Re: [libcamera-devel] [PATCH RFC 1/4] media: v4l2-ctrls: add lens group status controls for zoom and focus

From: Sakari Ailus
Date: Wed Apr 12 2023 - 11:12:32 EST


Hi Dave, Michael,

On Wed, Apr 12, 2023 at 02:55:56PM +0100, Dave Stevenson wrote:
> > > If the ranges aren't updated, where should that out-of-range lens
> > > movement leave the lens?
> >
> > This is up to the hardware controller, but I would guess it typically
> > stops one step before disaster. Wherever that may be, the error
> > condition and the current position can be read out via this new STATUS
> > control.
> >
> > Does this sound good so far?
>
> Sounds reasonable, but I'm not the gatekeeper (that would be Sakari or
> Laurent), and I'm just expressing my views based on the lenses I've
> encountered.
> All of my lenses have a single drive for focus, a single drive for
> zoom, and where there are multiple elements they are all connected
> mechanically. Your setup sounds far more complex and is likely to need
> a more extensive driver, but it'd be nice to not unnecessarily
> overcomplicate the interface.

Could we also have a driver that uses these new controls?

The controls themselves appear reasonable to me as well. I guess there are
changes to be made based on the discussion?

--
Regards,

Sakari Ailus