Re: uniform input device packets?

Vojtech Pavlik (vojtech@twilight.ucw.cz)
Thu, 25 Jun 1998 23:29:08 +0200


On Thu, Jun 25, 1998 at 12:46:55PM +0200, Pavel Machek wrote:

> > > > > I'd go for 4. We want to provide _lots_ of room to grow. Remember when
> > > > > 640k was enough for anybody? I think here 64k will do, but 256 is a bit
> > > > > short. (Yes, the current keyboard driver gets away with 128.)
> > > Whops. Memory-numbers-bad. I meant 3*.
> >
> > Good, I'm glad we agree here. So it's now:
> >
> > struct input_event {
> > __u32 timestamp;
>
> What does timestamp==1 mean? 1sec? 1msec? 1usec?

Not defined yet. I would go for 1 msec probably. Any pros/cons?

>
> > __u16 value;
> > __u16 number;
> > __u8 type;
> > __u8 device number; (Do we need this?)
> > };
>
> I would like structure to be 8bytes. (So 64bit machines could put it
> into register at once). 10bytes seems little weird size, to me.
>
> What about
>
> __u32 timestamp;
> __u16 value;
> __u8 type;
> __u8 spare;
>
> This is 8 bytes total.
>
> Where type==0: button press, type==1: button release (value is which
> button). Type >128 means (axis-128) moved.

Yes, this has already been discussed here. I still am not convinced which
way is better.

Vojtech

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