/* This short example shows how to set a serial line to RS485 on a device 
 * handled by the atmel_serial driver.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <unistd.h>

/* From arch/arm/include/asm/ioctls.h: */
#define TIOCGRS485      0x542E
#define TIOCSRS485      0x542F

/* From include/linux/serial.h: */
struct serial_rs485 {
	__u32	flags;			/* RS485 feature flags */
#define SER_RS485_ENABLED		(1 << 0)
#define SER_RS485_RTS_ON_SEND		(1 << 1)
#define SER_RS485_RTS_AFTER_SEND	(1 << 2)
	__u32	delay_rts_before_send;	/* Milliseconds */
	__u32	padding[6];		/* Memory is cheap, new structs
					   are a royal PITA .. */
};


int main (void) 
{
	/* Open device: */
	int fd = open ("/dev/mydevice", O_RDWR); 
	struct serial_rs485 rs485conf;
	/* Set RS485 mode: */
	rs485conf.flags |= SER_RS485_ENABLED;
	/* Set delay: */
	rs485conf.delay_rts_before_send = 0x00000004;
	ioctl (fd, TIOCSRS485, &rs485conf);
	close (fd);
	return 0;
}