On 11/25/09 19:20, Devin Heitmueller wrote:
On Wed, Nov 25, 2009 at 1:07 PM, Jarod Wilson<jarod@xxxxxxxxxxxx>
wrote:
Took me a minute to figure out exactly what you were talking
about. You're referring to the current in-kernel decoding done on
an ad-hoc basis for assorted remotes bundled with capture devices,
correct?
Admittedly, unifying those and the lirc driven devices hasn't
really been on my radar.
I think at the end of the day we'll want to have all IR drivers use the
same interface. The way the current in-kernel input layer drivers work
obviously isn't perfect too, so we *must* consider both worlds to get a
good solution for long-term ...
This is one of the key use cases I would be very concerned with. For
many users who have bought tuner products, the bundled remotes work
"out-of-the-box", regardless of whether lircd is installed.
I bet this simply isn't going to change.
I have no objection so much as to saying "well, you have to install
the lircd service now", but there needs to be a way for the driver to
automatically tell lirc what the default remote control should be,
to avoid a regression in functionality.
*Requiring* lircd for the current in-kernel drivers doesn't make sense
at all. Allowing lircd being used so it can do some more advanced stuff
makes sense though.
This is why I think we really should put together a list of use
cases, so that we can see how any given proposal addresses those use
cases. I offered to do such, but nobody seemed really interested in
this.
Lets have a look at the problems the current input layer bits have
compared to lirc:
(1) ir code (say rc5) -> keycode conversion looses information.
I think this can easily be addressed by adding a IR event type to the
input layer, which could look like this:
input_event->type = EV_IR
input_event->code = IR_RC5
input_event->value = <rc5 value>
In case the 32bit value is too small we might want send two events
instead, with ->code being set to IR_<code>_1 and IR_<code>_2
Advantages:
* Applications (including lircd) can get access to the unmodified
rc5/rc6/... codes.
* All the ir-code -> keycode mapping magic can be handled by the
core input layer then. All the driver needs to do is to pass on
the information which keymap should be loaded by default (for the
bundled remote if any). The configuration can happen in userspace
(sysfs attribute + udev + small utility in tools/ir/).
* lirc drivers which get ir codes from the hardware can be converted
to pure input layer drivers without regressions. lircd is not
required any more.
(2) input layer doesn't give access to the raw samples.
Not sure how to deal with that best. Passing them through the input
layer would certainly be possible to hack up. But what would be the
point? The input layer wouldn't do any processing on them. It wouldn't
buy us much. So we might want to simply stick with todays lirc
interface for the raw samples.
Drivers which support both ir codes (be it by hardware or by in-kernel
decoding) and raw samples would register two devices then, one input
device and one lirc device. It would probably a good idea to stop
sending events to the input layer as soon as someone (most likely lircd)
opens the lirc device to avoid keystrokes showing up twice.
By default the in-kernel bits will be at work, but optionally you can
have lircd grab the raw samples and do fancy advanced decoding.
(3) input layer doesn't allow transmitting IR codes.
If we keep the lirc interface for raw samples anyway, then we can keep
it for sending too, problem solved ;) How does sending hardware work
btw? Do they all accept just raw samples? Or does some hardware also
accept ir-codes?
cheers,
Gerd
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