Help required for Compiling a staging driver

[Kumar Gaurav <kumargauravgupta3@gmail.com>]

Hi All,

I'm trying to upgrade a driver using semaphore to use mutex. I have 
applied the required changes. Now i want to compile it to ensure that i 
didn't broke the kernel.

Driver Path:drivers/staging/dgap/
I Marked this driver to load as loadable module

     kumar@anandlinux:/usr/linux-git$ grep CONFIG_DGAP .config
     CONFIG_DGAP=m

Now I'm trying to compile it using below command and getting result as given
     kumar@anandlinux:/usr/linux-git$ sudo make M=drivers/staging/dgap/
       Building modules, stage 2.
       MODPOST 0 modules

So, No module is getting build and again i'm not getting any Error as 
well. Please tell me where i'm doing wrong.

Regards,
Kumar Gaurav