Commit 06b993af authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] doc-rst: media_drivers.rst: Fix paragraph headers for MC 



Fix the paragraph identation for the media controller
headers.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent d26a5d43

Documentation/media/media_drivers.rst

+24 −17
Original line number Diff line number Diff line
@@ -183,7 +183,8 @@ The media controller userspace API is documented in DocBook format in 
Documentation/DocBook/media/v4l/media-controller.xml. This document focus

on the kernel-side implementation of the media framework.



* Abstract media device model:

Abstract media device model

^^^^^^^^^^^^^^^^^^^^^^^^^^^



Discovering a device internal topology, and configuring it at runtime, is one

of the goals of the media framework. To achieve this, hardware devices are
@@ -205,8 +206,8 @@ A link is a point-to-point oriented connection between two pads, either 
on the same entity or on different entities. Data flows from a source

pad to a sink pad.





* Media device:

Media device

^^^^^^^^^^^^



A media device is represented by a struct &media_device instance, defined in

include/media/media-device.h. Allocation of the structure is handled by the
@@ -218,9 +219,8 @@ __media_device_register() via the macro media_device_register() 
and unregistered by calling

media_device_unregister().



* Entities, pads and links:



- Entities

Entities

^^^^^^^^



Entities are represented by a struct &media_entity instance, defined in

include/media/media-entity.h. The structure is usually embedded into a
@@ -235,7 +235,8 @@ media_device_register_entity() 
and unregistred by calling

media_device_unregister_entity().



- Interfaces

Interfaces

^^^^^^^^^^



Interfaces are represented by a struct &media_interface instance, defined in

include/media/media-entity.h. Currently, only one type of interface is
@@ -247,8 +248,8 @@ media_devnode_create() 
and remove them by calling:

media_devnode_remove().



- Pads



Pads

^^^^

Pads are represented by a struct &media_pad instance, defined in

include/media/media-entity.h. Each entity stores its pads in a pads array

managed by the entity driver. Drivers usually embed the array in a
@@ -267,7 +268,8 @@ Pads have flags that describe the pad capabilities and state. 
NOTE: One and only one of %MEDIA_PAD_FL_SINK and %MEDIA_PAD_FL_SOURCE must

be set for each pad.



- Links

Links

^^^^^



Links are represented by a struct &media_link instance, defined in

include/media/media-entity.h. There are two types of links:
@@ -289,7 +291,7 @@ Associate one interface to a Link. 
Drivers create interface to entity links by calling:

media_create_intf_link() and remove with media_remove_intf_links().



NOTE:

.. note::



   Links can only be created after having both ends already created.
@@ -297,7 +299,8 @@ Links have flags that describe the link capabilities and state. The 
valid values are described at media_create_pad_link() and

media_create_intf_link().



Graph traversal:

Graph traversal

^^^^^^^^^^^^^^^



The media framework provides APIs to iterate over entities in a graph.
@@ -339,7 +342,8 @@ Helper functions can be used to find a link between two given pads, or a pad 
connected to another pad through an enabled link

media_entity_find_link() and media_entity_remote_pad()



Use count and power handling:

Use count and power handling

^^^^^^^^^^^^^^^^^^^^^^^^^^^^



Due to the wide differences between drivers regarding power management

needs, the media controller does not implement power management. However,
@@ -351,12 +355,14 @@ The &media_entity.@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.



Links setup:

Links setup

^^^^^^^^^^^



Link properties can be modified at runtime by calling

media_entity_setup_link()



Pipelines and media streams:

Pipelines and media streams

^^^^^^^^^^^^^^^^^^^^^^^^^^^



When starting streaming, drivers must notify all entities in the pipeline to

prevent link states from being modified during streaming by calling
@@ -392,7 +398,8 @@ changing entities configuration parameters) drivers can explicitly check the 
media_entity stream_count field to find out if an entity is streaming. This

operation must be done with the media_device graph_mutex held.



Link validation:

Link validation

^^^^^^^^^^^^^^^



Link validation is performed by media_entity_pipeline_start() for any

entity which has sink pads in the pipeline. The