[PATCH 2/3] media: videodev2: add a flag for vdev-centric devices

Mauro Carvalho Chehab
2017-08-25T09:40:14Z

From: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

As both vdev-centric and mc-centric devices may implement the
same APIs, we need a flag to allow userspace to distinguish
between them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
Documentation/media/uapi/v4l/open.rst | 6 ++++++
Documentation/media/uapi/v4l/vidioc-querycap.rst | 4 ++++
include/uapi/linux/videodev2.h | 2 ++
3 files changed, 12 insertions(+)

diff --git a/Documentation/media/uapi/v4l/open.rst b/Documentation/media/uapi/v4l/open.rst
index a72d142897c0..eb3f0ec57edb 100644
--- a/Documentation/media/uapi/v4l/open.rst
+++ b/Documentation/media/uapi/v4l/open.rst
@@ -33,6 +33,12 @@ For **vdev-centric** control, the device and their corresponding hardware
pipelines are controlled via the **V4L2 device** node. They may optionally
expose via the :ref:`media controller API <media_controller>`.

+.. note::
+
+ **vdev-centric** devices should report V4L2_VDEV_CENTERED
+ :c:type:`v4l2_capability` flag (see :ref:`VIDIOC_QUERYCAP`).
+
+
For **MC-centric** control, before using the V4L2 device, it is required to
set the hardware pipelines via the
:ref:`media controller API <media_controller>`. For those devices, the
diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
index 12e0d9a63cd8..4856821b7608 100644
--- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
+++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
@@ -252,6 +252,10 @@ specification the ioctl returns an ``EINVAL`` error code.
* - ``V4L2_CAP_TOUCH``
- 0x10000000
- This is a touch device.
+ * - ``V4L2_VDEV_CENTERED``
+ - 0x20000000
+ - This is controlled via V4L2 device nodes (radio, video, vbi,
+ sdr
* - ``V4L2_CAP_DEVICE_CAPS``
- 0x80000000
- The driver fills the ``device_caps`` field. This capability can
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 45cf7359822c..d89090d99042 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -460,6 +460,8 @@ struct v4l2_capability {

#define V4L2_CAP_TOUCH 0x10000000 /* Is a touch device */

+#define V4L2_CAP_VDEV_CENTERED 0x20000000 /* V4L2 Device is controlled via V4L2 device devnode */
+
#define V4L2_CAP_DEVICE_CAPS 0x80000000 /* sets device capabilities field */

/*
--
2.13.3