Linux kernel driver for some Synaptics USB devices
This is a driver for some Synaptics USB devices for kernel 2.6 and higher. A version of this driver propagated into the main linux kernel tree and is available since kernel version 3.4-rc1; cPad display support is not yet included there. In order to make the cPad display work, you need this driver. Follow the installation instructions.
For newer touchpads with multitouch support, have a look at hid-multitouch.
In order to make use of the cPad display device, you may want to have a look at: