The input_id builtin assigns the various ID_INPUT based on the exported evdev
bits. In some cases, the device may not have the properties required to label
a device as one specific type but the physical form factor is clear.
e.g. in the case of #7197 it's a tablet pad that does not have x/y axes which
the kernel exports for pads for historical reasons.
A custom override is needed, best to be solved with a hwdb entry.
Related #7197
Peter Hutterer