PA-46 pilot reported loosing autopilot; autothrottle; yaw damper and trim during climbout resulting in inability to hold altitude. Pilot returned to the departure airport with ATC assistance. Allegedly; the issues were caused by an update to the G3000 system.

Narrative

Picked up airplane from annual inspection. After takeoff I had no Auto Pilot; Auto Throttle; Yaw Damper; or Trim because of a software update to the G3000. I struggled to maintain constant altitude because of no trim. Controller asked for altitude and I said 2200 ft. He advised to descend to 2000 ft. I advised that I was descending and was having problems with trim. Controller asked after another minute or so of intentions. I advised that I would like to return to ZZZ to have the problem addressed. Controller vectored me and asked if I was okay --I assume because I was having trouble maintaining a constant altitude. I varied from assigned (2000) between 1800 and 2200 ft. I was vectored for the approach and landed with no issues. Upon arrival; fire trucks had been deployed adjacent to the taxiway. Ground control asked if I needed further assistance and I said no; that I was having a trim issue and all was good. The controller was very professional and accommodating with my issue and in my opinion there was never a safety issue. I taxied to FBO; shut down; addressed the problem and subsequently re-filed and made the flight to ZZZ1.