Claim the WACF005 device.  This is the pen display pointing device on
the HP Compaq tc1100 Tablet PC.  More information about using this
device, including using it as an X pointer device:

    http://www.theory.bham.ac.uk/staff/schofield/linux/tc1100/

Christopher Kemp <ck231@cam.ac.uk> did the legwork of determining that
the WACF005 is really just a plain old UART and doing an initial ACPI
driver (before we had PNPACPI), and David Ludlow <dave@adsllc.com>
confirmed that PNPACPI + the attached patch is now sufficient:

    pnp: Device 00:05 activated.
    ttyS4 at I/O 0x300 (irq = 4) is a 16550A
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>