Recommended control V4L2_CID_IMAGE_STABILIZATION missing libcamera message

[Hans de Goede]

Hi,

On 2/4/24 11:20, Jacopo Mondi wrote:
> On Sun, Feb 04, 2024 at 10:45:55AM +0200, Laurent Pinchart wrote:
>> On Sun, Feb 04, 2024 at 08:44:01AM +0100, Hans de Goede wrote:
>>> Hi All,
>>>
>>> While working on the ov2680 driver to make it work with libcamera, I noticed
>>> that after adding vblank + hblank control I still get a message about
>>> Recommended V4control V4L2_CID_IMAGE_STABILIZATION missing libcamera message
>>> with a pointer to Documentation/sensor_driver_requirements.rst where
>>> this is not documented.
>>
>> That's not expected, libcamera doesn't require that control. 'git grep
>> IMAGE_STABILIZATION' returns a single hit, in
>> include/linux/v4l2-controls.h. Could you try to figure out what's
>> happening ?
>>
> 
> 
> The only recommanded control I see is
> #define V4L2_CID_CAMERA_ORIENTATION		(V4L2_CID_CAMERA_CLASS_BASE+34)
> 
> While
> #define V4L2_CID_IMAGE_STABILIZATION		(V4L2_CID_CAMERA_CLASS_BASE+22)
> 
> is it by chance that 22h = 34d ?

Yes that is the one my bad.

Reading: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-camera.html

I think that we probably need some helpers for sensors to call to
add V4L2_CID_CAMERA_ORIENTATION and V4L2_CID_CAMERA_SENSOR_ROTATION
ctrls based on some standardized device-properties for these.

These properties can then be added to the parent i2c-client-device through
device-tree or ACPI glue code.

Are there already standardized device-tree properties for this ?

I'll add this to my never ending todo list, no idea when I'll get
around to it though.

Regards,

Hans