diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst deleted file mode 100644 index 4b1b4bc78bfe..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst +++ /dev/null @@ -1,120 +0,0 @@ -.. 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/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _VIDIOC_SUBDEV_G_FRAME_INTERVAL: - -******************************************************************** -ioctl VIDIOC_SUBDEV_G_FRAME_INTERVAL, VIDIOC_SUBDEV_S_FRAME_INTERVAL -******************************************************************** - -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:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_FRAME_INTERVAL, struct v4l2_subdev_frame_interval *argp ) - :name: VIDIOC_SUBDEV_S_FRAME_INTERVAL - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to struct :c:type:`v4l2_subdev_frame_interval`. - - -Description -=========== - -These ioctls are used to get and set the frame interval at specific -subdev pads in the image pipeline. The frame interval only makes sense -for sub-devices that can control the frame period on their own. This -includes, for instance, image sensors and TV tuners. Sub-devices that -don't support frame intervals must not implement these ioctls. - -To retrieve the current frame interval applications set the ``pad`` -field of a struct -:c:type:`v4l2_subdev_frame_interval` to -the desired pad number as reported by the media controller API. When -they call the ``VIDIOC_SUBDEV_G_FRAME_INTERVAL`` ioctl with a pointer to -this structure the driver fills the members of the ``interval`` field. - -To change the current frame interval applications set both the ``pad`` -field and all members of the ``interval`` field. When they call the -``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` ioctl with a pointer to this -structure the driver verifies the requested interval, adjusts it based -on the hardware capabilities and configures the device. Upon return the -struct -:c:type:`v4l2_subdev_frame_interval` -contains the current frame interval as would be returned by a -``VIDIOC_SUBDEV_G_FRAME_INTERVAL`` call. - -Drivers must not return an error solely because the requested interval -doesn't match the device capabilities. They must instead modify the -interval to match what the hardware can provide. The modified interval -should be as close as possible to the original request. - -Changing the frame interval shall never change the format. Changing the -format, on the other hand, may change the frame interval. - -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}| - -.. flat-table:: struct v4l2_subdev_frame_interval - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``pad`` - - Pad number as reported by the media controller API. - * - struct :c:type:`v4l2_fract` - - ``interval`` - - Period, in seconds, between consecutive video frames. - * - __u32 - - ``reserved``\ [9] - - 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 frame interval 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_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. |