[Gta04-owner] X keycode of the Power/AUX buttons

[Neil Jerram]

On 12.11.2011 09:05, NeilBrown wrote:
> On Sat, 12 Nov 2011 09:55:32 +0100 "Dr. H. Nikolaus Schaller"
> <hns at goldelico.com> wrote:
>
>>
>> Am 12.11.2011 um 08:35 schrieb Dr. H. Nikolaus Schaller:
>>
>> >
>> > Am 11.11.2011 um 17:09 schrieb Neil Jerram:
>> >
>> >> I'm still not clear on whether and how there is a mapping from 
>> the values like KEY_OK that are fed _into_the_bottom_ of evdev, and 
>> the keycode values like <POWR> that come _out_of_the_top_ of evdev and 
>> feed into X.

Finally, from evdev_key.c:

#define MIN_KEYCODE 8
...
void
EvdevKeyProcess (InputInfoPtr pInfo, struct input_event *ev)
{
     int keycode = ev->code + MIN_KEYCODE;
...

So the magic mapping algorithm is just "+ 8".  Hence KEY_POWER (116) -> 
X keycode 124 as observed.

>> Maybe the best choice is to do it identical to the GTA02.
>>
>> Who knows the kernel key code of the GTA02?
>
> Power button returns code 116 - Power
> AUX button returns  code 169 - Phone
> The head-set button returns code 207 - Play

Yes, these look good.  Then,

- the AUX X keycode would be 177, for which XKB has keysym XF86Phone.  
The kernel constant for 169 is KEY_PHONE.

- the head-set button would be 215, for which XKB has keysym 
XF86AudioPlay.  The kernel constant for 207 is KEY_PLAY.


           Neil