Re: acpi/apm events as inputs: how to handle?

[Michael Tokarev <mjt@tls.msk.ru>]

Dmitry Torokhov wrote:
> Hi Michael,

Hello!

[]
> There are keyboards (USB, PS2) with Sleep and Suspend buttons
> that are not related to ACPI nor APM. We had 2 options - add
> an input handler that would translate input events into ACPI
> events and feed /proc/acpi/event[*] or go other way around and
> use input layer for delivering suspend and sleep requests for
> all types of keyboards/buttons, including ACPI buttons. The
> secons option is better because userspace solution using input
> layer will not be tied to a particular technology (ACPI) and
> can be used on other platforms as well.

Aha, this makes sense.
And it brings a few questions, too.

As far as I can see, there's little information about how to
actually use the input interface.  Let's suppose I'm about to
write an application (a daemon) that should replace acpid --
it's handling of the said buttons (power and sleep).  How to
find the right devices?  Should it use /dev/input/event* or
something else?  How about handling hot-plugged devices like
new (and removed) keyboards? (And yes, my keyboard has a sleep
button.)

And by the way, what INPUT can one expect from a PC speaker?
input: PC Speaker as /devices/platform/pcspkr/input/input0

Thanks!

/mjt