Hey @hitheshkaranth,
The first step is to configure one or both UARTs on your chip to be available to user space apps. This is discussed here: Need Information On UART.
I got tired of running these commands by hand all the time, so I built a small app to configure things for me: https://github.com/brnkl/cf3-config
This app uses the same API (le_tty) that you will need to communicate with your UART. In this app I use the device at /dev/ttyAT (the modem in the WP chip), but your UART device will show up as either /dev/ttyHS0 or /dev/ttyHSL (UART1 and UART2, not certain which is which).
Hopefully this is helpful,
Cheers!