With the current logic, each raw decoder needs to add a copy of the exact
same sysfs code. This is both unnecessary and also means that (re)loading
an IR driver after raw decoder modules have been loaded won't work as
expected.

This patch moves that logic into ir-raw-event and adds a single sysfs
file per device.

Reading that file returns something like:

	"rc5 [rc6] nec jvc [sony]"

(with enabled protocols in [] brackets)

Writing either "+protocol" or "-protocol" to that file will
enable or disable the according protocol decoder.

An additional benefit is that the disabling of a decoder will be
remembered across module removal/insertion so a previously
disabled decoder won't suddenly be activated again. The default
setting is to enable all decoders.

This is also necessary for the next patch which moves even more decoder
state into the central raw decoding structs.
Signed-off-by: NDavid Härdeman <david@hardeman.nu>
Acked-by: NJarod Wilson <jarod@redhat.com>
Tested-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Rather than registering all IR protocol decoders as enabled when bringing
up a new device, only enable the IR protocol decoder that matches the
keymap being loaded. Additional decoders can be enabled on the fly by
those that need to, either by twiddling sysfs bits or by using the
ir-keytable util from v4l-utils.

Functional testing done with the mceusb driver, and it behaves as expected,
only the rc6 decoder is enabled, keys are all handled properly, etc.
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

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

This patch adds NECx support to drivers/media/IR/ir-nec-decoder.c
Signed-off-by: NDavid Härdeman <david@hardeman.nu>
Signed-off-by: NMauro 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: NMauro 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: NDavid Härdeman <david@hardeman.nu>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Some spinlocks are not properly initialized on ir core:

[  471.714132] BUG: spinlock bad magic on CPU#0, modprobe/1899
[  471.719838]  lock: f92a08ac, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[  471.727301] Pid: 1899, comm: modprobe Not tainted 2.6.33 #36
[  471.733062] Call Trace:
[  471.735537]  [<c1498793>] ? printk+0x1d/0x22
[  471.739866]  [<c12694e3>] spin_bug+0xa3/0xf0
[  471.744224]  [<c126962d>] do_raw_spin_lock+0x7d/0x160
[  471.749364]  [<f92a01ff>] ? ir_rc5_register+0x6f/0xf0 [ir_rc5_decoder]

So, use static initialization for the static spinlocks, instead of the
dynamic ones (currently used), as proposed by David Härdeman on one
of his RFC patches.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

A previous cleanup patch removed more than needed. Re-add the logic that
disable the decoders.
Signed-off-by: NMauro 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: NMauro Carvalho Chehab <mchehab@redhat.com>

Remove dead code and properly name a few constants
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Thanks to Andy Walls <awalls@md.metrocast.net> for pointing me his
code, that gave me some ideas to better implement it.

After some work with saa7134 bits, I found a way to catch both IRQ
edge pulses. By enabling it, the NEC decoder can now take both
pulse and spaces into account, making it more precise.

Instead of the old strategy of handling the events all at once,
this code implements a state machine. Due to that, it handles
individual pulse or space events, validating them against the
protocol, producing a much more reliable decoding.

With the new implementation, the protocol trailer bits are properly
handled, making possible for the repeat key to work.

Also, the code is now capable of handling both NEC and NEC extended
IR devices. With NEC, it produces a 16 bits code, while with NEC
extended, a 24 bits code is returned.
Signed-off-by: NMauro 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: NDavid Härdeman <david@hardeman.nu>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

With the help of raw_register/raw_unregister, adds a sysfs group
associated with the decoder, inside the corresponding irrcv node.

Writing 1 to nec_decoder/enabled enables the decoder, while
writing 0 disables it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Some decoders and a lirc_dev interface may need some other operations to work.
For example: IR device register/unregister and ir_keydown events may need to
be tracked.

As some operations can occur in interrupt time, and a lock is needed to prevent
un-registering a decode while decoding a key, the lock needed to be convert
into a spin lock.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Instead of hardcoding the protocols into ir-core, add a register interface
for the IR protocol decoders, and convert ir-nec-decoder into a client of
ir-core.

With this approach, it is possible to dynamically load the needed IR protocols,
and to add a RAW IR interface module, registered as one IR raw protocol decoder.

This patch opens a way to register a lirc_dev interface to work as an userspace
IR protocol decoder.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

At raw_decode mode, the key is processed after the end of a timer. The
previous code resets the timer every time something is received at the IR
port. While this works fine with IR's that don't implement repeat, like
Avermedia RM-JX IR, it keeps waiting until keydown, on IR's that implement
NEC repeat command, like the Terratec yellow.

The solution is to change the behaviour to do the timeout after the first
received data.

The timeout is currently set to 15 ms, as it works fine with NEC protcocol.
It may need some adjustments to support other protocols and to better handle
spurious detections that may happen with some IR sensors.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

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

Adds a method to pass IR raw pulse/code events into ir-core. This is
needed in order to support LIRC. It also helps to move common code
from the drivers into the core.

In order to allow testing, it implements a simple NEC protocol decoder
at ir-nec-decoder.c file. The logic is about the same used at saa7134
driver that handles Avermedia M135A and Encore FM53 boards.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>