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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-03 20:59:38 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-03 20:59:38 -0700 |
commit | a98f670e41a99f53acb1fb33cee9c6abbb2e6f23 (patch) | |
tree | f8ae10a4cb91758ad7f9422053753a8c5d0f04dc /Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst | |
parent | ee01c4d72adffb7d424535adf630f2955748fa8b (diff) | |
parent | 938b29db3aa9c293c7c1366b16e55e308f1a1ddd (diff) |
Merge tag 'media/v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- Media documentation is now split into admin-guide, driver-api and
userspace-api books (a longstanding request from Jon);
- The media Kconfig was reorganized, in order to make easier to select
drivers and their dependencies;
- The testing drivers now has a separate directory;
- added a new driver for Rockchip Video Decoder IP;
- The atomisp staging driver was resurrected. It is meant to work with
4 generations of cameras on Atom-based laptops, tablets and cell
phones. So, it seems worth investing time to cleanup this driver and
making it in good shape.
- Added some V4L2 core ancillary routines to help with h264 codecs;
- Added an ov2740 image sensor driver;
- The si2157 gained support for Analog TV, which, in turn, added
support for some cx231xx and cx23885 boards to also support analog
standards;
- Added some V4L2 controls (V4L2_CID_CAMERA_ORIENTATION and
V4L2_CID_CAMERA_SENSOR_ROTATION) to help identifying where the camera
is located at the device;
- VIDIOC_ENUM_FMT was extended to support MC-centric devices;
- Lots of drivers improvements and cleanups.
* tag 'media/v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (503 commits)
media: Documentation: media: Refer to mbus format documentation from CSI-2 docs
media: s5k5baf: Replace zero-length array with flexible-array
media: i2c: imx219: Drop <linux/clk-provider.h> and <linux/clkdev.h>
media: i2c: Add ov2740 image sensor driver
media: ov8856: Implement sensor module revision identification
media: ov8856: Add devicetree support
media: dt-bindings: ov8856: Document YAML bindings
media: dvb-usb: Add Cinergy S2 PCIe Dual Port support
media: dvbdev: Fix tuner->demod media controller link
media: dt-bindings: phy: phy-rockchip-dphy-rx0: move rockchip dphy rx0 bindings out of staging
media: staging: dt-bindings: phy-rockchip-dphy-rx0: remove non-used reg property
media: atomisp: unify the version for isp2401 a0 and b0 versions
media: atomisp: update TODO with the current data
media: atomisp: adjust some code at sh_css that could be broken
media: atomisp: don't produce errs for ignored IRQs
media: atomisp: print IRQ when debugging
media: atomisp: isp_mmu: don't use kmem_cache
media: atomisp: add a notice about possible leak resources
media: atomisp: disable the dynamic and reserved pools
media: atomisp: turn on camera before setting it
...
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst new file mode 100644 index 000000000000..eb7401991d02 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst @@ -0,0 +1,125 @@ +.. 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_SUBDEV_ENUM_FRAME_SIZE: + +*********************************** +ioctl VIDIOC_SUBDEV_ENUM_FRAME_SIZE +*********************************** + +Name +==== + +VIDIOC_SUBDEV_ENUM_FRAME_SIZE - Enumerate media bus frame sizes + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_FRAME_SIZE, struct v4l2_subdev_frame_size_enum * argp ) + :name: VIDIOC_SUBDEV_ENUM_FRAME_SIZE + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``argp`` + Pointer to struct :c:type:`v4l2_subdev_frame_size_enum`. + + +Description +=========== + +This ioctl allows applications to enumerate all frame sizes supported by +a sub-device on the given pad for the given media bus format. Supported +formats can be retrieved with the +:ref:`VIDIOC_SUBDEV_ENUM_MBUS_CODE` +ioctl. + +To enumerate frame sizes applications initialize the ``pad``, ``which`` +, ``code`` and ``index`` fields of the struct +:c:type:`v4l2_subdev_mbus_code_enum` and +call the :ref:`VIDIOC_SUBDEV_ENUM_FRAME_SIZE` ioctl with a pointer to the +structure. Drivers fill the minimum and maximum frame sizes or return an +EINVAL error code if one of the input parameters is invalid. + +Sub-devices that only support discrete frame sizes (such as most +sensors) will return one or more frame sizes with identical minimum and +maximum values. + +Not all possible sizes in given [minimum, maximum] ranges need to be +supported. For instance, a scaler that uses a fixed-point scaling ratio +might not be able to produce every frame size between the minimum and +maximum values. Applications must use the +:ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>` ioctl to try the +sub-device for an exact supported frame size. + +Available frame sizes may depend on the current 'try' formats at other +pads of the sub-device, as well as on the current active links and the +current values of V4L2 controls. See +:ref:`VIDIOC_SUBDEV_G_FMT` for more +information about try formats. + + +.. c:type:: v4l2_subdev_frame_size_enum + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + +.. flat-table:: struct v4l2_subdev_frame_size_enum + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``index`` + - Number of the format in the enumeration, set by the application. + * - __u32 + - ``pad`` + - Pad number as reported by the media controller API. + * - __u32 + - ``code`` + - The media bus format code, as defined in + :ref:`v4l2-mbus-format`. + * - __u32 + - ``min_width`` + - Minimum frame width, in pixels. + * - __u32 + - ``max_width`` + - Maximum frame width, in pixels. + * - __u32 + - ``min_height`` + - Minimum frame height, in pixels. + * - __u32 + - ``max_height`` + - Maximum frame height, in pixels. + * - __u32 + - ``which`` + - Frame sizes to be enumerated, from enum + :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. + * - __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. + +EINVAL + The struct + :c:type:`v4l2_subdev_frame_size_enum` + ``pad`` references a non-existing pad, the ``code`` is invalid for + the given pad or the ``index`` field is out of bounds. |