rhaseven7h/pps-gpio-poll

GPIO polling PPS client for Linux

pps-gpio-poll

pps-gpio-poll is a Linux kernel module which provides a /dev/pps* device using a GPIO pin as the PPS source. With an NTP daemon like chrony or ntpd it can be used to accurately synchronize the system clock with a reference time source.

Unlike the pps-gpio module (which is included in the Linux tree) it doesn’t use interrupts. It uses a high-resolution timer and waits for the GPIO value to change in a busy loop instead. This means the PPS samples are more accurate and have less jitter, but more CPU time is consumed. Another difference is that the number of the GPIO pin is a parameter of the kernel module instead of relying on Device Tree.

This is a continuation of the openwrt-stratum1 project by Gabs Ricalde.