The actor appeared to suffer a highly public breakdown following an incident at a New York City hotel in 2010, when he was alleged to have trashed his suite and held an escort hostage during a search for his missing watch.
He went on to become embroiled in a public feud with bosses of his hit TV show, who eventually fired him in 2011 over his erratic behaviour, which included a series of bizarre media interviews and an ill-fated U.S. comedy tour.
Charlie's father, Martin, spoke of his worry for his estranged son at the time, but they eventually patched up their relationship and the West Wing star now even has a regular role in the actor's new sitcom Anger Management.
Charlie has now revealed Martin took him out for lunch at the height of his problems and gave him some good advice that helped him get back on track.
He tells TV host Piers Morgan, "There was a moment we had - I think the tour ended. He came back from Spain. And we had a nice lunch together. We didn't really talk about much. He says, 'How are things doing?' I said the tour was a mess. No more T-shirts? He's like 'yeah'. He says, 'No more interviews?' He said... 'Then why don't you go get your money and take care of your kids. Go get your money and take care of your kids'. That was pretty cool, yeah... It was (good advice). Just brought it down to basics..."
Charlie is now convinced their relationship is better than ever and he can always rely on his dad to help him out, adding, "We work together now. He's on the show. Yes, he's fabulous. And he's really funny. He doesn't even know it. He doesn't even know how good he is on the show... We're more friends than father/son relationship. But he's the guy I go to if there's something I can't figure. There's a lot I still can't. So why not go to the people who have been there before you?"