I have no repo, and you should probably thank me
Here is some relevant code I found in my project-
https://gist.github.com/anonymous/f9a13bd0dcdbc23d82f439a3c4c5e94fIt always takes me a while to decipher Microchips usb code, but I think the above code is the only relevant parts that are needed.
This is the abreviated process I used, as I remember-
I have a Ubuntu 16.xx pc that was used to test/troubleshoot before trying on the tv
downloaded pl2303hx datasheet, got usb descriptors to match datasheet (with ATEN's VID/PID )
plugged in pic usb, looked at messages with dmesg
found out linux not happy talking to pic (driver goes through vendor specific initial read/write sequence)
added vendor specific requests code linked above
plugged in pic usb, linux is happy, no errors, thinks its a pl2303 (ATEN)
set pic usb to debug output to serial (in my case I was not using the serial side, just using the pic to send commands via button press)
hooked up to tv, watched debug output- initial sequence matched linux
sent commands- worked ok
realized usb does not work when tv off (unlike rs232, cannot turn on if tv is off)
project comes to screeching halt
plan B, built a remote control-
http://www.mtcnet.net/~henryvm/lgir3.png( limited range/directional because its used to control a single tv in a group of tv's, 2 buttons- can turn on, turn off, ch up, ch dn, vol up, vol dn)
If I wanted to actually control an LG tv (as intended with their ports), I would consider ignoring them and just use IR- there will always be ir control, and I wouldn't count on the usb control feature to be around much longer (they only recognize a 20 year old usb/serial adapter- so obviously not considered an important feature by LG)