mirror of
https://github.com/torvalds/linux.git
synced 2024-12-26 04:42:12 +00:00
fea13a6935
There are lots of tables that are not properly displayed in LaTeX/PDF. Fix the tablecolumns, add longtable where needed and LaTeX formatting macros, in order to address such issues. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
105 lines
2.8 KiB
ReStructuredText
105 lines
2.8 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
|
|
.. c:namespace:: V4L
|
|
|
|
.. _VIDIOC_SUBDEV_QUERYCAP:
|
|
|
|
****************************
|
|
ioctl VIDIOC_SUBDEV_QUERYCAP
|
|
****************************
|
|
|
|
Name
|
|
====
|
|
|
|
VIDIOC_SUBDEV_QUERYCAP - Query sub-device capabilities
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. c:macro:: VIDIOC_SUBDEV_QUERYCAP
|
|
|
|
``int ioctl(int fd, VIDIOC_SUBDEV_QUERYCAP, struct v4l2_subdev_capability *argp)``
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :c:func:`open()`.
|
|
|
|
``argp``
|
|
Pointer to struct :c:type:`v4l2_subdev_capability`.
|
|
|
|
Description
|
|
===========
|
|
|
|
All V4L2 sub-devices support the ``VIDIOC_SUBDEV_QUERYCAP`` ioctl. It is used to
|
|
identify kernel devices compatible with this specification and to obtain
|
|
information about driver and hardware capabilities. The ioctl takes a pointer to
|
|
a struct :c:type:`v4l2_subdev_capability` which is filled by the driver. When
|
|
the driver is not compatible with this specification the ioctl returns
|
|
``ENOTTY`` error code.
|
|
|
|
.. tabularcolumns:: |p{1.5cm}|p{2.9cm}|p{12.9cm}|
|
|
|
|
.. c:type:: v4l2_subdev_capability
|
|
|
|
.. flat-table:: struct v4l2_subdev_capability
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 3 4 20
|
|
|
|
* - __u32
|
|
- ``version``
|
|
- Version number of the driver.
|
|
|
|
The version reported is provided by the V4L2 subsystem following the
|
|
kernel numbering scheme. However, it may not always return the same
|
|
version as the kernel if, for example, a stable or
|
|
distribution-modified kernel uses the V4L2 stack from a newer kernel.
|
|
|
|
The version number is formatted using the ``KERNEL_VERSION()``
|
|
macro:
|
|
* - :cspan:`2`
|
|
|
|
``#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))``
|
|
|
|
``__u32 version = KERNEL_VERSION(0, 8, 1);``
|
|
|
|
``printf ("Version: %u.%u.%u\\n",``
|
|
|
|
``(version >> 16) & 0xFF, (version >> 8) & 0xFF, version & 0xFF);``
|
|
* - __u32
|
|
- ``capabilities``
|
|
- Sub-device capabilities of the opened device, see
|
|
:ref:`subdevice-capabilities`.
|
|
* - __u32
|
|
- ``reserved``\ [14]
|
|
- Reserved for future extensions. Set to 0 by the V4L2 core.
|
|
|
|
.. tabularcolumns:: |p{6.8cm}|p{2.4cm}|p{8.1cm}|
|
|
|
|
.. _subdevice-capabilities:
|
|
|
|
.. cssclass:: longtable
|
|
|
|
.. flat-table:: Sub-Device Capabilities Flags
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 3 1 4
|
|
|
|
* - V4L2_SUBDEV_CAP_RO_SUBDEV
|
|
- 0x00000001
|
|
- The sub-device device node is registered in read-only mode.
|
|
Access to the sub-device ioctls that modify the device state is
|
|
restricted. Refer to each individual subdevice ioctl documentation
|
|
for a description of which restrictions apply to a read-only sub-device.
|
|
|
|
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.
|
|
|
|
ENOTTY
|
|
The device node is not a V4L2 sub-device.
|