Em Mon, 28 Aug 2017 11:41:58 +0200
Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
> > + control, and thus can't be used by **v4l2-centric** applications.
>
> vdev-centric
>
> TBD: I still think I prefer V4L2-centric over vdev-centric.
I'm splitting it on a separate thread, to make easier for us to discuss.
For those that aren't tracking the patchset that are documenting those
terms, when MC was added, we got a hole new series of V4L2 devices that
are incompatible with standard V4L2 applications, as they require
knowledge about the hardware sub-devices. We are referring to such
devices as MC-centric. We need another term to refer to the V4L2 devices
that can be used by a generic application, and are fully controlled via a
V4L2 device (/dev/video*, /dev/radio*, /dev/swradio*, /dev/vbi*,
/dev/v4l-touch*).
The proposed documentation patch series solves this issue by
adding a glossary (patch 1) that defines what a "V4L2 device node"
as:
V4L2 device node
A device node that it is associated to a V4L2 main driver,
as specified at :ref:`v4l2_device_naming`.
And, at the device naming chapter, at the spec (patch 2), it
explicitly lists all V4L2 device node names:
.. _v4l2_device_naming:
V4L2 Device Node Naming
=======================
...
The existing V4L2 device node types are:
======================== ======================================================
Default device node name Usage
======================== ======================================================
``/dev/videoX`` Video input/output devices
``/dev/vbiX`` Vertical blank data (i.e. closed captions, teletext)
``/dev/radioX`` Radio tuners and modulators
``/dev/swradioX`` Software Defined Radio tuners and modulators
``/dev/v4l-touchX`` Touch sensors
======================== ======================================================
So, the concept of "V4L2 Device Node" is now clear, and doesn't
include V4L2 sub-device device nodes (/dev/v4l-subdev*).
For devices controlled via media controller, everybody seems to be
comfortable of calling them as MC-centric.
There are currently two proposals to refer to the media hardware that
is controlled via a V4L2 Device Node:
- vdev-centric
- V4L2-centric
The last one sounds confusing to me, as subdev API is part of the V4L2
specification. "V4L2-centric" name sounds to include subdevs.
That's why IMHO, vdev-centric is better.
We could go to some other naming for them, that would also be
an alias for "V4L2 Device Node":
- VD-centric
- VDN-centric
Comments?
Thanks,
Mauro
