Hello Vishva,
In the linux reference manual, in the chapter about the Universal Asynchronous Receiver/Transmitter (UART) Driver, you will see where the UART driver is (which uses interrupt method).
Source Code Structure
Universal Asynchronous Receiver/Transmitter (UART) Driver
<ltib_dir>/rpm/BUILD/linux/drivers/tty/serial.
That would be the only available example.