gpu: ipu-v3: ipu-ic: Fully describe colorspace conversions

Only providing the input and output RGB/YUV space to the IC task init
functions is not sufficient. To fully characterize a colorspace
conversion, the Y'CbCr encoding standard, and quantization also
need to be specified.

Define a 'struct ipu_ic_colorspace' that includes all the above.

This allows to actually enforce the fact that the IC:

- can only encode to/from YUV and RGB full range. A follow-up patch will
  remove this restriction.
- can only encode using BT.601 standard. A follow-up patch will add
  Rec.709 encoding support.

The determination of the CSC coefficients based on the input/output
'struct ipu_ic_colorspace' are moved to a new exported function
ipu_ic_calc_csc(), and 'struct ic_csc_params' is exported as
'struct ipu_ic_csc_params'. ipu_ic_calc_csc() fills a 'struct ipu_ic_csc'
with the input/output 'struct ipu_ic_colorspace' and the calculated
'struct ic_csc_params' from those input/output colorspaces.

The functions ipu_ic_task_init(_rsc)() now take a filled 'struct
ipu_ic_csc'.

The existing CSC coefficient tables and ipu_ic_calc_csc() are moved
to a new module ipu-ic-csc.c. This is in preparation for adding more
coefficient tables for limited range quantization and more encoding
standards.

The existing ycbcr2rgb and inverse rgb2ycbcr tables defined the BT.601
Y'CbCr encoding coefficients. The rgb2ycbcr table specifically described
the BT.601 encoding from full range RGB to full range YUV. Table
comments have been added in ipu-ic-csc.c to make this more clear.

The ycbcr2rgb inverse table described encoding YUV limited range to RGB
full range. To be consistent with the rgb2ycbcr table, this table is
converted to YUV full range to RGB full range, and the comments are
expanded in ipu-ic-csc.c.

The ic_csc_rgb2rgb table was just an identity matrix, so it is renamed
'identity' in ipu-ic-csc.c.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
[p.zabel@pengutronix.de: removed a superfluous blank line]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 17 insertions, 11 deletions

diff --git a/drivers/gpu/ipu-v3/ipu-image-convert.c b/drivers/gpu/ipu-v3/ipu-image-convert.c
index 36e88434513a..d2457fde25fa 100644
--- a/drivers/gpu/ipu-v3/ipu-image-convert.c
+++ b/drivers/gpu/ipu-v3/ipu-image-convert.c
@@ -146,6 +146,7 @@ struct ipu_image_convert_ctx {
 	/* Source/destination image data and rotation mode */
 	struct ipu_image_convert_image in;
 	struct ipu_image_convert_image out;
+	struct ipu_ic_csc csc;
 	enum ipu_rotate_mode rot_mode;
 	u32 downsize_coeff_h;
 	u32 downsize_coeff_v;
@@ -1308,7 +1309,6 @@ static int convert_start(struct ipu_image_convert_run *run, unsigned int tile)
 	struct ipu_image_convert_priv *priv = chan->priv;
 	struct ipu_image_convert_image *s_image = &ctx->in;
 	struct ipu_image_convert_image *d_image = &ctx->out;
-	enum ipu_color_space src_cs, dest_cs;
 	unsigned int dst_tile = ctx->out_tile_map[tile];
 	unsigned int dest_width, dest_height;
 	unsigned int col, row;
@@ -1318,9 +1318,6 @@ static int convert_start(struct ipu_image_convert_run *run, unsigned int tile)
 	dev_dbg(priv->ipu->dev, "%s: task %u: starting ctx %p run %p tile %u -> %u\n",
 		__func__, chan->ic_task, ctx, run, tile, dst_tile);
 
-	src_cs = ipu_pixelformat_to_colorspace(s_image->fmt->fourcc);
-	dest_cs = ipu_pixelformat_to_colorspace(d_image->fmt->fourcc);
-
 	if (ipu_rot_mode_is_irt(ctx->rot_mode)) {
 		/* swap width/height for resizer */
 		dest_width = d_image->tile[dst_tile].height;
@@ -1343,13 +1340,12 @@ static int convert_start(struct ipu_image_convert_run *run, unsigned int tile)
 		s_image->tile[tile].height, dest_width, dest_height, rsc);
 
 	/* setup the IC resizer and CSC */
-	ret = ipu_ic_task_init_rsc(chan->ic,
-			       s_image->tile[tile].width,
-			       s_image->tile[tile].height,
-			       dest_width,
-			       dest_height,
-			       src_cs, dest_cs,
-			       rsc);
+	ret = ipu_ic_task_init_rsc(chan->ic, &ctx->csc,
+				   s_image->tile[tile].width,
+				   s_image->tile[tile].height,
+				   dest_width,
+				   dest_height,
+				   rsc);
 	if (ret) {
 		dev_err(priv->ipu->dev, "ipu_ic_task_init failed, %d\n", ret);
 		return ret;
@@ -2049,6 +2045,16 @@ ipu_image_convert_prepare(struct ipu_soc *ipu, enum ipu_ic_task ic_task,
 
 	calc_tile_resize_coefficients(ctx);
 
+	ret = ipu_ic_calc_csc(&ctx->csc,
+			s_image->base.pix.ycbcr_enc,
+			s_image->base.pix.quantization,
+			ipu_pixelformat_to_colorspace(s_image->fmt->fourcc),
+			d_image->base.pix.ycbcr_enc,
+			d_image->base.pix.quantization,
+			ipu_pixelformat_to_colorspace(d_image->fmt->fourcc));
+	if (ret)
+		goto out_free;
+
 	dump_format(ctx, s_image);
 	dump_format(ctx, d_image);