How can I set a custom baud rate in Linux?

Using DIGI TS 16. Redhat EL6. dgrp-1.9-30.x86_64. Cannot set custom baud rate. Ioctl calls return -1. Using ioctl calls with a non-DIGI usb to serial (RS422) device (code bellow) works fine. Trying to convert to use DIGI. Does DIGI have special ioctl call definitions for setting custom baud rate?

        /* Setup a Custom Divisor Baud Rate   */
        int rate=11520; //ICD says 12Kbps            
        struct serial_struct serinfo;
        serinfo.reserved_char[0] = 0;
        ioctl(xfd, TIOCGSERIAL, &serinfo);

        serinfo.flags &= ~ASYNC_SPD_MASK;
        serinfo.flags |= ASYNC_SPD_CUST;
        serinfo.custom_divisor = (serinfo.baud_base + (rate / 2)) / rate;

        if (serinfo.custom_divisor < 1) {
            serinfo.custom_divisor = 1;
        ioctl(xfd, TIOCSSERIAL, &serinfo);
        int speed = 0;
        struct termios options;
        fcntl(xfd, F_SETFL, 0);
        tcgetattr(xfd, &options);
        cfsetispeed(&options, speed ?: B38400);
        cfsetospeed(&options, speed ?: B38400);
        options.c_cflag &= ~CRTSCTS;
        options.c_cflag |= CS7|PARENB|PARODD|CREAD|CLOCAL;

        tcsetattr(xfd, TCSANOW, &options);