Subject: Re: [RFC v1 07/11] media: Add meta formats supported by NXP neoisp driver

From: Jacopo Mondi <[email-masked]>
Date: Wed, 4 Feb 2026 14:36:08 +0100

Hi Antoine

On Wed, Feb 04, 2026 at 02:31:47PM +0100, Antoine Bouyer wrote:
> Hi Jacopo
>
> Le 03/02/2026 à 18:11, Jacopo Mondi a écrit :
> >
> > Hi Antoine
> >
> > On Fri, Jan 23, 2026 at 09:09:34AM +0100, Antoine Bouyer wrote:
> > > This patch adds new v4l2 meta formats definitions and descriptions used by
> > > neoisp driver for the parameters and statistics buffers:
> > >   - `V4L2_META_FMT_NEO_ISP_PARAMS` used for the legacy fixed-size
> > > parameters buffer structure.
> > >   - `V4L2_META_FMT_NEO_ISP_EXT_PARAMS` used for the generic v4l2-isp
> > > extensible parameters structure, supporting a non-fixed-size buffer and
> > > changeable ISP configuration blocks.
> > >   - `V4L2_META_FMT_NEO_ISP_STATS` used for the legacy fixed-size statistics
> > > buffer structure.
> > >   - `V4L2_META_FMT_NEO_ISP_EXT_STATS` used for the generic v4l2-isp
> > > extensible statistics structure, supporting a non-fixed-size buffer
> > > and changeable ISP statistics blocks.
> >
> > Uh interesting, you have existing userspace that needs legacy formats ?
>
> Yes we do have some available here (version with extensible formats will be
> the next one):
> https://github.com/nxp-imx/libcamera
>
> Not in mainline, thought.

I see.

However I don't think the mainline driver should support both formats.

And looking at your libcamera branch, it seem it already supports the
extensible version.

>
> BR
> Antoine
>
> >
> > >
> > > Signed-off-by: Antoine Bouyer <[email-masked]>
> > > ---
> > >   drivers/media/v4l2-core/v4l2-ioctl.c | 4 ++++
> > >   include/uapi/linux/videodev2.h       | 6 ++++++
> > >   2 files changed, 10 insertions(+)
> > >
> > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > index 37d33d4a363d..c797cf11be38 100644
> > > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > @@ -1471,6 +1471,10 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > >        case V4L2_META_FMT_C3ISP_STATS:         descr = "Amlogic C3 ISP Statistics"; break;
> > >        case V4L2_META_FMT_MALI_C55_PARAMS:     descr = "ARM Mali-C55 ISP Parameters"; break;
> > >        case V4L2_META_FMT_MALI_C55_STATS:      descr = "ARM Mali-C55 ISP 3A Statistics"; break;
> > > +     case V4L2_META_FMT_NEO_ISP_PARAMS:      descr = "NXP Neo ISP 3A Parameters"; break;
> > > +     case V4L2_META_FMT_NEO_ISP_EXT_PARAMS:  descr = "NXP Neo ISP ext 3A Parameters"; break;
> > > +     case V4L2_META_FMT_NEO_ISP_STATS:       descr = "NXP Neo ISP 3A Statistics"; break;
> > > +     case V4L2_META_FMT_NEO_ISP_EXT_STATS:   descr = "NXP Neo ISP ext 3A Statistics"; break;
> > >        case V4L2_PIX_FMT_NV12_8L128:   descr = "NV12 (8x128 Linear)"; break;
> > >        case V4L2_PIX_FMT_NV12M_8L128:  descr = "NV12M (8x128 Linear)"; break;
> > >        case V4L2_PIX_FMT_NV12_10BE_8L128:      descr = "10-bit NV12 (8x128 Linear, BE)"; break;
> > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > > index 848e86617d5c..5f4992452c66 100644
> > > --- a/include/uapi/linux/videodev2.h
> > > +++ b/include/uapi/linux/videodev2.h
> > > @@ -889,6 +889,12 @@ struct v4l2_pix_format {
> > >   #define V4L2_META_FMT_MALI_C55_PARAMS        v4l2_fourcc('C', '5', '5', 'P') /* ARM Mali-C55 Parameters */
> > >   #define V4L2_META_FMT_MALI_C55_STATS v4l2_fourcc('C', '5', '5', 'S') /* ARM Mali-C55 3A Statistics */
> > >
> > > +/* Vendor specific - used for NXP NEOISP sub-system */
> > > +#define V4L2_META_FMT_NEO_ISP_PARAMS         v4l2_fourcc('N', 'N', 'I', 'P') /* NXP NEOISP Parameters */
> > > +#define V4L2_META_FMT_NEO_ISP_EXT_PARAMS     v4l2_fourcc('N', 'N', 'E', 'P') /* NXP NEOISP Ext Params */
> > > +#define V4L2_META_FMT_NEO_ISP_STATS          v4l2_fourcc('N', 'N', 'I', 'S') /* NXP NEOISP Statistics */
> > > +#define V4L2_META_FMT_NEO_ISP_EXT_STATS              v4l2_fourcc('N', 'N', 'E', 'S') /* NXP NEOISP Ext Stats */
> > > +
> > >   #ifdef __KERNEL__
> > >   /*
> > >    * Line-based metadata formats. Remember to update v4l_fill_fmtdesc() when
> > > --
> > > 2.52.0
> > >
> > >
>