Default native programming question: smd_open()

Just ask a basic question here:

in the source tree: msm\msm\arch\arm\mach-msm\smd.c
There is a method smd_open() and other smd_xxx methods.
Am I able to call them from a native application? Or can I make a driver to call them, then have java to read/write my char dirver as a file?

If I get the tool chain, can I compile and link to this method? I guess I only have the header file here, how to link? I am new the linux...