Dimmer switches are big in all lighting applications but they particularly difficult for LED lamps.
- What are the best ways to design flickerless dimmers for LED lamps?
- What are the design gotchas to look out for when designing the dimmer for the LED?
Here is an app note covering the topic:
Here is a ready made evaluation board.
Looks like everyone makes a driver, Google "Triac dimmable LED driver"