The touchscreen controller is an Atmel mXT1386, a 4-chip controller designed for touchscreens up to 15.6". It supports as many as 15 distinct inputs.

This is a large application version of the mXT224 touchscreen controller used in the Motorola Atrix.

The mXT1386 is Atmel's largest application touchscreen controller. The next smallest handles screen sizes up to 10.1", suggesting that this one was designed specifically for devices like the Xoom.