aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml')
-rw-r--r--Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml86
1 files changed, 86 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml b/Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml
new file mode 100644
index 000000000000..d95f1785080c
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml
@@ -0,0 +1,86 @@
+<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>