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>

With the new dmx mmap interface, those two syscalls are now
handled by the subsystem. Document them.

This patch is based on the V4L2 text for those ioctls.

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

This commit adds a new property DTV_SCRAMBLING_SEQUENCE_INDEX.

This 18 bit field, when present, carries the index of the DVB-S2 physical
layer scrambling sequence as defined in clause 5.5.4 of EN 302 307.
There is no explicit signalling method to convey scrambling sequence index
to the receiver. If S2 satellite delivery system descriptor is available
it can be used to read the scrambling sequence index (EN 300 468 table 41).

By default, gold scrambling sequence index 0 is used. The valid scrambling
sequence index range is from 0 to 262142.

Increase the DVB API version in order userspace to be aware of the changes.

Signed-off-by: Athanasios Oikonomou <athoik@gmail.com>
Acked-by: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

That section is too outdated and got superseded by DVBv5 and
by libdvbv5.

Maybe some day we'll end adding updated examples there, but
while nobody has time or interest of doing that, just mention
that there and get rid of the current examples for good.

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

That's the last DVB kAPI that misses documentation.

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

There are several problems with regards to the return of
FE_SET_PROPERTY. The original idea were to return per-property
return codes via tvp->result field, and to return an updated
set of values.

However, that never worked. What's actually implemented is:

- the FE_SET_PROPERTY implementation doesn't call .get_frontend
  callback in order to get the actual parameters after return;

- the tvp->result field is only filled if there's no error.
  So, it is always filled with zero;

- FE_SET_PROPERTY doesn't call memdup_user() nor any other
  copy_to_user() function. So, any changes to the properties
  will be lost;

- FE_SET_PROPERTY is declared as a write-only ioctl (IOW).

While we could fix the above, it could cause regressions.

So, let's just assume what the code really does, updating
the documentation accordingly and removing the logic that
would update the discarded tvp->result.

Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

There's a chapter for the legacy APIs. Move the frontend DVBv3
API to it, and update the chapter's introduction accordingly.

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

The "Table of Contents" of a PDF file is generated only once,
at the beginning fo the output. It doesn't produce it on
each part.

So, don't output this text on each part of the document.

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