Re: input devices handling

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Mon, Jan 12, 2009 at 11:19:20PM +0300, Michael Tokarev wrote:
> [Repost for:
> Message-ID: <48FF9737.5050207@msgid.tls.msk.ru>
> Date:	Thu, 23 Oct 2008 01:12:23 +0400
> To: linux-kernel@vger.kernel.org,
> which is a repost of earlier message with similar
> content/question, both went unanswered]
> 
> Hello.
> 
> Similar question has been asked already by me in the past,
> regarding "conversions" of ACPI button events to "keyboard
> events".  The talk is about how one is supposed to handle
> various "common" "meta-buttons" like Power, Sleep, and so
> on.
> 
> Before, there was /proc/acpi/event and /etc/acpid/* stuff,
> and it was easy (but somewhat clumsy) to act to system power
> down button.  But the "proper way" now is to handle
> /dev/input/event* interface, because such "Power" button can
> be on a keyboard, on a remote control, and so on.  I understand
> the idea, and I like it.
> 
> But now the question.  How one supposed to find all the devices
> which generate such events?  I mean not about scanning the /dev
> directory, which can be done once at startup, but about REscanning
> it to find which NEW keyboards and the like appeared since last
> (re)scan and which were removed.
> 

You can either listen to hotplug events or poll (select)
/proc/bus/input/devices - waiters are woken up every time we
add or remove a new input device or a new input handler.

-- 
Dmitry