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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2016-07-27 06:32:31 -0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2016-07-28 20:08:19 -0300
commit43f71d93a0cb342f0c918fba3f6abb7661e40ad2 (patch)
treea1dc7288bc480e7027ca1827ca4876472fa12e40 /Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
parentMerge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media (diff)
downloadlinux-dev-43f71d93a0cb342f0c918fba3f6abb7661e40ad2.tar.xz
linux-dev-43f71d93a0cb342f0c918fba3f6abb7661e40ad2.zip
doc-rst: Remove the media docbook
Now that all media documentation was converted to Sphinx, we should get rid of the old DocBook one, as we don't want people to submit patches against the old stuff. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-create-bufs.xml')
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diff --git a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
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--- a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml
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@@ -1,158 +0,0 @@
-<refentry id="vidioc-create-bufs">
- <refmeta>
- <refentrytitle>ioctl VIDIOC_CREATE_BUFS</refentrytitle>
- &manvol;
- </refmeta>
-
- <refnamediv>
- <refname>VIDIOC_CREATE_BUFS</refname>
- <refpurpose>Create buffers for Memory Mapped or User Pointer or DMA Buffer
- I/O</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 v4l2_create_buffers *<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>VIDIOC_CREATE_BUFS</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><parameter>argp</parameter></term>
- <listitem>
- <para></para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
-
- <refsect1>
- <title>Description</title>
-
- <para>This ioctl is used to create buffers for <link linkend="mmap">memory
-mapped</link> or <link linkend="userp">user pointer</link> or <link
-linkend="dmabuf">DMA buffer</link> I/O. It can be used as an alternative or in
-addition to the &VIDIOC-REQBUFS; ioctl, when a tighter
-control over buffers is required. This ioctl can be called multiple times to
-create buffers of different sizes.</para>
-
- <para>To allocate the device buffers applications must initialize the
-relevant fields of the <structname>v4l2_create_buffers</structname> structure.
-The <structfield>count</structfield> field must be set to the number of
-requested buffers, the <structfield>memory</structfield> field specifies the
-requested I/O method and the <structfield>reserved</structfield> array must be
-zeroed.</para>
-
- <para>The <structfield>format</structfield> field specifies the image format
-that the buffers must be able to handle. The application has to fill in this
-&v4l2-format;. Usually this will be done using the &VIDIOC-TRY-FMT; or &VIDIOC-G-FMT; ioctls
-to ensure that the requested format is supported by the driver.
-Based on the format's <structfield>type</structfield> field the requested buffer
-size (for single-planar) or plane sizes (for multi-planar formats) will be
-used for the allocated buffers. The driver may return an error if the size(s)
-are not supported by the hardware (usually because they are too small).</para>
-
- <para>The buffers created by this ioctl will have as minimum size the size
-defined by the <structfield>format.pix.sizeimage</structfield> field (or the
-corresponding fields for other format types). Usually if the
-<structfield>format.pix.sizeimage</structfield> field is less than the minimum
-required for the given format, then an error will be returned since drivers will
-typically not allow this. If it is larger, then the value will be used as-is.
-In other words, the driver may reject the requested size, but if it is accepted
-the driver will use it unchanged.</para>
-
- <para>When the ioctl is called with a pointer to this structure the driver
-will attempt to allocate up to the requested number of buffers and store the
-actual number allocated and the starting index in the
-<structfield>count</structfield> and the <structfield>index</structfield> fields
-respectively. On return <structfield>count</structfield> can be smaller than
-the number requested.</para>
-
- <table pgwide="1" frame="none" id="v4l2-create-buffers">
- <title>struct <structname>v4l2_create_buffers</structname></title>
- <tgroup cols="3">
- &cs-str;
- <tbody valign="top">
- <row>
- <entry>__u32</entry>
- <entry><structfield>index</structfield></entry>
- <entry>The starting buffer index, returned by the driver.</entry>
- </row>
- <row>
- <entry>__u32</entry>
- <entry><structfield>count</structfield></entry>
- <entry>The number of buffers requested or granted. If count == 0, then
- <constant>VIDIOC_CREATE_BUFS</constant> will set <structfield>index</structfield>
- to the current number of created buffers, and it will check the validity of
- <structfield>memory</structfield> and <structfield>format.type</structfield>.
- If those are invalid -1 is returned and errno is set to &EINVAL;,
- otherwise <constant>VIDIOC_CREATE_BUFS</constant> returns 0. It will
- never set errno to &EBUSY; in this particular case.</entry>
- </row>
- <row>
- <entry>__u32</entry>
- <entry><structfield>memory</structfield></entry>
- <entry>Applications set this field to
-<constant>V4L2_MEMORY_MMAP</constant>,
-<constant>V4L2_MEMORY_DMABUF</constant> or
-<constant>V4L2_MEMORY_USERPTR</constant>. See <xref linkend="v4l2-memory"
-/></entry>
- </row>
- <row>
- <entry>&v4l2-format;</entry>
- <entry><structfield>format</structfield></entry>
- <entry>Filled in by the application, preserved by the driver.</entry>
- </row>
- <row>
- <entry>__u32</entry>
- <entry><structfield>reserved</structfield>[8]</entry>
- <entry>A place holder for future extensions. Drivers and applications
-must set the array to zero.</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </refsect1>
-
- <refsect1>
- &return-value;
-
- <variablelist>
- <varlistentry>
- <term><errorcode>ENOMEM</errorcode></term>
- <listitem>
- <para>No memory to allocate buffers for <link linkend="mmap">memory
-mapped</link> I/O.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><errorcode>EINVAL</errorcode></term>
- <listitem>
- <para>The buffer type (<structfield>format.type</structfield> field),
-requested I/O method (<structfield>memory</structfield>) or format
-(<structfield>format</structfield> field) is not valid.</para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
-</refentry>