From: Mauro Carvalho Chehab <mchehab@s-opensource.com>
To: Linux Doc Mailing List <linux-doc@vger.kernel.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
Mauro Carvalho Chehab <mchehab@infradead.org>,
linux-kernel@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
Hans Verkuil <hans.verkuil@cisco.com>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Mauro Carvalho Chehab <mchehab@s-opensource.com>
Subject: [PATCH v2 3/3] media: videodev2: add a flag for MC-centric devices
Date: Fri, 25 Aug 2017 09:52:42 -0300 [thread overview]
Message-ID: <53b52be3d01aa803f1c4342a07778517641990c0.1503665390.git.mchehab@s-opensource.com> (raw)
In-Reply-To: <cover.1503665390.git.mchehab@s-opensource.com>
In-Reply-To: <cover.1503665390.git.mchehab@s-opensource.com>
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 | 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
prev parent reply other threads:[~2017-08-25 12:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-25 12:52 [PATCH v2 0/3] document types of hardware control for V4L2 Mauro Carvalho Chehab
2017-08-25 12:52 ` [PATCH v2 1/3] media: open.rst: better document device node naming Mauro Carvalho Chehab
2017-08-25 12:58 ` Mauro Carvalho Chehab
2017-08-25 13:31 ` Hans Verkuil
2017-08-25 12:52 ` [PATCH v2 2/3] media: open.rst: document devnode-centric and mc-centric types Mauro Carvalho Chehab
2017-08-25 13:42 ` Hans Verkuil
2017-08-26 10:58 ` Mauro Carvalho Chehab
2017-08-25 12:52 ` Mauro Carvalho Chehab [this message]
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