	}

	close(fd2);

}