@@ -6,6 +6,8 @@
Opening and Closing Devices
***************************
+.. _v4l2_hardware_control:
+
Types of V4L2 hardware control
==============================
@@ -33,6 +35,13 @@ 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::
+
+ Devices that are **not** capable of **vdev-centric** hardware control
+ should report a ``V4L2_MC_CENTRIC`` :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
@@ -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 only provides **mc-centric** hardware
+ control, and 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
@@ -460,6 +460,8 @@ struct v4l2_capability {
#define V4L2_CAP_TOUCH 0x10000000 /* Is a touch device */
+#define V4L2_CAP_MC_CENTRIC 0x20000000 /* Device can't be controlled via V4L2 device devnodes */
+
#define V4L2_CAP_DEVICE_CAPS 0x80000000 /* sets device capabilities field */
/*