diff options
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst index 7e0b177e70aa..c8022809ac35 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst @@ -1,4 +1,5 @@ .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L .. _VIDIOC_SUBDEV_G_FRAME_INTERVAL: @@ -11,27 +12,26 @@ Name VIDIOC_SUBDEV_G_FRAME_INTERVAL - VIDIOC_SUBDEV_S_FRAME_INTERVAL - Get or set the frame interval on a subdev pad - Synopsis ======== -.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_FRAME_INTERVAL, struct v4l2_subdev_frame_interval *argp ) - :name: VIDIOC_SUBDEV_G_FRAME_INTERVAL +.. c:macro:: VIDIOC_SUBDEV_G_FRAME_INTERVAL + +``int ioctl(int fd, VIDIOC_SUBDEV_G_FRAME_INTERVAL, struct v4l2_subdev_frame_interval *argp)`` -.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_FRAME_INTERVAL, struct v4l2_subdev_frame_interval *argp ) - :name: VIDIOC_SUBDEV_S_FRAME_INTERVAL +.. c:macro:: VIDIOC_SUBDEV_S_FRAME_INTERVAL +``int ioctl(int fd, VIDIOC_SUBDEV_S_FRAME_INTERVAL, struct v4l2_subdev_frame_interval *argp)`` Arguments ========= ``fd`` - File descriptor returned by :ref:`open() <func-open>`. + File descriptor returned by :c:func:`open()`. ``argp`` Pointer to struct :c:type:`v4l2_subdev_frame_interval`. - Description =========== @@ -58,8 +58,9 @@ struct contains the current frame interval as would be returned by a ``VIDIOC_SUBDEV_G_FRAME_INTERVAL`` call. -Calling ``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` on a subdev device node that has been -registered in read-only mode is not allowed. An error is returned and the errno +If the subdev device node has been registered in read-only mode, calls to +``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` are only valid if the ``which`` field is set +to ``V4L2_SUBDEV_FORMAT_TRY``, otherwise an error is returned and the errno variable is set to ``-EPERM``. Drivers must not return an error solely because the requested interval @@ -74,10 +75,9 @@ Sub-devices that support the frame interval ioctls should implement them on a single pad only. Their behaviour when supported on multiple pads of the same sub-device is not defined. - .. c:type:: v4l2_subdev_frame_interval -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| .. flat-table:: struct v4l2_subdev_frame_interval :header-rows: 0 @@ -91,11 +91,17 @@ the same sub-device is not defined. - ``interval`` - Period, in seconds, between consecutive video frames. * - __u32 - - ``reserved``\ [9] + - ``stream`` + - Stream identifier. + * - __u32 + - ``which`` + - Active or try frame interval, from enum + :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. + * - __u32 + - ``reserved``\ [7] - Reserved for future extensions. Applications and drivers must set the array to zero. - Return Value ============ @@ -111,11 +117,10 @@ EBUSY ``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` EINVAL - The struct - :c:type:`v4l2_subdev_frame_interval` - ``pad`` references a non-existing pad, or the pad doesn't support - frame intervals. + The struct :c:type:`v4l2_subdev_frame_interval` ``pad`` references a + non-existing pad, the ``which`` field has an unsupported value, or the pad + doesn't support frame intervals. EPERM The ``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` ioctl has been called on a read-only - subdevice. + subdevice and the ``which`` field is set to ``V4L2_SUBDEV_FORMAT_ACTIVE``. |