pps-gpio in HummingBoard

[Gyver]

Hello everyone,

I was used to use the cubox-i running on a hummingboard (2 years ago) and tried to install a pps source using pps-gpio module and the GPIO1 (pin 7) of the HummingBoard jumpers. Given that pps-gpio requires an entry in the device tree for pps, and I couldn't find/patch/recompile again sources (image was built by another person), I decompiled the imx6q-hummingvboard.dtb present in /boot, then modified it adding :

 

    pps {
        compatible = "pps-gpio";
        gpios = <0x01 0x01 0x01>;
    };

 

and then I recompiled this source and copied into /boot.

When I rebooted, the new /dev/pps1 was created and the pulses were received by the hummingboard (checked using ppstest program from pps-tools package).

 

Then I installed the armbian in the same Hummingboard (from image downloaded from this website) and followed the same procedure; the problem is that i got the error in dmesg:

 

[    0.090676] pps_core: LinuxPPS API ver. 1 registered
[    0.090685] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[   23.022017] /pps: could not get #gpio-cells for /interrupt-controller@00a01000
[   23.027445] pps-gpio pps.24: failed to get GPIO from device tree
[   23.039236] pps-gpio: probe of pps.24 failed with error -22

 

and the pps source is not created. 

Would anyone help me with the right definition of the device tree in order to make it work?

Thank you very much!

 

Gyver

 

[zador.blood.stained]

First cell (number) in "gpios" property should be the phandle of your GPIO controller, it's not a fixed number.

[Gyver]

Thanks a lot! I found that the phandle was 0x24 and put that number as first cell in gpios. The pps source is created now and it works.

God Blesses!

Thank you!