/sys/bus/pnp/devices$ ls -al
total 0
drwxr-xr-x 2 root root 0 2008-03-10 12:55 .
drwxr-xr-x 4 root root 0 2008-01-21 16:35 ..
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:00 -> ../../../devices/pnp0/00:00
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:01 -> ../../../devices/pnp0/00:01
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:02 -> ../../../devices/pnp0/00:02
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:03 -> ../../../devices/pnp0/00:03
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:04 -> ../../../devices/pnp0/00:04
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:05 -> ../../../devices/pnp0/00:05
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:06 -> ../../../devices/pnp0/00:06
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:07 -> ../../../devices/pnp0/00:07
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:08 -> ../../../devices/pnp0/00:08
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:09 -> ../../../devices/pnp0/00:09
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:0a -> ../../../devices/pnp0/00:0a
lrwxrwxrwx 1 root root 0 2008-03-10 12:55 00:0b -> ../../../devices/pnp0/00:0b

$ cd /sys/bus/pnp/devices

$ ls
00:00  00:01  00:02  00:03  00:04  00:05  00:06  00:07  00:08  00:09  00:0a  00:0b

$ readlink -f 00:00
/sys/devices/pnp0/00:00

$ cd 00:00
user@machine:/sys/bus/pnp/devices/00:00$