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, 67 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst
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+.. 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
+
+.. _image-source-controls:
+
+******************************
+Image Source Control Reference
+******************************
+
+The Image Source control class is intended for low-level control of
+image source devices such as image sensors. The devices feature an
+analogue to digital converter and a bus transmitter to transmit the
+image data out of the device.
+
+
+.. _image-source-control-id:
+
+Image Source Control IDs
+========================
+
+``V4L2_CID_IMAGE_SOURCE_CLASS (class)``
+    The IMAGE_SOURCE class descriptor.
+
+``V4L2_CID_VBLANK (integer)``
+    Vertical blanking. The idle period after every frame during which no
+    image data is produced. The unit of vertical blanking is a line.
+    Every line has length of the image width plus horizontal blanking at
+    the pixel rate defined by ``V4L2_CID_PIXEL_RATE`` control in the
+    same sub-device.
+
+``V4L2_CID_HBLANK (integer)``
+    Horizontal blanking. The idle period after every line of image data
+    during which no image data is produced. The unit of horizontal
+    blanking is pixels.
+
+``V4L2_CID_ANALOGUE_GAIN (integer)``
+    Analogue gain is gain affecting all colour components in the pixel
+    matrix. The gain operation is performed in the analogue domain
+    before A/D conversion.
+
+``V4L2_CID_TEST_PATTERN_RED (integer)``
+    Test pattern red colour component.
+
+``V4L2_CID_TEST_PATTERN_GREENR (integer)``
+    Test pattern green (next to red) colour component.
+
+``V4L2_CID_TEST_PATTERN_BLUE (integer)``
+    Test pattern blue colour component.
+
+``V4L2_CID_TEST_PATTERN_GREENB (integer)``
+    Test pattern green (next to blue) colour component.
+
+``V4L2_CID_UNIT_CELL_SIZE (struct)``
+    This control returns the unit cell size in nanometers. The struct
+    :c:type:`v4l2_area` provides the width and the height in separate
+    fields to take into consideration asymmetric pixels.
+    This control does not take into consideration any possible hardware
+    binning.
+    The unit cell consists of the whole area of the pixel, sensitive and
+    non-sensitive.
+    This control is required for automatic calibration of sensors/cameras.