media: imon_raw: respect DMA coherency

No buffer can be embedded inside a descriptor, not even a simple be64.
Use a separate kmalloc()

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: rc: harmonize infrared durations to microseconds

rc-core kapi uses nanoseconds for infrared durations for receiving, and
microseconds for sending. The uapi already uses microseconds for both,
so this patch does not change the uapi.

Infrared durations do not need nanosecond resolution. IR protocols do not
have durations shorter than about 100 microseconds. Some IR hardware offers
250 microseconds resolution, which is sufficient for most protocols.
Better hardware has 50 microsecond resolution and is enough for every
protocol I am aware off.

Unify on microseconds everywhere. This simplifies the code since less
conversion between microseconds and nanoseconds needs to be done.

This affects:
- rx_resolution member of struct rc_dev
- timeout member of struct rc_dev
- duration member in struct ir_raw_event

Cc: "Bruno Prémont" <bonbons@linux-vserver.org>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Patrick Lerda <patrick9876@free.fr>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: "David Härdeman" <david@hardeman.nu>
Cc: Benjamin Valentin <benpicco@googlemail.com>
Cc: Antti Palosaari <crope@iki.fi>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: imon_raw: simplify loop

The code for pulse and space is the same so remove duplication.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: imon_raw: prevent "nonsensical timing event of duration 0"

Sometimes the device sends IR data which is all space, no pulses
whatsoever. Add the end of this the driver will put the rc device into
idle mode when it already is in idle mode. The following will be logged:

rc rc0: nonsensical timing event of duration 0
rc rc0: two consecutive events of type space

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: imon_raw: simplify and explain bit operations

This code needs some explanation.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: rc: imon_raw: use fls rather than loop per bit

Previously, the code would loop for each of the 40 bits. Now it will
branch for each edge in the IR, which will be much less.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: rc: Remove init_ir_raw_event and DEFINE_IR_RAW_EVENT macros

This can be done with c99 initializers, which makes the code cleaner
and more transparent. It does require gcc 4.6, because of this bug
in earlier versions:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10676

Since commit cafa0010cd51 ("Raise the minimum required gcc version to
4.6"), this is the case.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: rc: new driver for early iMon device

These devices were supported by the lirc_imon.c driver which was removed
from staging in commit f41003a23a02 ("[media] staging: lirc_imon: port
remaining usb ids to imon and remove").

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>