Cleanup the media controller entities description:
- remove MEDIA_ENT_T_DEVNODE and MEDIA_ENT_T_V4L2_SUBDEV entity
  types, as they don't mean anything;
- add MEDIA_ENT_T_UNKNOWN with a proper description;
- remove ALSA and FB entity types. Those should not be used, as
  the types are deprecated. We'll soon be adidng ALSA, but with
  a different entity namespace;
- improve the description of some entities.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Put the legacy MEDIA_ENT_* macros under a #ifndef __KERNEL__,
in order to be sure that none of those old symbols are used
inside the Kernel.
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Don't use anymore the type/subtype entity data/macros
inside the Kernel.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Instead of abusing MEDIA_ENT_T_V4L2_SUBDEV, initialize
new subdev entities as MEDIA_ENT_T_UNKNOWN.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As we're getting rid of an specific number range for the V4L2 subdev,
we need to replace the check for MEDIA_ENT_T_V4L2_SUBDEV by a macro.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This driver is abusing MEDIA_ENT_T_V4L2_SUBDEV:

- it uses a hack to check if the remote entity is a subdev;
- it still uses the legacy entity subtype check macro, that
  will be removed soon.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The driver creates two subdevs, one for the image sensor pixel array
(and the related readout logic) and one for an ISP.

The first subdev already uses the MEDIA_ENT_T_V4L2_SUBDEV_SENSOR type,
but the second subdev isn't a sensor pixel array.

So, rename the second subdev as MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This sensor driver is abusing MEDIA_ENT_T_V4L2_SUBDEV, creating
some subdevs with a non-existing type.

As this is a sensor driver, one of the entries is
MEDIA_ENT_T_CAM_SENSOR. The other one will be using
MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN, because the subdev is not
any of the already existing types.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

On omap3/omap4/davinci drivers, MEDIA_ENT_T_V4L2_SUBDEV macro is
abused in order to "simplify" the pad checks.

Basically, it does a logical or of this macro, in order to check
for a local index and if the entity is either a subdev or not.

As we'll get rid of MEDIA_ENT_T_V4L2_SUBDEV macro, replace it by
2 << 16 where it occurs, and add a note saying that the code
there is actually a hack.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Instead of relying on media subtype, use the new macros to detect
if an entity is a subdev or an A/V DMA entity.

Please note that most drivers assume that there's just AV_DMA or
V4L2 subdevs. This is not true anymore, as we've added MC support
for DVB, and there are plans to add support for ALSA and FB/DRM
too.

Ok, on the current pipelines supported by those drivers, just V4L
stuff are there, but, assuming that some day a pipeline that also
works with other subsystems will ever added, it is better to add
explicit checks for the AV_DMA stuff.
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As we'll be removing entity subtypes from the Kernel, we need
to provide a way for drivers and core to check if a given
entity is represented by a V4L2 subdev or if it is an V4L2
I/O entity (typically with DMA).

Drivers that create entities that don't belong to any defined subdev
category should use MEDIA_ENT_T_V4L2_SUBDEV_UNKNOWN.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that interfaces and entities are distinct, it makes no sense
of keeping something named as MEDIA_ENT_T_DEVNODE_DVB_foo.

Made via this script:
	for i in $(git grep -l MEDIA_ENT_T|grep -v uapi/linux/media.h); do sed s,MEDIA_ENT_T_DEVNODE_DVB_,MEDIA_ENT_T_DVB_, <$i >a && mv a $i; done
	for i in $(git grep -l MEDIA_ENT_T|grep -v uapi/linux/media.h); do sed s,MEDIA_ENT_T_DVB_DVR,MEDIA_ENT_T_DVB_TSOUT, <$i >a && mv a $i; done
	for i in $(git grep -l MEDIA_ENT_T|grep -v uapi/linux/media.h); do sed s,MEDIA_ENT_T_DVB_FE,MEDIA_ENT_T_DVB_DEMOD, <$i >a && mv a $i; done
	for i in $(git grep -l MEDIA_ENT_T|grep -v uapi/linux/media.h); do sed s,MEDIA_ENT_T_DVB_NET,MEDIA_ENT_T_DVB_DEMOD_NET_DECAP, <$i >a && mv a $i; done
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that interfaces and entities are distinct, it makes no sense
of keeping something named as MEDIA_ENT_T_DEVNODE.

This change was done with this script:

	for i in $(git grep -l MEDIA_ENT_T|grep -v uapi/linux/media.h); do sed s,MEDIA_ENT_T_DEVNODE_V4L,MEDIA_ENT_T_V4L2_VIDEO, <$i >a && mv a $i; done
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that interfaces got created, we need to fix the entity
namespace.

So, let's create a consistent new namespace and add backward
compatibility macros to keep the old namespace preserved.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Some interfaces indirectly control multiple entities.
Add support for those.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media device should list the interface objects, so add a linked list
for those interfaces in struct media_device.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that the infrastruct for that is set, add support for
interfaces.

Please notice that we're missing two links:
	DVB FE intf    -> tuner
	DVB demux intf -> dvr

Those should be added latter, after having the entire graph
set. With the current infrastructure, those should be added
at dvb_create_media_graph(), but it would also require some
extra core changes, to allow the function to enumerate the
interfaces.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

As we'll be adding other interface types in the future, put the
common interface create code on a separate function.
Suggested-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that we have a new graph object called "interfaces", we
need to be able to link them to the entities.

Add a linked list to the interfaces to allow them to be
linked to the entities.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Remove entity name from the link as this exists only if the object
type is PAD on both link ends.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

By adding an union at media_link, we get for free a way to
represent interface->entity links.

No need to change anything at the code, just at the internal
header file.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The media_entity_add_link() function takes an entity
as an argument just to get the list head.

Make it more generic by changing the function argument
to list_head.

No functional changes.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The entire logic that represent graph links were developed on a
time where there were no needs to dynamic remove links. So,
although links are created/removed one by one via some
functions, they're stored as an array inside the entity struct.

As the array may grow, there's a logic inside the code that
checks if the amount of space is not enough to store
the needed links. If it isn't the core uses krealloc()
to change the size of the link, with is bad, as it
leaves the memory fragmented.

So, convert links into a list.

Also, currently,  both source and sink entities need the link
at the graph traversal logic inside media_entity. So there's
a logic duplicating all links. That makes it to spend
twice the memory needed. This is not a big deal for today's
usage, where the number of links are not big.

Yet, if during the MC workshop discussions, it was said that
IIO graphs could have up to 4,000 entities. So, we may
want to remove the duplication on some future. The problem
is that it would require a separate linked list to store
the backlinks inside the entity, or to use a more complex
algorithm to do graph backlink traversal, with is something
that the current graph traversal inside the core can't cope
with. So, let's postpone a such change if/when it is actually
needed.

It should also be noticed that the media_link structure uses
44 bytes on 32-bit architectures and 84 bytes on 64-bit
architecture. It will thus be allocated out of the 64-bytes and
96-bytes pools respectively. That's a 12.5% memory waste on
64-bit architectures and 31.25% on 32-bit architecture.
A linked list is less efficient than an array in this case, but
this could later be optimized if we can get rid of the reverse
links (with would reduce memory allocation by 50%).
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Links are graph objects that represent the links of two already
existing objects in the graph.

While with the current implementation, it is possible to create
the links earlier, It doesn't make any sense to allow linking
two objects when they are not both created.

So, remove the code that would be handling those early-created
links and add a BUG_ON() to ensure that.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The smiapp driver creates the pads links before the media entity is
registered with the media device. This doesn't work now that object
IDs are used to create links so the media_device has to be set.

Move entity registration logic before pads links creation.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The uvc driver creates the pads links before the media entity is
registered with the media device. This doesn't work now that obj
IDs are used to create links so the media_device has to be set.

Move entities registration logic before pads links creation.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The vsp1 driver initializes the entities and creates the pads links
before the entities are registered with the media device. This doesn't
work now that object IDs are used to create links so the media_device
has to be set.

Split out the pads links creation from the entity initialization so are
made after the entities registration.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The vsp1 driver creates the pads links before the media entities are
registered with the media device. This doesn't work now that object
IDs are used to create links so the media_device has to be set.

Move entities registration logic before pads links creation.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The omap4iss driver initializes the entities and creates the pads links
before the entities are registered with the media device. This does not
work now that object IDs are used to create links so the media_device
has to be set.

Split out the pads links creation from the entity initialization so are
made after the entities registration.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The omap3isp driver parses the graph endpoints to know how many subdevices
needs to be registered async and register notifiers callbacks for to know
when these are bound and when the async registrations are completed.

Currently the entities pad are linked with the correct ISP input interface
when the subdevs are bound but it happens before entitities are registered
with the media device so that won't work now that the entity links list is
initialized on device registration.

So instead creating the pad links when the subdevice is bound, create them
on the complete callback once all the subdevices have been bound but only
try to create for the ones that have a bus configuration set during bound.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The omap3isp driver initializes the entities and creates the pads links
before the entities are registered with the media device. This does not
work now that object IDs are used to create links so the media_device
has to be set.

Split out the pads links creation from the entity initialization so the links
are created after the entities have been registered with the media device.
Suggested-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Interfaces are different than entities: they represent a
Kernel<->userspace interaction, while entities represent a
piece of hardware/firmware/software that executes a function.

Let's distinguish them by creating a separate structure to
store the interfaces.

Later patches should change the existing drivers and logic
to split the current interface embedded inside the entity
structure (device nodes) into a separate object of the graph.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Declare the interface types that will be used by the new
G_TOPOLOGY ioctl that will be defined later on.

For now, we need those types, as they'll be used on the
internal structs associated with the new media_interface
graph object defined on the next patch.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Now that the struct media_entity .parent field is unused, it can be
safely removed. Since all the previous users were converted to use
the .mdev field from the embedded struct media_gobj instead.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The struct media_entity has a .parent field that stores a pointer
to the parent struct media_device. But recently a media_gobj was
embedded into the entities and since struct media_gojb already has
a pointer to a struct media_device in the .mdev field, the .parent
field becomes redundant and can be removed.

This patch replaces all the usage of .parent by .graph_obj.mdev so
that field will become unused and can be removed on a later patch.

No functional changes.

The transformation was made using the following coccinelle spatch:

@@
struct media_entity *me;
@@

- me->parent
+ me->graph_obj.mdev

@@
struct media_entity *link;
@@

- link->source->entity->parent
+ link->source->entity->graph_obj.mdev

@@
struct exynos_video_entity *ve;
@@

- ve->vdev.entity.parent
+ ve->vdev.entity.graph_obj.mdev
Suggested-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

With the new API, a link can be either between two PADs or between an interface
and an entity. So, we need to use a better name for the function that create
links between two pads.

So, rename the such function to media_create_pad_link().

No functional changes.

This patch was created via this shell script:
	for i in $(find drivers/media -name '*.[ch]' -type f) $(find drivers/staging/media -name '*.[ch]' -type f) $(find include/ -name '*.h' -type f) ; do sed s,media_entity_create_link,media_create_pad_link,g <$i >a && mv a $i; done
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

It helps to check if the media controller is doing the
right thing with the object creation and removal.

No extra code/data will be produced if DEBUG or
CONFIG_DYNAMIC_DEBUG is not enabled.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

We can only free the media device after being sure that no
graph object is used.

In order to help tracking it, let's add debug messages
that will print when the media controller gets registered
or unregistered.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Just like entities and pads, links also need to have unique
Object IDs along a given media controller.

So, let's add a media_gobj inside it and initialize
the object then a new link is created.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

PADs also need unique object IDs that won't conflict with
the entity object IDs.

The pad objects are currently created via media_entity_init()
and, once created, never change.

While this will likely change in the future in order to
support dynamic changes, for now we'll keep PADs as arrays
and initialize the media_gobj embedded structs when
registering the entity.
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>