How to enable GPIO of DRIVE AGX Xavier™ Developer Kit?

It seems that DRIVE AGX Xavier™ Developer Kit has 4 GPIO ports. But no relevant information could be found in DriveWorks SDK Reference Documentation or NVIDIA DRIVE OS Linux Development Guide. How to enable these ports? Is there any sample code?
Thanks a lot.

Software Version
NVIDIA DRIVE™ Software 10.0 (Linux)

Target Operating System

Hardware Platform
NVIDIA DRIVE™ AGX Xavier DevKit (E3550)

SDK Manager Version

Host Machine Version
native Ubuntu 18.04

Dear @lishaohua ,
We don’t have any sample code in DW to enable GPIO. Could you share your use case . I will check internally and get back to you.

Thanks so much for your quick response!
We want to use GPIO to generate pulse signals for triggering the lidar and a custom camera. The lidar and the camera are not supported by the SDK itself.

Dear @lishaohua ,
If you are looking to synchronize lidar and camera, Please see How to synchronize camera with lidar? if it helps

Thanks so much for your reply.
The question is that our camera, which is provided by a local supplier, is not supported by DW and we have to use another PC to record the data of the camera and lidar. But we will still use the Drive AGX Xavier to record the data of another four fisheye cameras. Since the Drive AGX Xavier has GPIO ports, we are wondering if the ports can be used as pulse signal sources to trigger the camera mentioned at the beginning. So what we need is how to program those GPIO ports.