Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 118 insertions, 0 deletions

diff --git a/Documentation/media/uapi/v4l/vidioc-subdev-g-crop.rst b/Documentation/media/uapi/v4l/vidioc-subdev-g-crop.rst
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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _VIDIOC_SUBDEV_G_CROP:
+
+************************************************
+ioctl VIDIOC_SUBDEV_G_CROP, VIDIOC_SUBDEV_S_CROP
+************************************************
+
+Name
+====
+
+VIDIOC_SUBDEV_G_CROP - VIDIOC_SUBDEV_S_CROP - Get or set the crop rectangle on a subdev pad
+
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_CROP, struct v4l2_subdev_crop *argp )
+    :name: VIDIOC_SUBDEV_G_CROP
+
+.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_CROP, const struct v4l2_subdev_crop *argp )
+    :name: VIDIOC_SUBDEV_S_CROP
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <func-open>`.
+
+``argp``
+    Pointer to struct :c:type:`v4l2_subdev_crop`.
+
+
+Description
+===========
+
+.. note::
+
+    This is an :ref:`obsolete` interface and may be removed
+    in the future. It is superseded by
+    :ref:`the selection API <VIDIOC_SUBDEV_G_SELECTION>`.
+
+To retrieve the current crop rectangle applications set the ``pad``
+field of a struct :c:type:`v4l2_subdev_crop` to the
+desired pad number as reported by the media API and the ``which`` field
+to ``V4L2_SUBDEV_FORMAT_ACTIVE``. They then call the
+``VIDIOC_SUBDEV_G_CROP`` ioctl with a pointer to this structure. The
+driver fills the members of the ``rect`` field or returns ``EINVAL`` error
+code if the input arguments are invalid, or if cropping is not supported
+on the given pad.
+
+To change the current crop rectangle applications set both the ``pad``
+and ``which`` fields and all members of the ``rect`` field. They then
+call the ``VIDIOC_SUBDEV_S_CROP`` ioctl with a pointer to this
+structure. The driver verifies the requested crop rectangle, adjusts it
+based on the hardware capabilities and configures the device. Upon
+return the struct :c:type:`v4l2_subdev_crop`
+contains the current format as would be returned by a
+``VIDIOC_SUBDEV_G_CROP`` call.
+
+Applications can query the device capabilities by setting the ``which``
+to ``V4L2_SUBDEV_FORMAT_TRY``. When set, 'try' crop rectangles are not
+applied to the device by the driver, but are mangled exactly as active
+crop rectangles and stored in the sub-device file handle. Two
+applications querying the same sub-device would thus not interact with
+each other.
+
+Drivers must not return an error solely because the requested crop
+rectangle doesn't match the device capabilities. They must instead
+modify the rectangle to match what the hardware can provide. The
+modified format should be as close as possible to the original request.
+
+
+.. c:type:: v4l2_subdev_crop
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+
+.. flat-table:: struct v4l2_subdev_crop
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``pad``
+      - Pad number as reported by the media framework.
+    * - __u32
+      - ``which``
+      - Crop rectangle to get or set, from enum
+	:ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`.
+    * - struct :c:type:`v4l2_rect`
+      - ``rect``
+      - Crop rectangle boundaries, in pixels.
+    * - __u32
+      - ``reserved``\ [8]
+      - Reserved for future extensions. Applications and drivers must set
+	the array to zero.
+
+
+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.
+
+EBUSY
+    The crop rectangle can't be changed because the pad is currently
+    busy. This can be caused, for instance, by an active video stream on
+    the pad. The ioctl must not be retried without performing another
+    action to fix the problem first. Only returned by
+    ``VIDIOC_SUBDEV_S_CROP``
+
+EINVAL
+    The struct :c:type:`v4l2_subdev_crop` ``pad``
+    references a non-existing pad, the ``which`` field references a
+    non-existing format, or cropping is not supported on the given
+    subdev pad.