Odroid N2 - No RTC and GPIO not working

[Burschi500]

Armbianmonitor:

http://ix.io/2hyL

Good morning,

 

after some time using armbian on my OdroidN2 with great success (got Nextcloud with working Talk installed, external USB, Minecraft server, nginx, LetsEncrypt, Netdata...) I encountered some problems I am not able to solve by myself:

I bought a RTC battery and a LED power button to "finalize" my Odroid (hardwarewise), and to my surprise both did not work as expected. 

 

RTC:

 It says:

chris@OdroidN2:~$ sudo hwclock
hwclock: select() to /dev/rtc0 to wait for clock tick timed out

cat /proc/interrupts |grep rtc

...gives me also no return (empty string), so i guess there is a module missing in the kernel :

chris@OdroidN2:~$ uname -a
Linux OdroidN2 5.4.28-meson64 #20.02.8 SMP PREEMPT Mon Mar 30 09:12:52 CEST 2020 aarch64 aarch64 aarch64 GNU/Linux

There is a post on RTC here in the forums which looks like my problem, its here. Maybe it is the same problem?

 

Next problem is GPIO:

As mentioned above i tried to install a LED power button, and used this to set it up. I got the LED working as expected (Pin 1 and 6), but the power on-off is not working (Pin 9 and 11). The button i purchased is a NO-switch, and after checking the correct wiring i also tested the button for funcion. Everything is fine according to the multimeter. After some reading i tested for working GPIO (installed wiringpi with this instruction), and it looks like this is the problem:

chris@OdroidN2:~$ sudo gpio readall
No "Hardware" linechris@OdroidN2:~$

 

It looks to me as there is also some module missing or am i wrong? I also have no i2c bus, in /dev/ there is only i2c-0.

 

Now - what is wrong and what can i do about it? Is there information missing i should provide to solve my problem?

[martinayotte]

11 hours ago, Burschi500 said:

I also have no i2c bus, in /dev/ there is only i2c-0.

Odroid-N2 external RTC is attached on I2C3 which isn't enabled by default.

To enable it, use this overlay source and compile it and load it.

/dts-v1/;
/plugin/;

/ {
    compatible = "amlogic,meson-g12b";
    fragment@0 {
        target-path = "/aliases";
        __overlay__ {
            i2c3a = "/soc/bus@ffd00000/i2c@1c000";
        };
    };
    fragment@1 {
        target-path = "/soc/bus@ffd00000/i2c@1c000";
        __overlay__ {
            status = "okay";
            pinctrl-0 = <&i2c3_sda_a_pins>, <&i2c3_sck_a_pins>;
            pinctrl-names = "default";
            pcf8563: rtc@51 { /*I2C-bus slave address: read A3h and write A2h*/
		compatible = "nxp,pcf8563";
		reg = <0x51>;
            };
        };
    };
};

Then, the i2c will appear as well as module for PCF8563 will be loaded, it will be hookup as /dev/rtc1, you can then set the clock and re-read it using :

hwclock -w -f /dev/rtc1
hwclock -f /dev/rtc1

 

[Burschi500]

Thank you very much,

I used your instructions from over there, and it works (i got warnings but i guess these are ok)! Do I have to issue these commands at every boot, or is it "done" now? I read here that you have to put something in config.txt which might translate to boot.ini?

 

Any chance that i can get the GPIO working in a similar manner?

[martinayotte]

8 hours ago, Burschi500 said:

Do I have to issue these commands at every boot

To load the overlay ? Yes, it requires to be loaded at every boot, for example thru calls from /etc/rc.local, or using useroverlays variable in /boot/armbianEnv.txt.

8 hours ago, Burschi500 said:

Any chance that i can get the GPIO working in a similar manner?

I don't know, I've not used the WiringPi mentioned above, but you can try using sysfs gpio.

 

EDIT: Something looks a bit fishy : I've not been able to make gpio sysfs working ...

[Burschi500]

Actually i don't want to program with WiringPi, i just want to use the hardwarepins for a hardwarebutton. WiringPi and gpio readall was just a test if basic functionality is present (which is not). But as your EDIT says there might be a different problem than in WiringPi. It does not break Armbian on OdroidN2 for me, but ... i just want to have this shiny button working and not just shining :).

[martinayotte]

On 4/13/2020 at 4:24 AM, Burschi500 said:

But as your EDIT says there might be a different problem than in WiringPi

I've decided to take a look at the WiringPi issue, and I figured out that "cat /proc/cpuinfo" doesn't give same output under Armbian that WiringPi is expecting with HardKernel version.

But I figured out to comment out all the Hardware/Revision parsing of /proc/cpuinfo, and hard coded the the result as a OdroidN2 board, and the rest of the library is working fine.

I didn't the same with WiringPi python wrapper too ...

 

This is the recipe :

 

Comment out those lines : https://github.com/hardkernel/wiringPi/blob/master/wiringPi/wiringPi.c#L328-L449

and hardcode the following, just after the commenting :

               libwiring.model = MODEL_ODROID_N2;
               libwiring.maker = MAKER_AMLOGIC;
               libwiring.mem   = 4;
               libwiring.rev   = 1;

 

EDIT: Now, I will go back to gpio sysfs issue, but there is less hurry ...

[Burschi500]

Thanks for your effort.

 

I fear that i need more detailed instructions. Can you give me the command set i must use or a direction where to look?

[martinayotte]

7 hours ago, Burschi500 said:

I fear that i need more detailed instructions. Can you give me the command set i must use or a direction where to look?

As I said, after doing "git clone", simply commenting the whole detection code from line 328 to 449, and then hardcode the OdroidN2 definition mentioned above, then compile the library ...

[Burschi500]

Just noticed that an update for wiringpi was available - thank you - gpio readall is now working as expected as i get the table the link was referring to. Unfortunately the powerbutton is still not working when using the lines given above in boot.ini. I tested the same with a kernel from hardkernel (which i tried because my trial to move the system to ssd failed miserably) and there the button worked as expected. I guess it is still an issue of the kernel?

[onkel_enno]

Any success to enable the GPIO?

 

The Power Button was working on my old "Ubuntu Bionic with Armbian Linux 4.9.190" out of the box.

I create a new system using "Armbian 21.02.3 Focal with Linux 5.10.21-meson64" and it is not working anymore.

[Igor]

9 minutes ago, onkel_enno said:

and it is not working anymore

In general - kernel 5.y is not simple functional upgrade from private(!) 4.9.y. Functions needs to be developed and/or ported to support this and that functionality. Very expensive problem in term of development resources.

 

For specific functions - if things are working, they are working this way:

https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/tree/README
https://github.com/sgjava/java-periphery

[onkel_enno]

Am 15.3.2021 um 09:09 schrieb Igor:

In general - kernel 5.y is not simple functional upgrade from private(!) 4.9.y.

 

Very good hint, thank you.

 

I switched to the latest legacy kernel 4.9 with armbian-config and ... it works.