Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Use codespell to fix lots of typos over frontends.

Manually verified to avoid false-positives.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

All those files are under GFDL 1.1 or later, with no invariant sections.
Tag them as such.

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

While userspace can detect discontinuity errors, it is useful to
also let Kernelspace reporting discontinuity, as it can help to
identify if the data loss happened either at Kernel or userspace side.

Update documentation accordingly.

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

The "reserved" field was a way, used at V4L2 API, to add new
data to existing structs without breaking userspace. However,
there are now clever ways of doing that, without needing to add
an uneeded overhead. So, get rid of them.

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

5 new ioctls were added to the DVB demux API, in order to
handle memory maped I/O. Add documentation for them.

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