[PATCH v8 6/7] media: videodev2: add a flag for MC-centric devices

From: Mauro Carvalho Chehab
Date: Tue Oct 10 2017 - 07:46:08 EST


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@xxxxxxxxxxxxxxxx>
Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
Documentation/media/uapi/v4l/open.rst | 7 +++++++
Documentation/media/uapi/v4l/vidioc-querycap.rst | 5 +++++
Documentation/media/videodev2.h.rst.exceptions | 1 +
include/uapi/linux/videodev2.h | 2 ++
4 files changed, 15 insertions(+)

diff --git a/Documentation/media/uapi/v4l/open.rst b/Documentation/media/uapi/v4l/open.rst
index c9e6bc9280a6..58ab75959584 100644
--- a/Documentation/media/uapi/v4l/open.rst
+++ b/Documentation/media/uapi/v4l/open.rst
@@ -62,6 +62,13 @@ typically involves configuring the links using the **Media controller**
interface and the media bus formats on pads (at both ends of the links)
using the **V4L2 sub-device** interface.

+.. attention::
+
+ Devices that require **MC-centric** media hardware control should
+ report a ``V4L2_MC_CENTRIC`` :c:type:`v4l2_capability` flag
+ (see :ref:`VIDIOC_QUERYCAP`).
+
+
.. _v4l2_device_naming:

V4L2 Device Node Naming
diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
index 66fb1b3d6e6e..944bc5ba484f 100644
--- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
+++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
@@ -254,6 +254,11 @@ specification the ioctl returns an ``EINVAL`` error code.
* - ``V4L2_CAP_TOUCH``
- 0x10000000
- This is a touch device.
+ * - ``V4L2_MC_CENTRIC``
+ - 0x20000000
+ - Indicates that the device require **MC-centric** hardware
+ control, and thus can't be used by **vdevnode-centric** applications.
+ See :ref:`v4l2_hardware_control` for more details.
* - ``V4L2_CAP_DEVICE_CAPS``
- 0x80000000
- The driver fills the ``device_caps`` field. This capability can
diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
index a5cb0a8686ac..b51a575f9f75 100644
--- a/Documentation/media/videodev2.h.rst.exceptions
+++ b/Documentation/media/videodev2.h.rst.exceptions
@@ -157,6 +157,7 @@ replace define V4L2_CAP_META_CAPTURE device-capabilities
replace define V4L2_CAP_READWRITE device-capabilities
replace define V4L2_CAP_ASYNCIO device-capabilities
replace define V4L2_CAP_STREAMING device-capabilities
+replace define V4L2_CAP_MC_CENTRIC device-capabilities
replace define V4L2_CAP_DEVICE_CAPS device-capabilities
replace define V4L2_CAP_TOUCH device-capabilities

diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 185d6a0acc06..4ff1224719a7 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_MC_CENTRIC 0x20000000 /* Device require MC-centric hardware control */
+
#define V4L2_CAP_DEVICE_CAPS 0x80000000 /* sets device capabilities field */

/*
--
2.13.6