pleroma.debian.social

Today's level of yak shaving:
Wanted to get the cameras on my Dell Latitude 5290 working. Found out those are also IPU3 based ones. Then wondered why they wouldn't show up at all. Now I am compiling my own Debian kernel to at least see what's missing in terms of functionality.
On the upside I now know how to compile the kernel and will create a patch (soon™) for the IPU3 and CIO2 modules to be enabled by default in #Debian.

so I finished compiling the kernel. MR enabling the IPU3 and CIO2 modules by default is submitted and pending approval. This is what I like about free software: ones personal itch might just help another person.

Thanks to the helpful libcamera folks I now know that it needs some additional ov* drivers enabled. Also made a MR for that. With those enabled running the cameras should be as simple as installing the v4l2loopback kernel module and executing a launch script. Unfortunately the kernel module did not want to compile with my newer kernel, so I'll wait until this is mainlined. v4l2 --list returns the correct cameras now, so that's progress.

After some more digging it turns out that Intel was lazy. They used a similar camera setup in my device and the Surface device line. However, the voltage to the camera sensor is controlled by a tps68470 IC which can deliver variable voltages. Since the Linux kernel does not know the board (and the correct voltage levels), the camera is without power. Now I need to boot Windows (ugh) and get the correct values from reading the I2C traffic.

No progress on the debugging from windows. Though now the Debian kernel has the IPU3 and CIO2 modules enabled by default, starting with 6.12~rc.6.