diff options
author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-08 18:16:10 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-08 18:16:10 -0300 |
commit | cbb5c8355aaf42e95f1b925bb5ded494dea540d9 (patch) | |
tree | 168cbe90a17e4ef984178d85512d03268ed4fea9 /Documentation/DocBook/media/v4l/cec-func-poll.xml | |
parent | fb810cb5eda8c47e3afbb45ea6b9676841d29e8d (diff) | |
parent | c7169ad5616229b87cabf886bc5f9cbd1fc35a5f (diff) |
Merge branch 'topic/cec' into patchwork
* topic/cec:
[media] DocBook/media: add CEC documentation
[media] s5p_cec: get rid of an unused var
[media] move s5p-cec to staging
[media] vivid: add CEC emulation
[media] cec: s5p-cec: Add s5p-cec driver
[media] cec: adv7511: add cec support
[media] cec: adv7842: add cec support
[media] cec: adv7604: add cec support
[media] cec: add compat32 ioctl support
[media] cec/TODO: add TODO file so we know why this is still in staging
[media] cec: add HDMI CEC framework (api)
[media] cec: add HDMI CEC framework (adapter)
[media] cec: add HDMI CEC framework (core)
[media] cec-funcs.h: static inlines to pack/unpack CEC messages
[media] cec.h: add cec header
[media] cec-edid: add module for EDID CEC helper functions
[media] cec.txt: add CEC framework documentation
[media] rc: Add HDMI CEC protocol handling
Diffstat (limited to 'Documentation/DocBook/media/v4l/cec-func-poll.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/cec-func-poll.xml | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/cec-func-poll.xml b/Documentation/DocBook/media/v4l/cec-func-poll.xml new file mode 100644 index 000000000000..1bddbde0142d --- /dev/null +++ b/Documentation/DocBook/media/v4l/cec-func-poll.xml @@ -0,0 +1,94 @@ +<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 <sys/poll.h></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> |