The ELAN 3320KD-3100 multi-touch controller chip is a 64-pin QFD package. In the Asus T300CHI it is behind a BCM20730-A1KFBG Bluetooth radio controller in a detachable keyboard/trackpad dock. 

It identifies with the Asus ID 0B05:8502.

It works as a mouse but there is no scroll or gesture support.

$ cat /proc/bus/input/devices
...
I: Bus=0005 Vendor=0b05 Product=8502 Version=0001
N: Name="ASUS T300CHI DOCKING"
P: Phys=34:02:86:fc:ad:59
S: Sysfs=/devices/pci0000:00/0000:00:14.0/usb1/1-4/1-4:1.0/bluetooth/hci0/hci0:256/0005:0B05:8502.002B/input/input57
U: Uniq=1c:b7:2c:04:c7:fe
H: Handlers=sysrq kbd mouse3 event15 leds 
B: PROP=0
B: EV=12001f
B: KEY=20 0 0 2000 40000000000000 30000 1000002000007 ff9f387ad9405fff febeffdfffefffff fffffffffffffffe
B: REL=303
B: ABS=70000000000
B: MSC=10
B: LED=1f