What time does he get up in the morning? My son just turned 5 and he sleeps from 9pm-7am with no problem. He does not nap during the day. Maybe you should wake him up earlier if he is sleeping late. Do not let mim take a nap. Make sure you have a good bedtime routine that starts at the same time every night. We take a bath, put on pajamas, drink milk (it is supposed to make you sleep better), read books, have hugs/kisses, brush teeth, potty and then go to bed.
What does he do all night? Does he just lie in his bed? Does he get up and play? Does he get out of bed and come find you? We have a rule that if our kids get up without a good reason or call us upstairs without a good reason, they get counted. When they get to 3, we take away something they like at bedtime for the night such as a favorite toy or turn off their cd player. It usually works. They seldom get past "2" now.
Does he use a nightlight? Both my kids want to fall asleep with the bedroom door open and the hall light on. They both have ceiling fans with a dimmer on it that we dim to low as a nightlight. I close my son's door when I go to bed but he still has his fan light on. My dgt. requires her door to stay open right now because her fanlight is new. However, I hope to work toward closing her door too. Hope this helps. Good luck!