Re: Query last reported event state

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

On Tue, Nov 24, 2009 at 09:57:29PM +0200, Mika Westerberg wrote:
> Hi Daniel,
> 
> On Tue, Nov 24, 2009 at 06:33:56PM +0100, Daniel Mack wrote:
> > Hi,
> > 
> > is there a way to query the last state an input device reported,
> > preferably even for a special key mask? When a button is pressed and a
> > userspace application is started, it should be able to figure out the
> > current state, especially because those GPIO signals are likely
> > connected to other peripherals to report arbitrary events in the system.
> > Is there any such framework for that purpose?
> 
> Not sure whether this helps, but you can look <linux/input.h> and
> check what ioctl()s it provides for this purpose. At least there
> seems to be:
> 	EVIOCGKEY - get global keystate
> 	EVIOCGSW - get all switch states
> 	EVIOCGBIT - get event bits
> 
> Maybe you can use some of these to query current status of input events.

This is correct. The first 2 ioctls are there so userspace can get the
current state of input device. The last ioctl is to query capabilities,
not the state though.

-- 
Dmitry