media: docs: move uAPI book to userspace-api/media

Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("docs: Create a user-space API guide").

As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.

Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 105 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/dvb/video-command.rst b/Documentation/userspace-api/media/dvb/video-command.rst
new file mode 100644
index 000000000000..d96d764d0eef
--- /dev/null
+++ b/Documentation/userspace-api/media/dvb/video-command.rst
@@ -0,0 +1,105 @@
+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/userspace-api/media/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _VIDEO_COMMAND:
+
+=============
+VIDEO_COMMAND
+=============
+
+Name
+----
+
+VIDEO_COMMAND
+
+.. attention:: This ioctl is deprecated.
+
+Synopsis
+--------
+
+.. c:function:: int ioctl(int fd, VIDEO_COMMAND, struct video_command *cmd)
+    :name: VIDEO_COMMAND
+
+
+Arguments
+---------
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+
+    -  .. row 1
+
+       -  int fd
+
+       -  File descriptor returned by a previous call to open().
+
+    -  .. row 2
+
+       -  int request
+
+       -  Equals VIDEO_COMMAND for this command.
+
+    -  .. row 3
+
+       -  struct video_command \*cmd
+
+       -  Commands the decoder.
+
+
+Description
+-----------
+
+This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders
+this ioctl has been replaced by the
+:ref:`VIDIOC_DECODER_CMD` ioctl.
+
+This ioctl commands the decoder. The ``video_command`` struct is a
+subset of the ``v4l2_decoder_cmd`` struct, so refer to the
+:ref:`VIDIOC_DECODER_CMD` documentation for
+more information.
+
+.. c:type:: struct video_command
+
+.. code-block:: c
+
+	/* The structure must be zeroed before use by the application
+	This ensures it can be extended safely in the future. */
+	struct video_command {
+		__u32 cmd;
+		__u32 flags;
+		union {
+			struct {
+				__u64 pts;
+			} stop;
+
+			struct {
+				/* 0 or 1000 specifies normal speed,
+				1 specifies forward single stepping,
+				-1 specifies backward single stepping,
+				>1: playback at speed/1000 of the normal speed,
+				<-1: reverse playback at (-speed/1000) of the normal speed. */
+				__s32 speed;
+				__u32 format;
+			} play;
+
+			struct {
+				__u32 data[16];
+			} raw;
+		};
+	};
+
+
+Return Value
+------------
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.