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Diffstat (limited to 'Documentation/DocBook/media/v4l/cec-ioc-adap-g-phys-addr.xml')
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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 ≥ 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> |