media: vidtv: mux: Add check and kfree for kstrdup

Add check for the return value of kstrdup() and return the error
if it fails in order to avoid NULL pointer dereference.
Moreover, use kfree() in the later error handling in order to avoid
memory leak.

Fixes: c2f78f0cb294 ("media: vidtv: psi: add a Network Information Table (NIT)")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: vidtv: simplify EIT write function

- pass struct vidtv_psi_eit_write_args as a pointer;
- avoid initializing struct fields multiple times.

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

media: vidtv: simplify NIT write function

- pass struct vidtv_psi_nit_write_args as a pointer;
- avoid initializing struct fields multiple times.

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

media: vidtv: simplify SDT write function

- pass struct vidtv_psi_sdt_write_args as a pointer;
- avoid initializing struct fields multiple times.

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

media: vidtv: cleanup PMT write table function

- Pass struct vidtv_psi_pmt_write_args as a pointer;
- Avoid initializing structs multiple times.

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

media: vidtv: cleanup PAT write function

Avoid initializing the structs multiple times and pass the
PAT struct as a pointer, instead of a var.

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

media: vidtv: add a PID entry for the NIT table

On normal TS streams, the NIT table has its own entry at PAT,
but not at PMT.

While here, properly handle alloc problems when creating
PMT entries.

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

media: vidtv: cleanup null packet initialization logic

Initialize the destination buffer/size and the initial
offset when creating the local var.

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

media: vidtv: pre-initialize mux arrays

Instead of first zeroing all fields at the mux structs and
then filling, do some initialization for the const data
when they're created.

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

media: vidtv: do some cleanups at the driver

Do some cleanups at the coding style of the driver:
- remove "inline" declarations;
- use reverse xmas-tree for local var declarations;
- Adjust some indent to avoid breaking 80-cols;
- Cleanup some comments.

No functional changes.

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

media: vidtv: avoid copying data for PES structs

Minimize the number of data copies and initialization at
the code, passing them as pointers instead of duplicating
the data.

The only case where we're keeping the data copy is at
vidtv_pes_write_h(), as it needs a copy of the passed
arguments. On such case, we're being more explicit.

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

media: vidtv: avoid data copy when initializing the multiplexer

Initialize the fields of the arguments directly when
declaring it, and pass the args as a pointer, instead of
copying them.

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

media: vidtv: add error checks

Currently, there are not checks if something gets bad during
memory allocation: it will simply use NULL pointers and
crash.

Add error path at the logic which allocates memory for the
MPEG-TS generator code, propagating the errors up to the
vidtv_bridge. Now, if something wents bad, start_streaming
will return an error that userspace can detect:

ERROR DMX_SET_PES_FILTER failed (PID = 0x2000): 12 Cannot allocate memory

and the driver doesn't crash.

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

media: vidtv: reorganize includes

- Place the includes on alphabetical order;
- get rid of asm/byteorder.h;
- add bug.h at vidtv_s302m.c, as it is needed by
inux/fixp-arith.h

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

media: vidtv: psi: Implement an Event Information Table (EIT)

Implement an Event Information Table (EIT) as per EN 300 468
5.2.4.

The EIT provides information in chronological order regarding
the events contained within each service.

For now only present event information is supported.

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: vidtv: psi: add a Network Information Table (NIT)

Add a Network Information Table (NIT) as specified in ETSI EN 300 468.

This table conveys information relating to the physical organization of
the multiplexes carried via a given network and the characteristics of
the network itself.

It is conveyed in the output of vidtv as packets with TS PID of 0x0010

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: vidtv: rewrite the adaption field logic

When compared with a stream generated via ffmpeg, it can be
noticed that the PES doesn't contain any PCR info. That could
cause problems with userspace decoding. So, rewrite the
logic that fills the adaptation info, in order to allow it
to add PCR frames without breaking frame alignment.

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

media: vidtv: simplify PCR logic to get jiffies

There's no need to have a check when setting timing.past_jiffies,
as we can simply do the initialization earlier at vidtv_mux_init().

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

media: vidtv: fix build on 32bit architectures

Fix the following error for builds on 32bit architectures:

ERROR: modpost: "__udivdi3"
[drivers/media/test-drivers/vidtv/dvb-vidtv-bridge.ko] undefined!

Which is due to 64bit divisions that did not go through the helpers
in linux/math64.h

As vidtv_mux_check_mux_rate was not operational in its current form,
drop the entire function while it is not fixed properly.

For now, call vidtv_mux_pad_with_nulls with a constant number of packets
to avoid warnings due to unused functions when building this driver.

The 64bit division used in the s302m is not needed, remove them and use
a fixed number of frames and a constant PTS increment instead.

Fixes: f90cf6079bf67988 ("media: vidtv: add a bridge driver")
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: vidtv: add a poor guy's simulation to preBER stats

A typical digital TV stream has errors that are corrected
by Viterbi. While the error rate after Viterbi is usually
zero, with good signals, there are some chances of getting
random errors before that, which are auto-corrected by
the error code algorithm.

Add a poor guy's implementation that would show some
noise at the pre-BER part of the demod.

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

media: vidtv: increment byte and block counters

Add support for incrementing DVBv5 stats for block counters
and post/pre BER byte counts.

For now, the errors won't be incremented yet.

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

media: vidtv: prefer using dev_foo() instead of pr_foo()

It is better to use the higher level dev_foo() than pr_foo()
for printks.

Change them at vidtv at the more trivial places.

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

media: vidtv: add a bridge driver

Digital TV devices consist of several independent hardware components
which are controlled by different drivers.
Each media device is controlled by a group of cooperating drivers with the
bridge driver as the main driver.

This patch adds a bridge driver for the Virtual Digital TV driver [vidtv].

The bridge driver binds to the other drivers, that is, vidtv_tuner and
vidtv_demod and implements the digital demux logic, providing userspace
with a MPEG Transport Stream.

The MPEG related code is split in the following way:

- vidtv_ts: code to work with MPEG TS packets, such as TS headers,
adaptation fields, PCR packets and NULL packets.

- vidtv_psi: this is the PSI generator.
PSI packets contain general information about a MPEG Transport Stream.
A PSI generator is needed so userspace apps can retrieve information
about the Transport Stream and eventually tune into a (dummy) channel.

Because the generator is implemented in a separate file, it can be
reused elsewhere in the media subsystem.

Currently vidtv supports working with 3 PSI tables:
PAT, PMT and SDT.

- vidtv_pes: implements the PES logic to convert encoder data into
MPEG TS packets. These can then be fed into a TS multiplexer and
eventually into userspace.

- vidtv_s302m: implements a S302M encoder to make it possible to
insert PCM audio data in the generated MPEG Transport Stream.

This shall enable passing an audio signal into userspace so it can be
decoded and played by media software.

- vidtv_channels: Implements a 'channel' abstraction

When vidtv boots, it will create some hardcoded channels:

Their services will be concatenated to populate the SDT.
Their programs will be concatenated to populate the PAT
For each program in the PAT, a PMT section will be created
The PMT section for a channel will be assigned its streams.
Every stream will have its corresponding encoder polled to produce TS
packets
These packets may be interleaved by the mux and then delivered to the
bridge

- vidtv_mux - Implements a MPEG TS mux, loosely based on the ffmpeg
implementation

The multiplexer is responsible for polling encoders,
interleaving packets, padding the resulting stream with NULL packets if
necessary and then delivering the resulting TS packets to the bridge
driver so it can feed the demux.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>