http://qkpm2ov2rjhjkhfsftskqho77uj5rewd5y44unkf6cb7tdhaxwcvh2id.onion/books/apc/APCUPSD%20User%20Manual.html
A USB UPS needs all of these drivers -- the USB device filesystem,
the USB hub, the Human Interface Device subsystem driver, and the
Human Interface Device driver. If you are compiling your own
kernel, you want to enable CONFIG_USB
CONFIG_USB_HID
CONFIG_USB_HIDDEV
CONFIG_USB_DEVICEFS ...as well as at least one USB Host Controller Driver...