Recommended control V4L2_CID_IMAGE_STABILIZATION missing libcamera message

[Laurent Pinchart]

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().

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

-- 
Regards,

Laurent Pinchart