On Tue, Aug 23, 2022 at 08:18:35PM +0300, Laurent Pinchart wrote:
> The ISP output color space is configured through the ISP source pad. At
> the moment, only the quantization can be set. Extend it to the three
> other color space fields:
>
> - The ycbcr_enc field will be used to configure the RGB to YUV matrix
> (currently hardcoded to Rec. 601).
>
> - The colorspace (which controls the color primaries) and xfer_func
> fields will not be used to configure the ISP, as the corresponding
> hardware blocks (the cross-talk RGB to RGB matrix and the tone mapping
> curve) are programmed directly by applications through ISP parameters.
> Nonetheless, those two fields should be set by applications to match
> the ISP configuration, in order to propagate the correct color space
> down the pipeline up to the capture video nodes.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Reviewed-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
> ---
> Changes since v1:
>
> - Fix quantization setting that was set on sink pad by mistake
> ---
> .../platform/rockchip/rkisp1/rkisp1-isp.c | 55 ++++++++++++++++---
> 1 file changed, 48 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
> index d34f32271d74..7869f0cced62 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c
> @@ -609,6 +609,7 @@ static void rkisp1_isp_set_src_fmt(struct rkisp1_isp *isp,
> struct v4l2_mbus_framefmt *sink_fmt;
> struct v4l2_mbus_framefmt *src_fmt;
> const struct v4l2_rect *src_crop;
> + bool set_csc;
>
> sink_fmt = rkisp1_isp_get_pad_fmt(isp, sd_state,
> RKISP1_ISP_PAD_SINK_VIDEO, which);
> @@ -645,20 +646,60 @@ static void rkisp1_isp_set_src_fmt(struct rkisp1_isp *isp,
> src_fmt->height = src_crop->height;
>
> /*
> - * The CSC API is used to allow userspace to force full
> - * quantization on YUV formats.
> + * Copy the color space for the sink pad. When converting from Bayer to
> + * YUV, default to a limited quantization range.
> */
> - if (format->flags & V4L2_MBUS_FRAMEFMT_SET_CSC &&
> - format->quantization == V4L2_QUANTIZATION_FULL_RANGE &&
> + src_fmt->colorspace = sink_fmt->colorspace;
> + src_fmt->xfer_func = sink_fmt->xfer_func;
> + src_fmt->ycbcr_enc = sink_fmt->ycbcr_enc;
> +
> + if (sink_info->pixel_enc == V4L2_PIXEL_ENC_BAYER &&
> src_info->pixel_enc == V4L2_PIXEL_ENC_YUV)
> - src_fmt->quantization = V4L2_QUANTIZATION_FULL_RANGE;
> - else if (src_info->pixel_enc == V4L2_PIXEL_ENC_YUV)
> src_fmt->quantization = V4L2_QUANTIZATION_LIM_RANGE;
> else
> - src_fmt->quantization = V4L2_QUANTIZATION_FULL_RANGE;
> + src_fmt->quantization = sink_fmt->quantization;
> +
> + /*
> + * Allow setting the source color space fields when the SET_CSC flag is
> + * set and the source format is YUV. If the sink format is YUV, don't
> + * set the color primaries, transfer function or YCbCr encoding as the
> + * ISP is bypassed in that case and passes YUV data through without
> + * modifications.
> + *
> + * The color primaries and transfer function are configured through the
> + * cross-talk matrix and tone curve respectively. Settings for those
> + * hardware blocks are conveyed through the ISP parameters buffer, as
> + * they need to combine color space information with other image tuning
> + * characteristics and can't thus be computed by the kernel based on the
> + * color space. The source pad colorspace and xfer_func fields are thus
> + * ignored by the driver, but can be set by userspace to propagate
> + * accurate color space information down the pipeline.
> + */
> + set_csc = !!(format->flags & V4L2_MBUS_FRAMEFMT_SET_CSC);
> +
> + if (set_csc && src_info->pixel_enc == V4L2_PIXEL_ENC_YUV) {
> + if (sink_info->pixel_enc == V4L2_PIXEL_ENC_BAYER) {
> + if (format->colorspace != V4L2_COLORSPACE_DEFAULT)
> + src_fmt->colorspace = format->colorspace;
> + if (format->xfer_func != V4L2_XFER_FUNC_DEFAULT)
> + src_fmt->xfer_func = format->xfer_func;
> + if (format->ycbcr_enc != V4L2_YCBCR_ENC_DEFAULT)
> + src_fmt->ycbcr_enc = format->ycbcr_enc;
> + }
> +
> + if (format->quantization != V4L2_QUANTIZATION_DEFAULT)
> + src_fmt->quantization = format->quantization;
> + }
>
> *format = *src_fmt;
>
> + /*
> + * Restore the SET_CSC flag if it was set to indicate support for the
> + * CSC setting API.
> + */
> + if (set_csc)
> + format->flags |= V4L2_MBUS_FRAMEFMT_SET_CSC;
> +
> /* Store the source format info when setting the active format. */
> if (which == V4L2_SUBDEV_FORMAT_ACTIVE)
> isp->src_fmt = src_info;
