I am working in company.My next project is device driver for MMC in linux 2.6. I analyzed the MMC code present the kernel but i am not getting how it is invoking different function. In that code they are not mentioning any thing about the h/w ,instead they are using some structure i don't know how this structure is getting h/w information..
Your question is too ambiguous. Please tell us what structures you are trying to use, and what you know about creating kernel drivers. FWIW, there are good on-line documents for people learning how to build kernel drivers at The Linux Kernel Archives. A few documents you should read in detail:
The Linux Kernel Module Programming Guide
Writing Your Own Loadable Kernel Module
Character Device Drivers
In any case, the Linux documentation project has most everything you will need. The root URL is The Linux Documentation Project