Redock Thinkpad UltraBay - http://xqms.github.com/blog/redock_thinkpad_ultrabay.html

dock.c

static void eject_dock(struct dock_station *ds)
{
        struct acpi_object_list arg_list;
        union acpi_object arg;
        acpi_status status;
        acpi_handle tmp;

        /* all dock devices should have _EJ0, but check anyway */
        status = acpi_get_handle(ds->handle, "_EJ0", &tmp);
        if (ACPI_FAILURE(status)) {
                pr_debug("No _EJ0 support for dock device\n");
                return;
        }

        arg_list.count = 1;
        arg_list.pointer = &arg;
        arg.type = ACPI_TYPE_INTEGER;
        arg.integer.value = 1;

        status = acpi_evaluate_object(ds->handle, "_EJ0", &arg_list, NULL);
        if (ACPI_FAILURE(status))
                pr_debug("Failed to evaluate _EJ0!\n");
}

dsdt_1

Method (_EJ0, 1, NotSerialized)
{
    \_SB.PCI0.LPC.EC.BEJ0 (Arg0)
}

dsdt_2

Method (BEJ0, 1, NotSerialized)
{
    If (Arg0)
    {
        BDIS ()
        LED (0x04, 0x00)
        \BHDP (0x01, 0x00)
        Store (0x01, BSTS)
        If (BHKE)
        {
            Store (0x00, BHKE)
            \_SB.PCI0.LPC.EC.HKEY.MHKQ (0x3003)
        }
    }
    Else
    {
        LED (0x04, 0x80)
        Store (0x00, BSTS)
    }
}

dsdt_3

Method (BDIS, 0, NotSerialized)
{
    If (LNot (\_SB.PCI0.LPC.CSON))
    {
        Store (0x01, \_SB.PCI0.LPC.CSON)
        Store (0x0F, \IDET)
    }
}

Method (BPON, 1, NotSerialized)
{
    If (\_SB.PCI0.LPC.CSON)
    {
        Store (0x00, \_SB.PCI0.LPC.CSON)
    }
}

undock.sh

echo undock > /sys/devices/platform/dock.2/undock