Im trying to get the PPS-GPIO loaded on trixie on a rpi 5.
/etc/modules does have pps-gpio
config.txt has dtoverlay=pps-gpio,gpiopin=18
if I run ppstest /dev/pps0, it does find the PPS signals from the GPS. (assert lines each second)
Checking the name of pps0:
root@raspberrypi:/home/pi# cat /sys/class/pps/pps0/name
pps@12.-1
HOWEVER, when checking lsmod | grep pps, it does NOT find the pps_core, it only finds pps_gpio module.
I then check dmesg:
[ 0.037147] pps_core: LinuxPPS API ver. 1 registered
[ 0.037150] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giome tti <giometti@linux.it>
[ 0.037155] PTP clock support registered
It seems that when it finds the PTP clock, it just stops searching, and ignores that there is a valid PPS-GPIO clock.
So I guess, I need to disable PTP right?
How I do to disable PTP?
Or what can the problem be?
/etc/modules does have pps-gpio
config.txt has dtoverlay=pps-gpio,gpiopin=18
if I run ppstest /dev/pps0, it does find the PPS signals from the GPS. (assert lines each second)
Checking the name of pps0:
root@raspberrypi:/home/pi# cat /sys/class/pps/pps0/name
pps@12.-1
HOWEVER, when checking lsmod | grep pps, it does NOT find the pps_core, it only finds pps_gpio module.
I then check dmesg:
[ 0.037147] pps_core: LinuxPPS API ver. 1 registered
[ 0.037150] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giome tti <giometti@linux.it>
[ 0.037155] PTP clock support registered
It seems that when it finds the PTP clock, it just stops searching, and ignores that there is a valid PPS-GPIO clock.
So I guess, I need to disable PTP right?
How I do to disable PTP?
Or what can the problem be?
Statistics: Posted by sebastiannielsen — Sun Nov 02, 2025 3:10 am