As we now have a glossary, some terms used on open.rst require adjustments. Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> --- Documentation/media/uapi/v4l/open.rst | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/Documentation/media/uapi/v4l/open.rst b/Documentation/media/uapi/v4l/open.rst index 1a8a9e1d0e84..c9e6bc9280a6 100644 --- a/Documentation/media/uapi/v4l/open.rst +++ b/Documentation/media/uapi/v4l/open.rst @@ -159,27 +159,28 @@ Related Devices Devices can support several functions. For example video capturing, VBI capturing and radio support. -The V4L2 API creates different nodes for each of these functions. +The V4L2 API creates different :term:`V4L2 device nodes <v4l2 device node>` +types for each of these functions. -The V4L2 API was designed with the idea that one device node could +The V4L2 API was designed with the idea that one :term:`device node` could support all functions. However, in practice this never worked: this -'feature' was never used by applications and many drivers did not -support it and if they did it was certainly never tested. In addition, +'feature' was never used by applications and many :term:`drivers <driver>` +did not support it and if they did it was certainly never tested. In addition, switching a device node between different functions only works when using the streaming I/O API, not with the :ref:`read() <func-read>`/\ :ref:`write() <func-write>` API. -Today each device node supports just one function. +Today each V4L2 device node supports just one function. -Besides video input or output the hardware may also support audio -sampling or playback. If so, these functions are implemented as ALSA PCM -devices with optional ALSA audio mixer devices. +Besides video input or output, the :term:`media hardware` may also support +audio sampling or playback. If so, these functions are implemented as ALSA +PCM devices with optional ALSA audio mixer devices. One problem with all these devices is that the V4L2 API makes no -provisions to find these related devices. Some really complex devices -use the Media Controller (see :ref:`media_controller`) which can be -used for this purpose. But most drivers do not use it, and while some -code exists that uses sysfs to discover related devices (see +provisions to find these related V4L2 device nodes. Some really complex +hardware use the :term:`media controller` (see :ref:`media_controller`) which +can be used for this purpose. But several drivers do not use it, and while +some code exists that uses sysfs to discover related V4L2 device nodes (see libmedia_dev in the `v4l-utils <http://git.linuxtv.org/cgit.cgi/v4l-utils.git/>`__ git repository), there is no library yet that can provide a single API -- 2.13.6
