[libcamera-devel] [PATCH v1 13/14] libcamera: camera_sensor: Add Sony IMX708 sensor properties

[Laurent Pinchart]

On Mon, Jan 23, 2023 at 10:33:35AM +0000, Naushir Patuck wrote:
> On Mon, 23 Jan 2023 at 10:01, Laurent Pinchart wrote:
> > On Mon, Jan 23, 2023 at 09:07:53AM +0000, Naushir Patuck wrote:
> > > On Sun, 22 Jan 2023 at 18:58, Laurent Pinchart wrote:
> > > > On Thu, Jan 19, 2023 at 01:03:04PM +0000, Kieran Bingham via libcamera-devel wrote:
> > > > > Quoting Naushir Patuck via libcamera-devel (2023-01-19 10:45:43)
> > > > > > From: Nick Hollinghurst <nick.hollinghurst at raspberrypi.com>
> > > > > >
> > > > > > The IMX708 sensor driver advertises its module variants (narrow/wide angle lens,
> > > > > > IR block/pass) by modifying the media entity name string. So add duplicate
> > > > > > entries for each variant.
> > > > >
> > > > > The duplication here is a bit of a pain. Are there any sensor properties
> > > > > we might register that would change in each of these variants?
> > > > >
> > > > > Or should we make the CameraSensorProperties class more intelligent so
> > > > > it just does the lookup on the sensor only. Of course ideally we should
> > > > > be able to identify the sensor and the variant separately from the
> > > > > kernel - which might not be possible right now - in which case, given
> > > > > how little information is actually duplicated here I'd be fine with this
> > > > > for now.
> > > >
> > > > I'm concerned by this too. The kernel shouldn't report different entity
> > > > names for different lenses. There should thus be a single entry in the
> > > > camera sensors properties table, and lens information should be reported
> > > > separately.
> > >
> > > I agree this is not the tidiest thing to do.  Right now, we have no other way of
> > > getting the variant details from the kernel driver into userland.  I believe
> > > @Dave Stevenson raised this topic at the last Embedded Linux Conference, but no
> > > consensus was reached.  Once we have a mechanism in the kernel to report lens
> > > properties, we will remove this workaround.  Would a \todo suffice for now?
> >
> > If adding a \todo was enough to make a mechanism for this appear
> > upstream by magic, I'd say it's fine. Unfortunately, that doesn't match
> > my experience :-)
> 
> If only! :)
> 
> > One middleground option would be to merge the first "variant" (the
> > "imx708") when the driver gets posted to the linux-media mailing list,
> > while the rest gets developed, but in any case it will require someone
> > making a proposal upstream.
> 
> We will post a variant-less driver to the mailing list and chat with Dave about
> a proposal for module variant reporting.

You could also include variant support in the driver posted to
linux-media, so the proposal could be discussed during reviews. Up to
you.

> The reason we added the other variants in the CameraSensorProperties was to
> quiet the warning log message when a device is not listed. Would it be ok to
> keep all variants listed like this with a \todo to clean-up?  If not, we will have to
> make this change in our downstream tree which we are trying hard to deprecate :(

What concerns me is when that would be cleaned up. Unless there's a real
effort to design and upstream a mechanism for this, it won't happen, so
I want to see someone taking the lead and bringing it to completion.
Merging support for a device in libcamera before the kernel driver is
ready upstream is already a middleground.

> > > > > Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > > > >
> > > > > > Signed-off-by: Nick Hollinghurst <nick.hollinghurst at raspberrypi.com>
> > > > > > Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> > > > > > Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
> > > > > > Reviewed-by: David Plowman <david.plowman at raspberrypi.com>
> > > > > > ---
> > > > > >  src/libcamera/camera_sensor_properties.cpp | 16 ++++++++++++++++
> > > > > >  1 file changed, 16 insertions(+)
> > > > > >
> > > > > > diff --git a/src/libcamera/camera_sensor_properties.cpp b/src/libcamera/camera_sensor_properties.cpp
> > > > > > index c3c2caced906..3afd500ea3be 100644
> > > > > > --- a/src/libcamera/camera_sensor_properties.cpp
> > > > > > +++ b/src/libcamera/camera_sensor_properties.cpp
> > > > > > @@ -123,6 +123,22 @@ const CameraSensorProperties *CameraSensorProperties::get(const std::string &sen
> > > > > >                                  */
> > > > > >                         },
> > > > > >                 } },
> > > > > > +               { "imx708", {
> > > > > > +                       .unitCellSize = { 1400, 1400 },
> > > > > > +                       .testPatternModes = {},
> > > > > > +               } },
> > > > > > +               { "imx708_noir", {
> > > > > > +                       .unitCellSize = { 1400, 1400 },
> > > > > > +                       .testPatternModes = {},
> > > > > > +               } },
> > > > > > +               { "imx708_wide", {
> > > > > > +                       .unitCellSize = { 1400, 1400 },
> > > > > > +                       .testPatternModes = {},
> > > > > > +               } },
> > > > > > +               { "imx708_wide_noir", {
> > > > > > +                       .unitCellSize = { 1400, 1400 },
> > > > > > +                       .testPatternModes = {},
> > > > > > +               } },
> > > > > >                 { "ov2740", {
> > > > > >                         .unitCellSize = { 1400, 1400 },
> > > > > >                         .testPatternModes = {

-- 
Regards,

Laurent Pinchart