Commit c7169ad5 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[media] DocBook/media: add CEC documentation

Add DocBook documentation for the CEC API.
Signed-off-by: default avatarHans Verkuil <hansverk@cisco.com>
[k.debski@samsung.com: add documentation for passthrough mode]
[k.debski@samsung.com: minor fixes and change of reserved field sizes]
Signed-off-by: default avatarKamil Debski <kamil@wypas.org>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent c51202d3
...@@ -272,6 +272,9 @@ X!Isound/sound_firmware.c ...@@ -272,6 +272,9 @@ X!Isound/sound_firmware.c
!Iinclude/media/media-devnode.h !Iinclude/media/media-devnode.h
!Iinclude/media/media-entity.h !Iinclude/media/media-entity.h
</sect1> </sect1>
<sect1><title>Consumer Electronics Control devices</title>
!Iinclude/media/cec-edid.h
</sect1>
</chapter> </chapter>
......
...@@ -64,6 +64,7 @@ IOCTLS = \ ...@@ -64,6 +64,7 @@ IOCTLS = \
$(shell perl -ne 'print "$$1 " if /\#define\s+([A-Z][^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/dvb/net.h) \ $(shell perl -ne 'print "$$1 " if /\#define\s+([A-Z][^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/dvb/net.h) \
$(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/dvb/video.h) \ $(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/dvb/video.h) \
$(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/media.h) \ $(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/media.h) \
$(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/linux/cec.h) \
$(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/v4l2-subdev.h) \ $(shell perl -ne 'print "$$1 " if /\#define\s+([^\s]+)\s+_IO/' $(srctree)/include/uapi/linux/v4l2-subdev.h) \
DEFINES = \ DEFINES = \
...@@ -100,6 +101,7 @@ STRUCTS = \ ...@@ -100,6 +101,7 @@ STRUCTS = \
$(shell perl -ne 'print "$$1 " if (/^struct\s+([^\s]+)\s+/ && !/_old/)' $(srctree)/include/uapi/linux/dvb/net.h) \ $(shell perl -ne 'print "$$1 " if (/^struct\s+([^\s]+)\s+/ && !/_old/)' $(srctree)/include/uapi/linux/dvb/net.h) \
$(shell perl -ne 'print "$$1 " if (/^struct\s+([^\s]+)\s+/)' $(srctree)/include/uapi/linux/dvb/video.h) \ $(shell perl -ne 'print "$$1 " if (/^struct\s+([^\s]+)\s+/)' $(srctree)/include/uapi/linux/dvb/video.h) \
$(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/uapi/linux/media.h) \ $(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/uapi/linux/media.h) \
$(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/linux/cec.h) \
$(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/uapi/linux/v4l2-subdev.h) \ $(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/uapi/linux/v4l2-subdev.h) \
$(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/uapi/linux/v4l2-mediabus.h) $(shell perl -ne 'print "$$1 " if /^struct\s+([^\s]+)\s+/' $(srctree)/include/uapi/linux/v4l2-mediabus.h)
......
...@@ -342,6 +342,16 @@ in the frequency range from 87,5 to 108,0 MHz</title> ...@@ -342,6 +342,16 @@ in the frequency range from 87,5 to 108,0 MHz</title>
<subtitle>Specification Version 1.4a</subtitle> <subtitle>Specification Version 1.4a</subtitle>
</biblioentry> </biblioentry>
<biblioentry id="hdmi2">
<abbrev>HDMI2</abbrev>
<authorgroup>
<corpauthor>HDMI Licensing LLC
(<ulink url="http://www.hdmi.org">http://www.hdmi.org</ulink>)</corpauthor>
</authorgroup>
<title>High-Definition Multimedia Interface</title>
<subtitle>Specification Version 2.0</subtitle>
</biblioentry>
<biblioentry id="dp"> <biblioentry id="dp">
<abbrev>DP</abbrev> <abbrev>DP</abbrev>
<authorgroup> <authorgroup>
......
<partinfo>
<authorgroup>
<author>
<firstname>Hans</firstname>
<surname>Verkuil</surname>
<affiliation><address><email>hans.verkuil@cisco.com</email></address></affiliation>
<contrib>Initial version.</contrib>
</author>
</authorgroup>
<copyright>
<year>2016</year>
<holder>Hans Verkuil</holder>
</copyright>
<revhistory>
<!-- Put document revisions here, newest first. -->
<revision>
<revnumber>1.0.0</revnumber>
<date>2016-03-17</date>
<authorinitials>hv</authorinitials>
<revremark>Initial revision</revremark>
</revision>
</revhistory>
</partinfo>
<title>CEC API</title>
<chapter id="cec-api">
<title>CEC: Consumer Electronics Control</title>
<section id="cec-intro">
<title>Introduction</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>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
(<xref linkend="hdmi" />) specification and the extensions added to CEC version 2.0
are defined in chapter 11 of the HDMI 2.0 (<xref linkend="hdmi2" />) specification.
</para>
<para>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.</para>
<para>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.</para>
<para>Drivers that support CEC will create a CEC device node (/dev/cecX)
to give userspace access to the CEC adapter. The &CEC-ADAP-G-CAPS; ioctl will tell userspace
what it is allowed to do.</para>
</section>
</chapter>
<appendix id="cec-user-func">
<title>Function Reference</title>
<!-- Keep this alphabetically sorted. -->
&sub-cec-func-open;
&sub-cec-func-close;
&sub-cec-func-ioctl;
&sub-cec-func-poll;
<!-- All ioctls go here. -->
&sub-cec-ioc-adap-g-caps;
&sub-cec-ioc-adap-g-log-addrs;
&sub-cec-ioc-adap-g-phys-addr;
&sub-cec-ioc-dqevent;
&sub-cec-ioc-g-mode;
&sub-cec-ioc-receive;
</appendix>
<refentry id="cec-func-close">
<refmeta>
<refentrytitle>cec close()</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>cec-close</refname>
<refpurpose>Close a cec device</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;unistd.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>close</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>Closes the cec device. Resources associated with the file descriptor
are freed. The device configuration remain unchanged.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para><function>close</function> returns 0 on success. On error, -1 is
returned, and <varname>errno</varname> is set appropriately. Possible error
codes are:</para>
<variablelist>
<varlistentry>
<term><errorcode>EBADF</errorcode></term>
<listitem>
<para><parameter>fd</parameter> is not a valid open file descriptor.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
<refentry id="cec-func-ioctl">
<refmeta>
<refentrytitle>cec ioctl()</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>cec-ioctl</refname>
<refpurpose>Control a cec device</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;sys/ioctl.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>void *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC ioctl request code as defined in the cec.h header file,
for example CEC_ADAP_G_CAPS.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para>Pointer to a request-specific structure.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>The <function>ioctl()</function> function manipulates cec device
parameters. The argument <parameter>fd</parameter> must be an open file
descriptor.</para>
<para>The ioctl <parameter>request</parameter> code specifies the cec
function to be called. It has encoded in it whether the argument is an
input, output or read/write parameter, and the size of the argument
<parameter>argp</parameter> in bytes.</para>
<para>Macros and structures definitions specifying cec ioctl requests and
their parameters are located in the cec.h header file. All cec ioctl
requests, their respective function and parameters are specified in
<xref linkend="cec-user-func" />.</para>
</refsect1>
<refsect1>
&return-value;
<para>Request-specific error codes are listed in the
individual requests descriptions.</para>
<para>When an ioctl that takes an output or read/write parameter fails,
the parameter remains unmodified.</para>
</refsect1>
</refentry>
<refentry id="cec-func-open">
<refmeta>
<refentrytitle>cec open()</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>cec-open</refname>
<refpurpose>Open a cec device</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;fcntl.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>open</function></funcdef>
<paramdef>const char *<parameter>device_name</parameter></paramdef>
<paramdef>int <parameter>flags</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>device_name</parameter></term>
<listitem>
<para>Device to be opened.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>flags</parameter></term>
<listitem>
<para>Open flags. Access mode must be <constant>O_RDWR</constant>.
</para>
<para>When the <constant>O_NONBLOCK</constant> flag is
given, the &CEC-RECEIVE; ioctl will return &EAGAIN; when no message is
available, and the &CEC-TRANSMIT;, &CEC-ADAP-S-PHYS-ADDR; and
&CEC-ADAP-S-LOG-ADDRS; ioctls all act in non-blocking mode.</para>
<para>Other flags have no effect.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>To open a cec device applications call <function>open()</function>
with the desired device name. The function has no side effects; the device
configuration remain unchanged.</para>
<para>When the device is opened in read-only mode, attempts to modify its
configuration will result in an error, and <varname>errno</varname> will be
set to <errorcode>EBADF</errorcode>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para><function>open</function> returns the new file descriptor on success.
On error, -1 is returned, and <varname>errno</varname> is set appropriately.
Possible error codes include:</para>
<variablelist>
<varlistentry>
<term><errorcode>EACCES</errorcode></term>
<listitem>
<para>The requested access to the file is not allowed.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EMFILE</errorcode></term>
<listitem>
<para>The process already has the maximum number of files open.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>ENFILE</errorcode></term>
<listitem>
<para>The system limit on the total number of open files has been
reached.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>ENOMEM</errorcode></term>
<listitem>
<para>Insufficient kernel memory was available.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>ENXIO</errorcode></term>
<listitem>
<para>No device corresponding to this device special file exists.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
<refentry id="cec-func-poll">
<refmeta>
<refentrytitle>cec poll()</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>cec-poll</refname>
<refpurpose>Wait for some event on a file descriptor</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;sys/poll.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>poll</function></funcdef>
<paramdef>struct pollfd *<parameter>ufds</parameter></paramdef>
<paramdef>unsigned int <parameter>nfds</parameter></paramdef>
<paramdef>int <parameter>timeout</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>With the <function>poll()</function> function applications
can wait for CEC events.</para>
<para>On success <function>poll()</function> returns the number of
file descriptors that have been selected (that is, file descriptors
for which the <structfield>revents</structfield> field of the
respective <structname>pollfd</structname> structure is non-zero).
CEC devices set the <constant>POLLIN</constant> and
<constant>POLLRDNORM</constant> flags in the
<structfield>revents</structfield> field if there are messages in the
receive queue. If the transmit queue has room for new messages, the
<constant>POLLOUT</constant> and <constant>POLLWRNORM</constant>
flags are set. If there are events in the event queue, then the
<constant>POLLPRI</constant> flag is set.
When the function timed out it returns a value of zero, on
failure it returns <returnvalue>-1</returnvalue> and the
<varname>errno</varname> variable is set appropriately.
</para>
<para>For more details see the
<function>poll()</function> manual page.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, <function>poll()</function> returns the number
structures which have non-zero <structfield>revents</structfield>
fields, or zero if the call timed out. On error
<returnvalue>-1</returnvalue> is returned, and the
<varname>errno</varname> variable is set appropriately:</para>
<variablelist>
<varlistentry>
<term><errorcode>EBADF</errorcode></term>
<listitem>
<para>One or more of the <parameter>ufds</parameter> members
specify an invalid file descriptor.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EFAULT</errorcode></term>
<listitem>
<para><parameter>ufds</parameter> references an inaccessible
memory area.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EINTR</errorcode></term>
<listitem>
<para>The call was interrupted by a signal.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><errorcode>EINVAL</errorcode></term>
<listitem>
<para>The <parameter>nfds</parameter> argument is greater
than <constant>OPEN_MAX</constant>.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
</refentry>
<refentry id="cec-ioc-adap-g-caps">
<refmeta>
<refentrytitle>ioctl CEC_ADAP_G_CAPS</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>CEC_ADAP_G_CAPS</refname>
<refpurpose>Query device capabilities</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct cec_caps *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='cec-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC_ADAP_G_CAPS</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>All cec devices must support the <constant>CEC_ADAP_G_CAPS</constant>
ioctl. To query device information, applications call the ioctl with a
pointer to a &cec-caps;. The driver fills the structure and returns
the information to the application.
The ioctl never fails.</para>
<table pgwide="1" frame="none" id="cec-caps">
<title>struct <structname>cec_caps</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>char</entry>
<entry><structfield>driver[32]</structfield></entry>
<entry>The name of the cec adapter driver.</entry>
</row>
<row>
<entry>char</entry>
<entry><structfield>name[32]</structfield></entry>
<entry>The name of this CEC adapter. The combination <structfield>driver</structfield>
and <structfield>name</structfield> must be unique.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>capabilities</structfield></entry>
<entry>The capabilities of the CEC adapter, see <xref
linkend="cec-capabilities" />.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>version</structfield></entry>
<entry>CEC Framework API version, formatted with the
<constant>KERNEL_VERSION()</constant> macro.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-capabilities">
<title>CEC Capabilities Flags</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_CAP_PHYS_ADDR</constant></entry>
<entry>0x00000001</entry>
<entry>Userspace has to configure the physical address by
calling &CEC-ADAP-S-PHYS-ADDR;. If this capability isn't set,
then setting the physical address is handled by the kernel
whenever the EDID is set (for an HDMI receiver) or read (for
an HDMI transmitter).</entry>
</row>
<row>
<entry><constant>CEC_CAP_LOG_ADDRS</constant></entry>
<entry>0x00000002</entry>
<entry>Userspace has to configure the logical addresses by
calling &CEC-ADAP-S-LOG-ADDRS;. If this capability isn't set,
then the kernel will have configured this.</entry>
</row>
<row>
<entry><constant>CEC_CAP_TRANSMIT</constant></entry>
<entry>0x00000004</entry>
<entry>Userspace can transmit CEC messages by calling &CEC-TRANSMIT;. This
implies that userspace can be a follower as well, since being able to
transmit messages is a prerequisite of becoming a follower. If this
capability isn't set, then the kernel will handle all CEC transmits
and process all CEC messages it receives.
</entry>
</row>
<row>
<entry><constant>CEC_CAP_PASSTHROUGH</constant></entry>
<entry>0x00000008</entry>
<entry>Userspace can use the passthrough mode by
calling &CEC-S-MODE;.</entry>
</row>
<row>
<entry><constant>CEC_CAP_RC</constant></entry>
<entry>0x00000010</entry>
<entry>This adapter supports the remote control protocol.</entry>
</row>
<row>
<entry><constant>CEC_CAP_MONITOR_ALL</constant></entry>
<entry>0x00000020</entry>
<entry>The CEC hardware can monitor all messages, not just directed and
broadcast messages.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
<refentry id="cec-ioc-adap-g-log-addrs">
<refmeta>
<refentrytitle>ioctl CEC_ADAP_G_LOG_ADDRS, CEC_ADAP_S_LOG_ADDRS</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>CEC_ADAP_G_LOG_ADDRS</refname>
<refname>CEC_ADAP_S_LOG_ADDRS</refname>
<refpurpose>Get or set the logical addresses</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct cec_log_addrs *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='cec-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC_ADAP_G_LOG_ADDRS, CEC_ADAP_S_LOG_ADDRS</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>To query the current CEC logical addresses, applications call the
<constant>CEC_ADAP_G_LOG_ADDRS</constant> ioctl with a pointer to a
<structname>cec_log_addrs</structname> structure where the drivers stores the
logical addresses.</para>
<para>To set new logical addresses, applications fill in struct <structname>cec_log_addrs</structname>
and call the <constant>CEC_ADAP_S_LOG_ADDRS</constant> ioctl with a pointer to this struct.
The <constant>CEC_ADAP_S_LOG_ADDRS</constant> ioctl is only available if
<constant>CEC_CAP_LOG_ADDRS</constant> is set (&ENOTTY; is returned otherwise). This ioctl will block until all
requested logical addresses have been claimed. <constant>CEC_ADAP_S_LOG_ADDRS</constant>
can only be called by a file handle in initiator mode (see &CEC-S-MODE;).</para>
<table pgwide="1" frame="none" id="cec-log-addrs">
<title>struct <structname>cec_log_addrs</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u8</entry>
<entry><structfield>log_addr</structfield>[CEC_MAX_LOG_ADDRS]</entry>
<entry>The actual logical addresses that were claimed. This is set by the
driver. If no logical address could be claimed, then it is set to
<constant>CEC_LOG_ADDR_INVALID</constant>. If this adapter is Unregistered,
then <structfield>log_addr[0]</structfield> is set to 0xf and all others to
<constant>CEC_LOG_ADDR_INVALID</constant>.</entry>
</row>
<row>
<entry>__u16</entry>
<entry><structfield>log_addr_mask</structfield></entry>
<entry>The bitmask of all logical addresses this adapter has claimed.
If this adapter is Unregistered then <structfield>log_addr_mask</structfield>
sets bit 15 and clears all other bits. If this adapter is not configured at all, then
<structfield>log_addr_mask</structfield> is set to 0. Set by the driver.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>cec_version</structfield></entry>
<entry>The CEC version that this adapter shall use. See
<xref linkend="cec-versions" />.
Used to implement the <constant>CEC_MSG_CEC_VERSION</constant> and
<constant>CEC_MSG_REPORT_FEATURES</constant> messages. Note that
<constant>CEC_OP_CEC_VERSION_1_3A</constant> is not allowed
by the CEC framework.
</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>num_log_addrs</structfield></entry>
<entry>Number of logical addresses to set up. Must be &le;
<structfield>available_log_addrs</structfield> as returned by
&CEC-ADAP-G-CAPS;. All arrays in this structure are only filled up to
index <structfield>available_log_addrs</structfield>-1. The remaining
array elements will be ignored. Note that the CEC 2.0 standard allows
for a maximum of 2 logical addresses, although some hardware has support
for more. <constant>CEC_MAX_LOG_ADDRS</constant> is 4. The driver will
return the actual number of logical addresses it could claim, which may
be less than what was requested. If this field is set to 0, then the
CEC adapter shall clear all claimed logical addresses and all other
fields will be ignored.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>vendor_id</structfield></entry>
<entry>The vendor ID is a 24-bit number that identifies the specific
vendor or entity. Based on this ID vendor specific commands may be
defined. If you do not want a vendor ID then set it to
<constant>CEC_VENDOR_ID_NONE</constant>.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>flags</structfield></entry>
<entry>Flags. No flags are defined yet, so set this to 0.</entry>
</row>
<row>
<entry>char</entry>
<entry><structfield>osd_name</structfield>[15]</entry>
<entry>The On-Screen Display name as is returned by the
<constant>CEC_MSG_SET_OSD_NAME</constant> message.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>primary_device_type</structfield>[CEC_MAX_LOG_ADDRS]</entry>
<entry>Primary device type for each logical address. See
<xref linkend="cec-prim-dev-types" /> for possible types.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>log_addr_type</structfield>[CEC_MAX_LOG_ADDRS]</entry>
<entry>Logical address types. See <xref linkend="cec-log-addr-types" /> for
possible types. The driver will update this with the actual logical address
type that it claimed (e.g. it may have to fallback to
<constant>CEC_LOG_ADDR_TYPE_UNREGISTERED</constant>).</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>all_device_types</structfield>[CEC_MAX_LOG_ADDRS]</entry>
<entry>CEC 2.0 specific: all device types. See <xref linkend="cec-all-dev-types-flags" />.
Used to implement the <constant>CEC_MSG_REPORT_FEATURES</constant> message.
This field is ignored if <structfield>cec_version</structfield> &lt;
<constant>CEC_OP_CEC_VERSION_2_0</constant>.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>features</structfield>[CEC_MAX_LOG_ADDRS][12]</entry>
<entry>Features for each logical address. Used to implement the
<constant>CEC_MSG_REPORT_FEATURES</constant> message. The 12 bytes include
both the RC Profile and the Device Features.
This field is ignored if <structfield>cec_version</structfield> &lt;
<constant>CEC_OP_CEC_VERSION_2_0</constant>.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-versions">
<title>CEC Versions</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_OP_CEC_VERSION_1_3A</constant></entry>
<entry>4</entry>
<entry>CEC version according to the HDMI 1.3a standard.</entry>
</row>
<row>
<entry><constant>CEC_OP_CEC_VERSION_1_4B</constant></entry>
<entry>5</entry>
<entry>CEC version according to the HDMI 1.4b standard.</entry>
</row>
<row>
<entry><constant>CEC_OP_CEC_VERSION_2_0</constant></entry>
<entry>6</entry>
<entry>CEC version according to the HDMI 2.0 standard.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-prim-dev-types">
<title>CEC Primary Device Types</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_TV</constant></entry>
<entry>0</entry>
<entry>Use for a TV.</entry>
</row>
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_RECORD</constant></entry>
<entry>1</entry>
<entry>Use for a recording device.</entry>
</row>
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_TUNER</constant></entry>
<entry>3</entry>
<entry>Use for a device with a tuner.</entry>
</row>
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_PLAYBACK</constant></entry>
<entry>4</entry>
<entry>Use for a playback device.</entry>
</row>
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_AUDIOSYSTEM</constant></entry>
<entry>5</entry>
<entry>Use for an audio system (e.g. an audio/video receiver).</entry>
</row>
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_SWITCH</constant></entry>
<entry>6</entry>
<entry>Use for a CEC switch.</entry>
</row>
<row>
<entry><constant>CEC_OP_PRIM_DEVTYPE_VIDEOPROC</constant></entry>
<entry>7</entry>
<entry>Use for a video processor device.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-log-addr-types">
<title>CEC Logical Address Types</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_TV</constant></entry>
<entry>0</entry>
<entry>Use for a TV.</entry>
</row>
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_RECORD</constant></entry>
<entry>1</entry>
<entry>Use for a recording device.</entry>
</row>
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_TUNER</constant></entry>
<entry>2</entry>
<entry>Use for a tuner device.</entry>
</row>
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_PLAYBACK</constant></entry>
<entry>3</entry>
<entry>Use for a playback device.</entry>
</row>
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_AUDIOSYSTEM</constant></entry>
<entry>4</entry>
<entry>Use for an audio system device.</entry>
</row>
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_SPECIFIC</constant></entry>
<entry>5</entry>
<entry>Use for a second TV or for a video processor device.</entry>
</row>
<row>
<entry><constant>CEC_LOG_ADDR_TYPE_UNREGISTERED</constant></entry>
<entry>6</entry>
<entry>Use this if you just want to remain unregistered.
Used for pure CEC switches or CDC-only devices (CDC:
Capability Discovery and Control).</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-all-dev-types-flags">
<title>CEC All Device Types Flags</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_OP_ALL_DEVTYPE_TV</constant></entry>
<entry>0x80</entry>
<entry>This supports the TV type.</entry>
</row>
<row>
<entry><constant>CEC_OP_ALL_DEVTYPE_RECORD</constant></entry>
<entry>0x40</entry>
<entry>This supports the Recording type.</entry>
</row>
<row>
<entry><constant>CEC_OP_ALL_DEVTYPE_TUNER</constant></entry>
<entry>0x20</entry>
<entry>This supports the Tuner type.</entry>
</row>
<row>
<entry><constant>CEC_OP_ALL_DEVTYPE_PLAYBACK</constant></entry>
<entry>0x10</entry>
<entry>This supports the Playback type.</entry>
</row>
<row>
<entry><constant>CEC_OP_ALL_DEVTYPE_AUDIOSYSTEM</constant></entry>
<entry>0x08</entry>
<entry>This supports the Audio System type.</entry>
</row>
<row>
<entry><constant>CEC_OP_ALL_DEVTYPE_SWITCH</constant></entry>
<entry>0x04</entry>
<entry>This supports the CEC Switch or Video Processing type.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
<refentry id="cec-ioc-adap-g-phys-addr">
<refmeta>
<refentrytitle>ioctl CEC_ADAP_G_PHYS_ADDR, CEC_ADAP_S_PHYS_ADDR</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>CEC_ADAP_G_PHYS_ADDR</refname>
<refname>CEC_ADAP_S_PHYS_ADDR</refname>
<refpurpose>Get or set the physical address</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>__u16 *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='cec-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC_ADAP_G_PHYS_ADDR, CEC_ADAP_S_PHYS_ADDR</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>To query the current physical address applications call the
<constant>CEC_ADAP_G_PHYS_ADDR</constant> ioctl with a pointer to an __u16
where the driver stores the physical address.</para>
<para>To set a new physical address applications store the physical address in
an __u16 and call the <constant>CEC_ADAP_S_PHYS_ADDR</constant> ioctl with a
pointer to this integer. <constant>CEC_ADAP_S_PHYS_ADDR</constant> is only
available if <constant>CEC_CAP_PHYS_ADDR</constant> is set (&ENOTTY; will be returned
otherwise). <constant>CEC_ADAP_S_PHYS_ADDR</constant>
can only be called by a file handle in initiator mode (see &CEC-S-MODE;), if not
&EBUSY; will be returned.</para>
<para>The physical address is a 16-bit number where each group of 4 bits
represent a digit of the physical address a.b.c.d where the most significant
4 bits represent 'a'. The CEC root device (usually the TV) has address 0.0.0.0.
Every device that is hooked up to an input of the TV has address a.0.0.0 (where
'a' is &ge; 1), devices hooked up to those in turn have addresses a.b.0.0, etc.
So a topology of up to 5 devices deep is supported. The physical address a
device shall use is stored in the EDID of the sink.</para>
<para>For example, the EDID for each HDMI input of the TV will have a different
physical address of the form a.0.0.0 that the sources will read out and use as
their physical address.</para>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
<refentry id="cec-ioc-g-event">
<refmeta>
<refentrytitle>ioctl CEC_DQEVENT</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>CEC_DQEVENT</refname>
<refpurpose>Dequeue a CEC event</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct cec_event *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='cec-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC_DQEVENT</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>CEC devices can send asynchronous events. These can be retrieved by calling
the <constant>CEC_DQEVENT</constant> ioctl. If the file descriptor is in non-blocking
mode and no event is pending, then it will return -1 and set errno to the &EAGAIN;.</para>
<para>The internal event queues are per-filehandle and per-event type. If there is
no more room in a queue then the last event is overwritten with the new one. This
means that intermediate results can be thrown away but that the latest event is always
available. This also means that is it possible to read two successive events that have
the same value (e.g. two CEC_EVENT_STATE_CHANGE events with the same state). In that
case the intermediate state changes were lost but it is guaranteed that the state
did change in between the two events.</para>
<table pgwide="1" frame="none" id="cec-event-state-change">
<title>struct <structname>cec_event_state_change</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u16</entry>
<entry><structfield>phys_addr</structfield></entry>
<entry>The current physical address.</entry>
</row>
<row>
<entry>__u16</entry>
<entry><structfield>log_addr_mask</structfield></entry>
<entry>The current set of claimed logical addresses.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-event-lost-msgs">
<title>struct <structname>cec_event_lost_msgs</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u32</entry>
<entry><structfield>lost_msgs</structfield></entry>
<entry>Set to the number of lost messages since the filehandle
was opened or since the last time this event was dequeued for
this filehandle. The messages lost are the oldest messages. So
when a new message arrives and there is no more room, then the
oldest message is discarded to make room for the new one. The
internal size of the message queue guarantees that all messages
received in the last two seconds will be stored. Since messages
should be replied to within a second according to the CEC
specification, this is more than enough.
</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-event">
<title>struct <structname>cec_event</structname></title>
<tgroup cols="4">
&cs-str;
<tbody valign="top">
<row>
<entry>__u64</entry>
<entry><structfield>ts</structfield></entry>
<entry>Timestamp of the event in ns.</entry>
<entry></entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>event</structfield></entry>
<entry>The CEC event type, see <xref linkend="cec-events" />.</entry>
<entry></entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>flags</structfield></entry>
<entry>Event flags, see <xref linkend="cec-event-flags" />.</entry>
<entry></entry>
</row>
<row>
<entry>union</entry>
<entry>(anonymous)</entry>
<entry></entry>
<entry></entry>
</row>
<row>
<entry></entry>
<entry>struct cec_event_state_change</entry>
<entry><structfield>state_change</structfield></entry>
<entry>The new adapter state as sent by the <constant>CEC_EVENT_STATE_CHANGE</constant>
event.</entry>
</row>
<row>
<entry></entry>
<entry>struct cec_event_lost_msgs</entry>
<entry><structfield>lost_msgs</structfield></entry>
<entry>The number of lost messages as sent by the <constant>CEC_EVENT_LOST_MSGS</constant>
event.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-events">
<title>CEC Events Types</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_EVENT_STATE_CHANGE</constant></entry>
<entry>1</entry>
<entry>Generated when the CEC Adapter's state changes. When open() is
called an initial event will be generated for that filehandle with the
CEC Adapter's state at that time.
</entry>
</row>
<row>
<entry><constant>CEC_EVENT_LOST_MSGS</constant></entry>
<entry>2</entry>
<entry>Generated if one or more CEC messages were lost because the
application didn't dequeue CEC messages fast enough.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-event-flags">
<title>CEC Event Flags</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_EVENT_FL_INITIAL_VALUE</constant></entry>
<entry>1</entry>
<entry>Set for the initial events that are generated when the device is
opened. See the table above for which events do this. This allows
applications to learn the initial state of the CEC adapter at open()
time.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
<refentry id="cec-ioc-g-mode">
<refmeta>
<refentrytitle>ioctl CEC_G_MODE, CEC_S_MODE</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>CEC_G_MODE</refname>
<refname>CEC_S_MODE</refname>
<refpurpose>Get or set exclusive use of the CEC adapter</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>__u32 *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='cec-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC_G_MODE, CEC_S_MODE</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>By default any filehandle can use &CEC-TRANSMIT; and &CEC-RECEIVE;, but
in order to prevent applications from stepping on each others toes it must be possible
to obtain exclusive access to the CEC adapter. This ioctl sets the filehandle
to initiator and/or follower mode which can be exclusive depending on the chosen
mode. The initiator is the filehandle that is used
to initiate messages, i.e. it commands other CEC devices. The follower is the filehandle
that receives messages sent to the CEC adapter and processes them. The same filehandle
can be both initiator and follower, or this role can be taken by two different
filehandles.</para>
<para>When a CEC message is received, then the CEC framework will decide how
it will be processed. If the message is a reply to an earlier transmitted message,
then the reply is sent back to the filehandle that is waiting for it. In addition
the CEC framework will process it.</para>
<para>If the message is not a reply, then the CEC framework will process it
first. If there is no follower, then the message is just discarded and a feature
abort is sent back to the initiator if the framework couldn't process it. If there
is a follower, then the message is passed on to the follower who will use
&CEC-RECEIVE; to dequeue the new message. The framework expects the follower to
make the right decisions.</para>
<para>The CEC framework will process core messages unless requested otherwise
by the follower. The follower can enable the passthrough mode. In that case, the
CEC framework will pass on most core messages without processing them and
the follower will have to implement those messages. There are some messages
that the core will always process, regardless of the passthrough mode. See
<xref linkend="cec-core-processing" /> for details.</para>
<para>If there is no initiator, then any CEC filehandle can use &CEC-TRANSMIT;.
If there is an exclusive initiator then only that initiator can call &CEC-TRANSMIT;.
The follower can of course always call &CEC-TRANSMIT;.</para>
<para>Available initiator modes are:</para>
<table pgwide="1" frame="none" id="cec-mode-initiator">
<title>Initiator Modes</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_MODE_NO_INITIATOR</constant></entry>
<entry>0x0</entry>
<entry>This is not an initiator, i.e. it cannot transmit CEC messages
or make any other changes to the CEC adapter.</entry>
</row>
<row>
<entry><constant>CEC_MODE_INITIATOR</constant></entry>
<entry>0x1</entry>
<entry>This is an initiator (the default when the device is opened) and it
can transmit CEC messages and make changes to the CEC adapter, unless there
is an exclusive initiator.</entry>
</row>
<row>
<entry><constant>CEC_MODE_EXCL_INITIATOR</constant></entry>
<entry>0x2</entry>
<entry>This is an exclusive initiator and this file descriptor is the only one
that can transmit CEC messages and make changes to the CEC adapter. If someone
else is already the exclusive initiator then an attempt to become one will return
the &EBUSY; error.</entry>
</row>
</tbody>
</tgroup>
</table>
<para>Available follower modes are:</para>
<table pgwide="1" frame="none" id="cec-mode-follower">
<title>Follower Modes</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_MODE_NO_FOLLOWER</constant></entry>
<entry>0x00</entry>
<entry>This is not a follower (the default when the device is opened).</entry>
</row>
<row>
<entry><constant>CEC_MODE_FOLLOWER</constant></entry>
<entry>0x10</entry>
<entry>This is a follower and it will receive CEC messages unless there is
an exclusive follower. You cannot become a follower if <constant>CEC_CAP_TRANSMIT</constant>
is not set or if <constant>CEC_MODE_NO_INITIATOR</constant> was specified,
&EINVAL; is returned in that case.</entry>
</row>
<row>
<entry><constant>CEC_MODE_EXCL_FOLLOWER</constant></entry>
<entry>0x20</entry>
<entry>This is an exclusive follower and only this file descriptor will receive
CEC messages for processing. If someone else is already the exclusive follower
then an attempt to become one will return the &EBUSY; error. You cannot become
a follower if <constant>CEC_CAP_TRANSMIT</constant> is not set or if
<constant>CEC_MODE_NO_INITIATOR</constant> was specified, &EINVAL; is returned
in that case.</entry>
</row>
<row>
<entry><constant>CEC_MODE_EXCL_FOLLOWER_PASSTHRU</constant></entry>
<entry>0x30</entry>
<entry>This is an exclusive follower and only this file descriptor will receive
CEC messages for processing. In addition it will put the CEC device into
passthrough mode, allowing the exclusive follower to handle most core messages
instead of relying on the CEC framework for that. If someone else is already the
exclusive follower then an attempt to become one will return the &EBUSY; error.
You cannot become a follower if <constant>CEC_CAP_TRANSMIT</constant>
is not set or if <constant>CEC_MODE_NO_INITIATOR</constant> was specified,
&EINVAL; is returned in that case.</entry>
</row>
<row>
<entry><constant>CEC_MODE_MONITOR</constant></entry>
<entry>0xe0</entry>
<entry>Put the file descriptor into monitor mode. Can only be used in combination
with <constant>CEC_MODE_NO_INITIATOR</constant>, otherwise &EINVAL; will be
returned. In monitor mode all messages this CEC device transmits and all messages
it receives (both broadcast messages and directed messages for one its logical
addresses) will be reported. This is very useful for debugging. This is only
allowed if the process has the <constant>CAP_NET_ADMIN</constant>
capability. If that is not set, then &EPERM; is returned.</entry>
</row>
<row>
<entry><constant>CEC_MODE_MONITOR_ALL</constant></entry>
<entry>0xf0</entry>
<entry>Put the file descriptor into 'monitor all' mode. Can only be used in combination
with <constant>CEC_MODE_NO_INITIATOR</constant>, otherwise &EINVAL; will be
returned. In 'monitor all' mode all messages this CEC device transmits and all messages
it receives, including directed messages for other CEC devices will be reported. This
is very useful for debugging, but not all devices support this. This mode requires that
the <constant>CEC_CAP_MONITOR_ALL</constant> capability is set, otherwise &EINVAL; is
returned. This is only allowed if the process has the <constant>CAP_NET_ADMIN</constant>
capability. If that is not set, then &EPERM; is returned.</entry>
</row>
</tbody>
</tgroup>
</table>
<para>Core message processing details:</para>
<table pgwide="1" frame="none" id="cec-core-processing">
<title>Core Message Processing</title>
<tgroup cols="2">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_MSG_GET_CEC_VERSION</constant></entry>
<entry>When in passthrough mode this message has to be handled by userspace,
otherwise the core will return the CEC version that was set with &CEC-ADAP-S-LOG-ADDRS;.</entry>
</row>
<row>
<entry><constant>CEC_MSG_GIVE_DEVICE_VENDOR_ID</constant></entry>
<entry>When in passthrough mode this message has to be handled by userspace,
otherwise the core will return the vendor ID that was set with &CEC-ADAP-S-LOG-ADDRS;.</entry>
</row>
<row>
<entry><constant>CEC_MSG_ABORT</constant></entry>
<entry>When in passthrough mode this message has to be handled by userspace,
otherwise the core will return a feature refused message as per the specification.</entry>
</row>
<row>
<entry><constant>CEC_MSG_GIVE_PHYSICAL_ADDR</constant></entry>
<entry>When in passthrough mode this message has to be handled by userspace,
otherwise the core will report the current physical address.</entry>
</row>
<row>
<entry><constant>CEC_MSG_GIVE_OSD_NAME</constant></entry>
<entry>When in passthrough mode this message has to be handled by userspace,
otherwise the core will report the current OSD name as was set with
&CEC-ADAP-S-LOG-ADDRS;.</entry>
</row>
<row>
<entry><constant>CEC_MSG_GIVE_FEATURES</constant></entry>
<entry>When in passthrough mode this message has to be handled by userspace,
otherwise the core will report the current features as was set with
&CEC-ADAP-S-LOG-ADDRS; or the message is ignore if the CEC version was
older than 2.0.</entry>
</row>
<row>
<entry><constant>CEC_MSG_USER_CONTROL_PRESSED</constant></entry>
<entry>If <constant>CEC_CAP_RC</constant> is set, then generate a remote control
key press. This message is always passed on to userspace.</entry>
</row>
<row>
<entry><constant>CEC_MSG_USER_CONTROL_RELEASED</constant></entry>
<entry>If <constant>CEC_CAP_RC</constant> is set, then generate a remote control
key release. This message is always passed on to userspace.</entry>
</row>
<row>
<entry><constant>CEC_MSG_REPORT_PHYSICAL_ADDR</constant></entry>
<entry>The CEC framework will make note of the reported physical address
and then just pass the message on to userspace.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
<refentry id="cec-ioc-receive">
<refmeta>
<refentrytitle>ioctl CEC_RECEIVE, CEC_TRANSMIT</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>CEC_RECEIVE</refname>
<refname>CEC_TRANSMIT</refname>
<refpurpose>Receive or transmit a CEC message</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>struct cec_msg *<parameter>argp</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>File descriptor returned by
<link linkend='cec-func-open'><function>open()</function></link>.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>CEC_RECEIVE, CEC_TRANSMIT</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>argp</parameter></term>
<listitem>
<para></para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Note: this documents the proposed CEC API. This API is not yet finalized and
is currently only available as a staging kernel module.
</para>
<para>To receive a CEC message the application has to fill in the
<structname>cec_msg</structname> structure and pass it to the
<constant>CEC_RECEIVE</constant> ioctl. <constant>CEC_RECEIVE</constant> is
only available if <constant>CEC_CAP_RECEIVE</constant> is set. If the
file descriptor is in non-blocking mode and there are no received
messages pending, then it will return -1 and set errno to the &EAGAIN;.
If the file descriptor is in blocking mode and <structfield>timeout</structfield>
is non-zero and no message arrived within <structfield>timeout</structfield>
milliseconds, then it will return -1 and set errno to the &ETIMEDOUT;.</para>
<para>To send a CEC message the application has to fill in the
<structname>cec_msg</structname> structure and pass it to the
<constant>CEC_TRANSMIT</constant> ioctl. <constant>CEC_TRANSMIT</constant> is
only available if <constant>CEC_CAP_TRANSMIT</constant> is set.
If there is no more room in the transmit queue, then it will return
-1 and set errno to the &EBUSY;.</para>
<table pgwide="1" frame="none" id="cec-msg">
<title>struct <structname>cec_msg</structname></title>
<tgroup cols="3">
&cs-str;
<tbody valign="top">
<row>
<entry>__u64</entry>
<entry><structfield>ts</structfield></entry>
<entry>Timestamp of when the message was transmitted in ns in the case
of <constant>CEC_TRANSMIT</constant> with <structfield>reply</structfield>
set to 0, or the timestamp of the received message in all other cases.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>len</structfield></entry>
<entry>The length of the message. For <constant>CEC_TRANSMIT</constant> this
is filled in by the application. The driver will fill this in for
<constant>CEC_RECEIVE</constant> and for <constant>CEC_TRANSMIT</constant>
it will be filled in with the length of the reply message if
<structfield>reply</structfield> was set.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>timeout</structfield></entry>
<entry>The timeout in milliseconds. This is the time the device will wait for a message to
be received before timing out. If it is set to 0, then it will wait indefinitely when it
is called by <constant>CEC_RECEIVE</constant>. If it is 0 and it is called by
<constant>CEC_TRANSMIT</constant>, then it will be replaced by 1000 if the
<structfield>reply</structfield> is non-zero or ignored if <structfield>reply</structfield>
is 0.</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>sequence</structfield></entry>
<entry>The sequence number is automatically assigned by the CEC
framework for all transmitted messages. It can be later used by the
framework to generate an event if a reply for a message was
requested and the message was transmitted in a non-blocking mode.
</entry>
</row>
<row>
<entry>__u32</entry>
<entry><structfield>flags</structfield></entry>
<entry>Flags. No flags are defined yet, so set this to 0.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>rx_status</structfield></entry>
<entry>The status bits of the received message. See <xref linkend="cec-rx-status" />
for the possible status values. It is 0 if this message was transmitted, not
received, unless this is the reply to a transmitted message. In that case both
<structfield>rx_status</structfield> and <structfield>tx_status</structfield>
are set.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>tx_status</structfield></entry>
<entry>The status bits of the transmitted message. See <xref linkend="cec-tx-status" />
for the possible status values. It is 0 if this messages was received, not
transmitted.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>msg</structfield>[16]</entry>
<entry>The message payload. For <constant>CEC_TRANSMIT</constant> this
is filled in by the application. The driver will fill this in for
<constant>CEC_RECEIVE</constant> and for <constant>CEC_TRANSMIT</constant>
it will be filled in with the payload of the reply message if
<structfield>reply</structfield> was set.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>reply</structfield></entry>
<entry>Wait until this message is replied. If <structfield>reply</structfield>
is 0 and the <structfield>timeout</structfield> is 0, then don't wait for a reply but
return after transmitting the message. If there was an error as indicated by a non-zero
<structfield>tx_status</structfield> field, then <structfield>reply</structfield> and
<structfield>timeout</structfield> are both set to 0 by the driver. Ignored by
<constant>CEC_RECEIVE</constant>. The case where <structfield>reply</structfield> is 0
(this is the opcode for the Feature Abort message) and <structfield>timeout</structfield>
is non-zero is specifically allowed to send a message and wait up to <structfield>timeout</structfield>
milliseconds for a Feature Abort reply. In this case <structfield>rx_status</structfield>
will either be set to <constant>CEC_RX_STATUS_TIMEOUT</constant> or
<constant>CEC_RX_STATUS_FEATURE_ABORT</constant>.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>tx_arb_lost_cnt</structfield></entry>
<entry>A counter of the number of transmit attempts that resulted in the
Arbitration Lost error. This is only set if the hardware supports this, otherwise
it is always 0. This counter is only valid if the <constant>CEC_TX_STATUS_ARB_LOST</constant>
status bit is set.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>tx_nack_cnt</structfield></entry>
<entry>A counter of the number of transmit attempts that resulted in the
Not Acknowledged error. This is only set if the hardware supports this, otherwise
it is always 0. This counter is only valid if the <constant>CEC_TX_STATUS_NACK</constant>
status bit is set.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>tx_low_drive_cnt</structfield></entry>
<entry>A counter of the number of transmit attempts that resulted in the
Arbitration Lost error. This is only set if the hardware supports this, otherwise
it is always 0. This counter is only valid if the <constant>CEC_TX_STATUS_LOW_DRIVE</constant>
status bit is set.</entry>
</row>
<row>
<entry>__u8</entry>
<entry><structfield>tx_error_cnt</structfield></entry>
<entry>A counter of the number of transmit errors other than Arbitration Lost
or Not Acknowledged. This is only set if the hardware supports this, otherwise
it is always 0. This counter is only valid if the <constant>CEC_TX_STATUS_ERROR</constant>
status bit is set.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-tx-status">
<title>CEC Transmit Status</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_TX_STATUS_OK</constant></entry>
<entry>0x01</entry>
<entry>The message was transmitted successfully. This is mutually exclusive with
<constant>CEC_TX_STATUS_MAX_RETRIES</constant>. Other bits can still be set if
earlier attempts met with failure before the transmit was eventually successful.</entry>
</row>
<row>
<entry><constant>CEC_TX_STATUS_ARB_LOST</constant></entry>
<entry>0x02</entry>
<entry>CEC line arbitration was lost.</entry>
</row>
<row>
<entry><constant>CEC_TX_STATUS_NACK</constant></entry>
<entry>0x04</entry>
<entry>Message was not acknowledged.</entry>
</row>
<row>
<entry><constant>CEC_TX_STATUS_LOW_DRIVE</constant></entry>
<entry>0x08</entry>
<entry>Low drive was detected on the CEC bus. This indicates that a follower
detected an error on the bus and requests a retransmission.</entry>
</row>
<row>
<entry><constant>CEC_TX_STATUS_ERROR</constant></entry>
<entry>0x10</entry>
<entry>Some error occurred. This is used for any errors that do not
fit the previous two, either because the hardware could not tell
which error occurred, or because the hardware tested for other conditions
besides those two.</entry>
</row>
<row>
<entry><constant>CEC_TX_STATUS_MAX_RETRIES</constant></entry>
<entry>0x20</entry>
<entry>The transmit failed after one or more retries. This status bit is mutually
exclusive with <constant>CEC_TX_STATUS_OK</constant>. Other bits can still be set
to explain which failures were seen.</entry>
</row>
</tbody>
</tgroup>
</table>
<table pgwide="1" frame="none" id="cec-rx-status">
<title>CEC Receive Status</title>
<tgroup cols="3">
&cs-def;
<tbody valign="top">
<row>
<entry><constant>CEC_RX_STATUS_OK</constant></entry>
<entry>0x01</entry>
<entry>The message was received successfully.</entry>
</row>
<row>
<entry><constant>CEC_RX_STATUS_TIMEOUT</constant></entry>
<entry>0x02</entry>
<entry>The reply to an earlier transmitted message timed out.</entry>
</row>
<row>
<entry><constant>CEC_RX_STATUS_FEATURE_ABORT</constant></entry>
<entry>0x04</entry>
<entry>The message was received successfully but the reply was
<constant>CEC_MSG_FEATURE_ABORT</constant>. This status is only
set if this message was the reply to an earlier transmitted
message.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
&return-value;
</refsect1>
</refentry>
...@@ -75,7 +75,7 @@ ...@@ -75,7 +75,7 @@
</mediaobject> </mediaobject>
</figure> </figure>
<para>The media infrastructure API was designed to control such <para>The media infrastructure API was designed to control such
devices. It is divided into four parts.</para> devices. It is divided into five parts.</para>
<para>The first part covers radio, video capture and output, <para>The first part covers radio, video capture and output,
cameras, analog TV devices and codecs.</para> cameras, analog TV devices and codecs.</para>
<para>The second part covers the <para>The second part covers the
...@@ -87,6 +87,7 @@ ...@@ -87,6 +87,7 @@
<xref linkend="fe-delivery-system-t" />.</para> <xref linkend="fe-delivery-system-t" />.</para>
<para>The third part covers the Remote Controller API.</para> <para>The third part covers the Remote Controller API.</para>
<para>The fourth part covers the Media Controller API.</para> <para>The fourth part covers the Media Controller API.</para>
<para>The fifth part covers the CEC (Consumer Electronics Control) API.</para>
<para>It should also be noted that a media device may also have audio <para>It should also be noted that a media device may also have audio
components, like mixers, PCM capture, PCM playback, etc, which components, like mixers, PCM capture, PCM playback, etc, which
are controlled via ALSA API.</para> are controlled via ALSA API.</para>
...@@ -107,6 +108,9 @@ ...@@ -107,6 +108,9 @@
<part id="media_common"> <part id="media_common">
&sub-media-controller; &sub-media-controller;
</part> </part>
<part id="cec">
&sub-cec-api;
</part>
<chapter id="gen_errors"> <chapter id="gen_errors">
&sub-gen-errors; &sub-gen-errors;
......
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