RE: [PATCH v2 2/3] media: rcar-vin: Add support for MEDIA_BUS_FMT_SRGGB8_1X8 format

From: Prabhakar Mahadev Lad
Date: Tue Mar 10 2020 - 09:42:30 EST


Hi Niklas,

Thank for the review.

> -----Original Message-----
> From: Niklas <niklas.soderlund@xxxxxxxxxxxx>
> Sent: 10 March 2020 12:46
> To: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>; linux-
> media@xxxxxxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Lad Prabhakar <prabhakar.csengg@xxxxxxxxx>
> Subject: Re: [PATCH v2 2/3] media: rcar-vin: Add support for
> MEDIA_BUS_FMT_SRGGB8_1X8 format
>
> Hi Lad,
>
> Thanks for your work.
>
> On 2020-03-10 11:06:03 +0000, Lad Prabhakar wrote:
> > Add support for MEDIA_BUS_FMT_SRGGB8_1X8 format in rcar-vin by
> setting
> > format type to RAW8 in VNMC register and appropriately setting the
> > bpp, bytesperline to enable V4L2_PIX_FMT_SRGGB8.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-
> lad.rj@xxxxxxxxxxxxxx>
> > ---
> > drivers/media/platform/rcar-vin/rcar-core.c | 1 +
> > drivers/media/platform/rcar-vin/rcar-dma.c | 9 ++++++++-
> > drivers/media/platform/rcar-vin/rcar-v4l2.c | 13 ++++++++++++-
> > 3 files changed, 21 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/platform/rcar-vin/rcar-core.c
> > b/drivers/media/platform/rcar-vin/rcar-core.c
> > index 7440c89..76daf2f 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-core.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> > @@ -469,6 +469,7 @@ static int rvin_parallel_subdevice_attach(struct
> rvin_dev *vin,
> > case MEDIA_BUS_FMT_UYVY8_2X8:
> > case MEDIA_BUS_FMT_UYVY10_2X10:
> > case MEDIA_BUS_FMT_RGB888_1X24:
> > +case MEDIA_BUS_FMT_SRGGB8_1X8:
> > vin->mbus_code = code.code;
> > vin_dbg(vin, "Found media bus format for %s: %d\n",
> > subdev->name, vin->mbus_code);
> > diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c
> > b/drivers/media/platform/rcar-vin/rcar-dma.c
> > index 1a30cd0..1c1fafa 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> > @@ -85,6 +85,7 @@
> > #define VNMC_INF_YUV8_BT601(1 << 16)
> > #define VNMC_INF_YUV10_BT656(2 << 16)
> > #define VNMC_INF_YUV10_BT601(3 << 16)
> > +#define VNMC_INF_RAW8(4 << 16)
> > #define VNMC_INF_YUV16(5 << 16)
> > #define VNMC_INF_RGB888(6 << 16)
> > #define VNMC_VUP(1 << 10)
> > @@ -587,7 +588,6 @@ void rvin_crop_scale_comp(struct rvin_dev *vin)
> > rvin_write(vin, vin->crop.top, VNSLPRC_REG);
> > rvin_write(vin, vin->crop.top + vin->crop.height - 1, VNELPRC_REG);
> >
> > -
> > /* TODO: Add support for the UDS scaler. */
> > if (vin->info->model != RCAR_GEN3)
> > rvin_crop_scale_comp_gen2(vin);
> > @@ -676,6 +676,9 @@ static int rvin_setup(struct rvin_dev *vin)
> >
> > input_is_yuv = true;
> > break;
> > +case MEDIA_BUS_FMT_SRGGB8_1X8:
> > +vnmc |= VNMC_INF_RAW8;
> > +break;
> > default:
> > break;
> > }
> > @@ -737,6 +740,9 @@ static int rvin_setup(struct rvin_dev *vin)
> > case V4L2_PIX_FMT_ABGR32:
> > dmr = VNDMR_A8BIT(vin->alpha) | VNDMR_EXRGB |
> VNDMR_DTMD_ARGB;
> > break;
> > +case V4L2_PIX_FMT_SRGGB8:
> > +dmr = 0;
> > +break;
> > default:
> > vin_err(vin, "Invalid pixelformat (0x%x)\n",
> > vin->format.pixelformat);
> > @@ -1110,6 +1116,7 @@ static int rvin_mc_validate_format(struct
> rvin_dev *vin, struct v4l2_subdev *sd,
> > case MEDIA_BUS_FMT_UYVY8_2X8:
> > case MEDIA_BUS_FMT_UYVY10_2X10:
> > case MEDIA_BUS_FMT_RGB888_1X24:
> > +case MEDIA_BUS_FMT_SRGGB8_1X8:
> > vin->mbus_code = fmt.format.code;
> > break;
> > default:
> > diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > index 5151a3c..4698099 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > @@ -66,6 +66,10 @@ static const struct rvin_video_format rvin_formats[]
> = {
> > .fourcc= V4L2_PIX_FMT_ABGR32,
> > .bpp= 4,
> > },
> > +{
> > +.fourcc= V4L2_PIX_FMT_SRGGB8,
> > +.bpp= 2,
>
> This does not look right, is not bytes-per-pixel 1 for a SRGGB8?
>
I guessed the bpp's were picked from VnIS table as I result I did the same.

> > +},
> > };
> >
> > const struct rvin_video_format *rvin_format_from_pixel(struct
> > rvin_dev *vin, @@ -102,6 +106,7 @@ static u32
> > rvin_format_bytesperline(struct rvin_dev *vin, {
> > const struct rvin_video_format *fmt;
> > u32 align;
> > +u8 div;
> >
> > fmt = rvin_format_from_pixel(vin, pix->pixelformat);
> >
> > @@ -112,16 +117,22 @@ static u32 rvin_format_bytesperline(struct
> rvin_dev *vin,
> > case V4L2_PIX_FMT_NV12:
> > case V4L2_PIX_FMT_NV16:
> > align = 0x20;
> > +div = 1;
> > +break;
> > +case V4L2_PIX_FMT_SRGGB8:
> > +align = 0x10;
> > +div = 2;
>
> Yes this does not look right at all, I think you should set bpp to 1 and drop the
> div handling here.
>
If I set bpp as 1 and drop the div VNIS_REG will be wrongly configured in
rvin_crop_scale_comp() and the image captured will be wrong.

For example for 640x480:

With the current patch bpp = 2:
bytesperline = 640
image size = 307200
stride = 320

And with bpp = 1 and div removed
bytesperline = 640
image size = 307200
stride = 640

Cheers,
--Prabhakar

> > break;
> > default:
> > align = 0x10;
> > +div = 1;
> > break;
> > }
> >
> > if (V4L2_FIELD_IS_SEQUENTIAL(pix->field))
> > align = 0x80;
> >
> > -return ALIGN(pix->width, align) * fmt->bpp;
> > +return ALIGN(pix->width / div, align) * fmt->bpp;
> > }
> >
> > static u32 rvin_format_sizeimage(struct v4l2_pix_format *pix)
> > --
> > 2.7.4
> >
>
> --
> Regards,
> Niklas Söderlund


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