linuxconsole-dev

Q: interface / way to "generate" input events ?

[Ralf A. <ra...@sh...>]

Hello,

after reading input.txt in the kernel documentation my question is:
 - Is there a way / interface to generate (feed into the kernel)
   events into the kernel?
   I mean - the opposite to /dev/input/eventX (that can be read) -
   i would like to use an interface (e.g. a named pipe) that i can
   feed data into (e.g. the bytes that normally arrive from a serially
   attached device) so that they trigger events like a real device.
Background - that would permit to use a network attached input device by
just "tunneling" its data to the final destination.
It would also permit very easy simulation / test of devices. Before i try
myself - does that mechanism exist already? Which semantics / API does it
have?

best regards
 ralf

Re: Q: interface / way to "generate" input events ?

[Vojtech P. <vo...@su...>]

On Fri, Jun 22, 2001 at 01:41:02PM +0200, Ralf Ackermann wrote:
> Hello,
> 
> after reading input.txt in the kernel documentation my question is:
>  - Is there a way / interface to generate (feed into the kernel)
>    events into the kernel?
>    I mean - the opposite to /dev/input/eventX (that can be read) -
>    i would like to use an interface (e.g. a named pipe) that i can
>    feed data into (e.g. the bytes that normally arrive from a serially
>    attached device) so that they trigger events like a real device.
> Background - that would permit to use a network attached input device by
> just "tunneling" its data to the final destination.
> It would also permit very easy simulation / test of devices. Before i try
> myself - does that mechanism exist already? Which semantics / API does it
> have?

For complete functionality like this you'll need something ala evdev,
but turned inside out. It hasn't been written yet, though I was planning
it.

You can also write() events to evdev, but that won't create the device,
of course.

-- 
Vojtech Pavlik
SuSE Labs

interface / way to "generate" input events ?

[Ralf A. <ra...@sh...>]

On Fri, 22 Jun 2001, Vojtech Pavlik wrote:

> On Fri, Jun 22, 2001 at 01:41:02PM +0200, Ralf Ackermann wrote:
> > Hello,
> >
> > after reading input.txt in the kernel documentation my question is:
> >  - Is there a way / interface to generate (feed into the kernel)
> >    events into the kernel?
> >    I mean - the opposite to /dev/input/eventX (that can be read) -
> For complete functionality like this you'll need something ala evdev,
> but turned inside out. It hasn't been written yet, though I was planning
> it.

Based on the information/code from Alessandro Rubini
	http://www.linux.it/kerneldocs/input/input.html
i've made a code snippet that lets you feed in keyboard (or other,
e.g. mouse, if you just do minor changes) events via a device /dev/key_in
into the kernel from user space. That makes testing input adapter programs
that can even be network-transparent (e.g. you feed in the input data via
the net) very easy.
	http://www.iptel-now.de/HOWTO/INPUT_DECOMPOSED/input_decomposed.html
There's a small Tcl/Tk program in a subdirectory that shows how it works
and lets you test.

I intend to use this mechanism for the PS/2-via serial input adapter
	http://www.iptel-now.de/HOWTO/PS2SER/ps2ser.html
that interleaves PS/2 keyboard and mouse input via just 1 serial line.
Keyboard input will be fed in this way whereas mouse input (for X only) uses the
a2x mechanism. The receiver program doing this can easily run in user
space now (at least for developing / testing).
I know how to combine the 2 serial outputs from the uCs doing the
PS/2=>serial conversion via just an AND gate and a mutex using 2 uC
input/output lines now - thanks to the wearable list that gave me valuable
hints. Complete schematics/code to be posted soon.

Hopefully the code can be an utility/example explaining how to use the
input layer in a "decomposed way" in general.

regards
 ralf


-- Best regards,
 Ralf Ackermann