From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
Documentation/media/uapi/v4l/open.rst | 11 +++++++++++
Documentation/media/uapi/v4l/vidioc-querycap.rst | 5 +++++
include/uapi/linux/videodev2.h | 2 ++
3 files changed, 18 insertions(+)
diff --git a/Documentation/media/uapi/v4l/open.rst b/Documentation/media/uapi/v4l/open.rst
index bbd1887f83a0..c6ab5fef4443 100644
--- a/Documentation/media/uapi/v4l/open.rst
+++ b/Documentation/media/uapi/v4l/open.rst
@@ -6,6 +6,10 @@
Opening and Closing Devices
***************************
+
+.. _v4l2_hardware_control:
+
+
Types of V4L2 hardware control
==============================
@@ -49,6 +53,13 @@ sub-devices' configuration can be controlled via the
:ref:`sub-device API <subdev>`, whith creates one device node
per sub-device.
+.. attention::
+
+ Devices that require **mc-centric** hardware control should report
+ a ``V4L2_MC_CENTRIC`` :c:type:`v4l2_capability` flag
+ (see :ref:`VIDIOC_QUERYCAP`).
+
+
In summary, for **MC-centric** hardware control:
- The **V4L2 device** node is responsible for controlling the streaming
diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
index 12e0d9a63cd8..2b08723375bc 100644
--- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
+++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
@@ -252,6 +252,11 @@ 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 **v4l2-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/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 45cf7359822c..7b490fe97980 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 */
/*
--
2.13.3
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