How to Control Brightness and Power via DDC/CI on NXP i.MX 8M Plus with Yocto (scarthgap

[masalcp]

Hi.

I want to control brightness, power, and other settings via HDMI DDC/CI.

Can this be done using only i2c-tools?

Alternatively, how can I add ddcutil?

Thank you for your help.

[JorgeCas]

Hello,

As mentioned in the below link you can add DDC/CI function.

https://community.nxp.com/t5/i-MX-Processors/how-to-set-brightness-on-a-hdmi-display/m-p/1275376#M17...

For more detail Please refer to this link.

https://github.com/rockowitz/ddcutil

If you do not have access to iMX8MP HDMI DDC pins. External I2C could be used to implement DDC/CI, dw-hdmi driver default support external I2C for DDC.

Best regards.

[masalcp]

Hello,

Regarding the link: Has operation been confirmed with Yocto 5.0 and the i.MX8Mplus?

Could you please provide specific instructions on how to operate DDC via I2C?

Also, will I2C and Weston conflict?

Best regards,

[JorgeCas]

Hello,

1. This have not been tested in our side.

2. The HDMI-DDC lines are managed by dedicated HDMI firmware, and there isn't any way to directly control those lines (outside of the HDMI firmware).

3. There shouldn't be a conflict.

Best regards.