PROCESSOR-SDK-J721E: How to access De-serializer register map for reading/writing

Tool/software:

Dear TI team.

This is my first time to ask. I kindly ask for your support.

I am developing a board based the TDA4VM platform using  SDK version 8.6.

I would like to access register map of de-serializer chip(MAX9296) for reading/writing.

First of all, I analyzed the source code about basic demo's single cam.

And I found source code related ISS. But it doesn't called. 

I try to call {rtos}/imaging/sensor_drv/src/iss_sensors.c from {rtos}/vision_apps/utils/iss/src/app_iss.c, but I failed.

How can I do this? or How can I use the ISS?

Please let me know it.

Thank you.

Inyoung Kim.