media: rkisp1: Allow setting color space on ISP sink pad

The ISP accepts different color spaces on its input: for YUV input, it
doesn't set any restrictions, and for Bayer inputs, any color primaries
or transfer function can be accepted (YCbCr encoding isn't applicable
there, and quantization range can only be full).

Allow setting a color space on the ISP sink pad, with the aforementioned
restrictions. The settings don't influence hardware yet (only the YUV
quantization range will, anything else has no direct effect on the ISP
configuration), but can already be set to allow color space information
to be coherent across the ISP sink link.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Dafna Hirschfeld <dafna@fastmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c

@@ -583,6 +583,7 @@ static void rkisp1_isp_set_sink_fmt(struct rkisp1_isp *isp,
 	const struct rkisp1_mbus_info *mbus_info;
 	struct v4l2_mbus_framefmt *sink_fmt;
 	struct v4l2_rect *sink_crop;
+	bool is_yuv;
 
 	sink_fmt = rkisp1_isp_get_pad_fmt(isp, sd_state,
 					  RKISP1_ISP_PAD_SINK_VIDEO,
@@ -603,6 +604,36 @@ static void rkisp1_isp_set_sink_fmt(struct rkisp1_isp *isp,
 				   RKISP1_ISP_MIN_HEIGHT,
 				   RKISP1_ISP_MAX_HEIGHT);
 
+	/*
+	 * Adjust the color space fields. Accept any color primaries and
+	 * transfer function for both YUV and Bayer. For YUV any YCbCr encoding
+	 * and quantization range is also accepted. For Bayer formats, the YCbCr
+	 * encoding isn't applicable, and the quantization range can only be
+	 * full.
+	 */
+	is_yuv = mbus_info->pixel_enc == V4L2_PIXEL_ENC_YUV;
+
+	sink_fmt->colorspace = format->colorspace ? :
+			       (is_yuv ? V4L2_COLORSPACE_SRGB :
+				V4L2_COLORSPACE_RAW);
+	sink_fmt->xfer_func = format->xfer_func ? :
+			      V4L2_MAP_XFER_FUNC_DEFAULT(sink_fmt->colorspace);
+	if (is_yuv) {
+		sink_fmt->ycbcr_enc = format->ycbcr_enc ? :
+			V4L2_MAP_YCBCR_ENC_DEFAULT(sink_fmt->colorspace);
+		sink_fmt->quantization = format->quantization ? :
+			V4L2_MAP_QUANTIZATION_DEFAULT(false, sink_fmt->colorspace,
+						      sink_fmt->ycbcr_enc);
+	} else {
+		/*
+		 * The YCbCr encoding isn't applicable for non-YUV formats, but
+		 * V4L2 has no "no encoding" value. Hardcode it to Rec. 601, it
+		 * should be ignored by userspace.
+		 */
+		sink_fmt->ycbcr_enc = V4L2_YCBCR_ENC_601;
+		sink_fmt->quantization = V4L2_QUANTIZATION_FULL_RANGE;
+	}
+
 	*format = *sink_fmt;
 
 	/* Propagate to in crop */