00:00.0 Host bridge: Intel Corporation Mobile 915GM/PM/GMS/910GML Express Processor to DRAM Controller (rev 03)
00:01.0 PCI bridge: Intel Corporation Mobile 915GM/PM Express PCI Express Root Port (rev 03)
00:1b.0 Audio device: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) PCI Express Port 1 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #3 (rev 03)
00:1d.3 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB UHCI #4 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) USB2 EHCI Controller (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev d3)
00:1f.0 ISA bridge: Intel Corporation 82801FBM (ICH6M) LPC Interface Bridge (rev 03)
00:1f.2 IDE interface: Intel Corporation 82801FBM (ICH6M) SATA Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) SMBus Controller (rev 03)
01:00.0 VGA compatible controller: nVidia Corporation NV43 [GeForce Go 6600] (rev a2)
06:05.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5788 Gigabit Ethernet (rev 03)
06:07.0 Network controller: Intel Corporation PRO/Wireless 2915ABG Network Connection (rev 05)
06:09.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev b3)
06:09.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C552 IEEE 1394 Controller (rev 08)
06:09.2 Generic system peripheral [0805]: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 17)
06:09.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 08)
06:09.4 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev 03)

The M50 Baako has a built in Bluetooth device.

cat /proc/bus/usb/devices shows this:

...
T:  Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=e0(unk. ) Sub=01 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0a5c ProdID=200a Rev= 0.01
S:  Manufacturer=Broadcom
S:  Product=Broadcom Bluetooth Module
C:* #Ifs= 4 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=1ms
E:  Ad=82(I) Atr=02(Bulk) MxPS=  64 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms
I:  If#= 1 Alt= 0 #EPs= 2 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   0 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   0 Ivl=1ms
I:  If#= 1 Alt= 1 #EPs= 2 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   9 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   9 Ivl=1ms
I:* If#= 1 Alt= 2 #EPs= 2 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  17 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  17 Ivl=1ms
I:  If#= 1 Alt= 3 #EPs= 2 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  32 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  32 Ivl=1ms
I:  If#= 1 Alt= 4 #EPs= 2 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  64 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  64 Ivl=1ms
I:  If#= 1 Alt= 5 #EPs= 2 Cls=e0(unk. ) Sub=01 Prot=01 Driver=hci_usb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  64 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  64 Ivl=1ms
I:* If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
E:  Ad=84(I) Atr=02(Bulk) MxPS=  32 Ivl=0ms
E:  Ad=04(O) Atr=02(Bulk) MxPS=  32 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 0 Cls=fe(app. ) Sub=01 Prot=00 Driver=(none)
...

or for better reading, lsusb output:

...
Bus 004 Device 002: ID 0a5c:200a Broadcom Corp. Bluetooth dongle
...

Needed Linux kernel modules:

<M>   L2CAP protocol support
<M>   SCO links support
<M>   RFCOMM protocol support
[*]     RFCOMM TTY support
<M>   BNEP protocol support
[*]     Multicast filter support
[*]     Protocol filter support
<M>   HIDP protocol support

and

<M> HCI USB driver
[*]   SCO (voice) support
< > HCI SDIO driver
< > HCI UART driver
< > HCI BCM203x USB driver
< > HCI BPA10x USB driver
< > HCI BlueFRITZ! USB driver
< > HCI VHCI (Virtual HCI device) driver

After booting the new kernel, load hci_usb

modprobe hci_usb

With the help of hciconfig -a from the bluez-utils, we see this:

hci0:   Type: USB
        BD Address: 00:00:00:00:00:00 ACL MTU: 0:0 SCO MTU: 0:0
        DOWN 
        RX bytes:0 acl:0 sco:0 events:0 errors:0
        TX bytes:0 acl:0 sco:0 commands:0 errors:0

Bringing up the device:

hciconfig hci0 up

After this the output of hciconfig -a has changed:

hci0:   Type: USB
        BD Address: 00:10:C6:81:A4:7C ACL MTU: 377:10 SCO MTU: 64:8
        UP RUNNING 
        RX bytes:348 acl:0 sco:0 events:11 errors:0
        TX bytes:38 acl:0 sco:0 commands:11 errors:0
        Features: 0xff 0xfe 0x0d 0x38 0x08 0x08 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
        Link policy: 
        Link mode: SLAVE ACCEPT 
        Name: 'Broadcom Bluetooth Module'
        Class: 0x000000
        Service Classes: Unspecified
        Device Class: Miscellaneous, 
        HCI Ver: 1.2 (0x2) HCI Rev: 0x2 LMP Ver: 1.2 (0x2) LMP Subver: 0x6965
        Manufacturer: Broadcom Corporation (15)

Quick check if there are some other Bluetooth devices arround, hcitool scan (also from the bluez-utils)

Scanning ...
        00:19:1D:7F:93:34       Nintendo RVL-CNT-01

It found one of my Nintendo Wii remotes.

You can find out what keycode is generated if you press a key by using xev.

Content of $HOME/.Xmodmap

keycode 160 = XF86AudioMute
keycode 174 = XF86AudioLowerVolume
keycode 176 = XF86AudioRaiseVolume

Put this in your .xinitrc or some other script which is executed if X is started.

test -r $HOME/.Xmodmap && xmodmap $HOME/.Xmodmap

Now all keys or keycombinations which produce a keycode of 160, 174 or 176 have gotten a keysym name.

There are several possibilities of assigning functionality to those keysyms, I am using xbindkeys.

Relevant lines of my configuration file ($HOME/.xbindkeysrc)

"amixer set PCM 1-"
XF86AudioLowerVolume
"amixer set PCM 1+"
XF86AudioRaiseVolume
"amixer set PCM toggle"
XF86AudioMute

Again put this in your .xinitrc or some other script which is executed if X is started.

test -r $HOME/.xbindkeysrc && xbindkeys &