This driver provides a tiny alternative to the ACPI Button driver.
The tiny power button driver only handles the power button. Rather
than notifying userspace via the input layer or a netlink event, this
driver directly signals the init process to shut down.

This driver is particularly suitable for cloud and VM environments,
which use a simulated power button to initiate a controlled poweroff,
but which may not want to run a separate userspace daemon to process
input events.