Commit da98a79b authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] doc-rst: make CEC look more like other parts of the book 



Better organize the contents of the CEC part, moving the
introduction to chapter 1, placing all ioctls at chapter 2
and numerating all chapters and items.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 96f69e0e

Documentation/media/uapi/cec/cec-api.rst

+5 −55
Original line number Diff line number Diff line
@@ -10,65 +10,15 @@ CEC API 


.. _cec-api:



*********************************

CEC: Consumer Electronics Control

*********************************





.. _cec-intro:



Introduction

============



Note: this documents the proposed CEC API. This API is not yet finalized

and is currently only available as a staging kernel module.



HDMI connectors provide a single pin for use by the Consumer Electronics

Control protocol. This protocol allows different devices connected by an

HDMI cable to communicate. The protocol for CEC version 1.4 is defined

in supplements 1 (CEC) and 2 (HEAC or HDMI Ethernet and Audio Return

Channel) of the HDMI 1.4a (:ref:`hdmi`) specification and the

extensions added to CEC version 2.0 are defined in chapter 11 of the

HDMI 2.0 (:ref:`hdmi2`) specification.



The bitrate is very slow (effectively no more than 36 bytes per second)

and is based on the ancient AV.link protocol used in old SCART

connectors. The protocol closely resembles a crazy Rube Goldberg

contraption and is an unholy mix of low and high level messages. Some

messages, especially those part of the HEAC protocol layered on top of

CEC, need to be handled by the kernel, others can be handled either by

the kernel or by userspace.



In addition, CEC can be implemented in HDMI receivers, transmitters and

in USB devices that have an HDMI input and an HDMI output and that

control just the CEC pin.



Drivers that support CEC will create a CEC device node (/dev/cecX) to

give userspace access to the CEC adapter. The

:ref:`CEC_ADAP_G_CAPS` ioctl will tell

userspace what it is allowed to do.





.. _cec-user-func:



******************

Function Reference

******************



This part describes the CEC: Consumer Electronics Control



.. toctree::

    :maxdepth: 1

    :numbered:

    :caption: Table of Contents



    cec-func-open

    cec-func-close

    cec-func-ioctl

    cec-func-poll

    cec-ioc-adap-g-caps

    cec-ioc-adap-g-log-addrs

    cec-ioc-adap-g-phys-addr

    cec-ioc-dqevent

    cec-ioc-g-mode

    cec-ioc-receive

    cec-intro

    cec-funcs

    cec-header

Documentation/media/uapi/cec/cec-funcs.rst

0 → 100644
+21 −0
Original line number Diff line number Diff line 
.. _cec-user-func:



******************

Function Reference

******************





.. toctree::

    :maxdepth: 1

    :numbered:



    cec-func-open

    cec-func-close

    cec-func-ioctl

    cec-func-poll

    cec-ioc-adap-g-caps

    cec-ioc-adap-g-log-addrs

    cec-ioc-adap-g-phys-addr

    cec-ioc-dqevent

    cec-ioc-g-mode

    cec-ioc-receive

Documentation/media/uapi/cec/cec-intro.rst

0 → 100644
+31 −0
Original line number Diff line number Diff line 
.. _cec-intro:



Introduction

============



Note: this documents the proposed CEC API. This API is not yet finalized

and is currently only available as a staging kernel module.



HDMI connectors provide a single pin for use by the Consumer Electronics

Control protocol. This protocol allows different devices connected by an

HDMI cable to communicate. The protocol for CEC version 1.4 is defined

in supplements 1 (CEC) and 2 (HEAC or HDMI Ethernet and Audio Return

Channel) of the HDMI 1.4a (:ref:`hdmi`) specification and the

extensions added to CEC version 2.0 are defined in chapter 11 of the

HDMI 2.0 (:ref:`hdmi2`) specification.



The bitrate is very slow (effectively no more than 36 bytes per second)

and is based on the ancient AV.link protocol used in old SCART

connectors. The protocol closely resembles a crazy Rube Goldberg

contraption and is an unholy mix of low and high level messages. Some

messages, especially those part of the HEAC protocol layered on top of

CEC, need to be handled by the kernel, others can be handled either by

the kernel or by userspace.



In addition, CEC can be implemented in HDMI receivers, transmitters and

in USB devices that have an HDMI input and an HDMI output and that

control just the CEC pin.



Drivers that support CEC will create a CEC device node (/dev/cecX) to

give userspace access to the CEC adapter. The

:ref:`CEC_ADAP_G_CAPS` ioctl will tell userspace what it is allowed to do.