Lalit Pratap Singh [off-list ref] wrote:

I just wanted to know that, How can i write the smallest driver and test it?

Linux Device Drivers 3rd edition (link provided by Rajat above) was
what got me started and is still my reference whenever I get stuck.
Chapter 2, pg 16 has the do-nothing 'hello world' driver you are
looking for.

Lalit Pratap Singh [off-list ref] wrote:

I want some basic tutorial links also.

You can find a decent tutorial at
http://www.freesoftwaremagazine.com/articles/drivers_linux?page=0%2C0