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, 169 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst b/Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst
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index 000000000000..60730c32bfe4
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@@ -0,0 +1,169 @@
+.. 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
+
+.. _VIDIOC_DV_TIMINGS_CAP:
+
+*********************************************************
+ioctl VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP
+*********************************************************
+
+Name
+====
+
+VIDIOC_DV_TIMINGS_CAP - VIDIOC_SUBDEV_DV_TIMINGS_CAP - The capabilities of the Digital Video receiver/transmitter
+
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, VIDIOC_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp )
+    :name: VIDIOC_DV_TIMINGS_CAP
+
+.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp )
+    :name: VIDIOC_SUBDEV_DV_TIMINGS_CAP
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <func-open>`.
+
+``argp``
+    Pointer to struct :c:type:`v4l2_dv_timings_cap`.
+
+
+Description
+===========
+
+To query the capabilities of the DV receiver/transmitter applications
+initialize the ``pad`` field to 0, zero the reserved array of struct
+:c:type:`v4l2_dv_timings_cap` and call the
+``VIDIOC_DV_TIMINGS_CAP`` ioctl on a video node and the driver will fill
+in the structure.
+
+.. note::
+
+   Drivers may return different values after
+   switching the video input or output.
+
+When implemented by the driver DV capabilities of subdevices can be
+queried by calling the ``VIDIOC_SUBDEV_DV_TIMINGS_CAP`` ioctl directly
+on a subdevice node. The capabilities are specific to inputs (for DV
+receivers) or outputs (for DV transmitters), applications must specify
+the desired pad number in the struct
+:c:type:`v4l2_dv_timings_cap` ``pad`` field and
+zero the ``reserved`` array. Attempts to query capabilities on a pad
+that doesn't support them will return an ``EINVAL`` error code.
+
+
+.. tabularcolumns:: |p{1.2cm}|p{3.0cm}|p{13.3cm}|
+
+.. c:type:: v4l2_bt_timings_cap
+
+.. flat-table:: struct v4l2_bt_timings_cap
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``min_width``
+      - Minimum width of the active video in pixels.
+    * - __u32
+      - ``max_width``
+      - Maximum width of the active video in pixels.
+    * - __u32
+      - ``min_height``
+      - Minimum height of the active video in lines.
+    * - __u32
+      - ``max_height``
+      - Maximum height of the active video in lines.
+    * - __u64
+      - ``min_pixelclock``
+      - Minimum pixelclock frequency in Hz.
+    * - __u64
+      - ``max_pixelclock``
+      - Maximum pixelclock frequency in Hz.
+    * - __u32
+      - ``standards``
+      - The video standard(s) supported by the hardware. See
+	:ref:`dv-bt-standards` for a list of standards.
+    * - __u32
+      - ``capabilities``
+      - Several flags giving more information about the capabilities. See
+	:ref:`dv-bt-cap-capabilities` for a description of the flags.
+    * - __u32
+      - ``reserved``\ [16]
+      - Reserved for future extensions.
+	Drivers must set the array to zero.
+
+
+
+.. tabularcolumns:: |p{1.0cm}|p{4.0cm}|p{3.5cm}|p{9.2cm}|
+
+.. c:type:: v4l2_dv_timings_cap
+
+.. flat-table:: struct v4l2_dv_timings_cap
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``type``
+      - Type of DV timings as listed in :ref:`dv-timing-types`.
+    * - __u32
+      - ``pad``
+      - Pad number as reported by the media controller API. This field is
+	only used when operating on a subdevice node. When operating on a
+	video node applications must set this field to zero.
+    * - __u32
+      - ``reserved``\ [2]
+      - Reserved for future extensions.
+
+	Drivers and applications must set the array to zero.
+    * - union {
+      - (anonymous)
+    * - struct :c:type:`v4l2_bt_timings_cap`
+      - ``bt``
+      - BT.656/1120 timings capabilities of the hardware.
+    * - __u32
+      - ``raw_data``\ [32]
+    * - }
+      -
+
+.. tabularcolumns:: |p{7.0cm}|p{10.5cm}|
+
+.. _dv-bt-cap-capabilities:
+
+.. flat-table:: DV BT Timing capabilities
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - Flag
+      - Description
+    * -
+      -
+    * - ``V4L2_DV_BT_CAP_INTERLACED``
+      - Interlaced formats are supported.
+    * - ``V4L2_DV_BT_CAP_PROGRESSIVE``
+      - Progressive formats are supported.
+    * - ``V4L2_DV_BT_CAP_REDUCED_BLANKING``
+      - CVT/GTF specific: the timings can make use of reduced blanking
+	(CVT) or the 'Secondary GTF' curve (GTF).
+    * - ``V4L2_DV_BT_CAP_CUSTOM``
+      - Can support non-standard timings, i.e. timings not belonging to
+	the standards set in the ``standards`` field.
+
+
+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.