The troubled actor drifted apart from his relatives last year (11) in the midst of a public breakdown which involved trashing a New York hotel suite, rehab and hospitalisations, and culminated in his firing from hit TV show Two and a Half Men.
The West Wing star publicly reached out to Charlie in a bid to get him to address his addiction issues and a year later, the Hot Shots actor is back on track with a new TV show, Anger Management.
Charlie has even invited his father to play his on-screen dad in one episode, and they sat down for a joint interview with U.S. news show Entertainment Tonight to show off their newly-united front.
When asked about the pair's current relationship, Charlie calls it "solid" while laughing and joking with his father, before praising his dad for standing by him despite everything he went through.
He says, "It was a satisfying feeling to have gone through all that thing... so publicly and everything else. Gone to hell. And come back, I would say, fairly quickly. Extremely quickly. In little over a year."
Martin adds, "I'm his number one fan."