Instead of copying exactly the same code on all USB devices,
add an ancillary routine that will create and fill the
struct media_device with the values imported from the USB
device.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Don't let it be included twice, to avoid compiler issues.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Instead of copyping the same code on all PCI devices that
would have a media controller, add a core ancillary routine.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The em28xx_v4l2_create_media_graph() is almost generic enough to
be at the core, as an ancillary function. Make it even more generic,
by getting rid of em28xx-specific code, relying only at the
media_device, in order to discover all entities found on PC-customer's
hardware and add it at the V4L2 core.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

We also need to standardize the PAD index macros for demods,
as they all should look the same in a media graph.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The audio and video IF-PLL decoders have one sink and one source
PAD. Add macro names for those pads and describe what kind of
signals are represented at such pads.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Analog TV tuners have a separate output pad for the audio
IF or audio sampled data. This pad is connected to a different
chipset.

Add an extra pad for it and improve the documentation.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The customer PC hardware can be shipped with lots of different
configurations, as vendors use to replace some of the chips on
their hardware along the time. All drivers that support such
devices are prepared to handle the hardware differences, using
their own auto-probing logic.

They do it in a way that number of inputs and outputs for a given
hardware type doesn't change.

Now that we're adding media controller capabilities to those drivers,
we need to standardize the number of inputs and outputs for each
hardware type, as we want to have a generic function at the V4L2
core that would create the links for the entities that are expected
on such hardware.

Such standard is already there for tuners, but tuner.h is not the
best place to store such data, as we'll need to add definitions also
for analog TV demodulators.

Also, we'll need a place to put a set of MC handling functions. So,
let's create a v4l2-mc.h to store such kind of definitions.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>