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author | Luca Ceresoli <luca@lucaceresoli.net> | 2019-06-13 10:18:22 -0400 |
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committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-21 17:04:03 -0400 |
commit | e36160b84253d7125d0fa4109a3d69f0c55fc5d0 (patch) | |
tree | 8322d6a64fb73f3c0697e5afe8dad494d1d12a82 | |
parent | 9e75efb0f2c56c7285f28bba877da14f428a730c (diff) | |
download | linux-e36160b84253d7125d0fa4109a3d69f0c55fc5d0.tar.bz2 |
media: docs: v4l2-controls: rearrange control initialization sequence
The code snippet showing how to add controls to the driver’s top-level
struct is present twice, but only the second time it is split in the V4L2
and subdev cases. Consolidate everything at the beginning.
Also remove the "Where foo->bar is of type struct baz" sentences, this
obvious from the code.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
-rw-r--r-- | Documentation/media/kapi/v4l2-controls.rst | 40 |
1 files changed, 17 insertions, 23 deletions
diff --git a/Documentation/media/kapi/v4l2-controls.rst b/Documentation/media/kapi/v4l2-controls.rst index 0c3f486727ed..5281c9b1fd66 100644 --- a/Documentation/media/kapi/v4l2-controls.rst +++ b/Documentation/media/kapi/v4l2-controls.rst @@ -52,15 +52,29 @@ Basic usage for V4L2 and sub-device drivers 1.1) Add the handler to your driver's top-level struct: +For V4L2 drivers: + .. code-block:: none struct foo_dev { ... + struct v4l2_device v4l2_dev; + ... struct v4l2_ctrl_handler ctrl_handler; ... }; - struct foo_dev *foo; +For sub-device drivers: + +.. code-block:: none + + struct foo_dev { + ... + struct v4l2_subdev sd; + ... + struct v4l2_ctrl_handler ctrl_handler; + ... + }; 1.2) Initialize the handler: @@ -74,43 +88,23 @@ information. It is a hint only. 1.3) Hook the control handler into the driver: -1.3.1) For V4L2 drivers do this: +For V4L2 drivers: .. code-block:: none - struct foo_dev { - ... - struct v4l2_device v4l2_dev; - ... - struct v4l2_ctrl_handler ctrl_handler; - ... - }; - foo->v4l2_dev.ctrl_handler = &foo->ctrl_handler; -Where foo->v4l2_dev is of type struct v4l2_device. - Finally, remove all control functions from your v4l2_ioctl_ops (if any): vidioc_queryctrl, vidioc_query_ext_ctrl, vidioc_querymenu, vidioc_g_ctrl, vidioc_s_ctrl, vidioc_g_ext_ctrls, vidioc_try_ext_ctrls and vidioc_s_ext_ctrls. Those are now no longer needed. -1.3.2) For sub-device drivers do this: +For sub-device drivers: .. code-block:: none - struct foo_dev { - ... - struct v4l2_subdev sd; - ... - struct v4l2_ctrl_handler ctrl_handler; - ... - }; - foo->sd.ctrl_handler = &foo->ctrl_handler; -Where foo->sd is of type struct v4l2_subdev. - 1.4) Clean up the handler at the end: .. code-block:: none |