Before you get started install the newest host tools for your SEGGER in my case I installed the Debian package of version V4.98b. On first start the JLinExe installs the apropriate Firmware.

$ JLinkExe -if jtag -device CC2650F128
SEGGER J-Link Commander V4.98b ('?' for help)
Compiled Apr 10 2015 20:27:38
Updating firmware:  J-Link V9 compiled Apr 10 2015 10:51:08
Replacing firmware: J-Link V9 compiled Feb 13 2015 20:37:28
Waiting for new firmware to boot
New firmware booted successfully

On the SimpleLink™ Bluetooth Smart®/Multi-Standard SensorTag they use the CC2650 with 128kB of Flash ROM. So you have to select -device CC2650F128 when running JLinkExe At the moment it seems the CC2650 only supports JTAG debugging and not the more common SWI debug like STM32 do use. Anyway The Segger can run both modes.

After a succesful firmawre update the communication looks like this

SEGGER J-Link Commander V4.98b ('?' for help)
Compiled Apr 10 2015 20:27:38
Info: Device "CC2650F128" selected.
DLL version V4.98b, compiled Apr 10 2015 20:27:35
Firmware: J-Link V9 compiled Apr 10 2015 10:51:08
Hardware: V9.30
Feature(s): FlashBP, GDB
VTarget = 2.800V
Info: TotalIRLen = 10, IRPrint = 0x0011
Info: Found Cortex-M3 r2p1, Little endian.
Info: FPUnit: 6 code (BP) slots and 2 literal slots
Info: CoreSight components:
Info: ROMTbl 0 @ E00FF000
Info: ROMTbl 0 [0]: FFF0F000, CID: B105E00D, PID: 000BB000 SCS
Info: ROMTbl 0 [1]: FFF02000, CID: B105E00D, PID: 003BB002 DWT
Info: ROMTbl 0 [2]: FFF03000, CID: B105E00D, PID: 002BB003 FPB
Info: ROMTbl 0 [3]: FFF01000, CID: B105E00D, PID: 003BB001 ITM
Info: ROMTbl 0 [4]: FFF41000, CID: B105900D, PID: 003BB923 TPIU-Lite
Found 2 JTAG devices, Total IRLen = 10:
 #0 Id: 0x4BA00477, IRLen: 04, IRPrint: 0x1, CoreSight JTAG-DP (ARM)
 #1 Id: 0x8B99A02F, IRLen: 06, IRPrint: 0x1, TI ICEPick
Cortex-M3 identified.
Target interface speed: 100 kHz

The next step is to create a firmware backup of the original firmware. This is needed because this little beast at the momemnt denies to build its firmware under Linux. The CodeComposerStudio Projekt is using some Windows Tools to build and expects a specific directory layout.