I home school so take this with a grain of salt. Find what he's hyper focused in, find his love. As long as he's putting in the effort any other reg kid does then that's good enough. Look/plan for the GED and either trade school or community college depending on his life goals. Avoid fighting about this. Ask his teacher how long each home work assignment should take and write down on the assignment your start time and finish time. Only spend that much time on each assignment.

I say this because around 5th grade I burnt out and hated school. I spent the rest of my time barely passing. My parents made me sit for hours trying to play catch up. So I stopped bringing home any work. I also stopped doing class work because I saw no point I was just going to fail anyway. I was constantly in in-school-suspension because they would just give me my work and leave me alone. I came to home room late, skipped class for lunch solely to get ISS. My school did EVERYTHING they could think of to help but I wasn't made for school. I too dropped out the day I could, on my birthday. With no studying.