Re: [PATCH v5 2/2] media: i2c: Add Sony IMX908 image sensor driver

[Laurent Pinchart]

On Wed, Oct 21, 2026 at 02:56:50PM +0300, Sakari Ailus wrote:
> On Tue, Oct 20, 2026 at 03:50:09PM +0100, Dave Stevenson wrote:
> > On Tue, 20 Oct 2026 at 13:56, Laurent Pinchart wrote:
> > > On Tue, Oct 20, 2026 at 01:47:11PM +0300, Sakari Ailus wrote:
> > > > On Mon, Oct 19, 2026 at 10:47:20AM +0900, Lachlan Michael wrote:
> > > > > The IMX908 is an 8.39 MP (3856x2176) CMOS image sensor with a MIPI CSI-2
> > > > > output interface. The driver supports RAW10 and RAW12 output formats,
> > > > > exposure and analogue gain controls, image flipping, blanking controls
> > > > > and test pattern generation.
> > > >
> > > > The imx908 appears to be a Starvis 3 sensor. How close is it to the Starvis
> > > > 2, for which Dave (Cc'd) is working on a driver (see
> > > > <URL:https://lore.kernel.org/linux-media/atdAsDGw_jvhaydM@kekkonen.localdomain/T/#m0c50ea017ef9ae0d3d76a36b840db9b6f7ac296c>)?
> > > > The register defines in the two drivers appear to be quite well aligned.
> > 
> > Asked and answered at v1
> > https://lore.kernel.org/linux-media/TY6PR01MB17839FF48671E744E7E23A93E92D42@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> > 
> > > The current version of the driver implements very few features of the
> > > IMX908 sensor, as crop support has been removed pending the raw camera
> > > sensor model, and Clear HDR3 is being developed. I expect more
> > > differences to appear when those features will be merged, so I believe
> > > it makes sense to have a separate driver here.
> > >
> > > In the future, I expect the raw camera sensor model to open the door to
> > > more code sharing and more drivers supporting a wider variety of
> > > devices. We can decide then if the imx908 should stay a standalone
> > > driver, support other sensors as well, possibly across the Starvis 2 and
> > > 3 families. I'm willing to help with the refactoring at that point if
> > > needed, the maintenance burden won't be on you (and I'm sure that
> > > Lachlan and his team will of course maintain the code base).
> > 
> > Agreed.
> > I have compared the datasheet for imx908 against the Starvis2 ones,
> > and when we start looking at HDR modes they diverge a reasonable
> > amount.
> > 
> > Even the later Starvis2 sensors (IMX585 and IMX676) have minor changes
> > to the earlier ones, so adding Starvis3 would need some care.
> 
> There's quite a bit of this in the CCS driver, due to the variance it
> allows for implementors. I don't see this being a problem as long as the
> foundations are reasonably similar, albeit we can see whether this could be
> further extended later on to other sensors.
> 
> I'm fine with having a separate imx908 driver for now. Dave's driver also
> exposes the variant information through the media entity name so that
> should be done by the imx908, too (at least if there can be multiple ones).

As far as I understand, the IMX908 does not have a mono version.
Lachlan, could you please confirm that ?

> I'll review the driver properly soonish but I reckon it's in a pretty good
> shape already.

-- 
Regards,

Laurent Pinchart