What you can do is to acknowledge what he does do - he hands in his work and stays out of trouble. Tell him that you are appreciative of those qualities and anything else he does that you are proud of. When he does good work, be sure and praise him for that. If you focus on what he does right, it will help him create a desire to do more to please you and the more he does well, the more he will enjoy school.
It is hard to be patient and wait for our children to find their way, but it is my opinion that your son will find his way with your encouragement.