serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */
serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */