Comment # 9 on bug 1193817 from Jiri Slaby

The code looks to create a mouse device by intention:
 * The Logitech K400 keyboard has an embedded touchpad which is seen
 * as a mouse from the OS point of view.

To have some progress on this topic, you'd better ask upstream maintainers
about this:
Jiri Kosina <jikos@kernel.org>
Benjamin Tissoires <benjamin.tissoires@redhat.com>
linux-input@vger.kernel.org