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Diffstat (limited to 'Documentation/DocBook/media/v4l/common.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/common.xml | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/DocBook/media/v4l/common.xml b/Documentation/DocBook/media/v4l/common.xml index 9028721438dc..a86f7a045529 100644 --- a/Documentation/DocBook/media/v4l/common.xml +++ b/Documentation/DocBook/media/v4l/common.xml @@ -236,7 +236,15 @@ important parts of the API.</para> <para>The &VIDIOC-QUERYCAP; ioctl is available to check if the kernel device is compatible with this specification, and to query the <link linkend="devices">functions</link> and <link linkend="io">I/O -methods</link> supported by the device. Other features can be queried +methods</link> supported by the device.</para> + + <para>Starting with kernel version 3.1, VIDIOC-QUERYCAP will return the +V4L2 API version used by the driver, with generally matches the Kernel version. +There's no need of using &VIDIOC-QUERYCAP; to check if an specific ioctl is +supported, the V4L2 core now returns ENOIOCTLCMD if a driver doesn't provide +support for an ioctl.</para> + + <para>Other features can be queried by calling the respective ioctl, for example &VIDIOC-ENUMINPUT; to learn about the number, types and names of video connectors on the device. Although abstraction is a major objective of this API, the |
