How to enable Bluetooth on ubuntu 15.10

[xuexingyang]

BlueZ version 5.26 was default installation on ubuntu 15.10, it's great.
connect on Bluetooth chip via USB-UART interface with ubuntu.

While from Bluetooth manager, cannot enable Bluetooth and the enable/disable still on gray color.
Using "hcitool dev" command, cannot found anything.

found /dev/ttyUSB0

My question is:

What 's the step to enable bluetooth on ubuntu with USB-2-UART interface BT chip module(controller side)?
Thanks in advance.

[xuexingyang]

if driver must be supported by local BT chip????