Recommended control V4L2_CID_IMAGE_STABILIZATION missing libcamera message

[Hans de Goede]

Hi,

On 2/4/24 14:09, Laurent Pinchart wrote:
> Hi Hans,
> 
> On Sun, Feb 04, 2024 at 02:03:57PM +0100, Hans de Goede wrote:
>> 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 ?
> 
> We have all this already :-) See v4l2_ctrl_new_fwnode_properties().

Ah great. Expect a patch-series making the ov2680 sensor kernel driver
fully libcamera compliant soon.

Regards,

Hans