centos man page for uart_get_baud_rate

UART_GET_BAUD_RATE(9)						 16x50 UART Driver					     UART_GET_BAUD_RATE(9)

NAME
       uart_get_baud_rate - return baud rate for a particular port

SYNOPSIS
       unsigned int uart_get_baud_rate(struct uart_port * port, struct ktermios * termios, struct ktermios * old, unsigned int min,
				       unsigned int max);

ARGUMENTS
       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

DESCRIPTION
       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").

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						     UART_GET_BAUD_RATE(9)