On 12/03/2018 09:02 AM, Sebastian Süsens wrote:
> Hello,
>
> I don't know how to get access to the v4l controls on a I2C camera sensor.
>
> My driver structure looks following:
>
> bridge driver -> csi-driver
> -> sensor driver (includes controls)
> register-async-notifer for csi driver register-async-notifer for
> sensor driver
> register video device
>
> The v4l2 API say:
> When a sub-device is registered with a V4L2 driver by calling
> v4l2_device_register_subdev() and the ctrl_handler fields of both v4l2_subdev
> and v4l2_device are set, then the controls of the subdev will become
> automatically available in the V4L2 driver as well. If the subdev driver
> contains controls that already exist in the V4L2 driver, then those will be
> skipped (so a V4L2 driver can always override a subdev control).
>
> But how can I get access to the controls by asynchronous registration,
> because the controls are not added to the video device automatically?
Yes, they are via v4l2_device_register_subdev(), which is called by the async
code
when the subdev driver arrives.
Note that this assumes that the bridge driver has a control handler that struct
v4l2_device points to (the ctrl_handler field).
Also note that certain types of drivers (media controller-based) such as the imx
driver do not 'inherit' controls since each subdev has its own v4l-subdevX
device node
through which its controls can be set. You do not mention which bridge driver
you are
using, so I can't tell whether or not it falls in this category.
Regards,
Hans
>
> Normally I can use:
>
> v4l2-ctl -l -d /dev/video0
>
> I don't know if this forum is the right place for this question, so please
> answer with a private e-mail s...@mycable.de
>
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