linux-toradex.git/drivers/media/media-entity.c, branch v3.12-rc2

[media] media: Add support for circular graph traversal

2013-08-18T10:16:48+00:00

The graph traversal API (media_entity_graph_walk_*) doesn't support
cyclic graphs and will fail to correctly walk a graph when circular
links exist. Support circular graph traversal by checking whether an
entity has already been visited before pushing it to the stack.

Signed-off-by: Laurent Pinchart 
Acked-by: Sakari Ailus 
Acked-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Add a function removing all links of a media entity

2013-06-19T11:59:54+00:00

This function allows to remove all media entity's links to other
entities, leaving no references to a media entity's links array
at its remote entities.
Currently, when a driver of some entity is removed it will free its
media entities links[] array, leaving dangling pointers at other
entities that are part of same media graph. This is troublesome when
drivers of a media device entities are in separate kernel modules,
removing only some modules will leave others in an incorrect state.
This function is intended to be used when an entity is being
unregistered from a media device.
With an assumption that normally the media links should be created
between media entities registered to a media device, with the graph
mutex held.

Signed-off-by: Sylwester Nawrocki 
Reviewed-by: Andrzej Hajda 
Signed-off-by: Kyungmin Park 
Acked-by: Laurent Pinchart 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Change media device link_notify behaviour

2013-06-13T01:16:27+00:00

Currently the media device link_notify callback is invoked before the
actual change of state of a link when the link is being enabled, and
after the actual change of state when the link is being disabled.
This doesn't allow a media device driver to perform any operations
on a full graph before a link is disabled, as well as performing
any tasks on a modified graph right after a link's state is changed.
This patch modifies signature of the link_notify callback. This
callback is now called always before and after a link's state change.
To distinguish the notifications a 'notification' argument is added
to the link_notify callback: MEDIA_DEV_NOTIFY_PRE_LINK_CH indicates
notification before link's state change and
MEDIA_DEV_NOTIFY_POST_LINK_CH corresponds to a notification after
link flags change.

[mchehab@redhat.com: whitespace cleanups]
Signed-off-by: Sylwester Nawrocki 
Signed-off-by: Kyungmin Park 
Acked-by: Laurent Pinchart 
Acked-by: Sakari Ailus 

Signed-off-by: Mauro Carvalho Chehab

[media] media: Rename media_entity_remote_source to media_entity_remote_pad

2013-06-09T00:47:11+00:00

Function media_entity_remote_source actually returns the remote pad to
the given one, regardless if this is the source or the sink pad.
Name media_entity_remote_pad is more adequate for this function.

Signed-off-by: Andrzej Hajda 
Signed-off-by: Kyungmin Park 
Acked-by: Sakari Ailus 
Acked-by: Sylwester Nawrocki 
Signed-off-by: Laurent Pinchart 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Add link_validate() op to check links to the sink pad

2012-05-14T11:44:11+00:00

The purpose of the link_validate() op is to allow an entity driver to ensure
that the properties of the pads at the both ends of the link are suitable
for starting the pipeline. link_validate is called on sink pads on active
links which belong to the active part of the graph.

Signed-off-by: Sakari Ailus 
Acked-by: Laurent Pinchart 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Properly handle link flags in link setup, link notify callback

2011-04-17T10:43:32+00:00

The link flags were not properly handled in __media_entity_setup_link
which could lead to link_notify callback to be called when the flags are
not modified. Fix this.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Pipelines and media streams

2011-03-22T07:53:17+00:00

Drivers often need to associate pipeline objects to entities, and to
take stream state into account when configuring entities and links. The
pipeline API helps drivers manage that information.

When starting streaming, drivers call media_entity_pipeline_start(). The
function marks all entities connected to the given entity through
enabled links, either directly or indirectly, as streaming. Similarly,
when stopping the stream, drivers call media_entity_pipeline_stop().

The media_entity_pipeline_start() function takes a pointer to a media
pipeline and stores it in every entity in the graph. Drivers should
embed the media_pipeline structure in higher-level pipeline structures
and can then access the pipeline through the media_entity structure.

Link configuration will fail with -EBUSY by default if either end of the
link is a streaming entity, unless the link is marked with the
MEDIA_LNK_FL_DYNAMIC flag.

Signed-off-by: Laurent Pinchart 
Acked-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Links setup

2011-03-22T07:53:16+00:00

Create the following ioctl and implement it at the media device level to
setup links.

- MEDIA_IOC_SETUP_LINK: Modify the properties of a given link

The only property that can currently be modified is the ENABLED link
flag to enable/disable a link. Links marked with the IMMUTABLE link flag
can not be enabled or disabled.

Enabling or disabling a link has effects on entities' use count. Those
changes are automatically propagated through the graph.

Signed-off-by: Laurent Pinchart 
Signed-off-by: Stanimir Varbanov 
Signed-off-by: Sakari Ailus 
Acked-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Entity use count

2011-03-22T07:53:12+00:00

Due to the wide differences between drivers regarding power management
needs, the media controller does not implement power management.
However, the media_entity structure includes a use_count field that
media drivers can use to track the number of users of every entity for
power management needs.

The use_count field is owned by media drivers and must not be touched by
entity drivers. Access to the field must be protected by the media
device graph_mutex lock.

Signed-off-by: Laurent Pinchart 
Acked-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

[media] media: Entity graph traversal

2011-03-22T07:53:11+00:00

Add media entity graph traversal. The traversal follows enabled links by
depth first. Traversing graph backwards is prevented by comparing the next
possible entity in the graph with the previous one. Multiply connected
graphs are thus not supported.

Signed-off-by: Sakari Ailus 
Signed-off-by: Laurent Pinchart 
Signed-off-by: Vimarsh Zutshi 
Acked-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab