Continuing the discussion from PTP synchronization and PPS output from Nvidia NX:
Sorry for the delayed response.
For the GPIO PPS code that was used in our project, I do not have access to it.
But we referred to the code and modified it from
http://www.linuxpps.org/pipermail/discussions/2013-May/004633.html
http://www.linuxpps.org/pipermail/discussions/attachments/20130517/bfc8bc7d/attachment-0002.c