/**
 *  uart_get_baud_rate - return baud rate for a particular port
 *  @port: uart_port structure describing the port in question.
 *  @termios: desired termios settings.
 *  @old: old termios (or NULL)
 *  @min: minimum acceptable baud rate
 *  @max: maximum acceptable baud rate
 *
 *  Decode the termios structure into a numeric baud rate,
 *  taking account of the magic 38400 baud rate (with spd_*
 *  flags), and mapping the %B0 rate to 9600 baud.
 *
 *  If the new baud rate is invalid, try the old termios setting.
 *  If it's still invalid, we try 9600 baud.
 *
 *  Update the @termios structure to reflect the baud rate
 *  we're actually going to be using. Don't do this for the case
 *  where B0 is requested ("hang up").
 */