Re: [RFC] Should we create a raw input interface for IR's ? - Was: Re: [PATCH 1/3 v2] lirc core device driver infrastructure

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(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.

Unfortunately with most hardware decoders the code that you get is only
remotely related to the actual code sent. Most RC-5 decoders strip off
start bits.

I would include only the actual data bits in the payload anyway.

Toggle-bits are thrown away. NEC decoders usually don't pass
through the address part.

Too bad. But information which isn't provided by the hardware can't be passed up anyway, no matter what kernel/userspace interface is used. Gone is gone.

There is no common standard which bit is sent first, LSB or MSB.

Input layer would have to define a bit order. And drivers which get it the other way from the hardware have to convert. Or maybe signal the order and the input core then will convert if needed.

Checksums are thrown away.

Don't include them.

To sum it up: I don't think this information will be useful at all for
lircd or anyone else.

Why not? With RC5 remotes applications can get the device address bits for example, which right now are simply get lost in the ir code -> keycode conversion step.

Actually lircd does not even know anything about
actual protocols. We only distinguish between certain protocol types, like
Manchester encoded, space encoded, pulse encoded etc. Everything else like
the actual timing is fully configurable.

I know that lircd does matching instead of decoding, which allows to handle unknown encodings. Thats why I think there will always be cases which only lircd will be able to handle (using raw samples).

That doesn't make attempts to actually decode the IR samples a useless exercise though ;)

cheers,
  Gerd

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