Missing Key-codes from input.h file.

anish kumar anish198519851985 at gmail.com
Wed Jun 27 07:49:50 EDT 2012


On Wed, 2012-06-27 at 11:20 +0530, Dharam Kumar wrote:
> On Tue, Jun 26, 2012 at 1:13 PM, Matthias Brugger
> <matthias.bgg at googlemail.com> wrote:
> > On 06/26/2012 08:47 AM, Dharam Kumar wrote:
> >>
> >> On Tue, Jun 26, 2012 at 12:02 PM, anish kumar
> >> <anish198519851985 at gmail.com> wrote:
> >>>
> >>> On Mon, 2012-06-25 at 23:24 +0530, Dharam Kumar wrote:
> >>>>
> >>>> On Mon, Jun 25, 2012 at 10:47 PM, anish kumar
> >>>> <anish198519851985 at gmail.com> wrote:
> >>>>>
> >>>>> On Mon, 2012-06-25 at 18:52 +0530, Dharam Kumar wrote:
> >>>>>>
> >>>>>> Hi,
> >>>>>> I'm working on a module which is an input device and hence it needs to
> >>>>>> report certain key events.
> >>>>>>
> >>>>>> While browsing through the <linux/input.h>, I did find most of the
> >>>>>> key-codes(which I need to use)already defined but not all.
> >>>>>>
> >>>>>>
> >>>>>> Few of the KEY_xxx which i could not find are:
> >>>>>>
> >>>>>>
> >>>>>> a.) A Key for going to the previous channel.
> >>>>>> b.) Keys for Moving upper-right, lower-right, upper-left and
> >>>>>> lower-left direction(probably a GUI(grid of icons),where you move
> >>>>>> diagonally)
> >>>>>> d.) A key for Subpicture (this 'subpicture' key is deeined in
> >>>>>> CEA-931C).
> >>>>>
> >>>>> I think you are interested in the user space implementation of
> >>>>> the keys reported by the input subsystem of kernel.
> >>>>> Keys reported by the driver->input subsystem->reported to user space.
> >>>>>
> >>>>> I am not sure about linux way of reporting keys but in android the key
> >>>>> is reported at a particular sysfs file and this sysfs file is read by
> >>>>> eventhub.cpp.This file in turn is responsible for sending the events
> >>>>> to particular application and it is the responsibility of the
> >>>>> application how they interpret this keys.It can interpret events by
> >>>>> moving diagonally a pointer/touch or going left/right.
> >>>>>
> >>>> Thanks Anish ! To be clear, i just want to know the key-code
> >>>> which will be used by the Input Subsytem of the Kernel.
> >>>>
> >>>> For example, in <linux/input.h> file you will find a lot of #defines
> >>>> like the below,mapping different kind of key events to some key-code
> >>>> or value :
> >>>> #define KEY_UP                 0xXYZ
> >>>> #define KEY_DOWN         0xABC and so on...
> >>>>
> >>>> Now, I'm looking for key events like:
> >>>> #define KEY_PREVIOUSCHANNEL   <???>
> >>>> #define KEY_RIGHTUP                         <???>
> >>>> #define kEY_RIGHTLEFT                     <???>
> >>>> #define kEY_SUBPICTURE                 <???> and so on...
> >>>>
> >>>> You are probably right , that Userspace reads the key-events/key-codes
> >>>> from certain sysfs entries exported by Android Linux Kernel and these
> >>>> key-codes/events will be handled accordingly by the respective
> >>>> Framework/Application. But  I'm really not interested in how and what
> >>>> Userspace gets from Kernel.
> >>>> I'm interested in what values the Kernel or input subsystem will
> >>>> provide to such keys..
> >>>
> >>> Do you have such keys in your device KEY_RIGHTUP?
> >>>
> >> Yes, my device is supposed to support such keys:
> >> RIGHTUP --> moves cursor upper-right direction.
> >> RIGHTDOWN ---> moves cursor lower-right direction.
> >> and similar keys for upper-left and lower-left cursor direction.
> >> Sadly, I could not find any #define in input.h file for such key events.
> >
> >
> > From your response I interpret that you have some kind of custom key-pad, or
> > anything similar which is not a standard keyboard.
> >
> You are right that it is not a standard keyboard. In fact, these are
> Remote Controller(or Remote Control) keys as  defined in MHL
> Specifications(www.mhltech.org).
> Now, MHL Specs is closely related to HDMI specifications.Hence, my
> assumption is that such keys might be the part of HDMI-CEC
> specifications and would have been picked from there to MHL Specs.
> 
> Although the current MHL specs does not shed much light on how these
> 'missing' Remote Control Keys will be handled by the device, what is
> still notable that these remote controller keys(if 'they' are part of
> HDMI-CEC standards) has not been added to Linux Kernel.
> As you said, it is highly possible that nobody had encountered the use
case which is unlikely.You can really maximise your chances by sending
mail to LKML and V4L2 group.
> of these keys. In any case, I need to dig more.
> 
> Thanks for your response !
> 
> > If there are no such defines in the Kernel, it's probably because no one has
> > had the need for them up to now.
> >
> > I think the implementation should be done as Anish described beforehand.
> > Anyway you can add some defines to your Kernel if this is a requirement for
> > you.
> >
> > Regards,
> > Matthias
> >
> >
> >>>>> Not sure if this is what you are interested in but would have been
> >>>>> better if you had described the problem in more detail.
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> Does anybody have any idea about this?
> >>>>>>
> >>>>>>
> >>>>>> -
> >>>>>> Dharam
> >>>>>> _______________________________________________
> >>>>>> Kernelnewbies mailing list
> >>>>>> Kernelnewbies at kernelnewbies.org
> >>>>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> >>>>>
> >>>>>
> >>>>>
> >>>
> >>>
> >>
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> >
> >





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