configuring gpio pin for pps-gpio on odroid c2 running 4.19.y

Recommended Posts



A GPS module ublox is connected to a odroid c2 board on GPIOX.12 and GPIOX.13 for the RX and TX and GPIOX.10 for the PPS.

The board is running the stable kernel 4.19.42-meson64 from Armbian based on Debian stretch which was dist-upgraded to Debian buster.

I am trying to get the /dev/pps0 entry using GPIOX.10 to finish the chrony setup but I cannot find the correct syntax in the DTS file.


Any pointer or idea ?


I try either of the gpios line below, none of them seems to be correct.

pps {
  gpios = "< 0x1e 0x66 0x0 >";
  #gpios = "<&gpiox 10 GPIO_ACTIVE_HIGH>";
  #gpios = "< 0x66 >";
  compatible = "pps-gpio";

The file include/dt-bindings/gpio/gxbb.h#L122 in the Linux kernel tree show the value of GPIOX.10 is set to 102 (aka 0x66 in hexa).


After reboot, the pps-gpio module is loaded and cannot find the GPS connected.

# dmesg | grep -i pps
[    1.414780] pps_core: LinuxPPS API ver. 1 registered
[    1.414783] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[    5.460824] OF: /pps: could not find phandle
[    5.460835] pps-gpio pps: failed to get GPIO from device tree
[    5.460849] pps-gpio: probe of pps failed with error -22

The previous pps-gpio kernel module had the option for the gpio_pin which seems a bit easier to use :-/


Thank you.

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.