Yocto support for embedded DisplayPort with apalis imx8

We have the first spin of hardware for a custom carrier board for the apalis imx8 quad plus. We routed the display signals for both eDP and HDMI. The HDMI is working for us, and now I’m starting to dig into the SW for the eDP.

We are using a recent version of the yocto bsp, and I’m wondering is there an example I can use to help me get it working.

I was able to get my eDP panel working with our custom design.

Varicite supports DP/eDP with their i.MX8QM SOM. Here is a link to their carrier board reference design. Page 7 has the HDMI/DP/eDP circuitry. Pay attention to the note about swapping HDMI lanes 0 and 2 for DP, and there are various lines with pull up/down and series caps.

Once you are sure the HW is right, you can take inspiration from their device tree from here (imx8qm-var-spear-dp.dts) for the device tree changes needed to get the panel working.