Drop the 'experimental' annotations. The only remaining part of the API
that is still marked 'experimental' are the debug ioctls/structs, and
that is intentional. Only the v4l2-dbg application should use those.

All others have been around for years, so it is time to drop the
'experimental' designation.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add documentation for V4L SDR transmitter (output) devices.
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

SDR receiver has ADC (Analog-to-Digital Converter) and SDR transmitter
has DAC (Digital-to-Analog Converter). Originally I though it could
be good idea to have own type for receiver and transmitter, but now I
feel one common type for SDR is enough. So lets rename it.
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Acked-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
[hans.verkuil@cisco.com: this was added in 4.4, so update 4.2 to 4.4]
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

New field buffersize was added to inform application maximum
buffer size used. Add it to documentation too.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Update the DocBook files accordingly.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Cc: Antti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Rename v4l2_format_sdr to v4l2_sdr_format in order to keep it in
line with other formats.
Reported-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Let it be experimental still as all SDR drivers are in staging.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

Document V4L2 SDR interface.

Cc: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>