[PATCH v7 00/11] drm: Add new pixel formats for Xilinx Zynqmp

[PATCH v7 00/11] drm: Add new pixel formats for Xilinx Zynqmp

[Tomi Valkeinen]

Add new DRM pixel formats and add support for those in the Xilinx zynqmp
display driver.

All other formats except XVUY2101010 are already supported in upstream
gstreamer, but gstreamer's kmssink does not have the support yet, as it
obviously cannot support the formats without kernel having the formats.

Xilinx has support for these formats in their BSP kernel, and Xilinx has
a branch here, adding the support to gstreamer kmssink:

https://github.com/Xilinx/gst-plugins-bad.git xlnx-rebase-v1.18.5

New formats added:

DRM_FORMAT_Y8
- 8-bit Y-only
- fourcc: "GREY"
- gstreamer: GRAY8

DRM_FORMAT_Y10_P32
- 10-bit Y-only, three pixels packed into 32-bits
- fourcc: "YPA4"
- gstreamer: GRAY10_LE32

DRM_FORMAT_XV15
- Like NV12, but with 10-bit components
- fourcc: "XV15"
- gstreamer: NV12_10LE32

DRM_FORMAT_XV20
- Like NV16, but with 10-bit components
- fourcc: "XV20"
- gstreamer: NV16_10LE32

DRM_FORMAT_X403
- 10-bit planar 4:4:4, with three samples packed into 32-bits
- fourcc: "X403"
- gstreamer: Y444_10LE32

XVUY2101010
- 10-bit 4:4:4, one pixel in 32 bits
- fourcc: "XY30"

Some notes:

I know the 8-bit greyscale format has been discussed before, and the
guidance was to use DRM_FORMAT_R8. While I'm not totally against that, I
would argue that adding DRM_FORMAT_Y8 makes sense, as:

1) We can mark it as 'is_yuv' in the drm_format_info, and this can help
   the drivers handle e.g. full/limited range. Probably some hardware
   handles grayscale as a value used for all RGB components, in which case
   R8 makes sense, but when the hardware handles the Y-only pixels as YCbCr,
   where Cb and Cr are "neutral", it makes more sense to consider the
   format as an YUV format rather than RGB.

2) We can have the same fourcc as in v4l2. While not strictly necessary,
   it's a constant source of confusion when the fourccs differ.

3) It (possibly) makes more sense for the user to use Y8/GREY format
   instead of R8, as, in my experience, the documentation usually refers
   to gray(scale) format or Y-only format.

As we add new Y-only formats, it makes sense to have similar terms, so
we need to adjust the Y10_P32 format name accordingly.

I have made some adjustments to the formats compared to the Xilinx's
branch. E.g. The DRM_FORMAT_Y10_P32 format in Xilinx's kmssink uses
fourcc "Y10 ", and DRM_FORMAT_Y10. I didn't like those, as the format is
a packed format, three 10-bit pixels in a 32-bit container, and I think
Y10 means a 10-bit pixel in a 16-bit container.

Generally speaking, if someone has good ideas for the format define
names or fourccs, speak up, as it's not easy to invent good names =).
That said, keeping them the same as in the Xilinx trees will, of course,
be slightly easier for the users of Xilinx platforms.

I made WIP additions to modetest to support most of these formats,
partially based on Xilinx's code:

https://github.com/tomba/libdrm.git xilinx

A few thoughts about that:

modetest uses bo_create_dumb(), and as highlighted in recent discussions
in the kernel list [1], dumb buffers are only for RGB formats. They may
work for non-RGB formats, but that's platform specific. None of the
formats I add here are RGB formats. Do we want to go this way with
modetest?

I also feel that the current structure of modetest is not well suited to
more complicated formats. Both the buffer allocation is a bit more
difficult (see "Add virtual_width and pixels_per_container"), and the
drawing is complicated (see, e.g., "Add support for DRM_FORMAT_XV15 &
DRM_FORMAT_XV20").

I have recently added support for these Xilinx formats to both kms++ [2] and
pykms/pixutils [3][4] (WIP), and it's not been easy... But I have to say I
think I like the template based version in kms++. That won't work in
modetest, of course, but a non-templated version might be implementable,
but probably much slower.

In any case, I slighly feel it's not worth merging the modetest patches
I have for these formats: they complicate the code quite a bit, break
the RGB-only rule, and I'm not sure if there really are (m)any users. If
we want to add support to modetest, I think a bigger rewrite of the test
pattern code might be in order.

[1] https://lore.kernel.org/all/20250109150310.219442-26-tzimmermann%40suse.de/
[2] git@github.com:tomba/kmsxx.git xilinx
[3] git@github.com:tomba/pykms.git xilinx
[4] git@github.com:tomba/pixutils.git xilinx

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
Changes in v7:
- Added Reviewed-bys
- Rebased on v6.18
- Link to v6: https://lore.kernel.org/r/20251001-xilinx-formats-v6-0-014b076b542a@ideasonboard.com

Changes in v6:
- Added tags for reviews
- Rebased on v6.17
- Link to v5: https://lore.kernel.org/r/20250425-xilinx-formats-v5-0-c74263231630@ideasonboard.com

Changes in v5:
- Add comment about Y-only formats, clarifying how the display pipeline
  handles them (they're handled as YCbCr, with Cb and Cr as "neutral")
- Clarify X403 format in the patch description
- Set unused Y-only CSC offsets to 0 (instead of 0x1800).
- Add R-bs
- Link to v4: https://lore.kernel.org/r/20250326-xilinx-formats-v4-0-322a300c6d72@ideasonboard.com

Changes in v4:
- Reformat the drm_format_info entries a bit
- Calculate block size only once in drm_format_info_bpp()
- Declare local variables in separate lines
- Add review tags
- Fix commit message referring to Y10_LE32 (should be Y10_P32)
- Link to v3: https://lore.kernel.org/r/20250212-xilinx-formats-v3-0-90d0fe106995@ideasonboard.com

Changes in v3:
- Drop "drm: xlnx: zynqmp: Fix max dma segment size". It is already
  pushed.
- Add XVUY2101010 format.
- Rename DRM_FORMAT_Y10_LE32 to DRM_FORMAT_Y10_P32.
- Link to v2: https://lore.kernel.org/r/20250115-xilinx-formats-v2-0-160327ca652a@ideasonboard.com

Changes in v2:
- I noticed V4L2 already has fourcc Y10P, referring to MIPI-style packed
  Y10 format. So I changed Y10_LE32 fourcc to YPA4. If logic has any
  relevance here, P means packed, A means 10, 4 means "in 4 bytes".
- Added tags to "Fix max dma segment size" patch
- Updated description for "Add warning for bad bpp"
- Link to v1: https://lore.kernel.org/r/20241204-xilinx-formats-v1-0-0bf2c5147db1@ideasonboard.com

---
Tomi Valkeinen (11):
      drm/fourcc: Add warning for bad bpp
      drm/fourcc: Add DRM_FORMAT_XV15/XV20
      drm/fourcc: Add DRM_FORMAT_Y8
      drm/fourcc: Add DRM_FORMAT_Y10_P32
      drm/fourcc: Add DRM_FORMAT_X403
      drm/fourcc: Add DRM_FORMAT_XVUY2101010
      drm: xlnx: zynqmp: Use drm helpers when calculating buffer sizes
      drm: xlnx: zynqmp: Add support for XV15 & XV20
      drm: xlnx: zynqmp: Add support for Y8 and Y10_P32
      drm: xlnx: zynqmp: Add support for X403
      drm: xlnx: zynqmp: Add support for XVUY2101010

 drivers/gpu/drm/drm_fourcc.c       | 28 ++++++++++++++++---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 55 +++++++++++++++++++++++++++++++++++---
 include/uapi/drm/drm_fourcc.h      | 29 ++++++++++++++++++++
 3 files changed, 105 insertions(+), 7 deletions(-)
---
base-commit: 7d0a66e4bb9081d75c82ec4957c50034cb0ea449
change-id: 20241120-xilinx-formats-f71901621833

Best regards,
-- 
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

[PATCH v7 01/11] drm/fourcc: Add warning for bad bpp

[Tomi Valkeinen]

drm_format_info_bpp() cannot be used for formats which do not have an
integer bits-per-pixel in a pixel block.

E.g. DRM_FORMAT_XV15's (not yet in upstream) plane 0 has three 10-bit
pixels (Y components), and two padding bits, in a 4 byte block. That is
10.666... bits per pixel when considering the whole 4 byte block, which
is what drm_format_info_bpp() does. Thus a driver that supports such
formats cannot use drm_format_info_bpp(),

It is a driver bug if this happens, but so handle wrong calls by
printing a warning and returning 0.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index e0d533611040..e662aea9d105 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -491,12 +491,20 @@ EXPORT_SYMBOL(drm_format_info_block_height);
  */
 unsigned int drm_format_info_bpp(const struct drm_format_info *info, int plane)
 {
+	unsigned int block_size;
+
 	if (!info || plane < 0 || plane >= info->num_planes)
 		return 0;
 
-	return info->char_per_block[plane] * 8 /
-	       (drm_format_info_block_width(info, plane) *
-		drm_format_info_block_height(info, plane));
+	block_size = drm_format_info_block_width(info, plane) *
+		     drm_format_info_block_height(info, plane);
+
+	if (info->char_per_block[plane] * 8 % block_size) {
+		pr_warn("unable to return an integer bpp\n");
+		return 0;
+	}
+
+	return info->char_per_block[plane] * 8 / block_size;
 }
 EXPORT_SYMBOL(drm_format_info_bpp);
 

-- 
2.43.0

[PATCH v7 02/11] drm/fourcc: Add DRM_FORMAT_XV15/XV20

[Tomi Valkeinen]

Add two new pixel formats:

DRM_FORMAT_XV15 ("XV15")
DRM_FORMAT_XV20 ("XV20")

The formats are 2 plane 10 bit per component YCbCr, with the XV15 2x2
subsampled whereas XV20 is 2x1 subsampled.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c  | 6 ++++++
 include/uapi/drm/drm_fourcc.h | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index e662aea9d105..b22ef86428a1 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -381,6 +381,12 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_S416,            .depth = 0,  .num_planes = 3,
 		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
 		  .hsub = 1, .vsub = 1, .is_yuv = true},
+		{ .format = DRM_FORMAT_XV15,		.depth = 0,  .num_planes = 2,
+		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
+		  .hsub = 2, .vsub = 2, .is_yuv = true },
+		{ .format = DRM_FORMAT_XV20,		.depth = 0,  .num_planes = 2,
+		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
+		  .hsub = 2, .vsub = 1, .is_yuv = true },
 	};
 
 	unsigned int i;
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index e527b24bd824..6c786701238e 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -322,6 +322,14 @@ extern "C" {
 #define DRM_FORMAT_RGB565_A8	fourcc_code('R', '5', 'A', '8')
 #define DRM_FORMAT_BGR565_A8	fourcc_code('B', '5', 'A', '8')
 
+/*
+ * 2 plane 10 bit per component YCrCb
+ * index 0 = Y plane, [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian
+ * index 1 = Cb:Cr plane, [63:0] x:Cr2:Cb2:Cr1:x:Cb1:Cr0:Cb0 2:10:10:10:2:10:10:10 little endian
+ */
+#define DRM_FORMAT_XV15		fourcc_code('X', 'V', '1', '5') /* 2x2 subsampled Cr:Cb plane 2:10:10:10 */
+#define DRM_FORMAT_XV20		fourcc_code('X', 'V', '2', '0') /* 2x1 subsampled Cr:Cb plane 2:10:10:10 */
+
 /*
  * 2 plane YCbCr
  * index 0 = Y plane, [7:0] Y

-- 
2.43.0

[PATCH v7 03/11] drm/fourcc: Add DRM_FORMAT_Y8

[Tomi Valkeinen]

Add greyscale Y8 format.

Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c  |  1 +
 include/uapi/drm/drm_fourcc.h | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index b22ef86428a1..a39b9d7a5b62 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
+		{ .format = DRM_FORMAT_Y8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
 		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
 		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 6c786701238e..5cfc188c4e72 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -459,6 +459,16 @@ extern "C" {
 #define DRM_FORMAT_YUV444	fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
 #define DRM_FORMAT_YVU444	fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
 
+/*
+ * Y-only (greyscale) formats
+ *
+ * The Y-only formats are handled similarly to the YCbCr formats in the display
+ * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
+ * also means that COLOR_RANGE property applies to the Y-only formats.
+ *
+ */
+
+#define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
 
 /*
  * Format Modifiers:

-- 
2.43.0

[PATCH v7 04/11] drm/fourcc: Add DRM_FORMAT_Y10_P32

[Tomi Valkeinen]

Add Y10_P32, a 10 bit greyscale format, with 3 pixels packed into
32-bit container.

The fourcc for the format is 'YPA4', which comes from Y - Y only, P -
packed, A - 10 (as in 0xA), 4 - 4 bytes.

Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c  | 3 +++
 include/uapi/drm/drm_fourcc.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index a39b9d7a5b62..0d222f6c1a30 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -388,6 +388,9 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_XV20,		.depth = 0,  .num_planes = 2,
 		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
 		  .hsub = 2, .vsub = 1, .is_yuv = true },
+		{ .format = DRM_FORMAT_Y10_P32,		.depth = 0,  .num_planes = 1,
+		  .char_per_block = { 4, 0, 0 }, .block_w = { 3, 0, 0 }, .block_h = { 1, 0, 0 },
+		  .hsub = 1, .vsub = 1, .is_yuv = true },
 	};
 
 	unsigned int i;
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 5cfc188c4e72..0fd99ae32a06 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -469,6 +469,7 @@ extern "C" {
  */
 
 #define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
+#define DRM_FORMAT_Y10_P32	fourcc_code('Y', 'P', 'A', '4')  /* [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian */
 
 /*
  * Format Modifiers:

-- 
2.43.0

[PATCH v7 05/11] drm/fourcc: Add DRM_FORMAT_X403

[Tomi Valkeinen]

Add X403, a 3 plane 10 bits per component non-subsampled YCbCr format.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c  | 3 +++
 include/uapi/drm/drm_fourcc.h | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0d222f6c1a30..ab643dedd6d4 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -391,6 +391,9 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_Y10_P32,		.depth = 0,  .num_planes = 1,
 		  .char_per_block = { 4, 0, 0 }, .block_w = { 3, 0, 0 }, .block_h = { 1, 0, 0 },
 		  .hsub = 1, .vsub = 1, .is_yuv = true },
+		{ .format = DRM_FORMAT_X403,		.depth = 0,  .num_planes = 3,
+		  .char_per_block = { 4, 4, 4 }, .block_w = { 3, 3, 3 }, .block_h = { 1, 1, 1 },
+		  .hsub = 1, .vsub = 1, .is_yuv = true },
 	};
 
 	unsigned int i;
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 0fd99ae32a06..abe6af8b5ac4 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -403,6 +403,15 @@ extern "C" {
  */
 #define DRM_FORMAT_Q401		fourcc_code('Q', '4', '0', '1')
 
+/*
+ * 3 plane non-subsampled (444) YCbCr
+ * 10 bpc, 30 bits per sample image data in a single contiguous buffer.
+ * index 0: Y plane,  [31:0] x:Y2:Y1:Y0    [2:10:10:10] little endian
+ * index 1: Cb plane, [31:0] x:Cb2:Cb1:Cb0 [2:10:10:10] little endian
+ * index 2: Cr plane, [31:0] x:Cr2:Cr1:Cr0 [2:10:10:10] little endian
+ */
+#define DRM_FORMAT_X403		fourcc_code('X', '4', '0', '3')
+
 /*
  * 3 plane YCbCr LSB aligned
  * In order to use these formats in a similar fashion to MSB aligned ones

-- 
2.43.0

[PATCH v7 06/11] drm/fourcc: Add DRM_FORMAT_XVUY2101010

[Tomi Valkeinen]

Add XVUY2101010, a 10 bits per component YCbCr format in a 32 bit
container.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/drm_fourcc.c  | 1 +
 include/uapi/drm/drm_fourcc.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index ab643dedd6d4..a736df2de3fc 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -288,6 +288,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_VYUY,		.depth = 0,  .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_XYUV8888,	.depth = 0,  .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_VUY888,          .depth = 0,  .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
+		{ .format = DRM_FORMAT_XVUY2101010,     .depth = 0,  .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_AYUV,		.depth = 0,  .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true, .is_yuv = true },
 		{ .format = DRM_FORMAT_Y210,            .depth = 0,  .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
 		{ .format = DRM_FORMAT_Y212,            .depth = 0,  .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index abe6af8b5ac4..ce28faf7ad75 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -264,6 +264,7 @@ extern "C" {
 #define DRM_FORMAT_XVUY8888	fourcc_code('X', 'V', 'U', 'Y') /* [31:0] X:Cr:Cb:Y 8:8:8:8 little endian */
 #define DRM_FORMAT_VUY888	fourcc_code('V', 'U', '2', '4') /* [23:0] Cr:Cb:Y 8:8:8 little endian */
 #define DRM_FORMAT_VUY101010	fourcc_code('V', 'U', '3', '0') /* Y followed by U then V, 10:10:10. Non-linear modifier only */
+#define DRM_FORMAT_XVUY2101010	fourcc_code('X', 'Y', '3', '0') /* [31:0] x:Cr:Cb:Y 2:10:10:10 little endian */
 
 /*
  * packed Y2xx indicate for each component, xx valid data occupy msb

-- 
2.43.0

[PATCH v7 07/11] drm: xlnx: zynqmp: Use drm helpers when calculating buffer sizes

[Tomi Valkeinen]

Use drm helpers, drm_format_info_plane_width(),
drm_format_info_plane_height() and drm_format_info_min_pitch() to
calculate sizes for the DMA.

This cleans up the code, but also makes it possible to support more
complex formats (like XV15, XV20).

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index 80d1e499a18d..b9883ea2d03e 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -1116,16 +1116,19 @@ int zynqmp_disp_layer_update(struct zynqmp_disp_layer *layer,
 		return 0;
 
 	for (i = 0; i < info->num_planes; i++) {
-		unsigned int width = state->crtc_w / (i ? info->hsub : 1);
-		unsigned int height = state->crtc_h / (i ? info->vsub : 1);
 		struct zynqmp_disp_layer_dma *dma = &layer->dmas[i];
 		struct dma_async_tx_descriptor *desc;
 		dma_addr_t dma_addr;
+		unsigned int width;
+		unsigned int height;
+
+		width = drm_format_info_plane_width(info, state->crtc_w, i);
+		height = drm_format_info_plane_height(info, state->crtc_h, i);
 
 		dma_addr = drm_fb_dma_get_gem_addr(state->fb, state, i);
 
 		dma->xt.numf = height;
-		dma->sgl.size = width * info->cpp[i];
+		dma->sgl.size = drm_format_info_min_pitch(info, i, width);
 		dma->sgl.icg = state->fb->pitches[i] - dma->sgl.size;
 		dma->xt.src_start = dma_addr;
 		dma->xt.frame_size = 1;

-- 
2.43.0

[PATCH v7 08/11] drm: xlnx: zynqmp: Add support for XV15 & XV20

[Tomi Valkeinen]

Add support for XV15 & XV20 formats.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index b9883ea2d03e..1dc77f2e4262 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -297,6 +297,16 @@ static const struct zynqmp_disp_format avbuf_vid_fmts[] = {
 		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV16CI_420,
 		.swap		= true,
 		.sf		= scaling_factors_888,
+	}, {
+		.drm_fmt	= DRM_FORMAT_XV15,
+		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV16CI_420_10,
+		.swap		= false,
+		.sf		= scaling_factors_101010,
+	}, {
+		.drm_fmt	= DRM_FORMAT_XV20,
+		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV16CI_10,
+		.swap		= false,
+		.sf		= scaling_factors_101010,
 	},
 };
 

-- 
2.43.0

[PATCH v7 09/11] drm: xlnx: zynqmp: Add support for Y8 and Y10_P32

[Tomi Valkeinen]

Add support for Y8 and Y10_P32 formats. We also need to add new csc
matrices for the y-only formats.

Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index 1dc77f2e4262..fe111fa8cc13 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -307,6 +307,16 @@ static const struct zynqmp_disp_format avbuf_vid_fmts[] = {
 		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV16CI_10,
 		.swap		= false,
 		.sf		= scaling_factors_101010,
+	}, {
+		.drm_fmt	= DRM_FORMAT_Y8,
+		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_MONO,
+		.swap		= false,
+		.sf		= scaling_factors_888,
+	}, {
+		.drm_fmt	= DRM_FORMAT_Y10_P32,
+		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YONLY_10,
+		.swap		= false,
+		.sf		= scaling_factors_101010,
 	},
 };
 
@@ -697,6 +707,16 @@ static const u32 csc_sdtv_to_rgb_offsets[] = {
 	0x0, 0x1800, 0x1800
 };
 
+static const u16 csc_sdtv_to_rgb_yonly_matrix[] = {
+	0x0, 0x0, 0x1000,
+	0x0, 0x0, 0x1000,
+	0x0, 0x0, 0x1000,
+};
+
+static const u32 csc_sdtv_to_rgb_yonly_offsets[] = {
+	0x0, 0x0, 0x0
+};
+
 /**
  * zynqmp_disp_blend_set_output_format - Set the output format of the blender
  * @disp: Display controller
@@ -846,7 +866,11 @@ static void zynqmp_disp_blend_layer_enable(struct zynqmp_disp *disp,
 				ZYNQMP_DISP_V_BLEND_LAYER_CONTROL(layer->id),
 				val);
 
-	if (layer->drm_fmt->is_yuv) {
+	if (layer->drm_fmt->format == DRM_FORMAT_Y8 ||
+	    layer->drm_fmt->format == DRM_FORMAT_Y10_P32) {
+		coeffs = csc_sdtv_to_rgb_yonly_matrix;
+		offsets = csc_sdtv_to_rgb_yonly_offsets;
+	} else if (layer->drm_fmt->is_yuv) {
 		coeffs = csc_sdtv_to_rgb_matrix;
 		offsets = csc_sdtv_to_rgb_offsets;
 	} else {

-- 
2.43.0

[PATCH v7 10/11] drm: xlnx: zynqmp: Add support for X403

[Tomi Valkeinen]

Add support for X403 format.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index fe111fa8cc13..b7cc7a7581ad 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -317,6 +317,11 @@ static const struct zynqmp_disp_format avbuf_vid_fmts[] = {
 		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YONLY_10,
 		.swap		= false,
 		.sf		= scaling_factors_101010,
+	}, {
+		.drm_fmt	= DRM_FORMAT_X403,
+		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV24_10,
+		.swap		= false,
+		.sf		= scaling_factors_101010,
 	},
 };
 

-- 
2.43.0

[PATCH v7 11/11] drm: xlnx: zynqmp: Add support for XVUY2101010

[Tomi Valkeinen]

Add support for XVUY2101010 format.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index b7cc7a7581ad..f548f375750e 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -322,6 +322,11 @@ static const struct zynqmp_disp_format avbuf_vid_fmts[] = {
 		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV24_10,
 		.swap		= false,
 		.sf		= scaling_factors_101010,
+	}, {
+		.drm_fmt	= DRM_FORMAT_XVUY2101010,
+		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YUV444_10,
+		.swap		= false,
+		.sf		= scaling_factors_101010,
 	},
 };
 

-- 
2.43.0

Re: [PATCH v7 03/11] drm/fourcc: Add DRM_FORMAT_Y8

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
> Add greyscale Y8 format.

I would explain here why we need a new format and can't just use
DRM_FORMAT_R8. You don't need to convince me, but I think it's important
to summarize the rationale should someone later wonder why we introduced
this.

> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/gpu/drm/drm_fourcc.c  |  1 +
>  include/uapi/drm/drm_fourcc.h | 10 ++++++++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index b22ef86428a1..a39b9d7a5b62 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
>  		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>  		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>  		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> +		{ .format = DRM_FORMAT_Y8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>  		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>  		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>  		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index 6c786701238e..5cfc188c4e72 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -459,6 +459,16 @@ extern "C" {
>  #define DRM_FORMAT_YUV444	fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
>  #define DRM_FORMAT_YVU444	fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
>  
> +/*
> + * Y-only (greyscale) formats
> + *
> + * The Y-only formats are handled similarly to the YCbCr formats in the display
> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
> + * also means that COLOR_RANGE property applies to the Y-only formats.
> + *

Extra blank line.

> + */
> +
> +#define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */

I would have gone for 'Y', '8', ' ', ' '

>  
>  /*
>   * Format Modifiers:

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 04/11] drm/fourcc: Add DRM_FORMAT_Y10_P32

[Laurent Pinchart]

On Mon, Dec 01, 2025 at 02:18:46PM +0200, Tomi Valkeinen wrote:
> Add Y10_P32, a 10 bit greyscale format, with 3 pixels packed into
> 32-bit container.
> 
> The fourcc for the format is 'YPA4', which comes from Y - Y only, P -
> packed, A - 10 (as in 0xA), 4 - 4 bytes.
> 
> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/gpu/drm/drm_fourcc.c  | 3 +++
>  include/uapi/drm/drm_fourcc.h | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index a39b9d7a5b62..0d222f6c1a30 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -388,6 +388,9 @@ const struct drm_format_info *__drm_format_info(u32 format)
>  		{ .format = DRM_FORMAT_XV20,		.depth = 0,  .num_planes = 2,
>  		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
>  		  .hsub = 2, .vsub = 1, .is_yuv = true },
> +		{ .format = DRM_FORMAT_Y10_P32,		.depth = 0,  .num_planes = 1,
> +		  .char_per_block = { 4, 0, 0 }, .block_w = { 3, 0, 0 }, .block_h = { 1, 0, 0 },
> +		  .hsub = 1, .vsub = 1, .is_yuv = true },
>  	};
>  
>  	unsigned int i;
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index 5cfc188c4e72..0fd99ae32a06 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -469,6 +469,7 @@ extern "C" {
>   */
>  
>  #define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
> +#define DRM_FORMAT_Y10_P32	fourcc_code('Y', 'P', 'A', '4')  /* [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian */
>  
>  /*
>   * Format Modifiers:

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 05/11] drm/fourcc: Add DRM_FORMAT_X403

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Mon, Dec 01, 2025 at 02:18:47PM +0200, Tomi Valkeinen wrote:
> Add X403, a 3 plane 10 bits per component non-subsampled YCbCr format.

This makes me wish for a X509 format, for maximum confusion :-)

> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/gpu/drm/drm_fourcc.c  | 3 +++
>  include/uapi/drm/drm_fourcc.h | 9 +++++++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index 0d222f6c1a30..ab643dedd6d4 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -391,6 +391,9 @@ const struct drm_format_info *__drm_format_info(u32 format)
>  		{ .format = DRM_FORMAT_Y10_P32,		.depth = 0,  .num_planes = 1,
>  		  .char_per_block = { 4, 0, 0 }, .block_w = { 3, 0, 0 }, .block_h = { 1, 0, 0 },
>  		  .hsub = 1, .vsub = 1, .is_yuv = true },
> +		{ .format = DRM_FORMAT_X403,		.depth = 0,  .num_planes = 3,
> +		  .char_per_block = { 4, 4, 4 }, .block_w = { 3, 3, 3 }, .block_h = { 1, 1, 1 },
> +		  .hsub = 1, .vsub = 1, .is_yuv = true },
>  	};
>  
>  	unsigned int i;
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index 0fd99ae32a06..abe6af8b5ac4 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -403,6 +403,15 @@ extern "C" {
>   */
>  #define DRM_FORMAT_Q401		fourcc_code('Q', '4', '0', '1')
>  
> +/*
> + * 3 plane non-subsampled (444) YCbCr
> + * 10 bpc, 30 bits per sample image data in a single contiguous buffer.
> + * index 0: Y plane,  [31:0] x:Y2:Y1:Y0    [2:10:10:10] little endian
> + * index 1: Cb plane, [31:0] x:Cb2:Cb1:Cb0 [2:10:10:10] little endian
> + * index 2: Cr plane, [31:0] x:Cr2:Cr1:Cr0 [2:10:10:10] little endian
> + */
> +#define DRM_FORMAT_X403		fourcc_code('X', '4', '0', '3')
> +
>  /*
>   * 3 plane YCbCr LSB aligned
>   * In order to use these formats in a similar fashion to MSB aligned ones
> 

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 09/11] drm: xlnx: zynqmp: Add support for Y8 and Y10_P32

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Mon, Dec 01, 2025 at 02:18:51PM +0200, Tomi Valkeinen wrote:
> Add support for Y8 and Y10_P32 formats. We also need to add new csc
> matrices for the y-only formats.
> 
> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/gpu/drm/xlnx/zynqmp_disp.c | 26 +++++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> index 1dc77f2e4262..fe111fa8cc13 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> @@ -307,6 +307,16 @@ static const struct zynqmp_disp_format avbuf_vid_fmts[] = {
>  		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV16CI_10,
>  		.swap		= false,
>  		.sf		= scaling_factors_101010,
> +	}, {
> +		.drm_fmt	= DRM_FORMAT_Y8,
> +		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_MONO,
> +		.swap		= false,
> +		.sf		= scaling_factors_888,
> +	}, {
> +		.drm_fmt	= DRM_FORMAT_Y10_P32,
> +		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YONLY_10,
> +		.swap		= false,
> +		.sf		= scaling_factors_101010,
>  	},
>  };
>  
> @@ -697,6 +707,16 @@ static const u32 csc_sdtv_to_rgb_offsets[] = {
>  	0x0, 0x1800, 0x1800
>  };
>  

A comment here to explain why the 1.0 value is in the third column
instead of the expected first column would be good.

> +static const u16 csc_sdtv_to_rgb_yonly_matrix[] = {
> +	0x0, 0x0, 0x1000,
> +	0x0, 0x0, 0x1000,
> +	0x0, 0x0, 0x1000,
> +};
> +
> +static const u32 csc_sdtv_to_rgb_yonly_offsets[] = {
> +	0x0, 0x0, 0x0
> +};
> +
>  /**
>   * zynqmp_disp_blend_set_output_format - Set the output format of the blender
>   * @disp: Display controller
> @@ -846,7 +866,11 @@ static void zynqmp_disp_blend_layer_enable(struct zynqmp_disp *disp,
>  				ZYNQMP_DISP_V_BLEND_LAYER_CONTROL(layer->id),
>  				val);
>  
> -	if (layer->drm_fmt->is_yuv) {
> +	if (layer->drm_fmt->format == DRM_FORMAT_Y8 ||
> +	    layer->drm_fmt->format == DRM_FORMAT_Y10_P32) {

We could replace is_yuv with a type enum to avoid checking the format
here, and use a switch statement. Up to you.

With those issues addressed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +		coeffs = csc_sdtv_to_rgb_yonly_matrix;
> +		offsets = csc_sdtv_to_rgb_yonly_offsets;
> +	} else if (layer->drm_fmt->is_yuv) {
>  		coeffs = csc_sdtv_to_rgb_matrix;
>  		offsets = csc_sdtv_to_rgb_offsets;
>  	} else {

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 02/11] drm/fourcc: Add DRM_FORMAT_XV15/XV20

[Laurent Pinchart]

Hi Tomi,

On Mon, Dec 01, 2025 at 02:18:44PM +0200, Tomi Valkeinen wrote:
> Add two new pixel formats:
> 
> DRM_FORMAT_XV15 ("XV15")
> DRM_FORMAT_XV20 ("XV20")
> 
> The formats are 2 plane 10 bit per component YCbCr, with the XV15 2x2
> subsampled whereas XV20 is 2x1 subsampled.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/gpu/drm/drm_fourcc.c  | 6 ++++++
>  include/uapi/drm/drm_fourcc.h | 8 ++++++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index e662aea9d105..b22ef86428a1 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -381,6 +381,12 @@ const struct drm_format_info *__drm_format_info(u32 format)
>  		{ .format = DRM_FORMAT_S416,            .depth = 0,  .num_planes = 3,
>  		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
>  		  .hsub = 1, .vsub = 1, .is_yuv = true},
> +		{ .format = DRM_FORMAT_XV15,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
> +		  .hsub = 2, .vsub = 2, .is_yuv = true },

Given the horizontal subsampling, don't we have 6 pixels in 8 bytes ?

> +		{ .format = DRM_FORMAT_XV20,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
> +		  .hsub = 2, .vsub = 1, .is_yuv = true },
>  	};
>  
>  	unsigned int i;
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index e527b24bd824..6c786701238e 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -322,6 +322,14 @@ extern "C" {
>  #define DRM_FORMAT_RGB565_A8	fourcc_code('R', '5', 'A', '8')
>  #define DRM_FORMAT_BGR565_A8	fourcc_code('B', '5', 'A', '8')
>  
> +/*
> + * 2 plane 10 bit per component YCrCb
> + * index 0 = Y plane, [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian
> + * index 1 = Cb:Cr plane, [63:0] x:Cr2:Cb2:Cr1:x:Cb1:Cr0:Cb0 2:10:10:10:2:10:10:10 little endian
> + */
> +#define DRM_FORMAT_XV15		fourcc_code('X', 'V', '1', '5') /* 2x2 subsampled Cr:Cb plane 2:10:10:10 */
> +#define DRM_FORMAT_XV20		fourcc_code('X', 'V', '2', '0') /* 2x1 subsampled Cr:Cb plane 2:10:10:10 */
> +
>  /*
>   * 2 plane YCbCr
>   * index 0 = Y plane, [7:0] Y

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 03/11] drm/fourcc: Add DRM_FORMAT_Y8

[Tomi Valkeinen]

Hi,

On 28/01/2026 13:49, Laurent Pinchart wrote:
> Hi Tomi,
> 
> Thank you for the patch.
> 
> On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
>> Add greyscale Y8 format.
> 
> I would explain here why we need a new format and can't just use
> DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> to summarize the rationale should someone later wonder why we introduced
> this.

Good point. I can take the text from the cover letter to this commit's
description.

Would this be fine:

==

Add greyscale Y8 format.

The 8-bit greyscale format has been discussed before, and the
earlier guidance was to use DRM_FORMAT_R8, as a single-channel 8-bit pixel.

However, adding DRM_FORMAT_Y8 makes sense, as:

1) We can mark it as 'is_yuv' in the drm_format_info, and this can help
   the drivers handle e.g. full/limited range. Probably some hardware
   handles grayscale as a value used for all RGB components, in which case
   R8 makes sense, but when the hardware handles the Y-only pixels as YCbCr,
   where Cb and Cr are "neutral", it makes more sense to consider the
   format as an YUV format rather than RGB.

2) We can have the same fourcc as in v4l2. While not strictly necessary,
   it's a constant source of confusion when the fourccs differ.

3) It (possibly) makes more sense for the user to use Y8/GREY format
   instead of R8, as, in my experience, the documentation usually refers
   to gray(scale) format or Y-only format.

4) We have other Y-only formats, like the Y10_P32 added in the following
   patches, with "Y" in the fourcc name.

==


 Tomi

>> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
>> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>>  drivers/gpu/drm/drm_fourcc.c  |  1 +
>>  include/uapi/drm/drm_fourcc.h | 10 ++++++++++
>>  2 files changed, 11 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
>> index b22ef86428a1..a39b9d7a5b62 100644
>> --- a/drivers/gpu/drm/drm_fourcc.c
>> +++ b/drivers/gpu/drm/drm_fourcc.c
>> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
>>  		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> +		{ .format = DRM_FORMAT_Y8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
>> index 6c786701238e..5cfc188c4e72 100644
>> --- a/include/uapi/drm/drm_fourcc.h
>> +++ b/include/uapi/drm/drm_fourcc.h
>> @@ -459,6 +459,16 @@ extern "C" {
>>  #define DRM_FORMAT_YUV444	fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
>>  #define DRM_FORMAT_YVU444	fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
>>  
>> +/*
>> + * Y-only (greyscale) formats
>> + *
>> + * The Y-only formats are handled similarly to the YCbCr formats in the display
>> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
>> + * also means that COLOR_RANGE property applies to the Y-only formats.
>> + *
> 
> Extra blank line.
> 
>> + */
>> +
>> +#define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
> 
> I would have gone for 'Y', '8', ' ', ' '
> 
>>  
>>  /*
>>   * Format Modifiers:
> 

Re: [PATCH v7 03/11] drm/fourcc: Add DRM_FORMAT_Y8

[Laurent Pinchart]

On Wed, Jan 28, 2026 at 02:31:57PM +0200, Tomi Valkeinen wrote:
> On 28/01/2026 13:49, Laurent Pinchart wrote:
> > On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
> >> Add greyscale Y8 format.
> > 
> > I would explain here why we need a new format and can't just use
> > DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> > to summarize the rationale should someone later wonder why we introduced
> > this.
> 
> Good point. I can take the text from the cover letter to this commit's
> description.
> 
> Would this be fine:
> 
> ==
> 
> Add greyscale Y8 format.
> 
> The 8-bit greyscale format has been discussed before, and the
> earlier guidance was to use DRM_FORMAT_R8, as a single-channel 8-bit pixel.
> 
> However, adding DRM_FORMAT_Y8 makes sense, as:
> 
> 1) We can mark it as 'is_yuv' in the drm_format_info, and this can help
>    the drivers handle e.g. full/limited range. Probably some hardware
>    handles grayscale as a value used for all RGB components, in which case
>    R8 makes sense, but when the hardware handles the Y-only pixels as YCbCr,
>    where Cb and Cr are "neutral", it makes more sense to consider the
>    format as an YUV format rather than RGB.
> 
> 2) We can have the same fourcc as in v4l2. While not strictly necessary,
>    it's a constant source of confusion when the fourccs differ.

I wouldn't consider that as a goal (see my comment below about the 4CC
value). V4L2 and DRM 4CCs differ, and applications must handle them
separately. Implying we can take shortcuts for a subset of formats will
in my opinion generate more harm than good.

> 3) It (possibly) makes more sense for the user to use Y8/GREY format
>    instead of R8, as, in my experience, the documentation usually refers
>    to gray(scale) format or Y-only format.
> 
> 4) We have other Y-only formats, like the Y10_P32 added in the following
>    patches, with "Y" in the fourcc name.

If those two were the only reasons, I'd tell you to use R8 :-) I would
drop 2-4 and only document 1, that's the real reason.

> >> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> >> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >> ---
> >>  drivers/gpu/drm/drm_fourcc.c  |  1 +
> >>  include/uapi/drm/drm_fourcc.h | 10 ++++++++++
> >>  2 files changed, 11 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> >> index b22ef86428a1..a39b9d7a5b62 100644
> >> --- a/drivers/gpu/drm/drm_fourcc.c
> >> +++ b/drivers/gpu/drm/drm_fourcc.c
> >> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
> >>  		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> +		{ .format = DRM_FORMAT_Y8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> >> index 6c786701238e..5cfc188c4e72 100644
> >> --- a/include/uapi/drm/drm_fourcc.h
> >> +++ b/include/uapi/drm/drm_fourcc.h
> >> @@ -459,6 +459,16 @@ extern "C" {
> >>  #define DRM_FORMAT_YUV444	fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
> >>  #define DRM_FORMAT_YVU444	fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
> >>  
> >> +/*
> >> + * Y-only (greyscale) formats
> >> + *
> >> + * The Y-only formats are handled similarly to the YCbCr formats in the display
> >> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
> >> + * also means that COLOR_RANGE property applies to the Y-only formats.
> >> + *
> > 
> > Extra blank line.
> > 
> >> + */
> >> +
> >> +#define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
> > 
> > I would have gone for 'Y', '8', ' ', ' '
> > 
> >>  
> >>  /*
> >>   * Format Modifiers:

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 02/11] drm/fourcc: Add DRM_FORMAT_XV15/XV20

[Tomi Valkeinen]

Hi,

On 28/01/2026 14:21, Laurent Pinchart wrote:
> Hi Tomi,
> 
> On Mon, Dec 01, 2025 at 02:18:44PM +0200, Tomi Valkeinen wrote:
>> Add two new pixel formats:
>>
>> DRM_FORMAT_XV15 ("XV15")
>> DRM_FORMAT_XV20 ("XV20")
>>
>> The formats are 2 plane 10 bit per component YCbCr, with the XV15 2x2
>> subsampled whereas XV20 is 2x1 subsampled.
>>
>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>>  drivers/gpu/drm/drm_fourcc.c  | 6 ++++++
>>  include/uapi/drm/drm_fourcc.h | 8 ++++++++
>>  2 files changed, 14 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
>> index e662aea9d105..b22ef86428a1 100644
>> --- a/drivers/gpu/drm/drm_fourcc.c
>> +++ b/drivers/gpu/drm/drm_fourcc.c
>> @@ -381,6 +381,12 @@ const struct drm_format_info *__drm_format_info(u32 format)
>>  		{ .format = DRM_FORMAT_S416,            .depth = 0,  .num_planes = 3,
>>  		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
>>  		  .hsub = 1, .vsub = 1, .is_yuv = true},
>> +		{ .format = DRM_FORMAT_XV15,		.depth = 0,  .num_planes = 2,
>> +		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
>> +		  .hsub = 2, .vsub = 2, .is_yuv = true },
> 
> Given the horizontal subsampling, don't we have 6 pixels in 8 bytes ?

No, the hsub is applied first.

If you look at framebuffer_check() and the called functions, the
calculations for the min_pitch for a 1920 wide XV15 buffer for the
second plane is:

width = frame_width / hsub
min_pitch = width * char_per_block[plane] / block_w[plane]

So:

width = 1920 / 2 = 960
min_pitch = 960 * 8 / 3 = 2560

 Tomi

Re: [PATCH v7 02/11] drm/fourcc: Add DRM_FORMAT_XV15/XV20

[Laurent Pinchart]

On Wed, Jan 28, 2026 at 03:53:21PM +0200, Tomi Valkeinen wrote:
> On 28/01/2026 14:21, Laurent Pinchart wrote:
> > On Mon, Dec 01, 2025 at 02:18:44PM +0200, Tomi Valkeinen wrote:
> >> Add two new pixel formats:
> >>
> >> DRM_FORMAT_XV15 ("XV15")
> >> DRM_FORMAT_XV20 ("XV20")
> >>
> >> The formats are 2 plane 10 bit per component YCbCr, with the XV15 2x2
> >> subsampled whereas XV20 is 2x1 subsampled.
> >>
> >> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >> ---
> >>  drivers/gpu/drm/drm_fourcc.c  | 6 ++++++
> >>  include/uapi/drm/drm_fourcc.h | 8 ++++++++
> >>  2 files changed, 14 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> >> index e662aea9d105..b22ef86428a1 100644
> >> --- a/drivers/gpu/drm/drm_fourcc.c
> >> +++ b/drivers/gpu/drm/drm_fourcc.c
> >> @@ -381,6 +381,12 @@ const struct drm_format_info *__drm_format_info(u32 format)
> >>  		{ .format = DRM_FORMAT_S416,            .depth = 0,  .num_planes = 3,
> >>  		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
> >>  		  .hsub = 1, .vsub = 1, .is_yuv = true},
> >> +		{ .format = DRM_FORMAT_XV15,		.depth = 0,  .num_planes = 2,
> >> +		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
> >> +		  .hsub = 2, .vsub = 2, .is_yuv = true },
> > 
> > Given the horizontal subsampling, don't we have 6 pixels in 8 bytes ?
> 
> No, the hsub is applied first.
> 
> If you look at framebuffer_check() and the called functions, the
> calculations for the min_pitch for a 1920 wide XV15 buffer for the
> second plane is:
> 
> width = frame_width / hsub
> min_pitch = width * char_per_block[plane] / block_w[plane]
> 
> So:
> 
> width = 1920 / 2 = 960
> min_pitch = 960 * 8 / 3 = 2560

Indeed. I was looking at drm_format_info_min_pitch() and missed that it
was supposed to be called with the subsampled with. The argument is
documented as

 * @buffer_width: buffer width in pixels

which is quite ambiguous. The char_per_block documentation also does not
mention subsampling, adding to the confusion. This should be fixed, but
as far as this patch is concerned,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 09/11] drm: xlnx: zynqmp: Add support for Y8 and Y10_P32

[Tomi Valkeinen]

Hi,

On 28/01/2026 14:10, Laurent Pinchart wrote:
> Hi Tomi,
> 
> Thank you for the patch.
> 
> On Mon, Dec 01, 2025 at 02:18:51PM +0200, Tomi Valkeinen wrote:
>> Add support for Y8 and Y10_P32 formats. We also need to add new csc
>> matrices for the y-only formats.
>>
>> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>>  drivers/gpu/drm/xlnx/zynqmp_disp.c | 26 +++++++++++++++++++++++++-
>>  1 file changed, 25 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
>> index 1dc77f2e4262..fe111fa8cc13 100644
>> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
>> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
>> @@ -307,6 +307,16 @@ static const struct zynqmp_disp_format avbuf_vid_fmts[] = {
>>  		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YV16CI_10,
>>  		.swap		= false,
>>  		.sf		= scaling_factors_101010,
>> +	}, {
>> +		.drm_fmt	= DRM_FORMAT_Y8,
>> +		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_MONO,
>> +		.swap		= false,
>> +		.sf		= scaling_factors_888,
>> +	}, {
>> +		.drm_fmt	= DRM_FORMAT_Y10_P32,
>> +		.buf_fmt	= ZYNQMP_DISP_AV_BUF_FMT_NL_VID_YONLY_10,
>> +		.swap		= false,
>> +		.sf		= scaling_factors_101010,
>>  	},
>>  };
>>  
>> @@ -697,6 +707,16 @@ static const u32 csc_sdtv_to_rgb_offsets[] = {
>>  	0x0, 0x1800, 0x1800
>>  };
>>  
> 
> A comment here to explain why the 1.0 value is in the third column
> instead of the expected first column would be good.

Sure.

>> +static const u16 csc_sdtv_to_rgb_yonly_matrix[] = {
>> +	0x0, 0x0, 0x1000,
>> +	0x0, 0x0, 0x1000,
>> +	0x0, 0x0, 0x1000,
>> +};
>> +
>> +static const u32 csc_sdtv_to_rgb_yonly_offsets[] = {
>> +	0x0, 0x0, 0x0
>> +};
>> +
>>  /**
>>   * zynqmp_disp_blend_set_output_format - Set the output format of the blender
>>   * @disp: Display controller
>> @@ -846,7 +866,11 @@ static void zynqmp_disp_blend_layer_enable(struct zynqmp_disp *disp,
>>  				ZYNQMP_DISP_V_BLEND_LAYER_CONTROL(layer->id),
>>  				val);
>>  
>> -	if (layer->drm_fmt->is_yuv) {
>> +	if (layer->drm_fmt->format == DRM_FORMAT_Y8 ||
>> +	    layer->drm_fmt->format == DRM_FORMAT_Y10_P32) {
> 
> We could replace is_yuv with a type enum to avoid checking the format
> here, and use a switch statement. Up to you.
True, but I'm not sure it helps too much here at the moment. I tried a
few different kinds of enums (for channels, RGB/YUV/Y, and for CSC type
DEFAULT/YUV/Y) and a boolean (is_y_only) to zynqmp_disp_format, but I
wasn't sure if they really fit (especially considering we already have
is_yuv in the DRM format).

Furthermore, if we at some point add configurable color ranges and
encodings, the code has to change and I'm not sure what enum, if any,
makes sense there.

 Tomi

> With those issues addressed,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
>> +		coeffs = csc_sdtv_to_rgb_yonly_matrix;
>> +		offsets = csc_sdtv_to_rgb_yonly_offsets;
>> +	} else if (layer->drm_fmt->is_yuv) {
>>  		coeffs = csc_sdtv_to_rgb_matrix;
>>  		offsets = csc_sdtv_to_rgb_offsets;
>>  	} else {
> 

Re: [PATCH v7 03/11] drm/fourcc: Add DRM_FORMAT_Y8

[Tomi Valkeinen]

Hi,

On 28/01/2026 13:49, Laurent Pinchart wrote:
> Hi Tomi,
> 
> Thank you for the patch.
> 
> On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
>> Add greyscale Y8 format.
> 
> I would explain here why we need a new format and can't just use
> DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> to summarize the rationale should someone later wonder why we introduced
> this.
> 
>> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
>> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>>  drivers/gpu/drm/drm_fourcc.c  |  1 +
>>  include/uapi/drm/drm_fourcc.h | 10 ++++++++++
>>  2 files changed, 11 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
>> index b22ef86428a1..a39b9d7a5b62 100644
>> --- a/drivers/gpu/drm/drm_fourcc.c
>> +++ b/drivers/gpu/drm/drm_fourcc.c
>> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
>>  		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> +		{ .format = DRM_FORMAT_Y8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>>  		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
>> index 6c786701238e..5cfc188c4e72 100644
>> --- a/include/uapi/drm/drm_fourcc.h
>> +++ b/include/uapi/drm/drm_fourcc.h
>> @@ -459,6 +459,16 @@ extern "C" {
>>  #define DRM_FORMAT_YUV444	fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
>>  #define DRM_FORMAT_YVU444	fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
>>  
>> +/*
>> + * Y-only (greyscale) formats
>> + *
>> + * The Y-only formats are handled similarly to the YCbCr formats in the display
>> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
>> + * also means that COLOR_RANGE property applies to the Y-only formats.
>> + *
> 
> Extra blank line.

I'll drop.

>> + */
>> +
>> +#define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
> 
> I would have gone for 'Y', '8', ' ', ' '
Missed these comments earlier...

Yes, "Y8  " makes sense. But I was trying to be nice, as there are
already users for Y8 ("GREY") with BSP kernels, and changing the fourcc
code would break their userspace...

 Tomi

Re: [PATCH v7 03/11] drm/fourcc: Add DRM_FORMAT_Y8

[Laurent Pinchart]

On Wed, Jan 28, 2026 at 05:38:11PM +0200, Tomi Valkeinen wrote:
> On 28/01/2026 13:49, Laurent Pinchart wrote:
> > On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
> >> Add greyscale Y8 format.
> > 
> > I would explain here why we need a new format and can't just use
> > DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> > to summarize the rationale should someone later wonder why we introduced
> > this.
> > 
> >> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> >> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >> ---
> >>  drivers/gpu/drm/drm_fourcc.c  |  1 +
> >>  include/uapi/drm/drm_fourcc.h | 10 ++++++++++
> >>  2 files changed, 11 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> >> index b22ef86428a1..a39b9d7a5b62 100644
> >> --- a/drivers/gpu/drm/drm_fourcc.c
> >> +++ b/drivers/gpu/drm/drm_fourcc.c
> >> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
> >>  		{ .format = DRM_FORMAT_YVU422,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_YUV444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_YVU444,		.depth = 0,  .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> +		{ .format = DRM_FORMAT_Y8,		.depth = 8,  .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_NV12,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_NV21,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >>  		{ .format = DRM_FORMAT_NV16,		.depth = 0,  .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> >> index 6c786701238e..5cfc188c4e72 100644
> >> --- a/include/uapi/drm/drm_fourcc.h
> >> +++ b/include/uapi/drm/drm_fourcc.h
> >> @@ -459,6 +459,16 @@ extern "C" {
> >>  #define DRM_FORMAT_YUV444	fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
> >>  #define DRM_FORMAT_YVU444	fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
> >>  
> >> +/*
> >> + * Y-only (greyscale) formats
> >> + *
> >> + * The Y-only formats are handled similarly to the YCbCr formats in the display
> >> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
> >> + * also means that COLOR_RANGE property applies to the Y-only formats.
> >> + *
> > 
> > Extra blank line.
> 
> I'll drop.
> 
> >> + */
> >> +
> >> +#define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
> > 
> > I would have gone for 'Y', '8', ' ', ' '
>
> Missed these comments earlier...
> 
> Yes, "Y8  " makes sense. But I was trying to be nice, as there are
> already users for Y8 ("GREY") with BSP kernels, and changing the fourcc
> code would break their userspace...

That's a more compeling argument than matching the V4L2 4CC. I have a
slight preference for 'Y8  ' for how it would appear in debug messages,
but I'm also fine being nice :-)

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

-- 
Regards,

Laurent Pinchart