Vim4 i2c A and i2c F not working

VIM4 Ubuntu
1

I am in the process of moving applications from a raspberry pi 4 to the vim4. On the raspberry pi I have a working i2c servo controller but when installed on the vim4 either i2c A (Pins 25 and 26) or i2c F (pins 22 and 23) the servo controller is not found. I have installed the following operating systems using oowow:

vim4-ubuntu-20.04-server-linux-5.4-fenix-1.0.11-220620-emmc-develop.raw.img.xz

vim4-ubuntu-22.04-gnome-linux-5.4-fenix-1.1-220721.img.xz

vim4-ubuntu-22.04-server-linux-5.4-fenix-1.1-220731.img.xz

According to the vim4 documentation i2c A is setup for 0 (i2cdetect -r -y 0) and i2c F is setup for 5 (i2cdetect -r -y 5).

When doing a ls /dev/i2c* on all three operating systems the following is returned:

/dev/i2c-1, /dev/i2c-2, /dev/ic2-3 and /dev/i2c-6.

Also the command sudo i2cdetect -l returns the following:

i2c-1 i2c meson i2c adapter i2cadapter

i2c-2 i2c meson i2c adapter i2c adapter

i2c-3 i2c meson i2c adapter i2c adapter

i2c-6 i2c meson i2c adapter i2c adapter

So I tired all of the i2c devices listed in the i2cdetect -l command

i2cdetect -r -y 1, i2cdetect -r -y 2, i2cdetect -r -y 3 and i2cdetect -r -y 6

none of the i2cdetects found the servo controller.

I also tried i2cdetect -r -y 0 and i2cdetect -r -y 5 and both returned the following error:

error: could not open file /dev/i2c-0 for the i2cdetect -r -y 0 command and error: could not open file /dev/i2c-5 for the i2cdetect -r -y 5 command.

So the question is: How do I get either i2c A or i2c F working on the VIM4, keep in mind that the servo controller works on the raspberry pi 4.

2

Hello @pmaiorana85

The I2C function is disabled by default, you can use latest image vim4-ubuntu-22.04-server-linux-5.4-fenix-1.1-220721.img.xz and follow the steps below to enable I2C-A and I2C-F.

Edit file /boot/dtb/amlogic/kvim4.dtb.overlay.env add i2cm_a and i2cm_f to node fdt_overlays=, save and reboot.

You will find the I2C node below:

I2CM F (PIN22 & PIN23) - /dev/i2c-5
I2CM A (PIN25 & PIN26) - /dev/i2c-0

3

Thanks Khadas support team, this did correct the issue.

I changed the kvim4,dtb,overlay.env file to this:
fdt_overlays=i2cm_a i2cm_f
saved the file and rebooted the system.
I did an ls -la on /dev/i2c* and now have /dev/i2c-0 and /dev/i2c-5.
I was then able to run the i2cdetect -r -y 0 command and my servo controller is identified.

I do have one suggestion: Please add this information to your I2C documentation for the VIM4.

Thanks again for your help.
Paul

4

Thanks for your suggestions, actually we already have such documentations in our new documentation framework, and will release soon.