[BRLTTY] Filter keyboard keypresses on Linux

[Samuel Thibault]

Mario Lang, le Sat 15 Dec 2007 23:11:40 +0100, a écrit :
> Samuel Thibault <samuel.thibault at ens-lyon.org> writes:
> 
> > Mario Lang, le Sat 15 Dec 2007 22:29:27 +0100, a écrit :
> >> Dave Mielke <dave at mielke.cc> writes:
> >> 
> >> > If we want most of the code to be common within the core then we probably need 
> >> > a scheme for portabilizing key representations. Does one already exist or do we 
> >> > need to invent it?
> >> 
> >> AIUI, what linux currently uses is derived from the HID
> >> standard (Human Interface Devices).
> >
> > Mmm, what do you mean by "what linux uses"? Internally, Linux uses
> > keycodes, which are derived from AT2 scancodes. For USB, it uses the
> > usb_kbd_keycode[] array for translating from HID to keycodes.
> 
> I mean the codes defined in input.h, are those keycodes?

Ah, no indeed these are not keycodes, as the header says, "Most of the
keys/buttons are modeled after USB HUT 1.12"

> What standard defines that 138 is HELP?  Is this a linux specific
> thing, or is it defined somewhere else?

In that particular case it looks like it is in the USB standard.

I don't know how good the coverage of the USB standard is, but I'd say
that it is better than AT scancodes.

Samuel