Hi folks,
wanted to close the loop.
After some feedback from CTI + tinkering, this is what works:
pps: pps_gpio {
gpios = <&tegra_main_gpio TEGRA_MAIN_GPIO(Y, 6) 0>;
compatible = “pps-gpio”;
status = “okay”;
};
along with the kernel config options i listed in the original message, on build, flash, boot up. You will now have a /dev/pps0 and /dev/pps1
The /dev/pps0 is the ktimer pps source, and /dev/pps1 will be triggered from the GPIO Port Y, Pin 6, which on the CTI Spacely carrier is P12, pin 17 (GPIO-IN). I beleive the ‘IN’ represents interrupt not input.
Once you have all that:
sudo apt install pps-tools
sudo ppstest /dev/pps0
should show timer triggers for each second the kernel timer is going.
sudo ppstest /dev/pps1
will show timer triggers for each pulse on the GPIO-IN pin. I can’t remember if it is rising or falling edge, but either way you get one timer trigger for each pulse.
Hope this helps other people