This patch implements the agreed upon 1:31 integer encoded pulse/duration
struct for ir-core raw decoders. All decoders have been tested after the
change. Comments are welcome.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

The imon driver I've previously submitted and have been porting to
use ir-core needs to use ir_g_keycode_from_table, as ir_keydown is
not sufficient, due to these things having really oddball hardware
decoders in them. This just moves the function declaration from
ir-core-priv.h over to ir-core.h.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

ir-core.h has the kABI to be used by the bridge drivers, when needing to register
IR protocols and pass IR events. However, the same file also contains IR subsystem
internal calls, meant to be used inside ir-core and between ir-core and the raw
decoders.

Better to move those functions to an internal header, for some reasons:

1) Header will be a little more cleaner;

2) It avoids the need of recompile everything (bridge/hardware drivers, etc),
   just because a new decoder were added, or some other internal change were needed;

3) Better organize the ir-core API, splitting the functions that are internal to
   IR core and the ancillary drivers (decoders, lirc_dev) from the features that
   should be exported to IR subsystem clients.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/IR/ir-raw-event.c is currently written with the assumption
that all "raw" hardware will generate events only on state change (i.e.
when a pulse or space starts).

However, some hardware (like mceusb, probably the most popular IR receiver
out there) only generates duration data (and that data is buffered so using
any kind of timing on the data is futile).

Furthermore, using signed int's to represent pulse/space durations is a
well-known approach when writing ir decoders.

With this patch:

- s64 int's are used to represent pulse/space durations in ns

- a workqueue is used to decode the ir protocols outside of interrupt context

- #defines are added to make decoders clearer

- decoder reset is implemented by passing a zero duration to the kfifo queue
  and decoders are updated accordingly

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Some devices have in-hardware Remote Controller decoder, while others
need a software decoder to get the IR code. As each software decoder
can be enabled/disabled individually, allowing multiple protocol
decoding capability.

On the other hand, hardware decoders have a limited protocol
support, often being able of decoding just one protocol each time.
So, each type needs a different set of capabilities to control the
supported protocol(s).

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

A few hardware Remote Controller decoders, even using a standard protocol,
aren't able to provide the entire scancode. Due to that, the capability
of using other IR's are limited on those hardware.

Adds a way to indicate to ir-core what are the bits that the hardware
provides, from a scancode, allowing the addition of a complete IR table
to the kernel and allowing a limited support for changing the Remote
Controller on those devices.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

The keymaps don't need to be recompiled every time a change at ir-core.h
happens, since it only depends on rc-map defines. By moving those
definitions to the proper header, the code became cleaner, and avoids
needing to recompile all the RC maps every time a non-related change
is introduced.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Now that the decoders are state machine, there's no need to create
an ancillary buffer while decoding the protocol. Just call the decoders
code directly, event by event.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This decoder is also based on a state machine, just like the NEC protocol
decoder. It is pedantic in the sense that accepts only 14 bits. As there
are some variants that outputs less bits, it needs to be improved to also
handle those.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Rewrites the keyup/keydown logic in drivers/media/IR/ir-keytable.c.

All knowledge of keystates etc is now internal to ir-keytable.c
and not scattered around ir-raw-event.c and ir-nec-decoder.c (where
it doesn't belong).

In addition, I've changed the API slightly so that ir_input_dev is
passed as the first argument rather than input_dev. If we're ever
going to support multiple keytables we need to move towards making
ir_input_dev the main interface from a driver POV and obscure away
the input_dev as an implementational detail in ir-core.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>