5.1 The Sony I/O Control Device

If you want these features:

Jogdial events (the small wheel on the side of Vaios)
capture button events (only on Vaio Picturebook series)
Fn keys

it is best to build your own kernel. As of Linux Kernel 2.4.7, these options have been included in the kernel.

When doing so, select the Sony Vaio Programmable I/O Control Device support option within the Character devices submenu, or (CONFIG_SONYPI=m).

You can read more on this driver in the file /path/to/kernel_source/Documentation/sonypi.txt. After installing the kernel, as sonypi.txt states, you will have to insert these lines in /etc/modules.conf:

alias char-major-10-250 sonypi
options sonypi minor=250 fnkeyinit=1

(Debian users: Don't edit /etc/modules.conf directly. Add those lines to /etc/modutils/sony and run update-modules.)

Then, create the node for this device:

mknod /dev/sonypi c 10 250

The utilities and daemon for these features can be downloaded from http://www.alcove-labs.org/en/software/sonypi/.