Set custom baud rate in Linux

custom_baud.c

#include <termios.h>
#include <sys/ioctl.h>

#define BAUD_RATE 128000  /* custom baud rate */

/* extended termios struct for custom baud rate */
struct termios2 {
	tcflag_t c_iflag;		/* input mode flags */
	tcflag_t c_oflag;		/* output mode flags */
	tcflag_t c_cflag;		/* control mode flags */
	tcflag_t c_lflag;		/* local mode flags */
	cc_t c_line;			/* line discipline */
	cc_t c_cc[NCCS];		/* control characters */
	speed_t c_ispeed;		/* input speed */
	speed_t c_ospeed;		/* output speed */
};

struct termios2 tio;
ioctl(fd, TCGETS2, &tio);
tio.c_cflag &= ~CBAUD;
tio.c_cflag |= CBAUDEX;
tio.c_ispeed = BAUD_RATE;
tio.c_ospeed = BAUD_RATE;
/* do other miscellaneous setup options with the flags here */
ioctl(fd, TCSETS2, &tio);