I'm using a CSR-Casira with BlueCore4-Chip and the following firmware-version:
The chip reports version 4279 (0x10b7):
  "cyt_8unified_fl_bt2.0_22_0702091828_encr56 2007-02-09"

I've the problem connecting the device to linux. I've tried out to setup a connection over USB and UART and both failed using Bluez3.18.

with USB:
-connecting with USB "hciconfig" says Casira is connected, but in "DOWN" modus. try to get it up with "hciconfig hci0 up" gives the error "Can't init device hci0: Connection timed out (110)"
-also "bccmd -t bcsp" says that the connection timed out
-Nevertheless "dfutool" archive/upgrade works fine...

with UART:
-setting it up with "hciattach /dev/ttyS0 bcsp 57600" works and "hciconfig" gives the same output as with USB ("DOWN" modus)
-"hciconfig hci0 up" also timed out
-only thing changed is that "bccmd" now says that "device is not available"
-try to set it up with "ttyS1" also says that "connection timed out"; so I'm
 not sure if ttyS0 or ttyS1 is the right device...

For me it looks like there is something missing (any PS_KEY wrong or something)
because connection via USB and dfutool works. I know that with dfutool the chip
changes in another mode (DFU-MODE), but I'm wondering why the chip cannot be
changed into "RUNNING"-state.
The PS_KEYS are setup and are well configured I think...

Any advice or help?
Best regards,
Bernd Krause