You mean the Synaptics Gesture Suite, which provides enhanced multitouch functionality, etc., not basic pointing drivers.
Sorry, even though it's "free", Synaptics has decreed you can only get that from your laptop manufacturer, presumably one who has decided to play very friendly with Linux (and those are few!):
SGS-L is provided free of charge to Synaptics OEM/ODM partners when ordered with Synaptics TouchPad and ClickPad™ products. To find out more about Synaptics Gesture Suite for Linux, please contact your Synaptics sales representative.