Alan,

Thanks for your response, suggested modification helped to get 4.8M baud
but not 4.05M as this is being approximated to 4.0M baud which happens in
tty_termios_encode_baud_rate(...).

I have precise and weird requirement to get 4.05M baud as uart
baud clock divisor value changes between 4.0M and 4.05M Baud.

Any suggestion?

Thanks,
Rajanikanth

-----Original Message-----
From: Alan Cox [mailto:alan at lxorguk.ukuu.org.uk] 
Sent: Wednesday, January 11, 2012 6:00 PM
To: Rajanikanth H V
Cc: linux-serial at vger.kernel.org; linux-kernel at vger.kernel.org; gregkh at sude.de; linux-arm-kernel at lists.infradead.org
Subject: Re: tty/serial: Need clarification on Support for 4+M Baudrate

On Wed, 11 Jan 2012 17:49:01 +0530

I have a requirement to interface UART with an external microcontroller 
using baud rate above 4Mbps, hence following is my approach to apply
the changes. Can any one review/provide me appropriate approach.

See TCGETS2/TCSETS2 and the BOTHER flag.

The kernel supports aetting arbitary baud rates already.

Alan