[PATCH v18 0/8] drm/vkms: Add support for YUV and DRM_FORMAT_R*

[PATCH v18 0/8] drm/vkms: Add support for YUV and DRM_FORMAT_R*

[Louis Chauvet]

This patchset is extracted from [1]. The goal is to introduce the YUV
support, thanks to Arthur's work.

- PATCH 2: Document pixel_arbg_u16
- PATCH 3: Add the support of YUV formats
- PATCH 4: Add some drm properties to expose more YUV features
- PATCH 5: Cleanup the todo
- PATCH 6..7: Add some kunit tests
- PATCH 8: Add the support of DRM_FORMAT_R1/2/4/8

[1]: https://lore.kernel.org/r/20241007-yuv-v12-0-01c1ada6fec8@bootlin.com

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
Changes in v18:
- Add PATCH 1
- Add documentation around pixel_yuv_u8
- Link to v17: https://lore.kernel.org/r/20250204-yuv-v17-0-9c623880d0ac@bootlin.com

Changes in v17:
- Rebased on drm-msic-next
- Updated comment in kunit test
- Updated test count in kunit test
- Link to v16: https://lore.kernel.org/r/20250121-yuv-v16-0-a61f95a99432@bootlin.com

Changes in v16:
- Rebased on drm-misc-next
- Updated comment and changed fail thresholds. 
- Link to v15: https://lore.kernel.org/r/20241231-yuv-v15-0-eda6bb3028e6@bootlin.com

Changes in v15:
- Export drm_get_color_encoding_name only for kunit tests
- Link to v14: https://lore.kernel.org/r/20241122-yuv-v14-0-e66d83d28d0c@bootlin.com

Changes in v14:
- Rebased on drm-misc-next
- Link to v13: https://lore.kernel.org/r/20241118-yuv-v13-0-ac0dd4129552@bootlin.com

Changes since previous series:
 - Fix build test as modules issue: https://lore.kernel.org/all/202410110407.EHvadSaF-lkp@intel.com/
 - Export required symbols in DRM core to use them in kunit
 - Update the kunit comments according to Maxime's feedback
 - Link to original series: https://lore.kernel.org/r/20241007-yuv-v12-0-01c1ada6fec8@bootlin.com

---
Arthur Grillo (5):
      drm/vkms: Add YUV support
      drm/vkms: Add range and encoding properties to the plane
      drm/vkms: Drop YUV formats TODO
      drm/vkms: Create KUnit tests for YUV conversions
      drm/vkms: Add how to run the Kunit tests

Louis Chauvet (3):
      drm/vkms: Document pixel_argb_u16
      drm: Export symbols to use in tests
      drm/vkms: Add support for DRM_FORMAT_R*

 Documentation/gpu/vkms.rst                    |  15 +-
 drivers/gpu/drm/drm_color_mgmt.c              |   3 +
 drivers/gpu/drm/vkms/tests/Makefile           |   1 +
 drivers/gpu/drm/vkms/tests/vkms_format_test.c | 280 +++++++++++++++
 drivers/gpu/drm/vkms/vkms_drv.h               |  35 ++
 drivers/gpu/drm/vkms/vkms_formats.c           | 467 +++++++++++++++++++++++++-
 drivers/gpu/drm/vkms/vkms_formats.h           |   9 +
 drivers/gpu/drm/vkms/vkms_plane.c             |  29 +-
 8 files changed, 835 insertions(+), 4 deletions(-)
---
base-commit: 81f6e0e0f3505809dd78eab129106f1c0cf2baf1
change-id: 20240201-yuv-1337d90d9576

Best regards,
-- 
Louis Chauvet <louis.chauvet@bootlin.com>

[PATCH v18 1/8] drm/vkms: Document pixel_argb_u16

[Louis Chauvet]

The meaning of each member of the structure was not specified. To clarify
the format used and the reason behind those choices, add some
documentation.

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_drv.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index a74a7fc3a056..3b7b46dd026f 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -45,6 +45,23 @@ struct vkms_frame_info {
 	unsigned int rotation;
 };
 
+/**
+ * struct pixel_argb_u16 - Internal representation of a pixel color.
+ * @a: Alpha component value, stored in 16 bits, without padding, using
+ *     machine endianness
+ * @r: Red component value, stored in 16 bits, without padding, using
+ *     machine endianness
+ * @g: Green component value, stored in 16 bits, without padding, using
+ *     machine endianness
+ * @b: Blue component value, stored in 16 bits, without padding, using
+ *     machine endianness
+ *
+ * The goal of this structure is to keep enough precision to ensure
+ * correct composition results in VKMS and simplifying color
+ * manipulation by splitting each component into its own field.
+ * Caution: the byte ordering of this structure is machine-dependent,
+ * you can't cast it directly to AR48 or xR48.
+ */
 struct pixel_argb_u16 {
 	u16 a, r, g, b;
 };

-- 
2.49.0

Re: [PATCH v18 1/8] drm/vkms: Document pixel_argb_u16

[Pekka Paalanen]

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On Tue, 15 Apr 2025 15:55:32 +0200
Louis Chauvet <louis.chauvet@bootlin.com> wrote:

> The meaning of each member of the structure was not specified. To clarify
> the format used and the reason behind those choices, add some
> documentation.
> 
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
>  drivers/gpu/drm/vkms/vkms_drv.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index a74a7fc3a056..3b7b46dd026f 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -45,6 +45,23 @@ struct vkms_frame_info {
>  	unsigned int rotation;
>  };
>  
> +/**
> + * struct pixel_argb_u16 - Internal representation of a pixel color.
> + * @a: Alpha component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + * @r: Red component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + * @g: Green component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + * @b: Blue component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + *
> + * The goal of this structure is to keep enough precision to ensure
> + * correct composition results in VKMS and simplifying color
> + * manipulation by splitting each component into its own field.
> + * Caution: the byte ordering of this structure is machine-dependent,
> + * you can't cast it directly to AR48 or xR48.
> + */
>  struct pixel_argb_u16 {
>  	u16 a, r, g, b;
>  };
> 

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>


Thanks,
pq

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Re: [PATCH v18 1/8] drm/vkms: Document pixel_argb_u16

[Pekka Paalanen]

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On Tue, 15 Apr 2025 15:55:32 +0200
Louis Chauvet <louis.chauvet@bootlin.com> wrote:

> The meaning of each member of the structure was not specified. To clarify
> the format used and the reason behind those choices, add some
> documentation.
> 
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
>  drivers/gpu/drm/vkms/vkms_drv.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index a74a7fc3a056..3b7b46dd026f 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -45,6 +45,23 @@ struct vkms_frame_info {
>  	unsigned int rotation;
>  };
>  
> +/**
> + * struct pixel_argb_u16 - Internal representation of a pixel color.
> + * @a: Alpha component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + * @r: Red component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + * @g: Green component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + * @b: Blue component value, stored in 16 bits, without padding, using
> + *     machine endianness
> + *
> + * The goal of this structure is to keep enough precision to ensure
> + * correct composition results in VKMS and simplifying color
> + * manipulation by splitting each component into its own field.
> + * Caution: the byte ordering of this structure is machine-dependent,
> + * you can't cast it directly to AR48 or xR48.
> + */
>  struct pixel_argb_u16 {
>  	u16 a, r, g, b;
>  };
> 

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>

(re-sent through a different address due issues on my side)


Thanks,
pq

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[PATCH v18 2/8] drm/vkms: Add YUV support

[Louis Chauvet]

From: Arthur Grillo <arthurgrillo@riseup.net>

Add support to the YUV formats bellow:

- NV12/NV16/NV24
- NV21/NV61/NV42
- YUV420/YUV422/YUV444
- YVU420/YVU422/YVU444

The conversion from yuv to rgb is done with fixed-point arithmetic, using
32.32 fixed-point numbers and the drm_fixed helpers.

To do the conversion, a specific matrix must be used for each color range
(DRM_COLOR_*_RANGE) and encoding (DRM_COLOR_*). This matrix is stored in
the `conversion_matrix` struct, along with the specific y_offset needed.
This matrix is queried only once, in `vkms_plane_atomic_update` and
stored in a `vkms_plane_state`. Those conversion matrices of each
encoding and range were obtained by rounding the values of the original
conversion matrices multiplied by 2^32. This is done to avoid the use of
floating point operations.

The same reading function is used for YUV and YVU formats. As the only
difference between those two category of formats is the order of field, a
simple swap in conversion matrix columns allows using the same function.

Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
[Louis Chauvet:
- Adapted Arthur's work
- Implemented the read_line_t callbacks for yuv
- add struct conversion_matrix
- store the whole conversion_matrix in the plane state
- remove struct pixel_yuv_u8
- update the commit message
- Merge the modifications from Arthur]
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_drv.h     |  18 ++
 drivers/gpu/drm/vkms/vkms_formats.c | 354 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_formats.h |   4 +
 drivers/gpu/drm/vkms/vkms_plane.c   |  16 +-
 4 files changed, 391 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 3b7b46dd026f..68b5e3fce455 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -119,17 +119,35 @@ typedef void (*pixel_read_line_t)(const struct vkms_plane_state *plane, int x_st
 				  int y_start, enum pixel_read_direction direction, int count,
 				  struct pixel_argb_u16 out_pixel[]);
 
+/**
+ * struct conversion_matrix - Matrix to use for a specific encoding and range
+ *
+ * @matrix: Conversion matrix from yuv to rgb. The matrix is stored in a row-major manner and is
+ * used to compute rgb values from yuv values:
+ *     [[r],[g],[b]] = @matrix * [[y],[u],[v]]
+ *   OR for yvu formats:
+ *     [[r],[g],[b]] = @matrix * [[y],[v],[u]]
+ *  The values of the matrix are signed fixed-point values with 32 bits fractional part.
+ * @y_offset: Offset to apply on the y value.
+ */
+struct conversion_matrix {
+	s64 matrix[3][3];
+	int y_offset;
+};
+
 /**
  * struct vkms_plane_state - Driver specific plane state
  * @base: base plane state
  * @frame_info: data required for composing computation
  * @pixel_read_line: function to read a pixel line in this plane. The creator of a
  *		     struct vkms_plane_state must ensure that this pointer is valid
+ * @conversion_matrix: matrix used for yuv formats to convert to rgb
  */
 struct vkms_plane_state {
 	struct drm_shadow_plane_state base;
 	struct vkms_frame_info *frame_info;
 	pixel_read_line_t pixel_read_line;
+	struct conversion_matrix conversion_matrix;
 };
 
 struct vkms_plane {
diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 30a64ecca87c..8f7a5d54a076 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -140,6 +140,51 @@ static void packed_pixels_addr_1x1(const struct vkms_frame_info *frame_info,
 	*addr = (u8 *)frame_info->map[0].vaddr + offset;
 }
 
+/**
+ * get_subsampling() - Get the subsampling divisor value on a specific direction
+ *
+ * @format: format to extarct the subsampling from
+ * @direction: direction of the subsampling requested
+ */
+static int get_subsampling(const struct drm_format_info *format,
+			   enum pixel_read_direction direction)
+{
+	switch (direction) {
+	case READ_BOTTOM_TO_TOP:
+	case READ_TOP_TO_BOTTOM:
+		return format->vsub;
+	case READ_RIGHT_TO_LEFT:
+	case READ_LEFT_TO_RIGHT:
+		return format->hsub;
+	}
+	WARN_ONCE(true, "Invalid direction for pixel reading: %d\n", direction);
+	return 1;
+}
+
+/**
+ * get_subsampling_offset() - An offset for keeping the chroma siting consistent regardless of
+ * x_start and y_start values
+ *
+ * @direction: direction of the reading to properly compute this offset
+ * @x_start: x coordinate of the starting point of the readed line
+ * @y_start: y coordinate of the starting point of the readed line
+ */
+static int get_subsampling_offset(enum pixel_read_direction direction, int x_start, int y_start)
+{
+	switch (direction) {
+	case READ_BOTTOM_TO_TOP:
+		return -y_start - 1;
+	case READ_TOP_TO_BOTTOM:
+		return y_start;
+	case READ_RIGHT_TO_LEFT:
+		return -x_start - 1;
+	case READ_LEFT_TO_RIGHT:
+		return x_start;
+	}
+	WARN_ONCE(true, "Invalid direction for pixel reading: %d\n", direction);
+	return 0;
+}
+
 /*
  * The following functions take pixel data (a, r, g, b, pixel, ...) and convert them to
  * &struct pixel_argb_u16
@@ -202,6 +247,38 @@ static struct pixel_argb_u16 argb_u16_from_RGB565(const __le16 *pixel)
 	return out_pixel;
 }
 
+static struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
+						  const struct conversion_matrix *matrix)
+{
+	u16 r, g, b;
+	s64 fp_y, fp_channel_1, fp_channel_2;
+	s64 fp_r, fp_g, fp_b;
+
+	fp_y = drm_int2fixp(((int)y - matrix->y_offset) * 257);
+	fp_channel_1 = drm_int2fixp(((int)channel_1 - 128) * 257);
+	fp_channel_2 = drm_int2fixp(((int)channel_2 - 128) * 257);
+
+	fp_r = drm_fixp_mul(matrix->matrix[0][0], fp_y) +
+	       drm_fixp_mul(matrix->matrix[0][1], fp_channel_1) +
+	       drm_fixp_mul(matrix->matrix[0][2], fp_channel_2);
+	fp_g = drm_fixp_mul(matrix->matrix[1][0], fp_y) +
+	       drm_fixp_mul(matrix->matrix[1][1], fp_channel_1) +
+	       drm_fixp_mul(matrix->matrix[1][2], fp_channel_2);
+	fp_b = drm_fixp_mul(matrix->matrix[2][0], fp_y) +
+	       drm_fixp_mul(matrix->matrix[2][1], fp_channel_1) +
+	       drm_fixp_mul(matrix->matrix[2][2], fp_channel_2);
+
+	fp_r = drm_fixp2int_round(fp_r);
+	fp_g = drm_fixp2int_round(fp_g);
+	fp_b = drm_fixp2int_round(fp_b);
+
+	r = clamp(fp_r, 0, 0xffff);
+	g = clamp(fp_g, 0, 0xffff);
+	b = clamp(fp_b, 0, 0xffff);
+
+	return argb_u16_from_u16161616(0xffff, r, g, b);
+}
+
 /*
  * The following functions are read_line function for each pixel format supported by VKMS.
  *
@@ -331,6 +408,92 @@ static void RGB565_read_line(const struct vkms_plane_state *plane, int x_start,
 	}
 }
 
+/*
+ * This callback can be used for YUV formats where U and V values are
+ * stored in the same plane (often called semi-planar formats). It will
+ * correctly handle subsampling as described in the drm_format_info of the plane.
+ *
+ * The conversion matrix stored in the @plane is used to:
+ * - Apply the correct color range and encoding
+ * - Convert YUV and YVU with the same function (a column swap is needed when setting up
+ * plane->conversion_matrix)
+ */
+static void semi_planar_yuv_read_line(const struct vkms_plane_state *plane, int x_start,
+				      int y_start, enum pixel_read_direction direction, int count,
+				      struct pixel_argb_u16 out_pixel[])
+{
+	u8 *y_plane;
+	u8 *uv_plane;
+
+	packed_pixels_addr_1x1(plane->frame_info, x_start, y_start, 0,
+			       &y_plane);
+	packed_pixels_addr_1x1(plane->frame_info,
+			       x_start / plane->frame_info->fb->format->hsub,
+			       y_start / plane->frame_info->fb->format->vsub, 1,
+			       &uv_plane);
+	int step_y = get_block_step_bytes(plane->frame_info->fb, direction, 0);
+	int step_uv = get_block_step_bytes(plane->frame_info->fb, direction, 1);
+	int subsampling = get_subsampling(plane->frame_info->fb->format, direction);
+	int subsampling_offset = get_subsampling_offset(direction, x_start, y_start);
+	const struct conversion_matrix *conversion_matrix = &plane->conversion_matrix;
+
+	for (int i = 0; i < count; i++) {
+		*out_pixel = argb_u16_from_yuv888(y_plane[0], uv_plane[0], uv_plane[1],
+						  conversion_matrix);
+		out_pixel += 1;
+		y_plane += step_y;
+		if ((i + subsampling_offset + 1) % subsampling == 0)
+			uv_plane += step_uv;
+	}
+}
+
+/*
+ * This callback can be used for YUV format where each color component is
+ * stored in a different plane (often called planar formats). It will
+ * correctly handle subsampling as described in the drm_format_info of the plane.
+ *
+ * The conversion matrix stored in the @plane is used to:
+ * - Apply the correct color range and encoding
+ * - Convert YUV and YVU with the same function (a column swap is needed when setting up
+ * plane->conversion_matrix)
+ */
+static void planar_yuv_read_line(const struct vkms_plane_state *plane, int x_start,
+				 int y_start, enum pixel_read_direction direction, int count,
+				 struct pixel_argb_u16 out_pixel[])
+{
+	u8 *y_plane;
+	u8 *channel_1_plane;
+	u8 *channel_2_plane;
+
+	packed_pixels_addr_1x1(plane->frame_info, x_start, y_start, 0,
+			       &y_plane);
+	packed_pixels_addr_1x1(plane->frame_info,
+			       x_start / plane->frame_info->fb->format->hsub,
+			       y_start / plane->frame_info->fb->format->vsub, 1,
+			       &channel_1_plane);
+	packed_pixels_addr_1x1(plane->frame_info,
+			       x_start / plane->frame_info->fb->format->hsub,
+			       y_start / plane->frame_info->fb->format->vsub, 2,
+			       &channel_2_plane);
+	int step_y = get_block_step_bytes(plane->frame_info->fb, direction, 0);
+	int step_channel_1 = get_block_step_bytes(plane->frame_info->fb, direction, 1);
+	int step_channel_2 = get_block_step_bytes(plane->frame_info->fb, direction, 2);
+	int subsampling = get_subsampling(plane->frame_info->fb->format, direction);
+	int subsampling_offset = get_subsampling_offset(direction, x_start, y_start);
+	const struct conversion_matrix *conversion_matrix = &plane->conversion_matrix;
+
+	for (int i = 0; i < count; i++) {
+		*out_pixel = argb_u16_from_yuv888(*y_plane, *channel_1_plane, *channel_2_plane,
+						  conversion_matrix);
+		out_pixel += 1;
+		y_plane += step_y;
+		if ((i + subsampling_offset + 1) % subsampling == 0) {
+			channel_1_plane += step_channel_1;
+			channel_2_plane += step_channel_2;
+		}
+	}
+}
+
 /*
  * The following functions take one &struct pixel_argb_u16 and convert it to a specific format.
  * The result is stored in @out_pixel.
@@ -456,6 +619,20 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
 		return &XRGB16161616_read_line;
 	case DRM_FORMAT_RGB565:
 		return &RGB565_read_line;
+	case DRM_FORMAT_NV12:
+	case DRM_FORMAT_NV16:
+	case DRM_FORMAT_NV24:
+	case DRM_FORMAT_NV21:
+	case DRM_FORMAT_NV61:
+	case DRM_FORMAT_NV42:
+		return &semi_planar_yuv_read_line;
+	case DRM_FORMAT_YUV420:
+	case DRM_FORMAT_YUV422:
+	case DRM_FORMAT_YUV444:
+	case DRM_FORMAT_YVU420:
+	case DRM_FORMAT_YVU422:
+	case DRM_FORMAT_YVU444:
+		return &planar_yuv_read_line;
 	default:
 		/*
 		 * This is a bug in vkms_plane_atomic_check(). All the supported
@@ -469,6 +646,183 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
 	}
 }
 
+/*
+ * Those matrices were generated using the colour python framework
+ *
+ * Below are the function calls used to generate each matrix, go to
+ * https://colour.readthedocs.io/en/develop/generated/colour.matrix_YCbCr.html
+ * for more info:
+ *
+ * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
+ *                                  is_legal = False,
+ *                                  bits = 8) * 2**32).astype(int)
+ */
+static const struct conversion_matrix no_operation = {
+	.matrix = {
+		{ 4294967296, 0,          0, },
+		{ 0,          4294967296, 0, },
+		{ 0,          0,          4294967296, },
+	},
+	.y_offset = 0,
+};
+
+static const struct conversion_matrix yuv_bt601_full = {
+	.matrix = {
+		{ 4294967296, 0,           6021544149 },
+		{ 4294967296, -1478054095, -3067191994 },
+		{ 4294967296, 7610682049,  0 },
+	},
+	.y_offset = 0,
+};
+
+/*
+ * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
+ *                                  is_legal = True,
+ *                                  bits = 8) * 2**32).astype(int)
+ */
+static const struct conversion_matrix yuv_bt601_limited = {
+	.matrix = {
+		{ 5020601039, 0,           6881764740 },
+		{ 5020601039, -1689204679, -3505362278 },
+		{ 5020601039, 8697922339,  0 },
+	},
+	.y_offset = 16,
+};
+
+/*
+ * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.709"],
+ *                                  is_legal = False,
+ *                                  bits = 8) * 2**32).astype(int)
+ */
+static const struct conversion_matrix yuv_bt709_full = {
+	.matrix = {
+		{ 4294967296, 0,          6763714498 },
+		{ 4294967296, -804551626, -2010578443 },
+		{ 4294967296, 7969741314, 0 },
+	},
+	.y_offset = 0,
+};
+
+/*
+ * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.709"],
+ *                                  is_legal = True,
+ *                                  bits = 8) * 2**32).astype(int)
+ */
+static const struct conversion_matrix yuv_bt709_limited = {
+	.matrix = {
+		{ 5020601039, 0,          7729959424 },
+		{ 5020601039, -919487572, -2297803934 },
+		{ 5020601039, 9108275786, 0 },
+	},
+	.y_offset = 16,
+};
+
+/*
+ * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.2020"],
+ *                                  is_legal = False,
+ *                                  bits = 8) * 2**32).astype(int)
+ */
+static const struct conversion_matrix yuv_bt2020_full = {
+	.matrix = {
+		{ 4294967296, 0,          6333358775 },
+		{ 4294967296, -706750298, -2453942994 },
+		{ 4294967296, 8080551471, 0 },
+	},
+	.y_offset = 0,
+};
+
+/*
+ * numpy.around(colour.matrix_YCbCr(K=colour.WEIGHTS_YCBCR["ITU-R BT.2020"],
+ *                                  is_legal = True,
+ *                                  bits = 8) * 2**32).astype(int)
+ */
+static const struct conversion_matrix yuv_bt2020_limited = {
+	.matrix = {
+		{ 5020601039, 0,          7238124312 },
+		{ 5020601039, -807714626, -2804506279 },
+		{ 5020601039, 9234915964, 0 },
+	},
+	.y_offset = 16,
+};
+
+/**
+ * swap_uv_columns() - Swap u and v column of a given matrix
+ *
+ * @matrix: Matrix in which column are swapped
+ */
+static void swap_uv_columns(struct conversion_matrix *matrix)
+{
+	swap(matrix->matrix[0][2], matrix->matrix[0][1]);
+	swap(matrix->matrix[1][2], matrix->matrix[1][1]);
+	swap(matrix->matrix[2][2], matrix->matrix[2][1]);
+}
+
+/**
+ * get_conversion_matrix_to_argb_u16() - Retrieve the correct yuv to rgb conversion matrix for a
+ * given encoding and range.
+ *
+ * @format: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h])
+ * @encoding: DRM_COLOR_* value for which to obtain a conversion matrix
+ * @range: DRM_COLOR_*_RANGE value for which to obtain a conversion matrix
+ * @matrix: Pointer to store the value into
+ */
+void get_conversion_matrix_to_argb_u16(u32 format,
+				       enum drm_color_encoding encoding,
+				       enum drm_color_range range,
+				       struct conversion_matrix *matrix)
+{
+	const struct conversion_matrix *matrix_to_copy;
+	bool limited_range;
+
+	switch (range) {
+	case DRM_COLOR_YCBCR_LIMITED_RANGE:
+		limited_range = true;
+		break;
+	case DRM_COLOR_YCBCR_FULL_RANGE:
+		limited_range = false;
+		break;
+	case DRM_COLOR_RANGE_MAX:
+		limited_range = false;
+		WARN_ONCE(true, "The requested range is not supported.");
+		break;
+	}
+
+	switch (encoding) {
+	case DRM_COLOR_YCBCR_BT601:
+		matrix_to_copy = limited_range ? &yuv_bt601_limited :
+						 &yuv_bt601_full;
+		break;
+	case DRM_COLOR_YCBCR_BT709:
+		matrix_to_copy = limited_range ? &yuv_bt709_limited :
+						 &yuv_bt709_full;
+		break;
+	case DRM_COLOR_YCBCR_BT2020:
+		matrix_to_copy = limited_range ? &yuv_bt2020_limited :
+						 &yuv_bt2020_full;
+		break;
+	case DRM_COLOR_ENCODING_MAX:
+		matrix_to_copy = &no_operation;
+		WARN_ONCE(true, "The requested encoding is not supported.");
+		break;
+	}
+
+	memcpy(matrix, matrix_to_copy, sizeof(*matrix_to_copy));
+
+	switch (format) {
+	case DRM_FORMAT_YVU420:
+	case DRM_FORMAT_YVU422:
+	case DRM_FORMAT_YVU444:
+	case DRM_FORMAT_NV21:
+	case DRM_FORMAT_NV61:
+	case DRM_FORMAT_NV42:
+		swap_uv_columns(matrix);
+		break;
+	default:
+		break;
+	}
+}
+EXPORT_SYMBOL(get_conversion_matrix_to_argb_u16);
+
 /**
  * get_pixel_write_function() - Retrieve the correct write_pixel function for a specific format.
  * The returned pointer is NULL for unsupported pixel formats. The caller must ensure that the
diff --git a/drivers/gpu/drm/vkms/vkms_formats.h b/drivers/gpu/drm/vkms/vkms_formats.h
index 8d2bef95ff79..d583855cb320 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.h
+++ b/drivers/gpu/drm/vkms/vkms_formats.h
@@ -9,4 +9,8 @@ pixel_read_line_t get_pixel_read_line_function(u32 format);
 
 pixel_write_t get_pixel_write_function(u32 format);
 
+void get_conversion_matrix_to_argb_u16(u32 format, enum drm_color_encoding encoding,
+				       enum drm_color_range range,
+				       struct conversion_matrix *matrix);
+
 #endif /* _VKMS_FORMATS_H_ */
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index e34f8c7f83c3..6388928412f6 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -18,7 +18,19 @@ static const u32 vkms_formats[] = {
 	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XRGB16161616,
 	DRM_FORMAT_ARGB16161616,
-	DRM_FORMAT_RGB565
+	DRM_FORMAT_RGB565,
+	DRM_FORMAT_NV12,
+	DRM_FORMAT_NV16,
+	DRM_FORMAT_NV24,
+	DRM_FORMAT_NV21,
+	DRM_FORMAT_NV61,
+	DRM_FORMAT_NV42,
+	DRM_FORMAT_YUV420,
+	DRM_FORMAT_YUV422,
+	DRM_FORMAT_YUV444,
+	DRM_FORMAT_YVU420,
+	DRM_FORMAT_YVU422,
+	DRM_FORMAT_YVU444,
 };
 
 static struct drm_plane_state *
@@ -119,6 +131,8 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
 	frame_info->rotation = new_state->rotation;
 
 	vkms_plane_state->pixel_read_line = get_pixel_read_line_function(fmt);
+	get_conversion_matrix_to_argb_u16(fmt, new_state->color_encoding, new_state->color_range,
+					  &vkms_plane_state->conversion_matrix);
 }
 
 static int vkms_plane_atomic_check(struct drm_plane *plane,

-- 
2.49.0

[PATCH v18 3/8] drm/vkms: Add range and encoding properties to the plane

[Louis Chauvet]

From: Arthur Grillo <arthurgrillo@riseup.net>

Now that the driver internally handles these quantization ranges and YUV
encoding matrices, expose the UAPI for setting them.

Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
[Louis Chauvet: retained only relevant parts, updated the commit message]
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_plane.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 6388928412f6..fbfbe424e558 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -219,5 +219,14 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
 	drm_plane_create_rotation_property(&plane->base, DRM_MODE_ROTATE_0,
 					   DRM_MODE_ROTATE_MASK | DRM_MODE_REFLECT_MASK);
 
+	drm_plane_create_color_properties(&plane->base,
+					  BIT(DRM_COLOR_YCBCR_BT601) |
+					  BIT(DRM_COLOR_YCBCR_BT709) |
+					  BIT(DRM_COLOR_YCBCR_BT2020),
+					  BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
+					  BIT(DRM_COLOR_YCBCR_FULL_RANGE),
+					  DRM_COLOR_YCBCR_BT601,
+					  DRM_COLOR_YCBCR_FULL_RANGE);
+
 	return plane;
 }

-- 
2.49.0

[PATCH v18 4/8] drm/vkms: Drop YUV formats TODO

[Louis Chauvet]

From: Arthur Grillo <arthurgrillo@riseup.net>

VKMS has support for YUV formats now. Remove the task from the TODO
list.

Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 Documentation/gpu/vkms.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
index ba04ac7c2167..88e0913ca33a 100644
--- a/Documentation/gpu/vkms.rst
+++ b/Documentation/gpu/vkms.rst
@@ -122,8 +122,8 @@ There's lots of plane features we could add support for:
 
 - Scaling.
 
-- Additional buffer formats, especially YUV formats for video like NV12.
-  Low/high bpp RGB formats would also be interesting.
+- Additional buffer formats. Low/high bpp RGB formats would be interesting
+  [Good to get started].
 
 - Async updates (currently only possible on cursor plane using the legacy
   cursor api).

-- 
2.49.0

[PATCH v18 5/8] drm: Export symbols to use in tests

[Louis Chauvet]

The functions drm_get_color_encoding_name and drm_get_color_range_name
are useful for clarifying test results. Therefore, export them so they
can be used in tests built as modules.

Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/drm_color_mgmt.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
index 3969dc548cff..b73a998352d1 100644
--- a/drivers/gpu/drm/drm_color_mgmt.c
+++ b/drivers/gpu/drm/drm_color_mgmt.c
@@ -28,6 +28,7 @@
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_print.h>
+#include <kunit/visibility.h>
 
 #include "drm_crtc_internal.h"
 
@@ -494,6 +495,7 @@ const char *drm_get_color_encoding_name(enum drm_color_encoding encoding)
 
 	return color_encoding_name[encoding];
 }
+EXPORT_SYMBOL_IF_KUNIT(drm_get_color_encoding_name);
 
 /**
  * drm_get_color_range_name - return a string for color range
@@ -509,6 +511,7 @@ const char *drm_get_color_range_name(enum drm_color_range range)
 
 	return color_range_name[range];
 }
+EXPORT_SYMBOL_IF_KUNIT(drm_get_color_range_name);
 
 /**
  * drm_plane_create_color_properties - color encoding related plane properties

-- 
2.49.0

[PATCH v18 6/8] drm/vkms: Create KUnit tests for YUV conversions

[Louis Chauvet]

From: Arthur Grillo <arthurgrillo@riseup.net>

Create KUnit tests to test the conversion between YUV and RGB. Test each
conversion and range combination with some common colors.

The code used to compute the expected result can be found in comment.

[Louis Chauvet:
- fix minor formating issues (whitespace, double line)
- change expected alpha from 0x0000 to 0xffff
- adapt to the new get_conversion_matrix usage
- apply the changes from Arthur
- move struct pixel_yuv_u8 to the test itself]

Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/tests/Makefile           |   1 +
 drivers/gpu/drm/vkms/tests/vkms_format_test.c | 280 ++++++++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_formats.c           |   7 +-
 drivers/gpu/drm/vkms/vkms_formats.h           |   5 +
 4 files changed, 291 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vkms/tests/Makefile b/drivers/gpu/drm/vkms/tests/Makefile
index 9ded37b67a46..0ee077942ae2 100644
--- a/drivers/gpu/drm/vkms/tests/Makefile
+++ b/drivers/gpu/drm/vkms/tests/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 obj-$(CONFIG_DRM_VKMS_KUNIT_TEST) += vkms_config_test.o
+obj-$(CONFIG_DRM_VKMS_KUNIT_TESTS) += vkms_format_test.o
diff --git a/drivers/gpu/drm/vkms/tests/vkms_format_test.c b/drivers/gpu/drm/vkms/tests/vkms_format_test.c
new file mode 100644
index 000000000000..2e1daef94831
--- /dev/null
+++ b/drivers/gpu/drm/vkms/tests/vkms_format_test.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <kunit/test.h>
+
+#include <drm/drm_fixed.h>
+#include <drm/drm_fourcc.h>
+
+#include "../../drm_crtc_internal.h"
+
+#include "../vkms_formats.h"
+
+#define TEST_BUFF_SIZE 50
+
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
+/**
+ * struct pixel_yuv_u8 - Internal representation of a pixel color.
+ * @y: Luma value, stored in 8 bits, without padding, using
+ *     machine endianness
+ * @u: Blue difference chroma value, stored in 8 bits, without padding, using
+ *     machine endianness
+ * @v: Red difference chroma value, stored in 8 bits, without padding, using
+ *     machine endianness
+ */
+struct pixel_yuv_u8 {
+	u8 y, u, v;
+};
+
+/*
+ * struct yuv_u8_to_argb_u16_case - Reference values to test the color
+ * conversions in VKMS between YUV to ARGB
+ *
+ * @encoding: Encoding used to convert RGB to YUV
+ * @range: Range used to convert RGB to YUV
+ * @n_colors: Count of test colors in this case
+ * @format_pair.name: Name used for this color conversion, used to
+ *                    clarify the test results
+ * @format_pair.rgb: RGB color tested
+ * @format_pair.yuv: Same color as @format_pair.rgb, but converted to
+ *                   YUV using @encoding and @range.
+ */
+struct yuv_u8_to_argb_u16_case {
+	enum drm_color_encoding encoding;
+	enum drm_color_range range;
+	size_t n_colors;
+	struct format_pair {
+		char *name;
+		struct pixel_yuv_u8 yuv;
+		struct pixel_argb_u16 argb;
+	} colors[TEST_BUFF_SIZE];
+};
+
+/*
+ * The YUV color representation were acquired via the colour python framework.
+ * Below are the function calls used for generating each case.
+ *
+ * For more information got to the docs:
+ * https://colour.readthedocs.io/en/master/generated/colour.RGB_to_YCbCr.html
+ */
+static struct yuv_u8_to_argb_u16_case yuv_u8_to_argb_u16_cases[] = {
+	/*
+	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
+	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
+	 *                     in_bits = 16,
+	 *                     in_legal = False,
+	 *                     in_int = True,
+	 *                     out_bits = 8,
+	 *                     out_legal = False,
+	 *                     out_int = True)
+	 *
+	 * Tests cases for color conversion generated by converting RGB
+	 * values to YUV BT601 full range using the ITU-R BT.601 weights.
+	 */
+	{
+		.encoding = DRM_COLOR_YCBCR_BT601,
+		.range = DRM_COLOR_YCBCR_FULL_RANGE,
+		.n_colors = 6,
+		.colors = {
+			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x4c, 0x55, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0x96, 0x2c, 0x15 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x1d, 0xff, 0x6b }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		},
+	},
+	/*
+	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
+	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
+	 *                     in_bits = 16,
+	 *                     in_legal = False,
+	 *                     in_int = True,
+	 *                     out_bits = 8,
+	 *                     out_legal = True,
+	 *                     out_int = True)
+	 * Tests cases for color conversion generated by converting RGB
+	 * values to YUV BT601 limited range using the ITU-R BT.601 weights.
+	 */
+	{
+		.encoding = DRM_COLOR_YCBCR_BT601,
+		.range = DRM_COLOR_YCBCR_LIMITED_RANGE,
+		.n_colors = 6,
+		.colors = {
+			{ "white", { 0xeb, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x7e, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x10, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x51, 0x5a, 0xf0 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0x91, 0x36, 0x22 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x29, 0xf0, 0x6e }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		},
+	},
+	/*
+	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
+	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.709"],
+	 *                     in_bits = 16,
+	 *                     in_legal = False,
+	 *                     in_int = True,
+	 *                     out_bits = 8,
+	 *                     out_legal = False,
+	 *                     out_int = True)
+	 * Tests cases for color conversion generated by converting RGB
+	 * values to YUV BT709 full range using the ITU-R BT.709 weights.
+	 */
+	{
+		.encoding = DRM_COLOR_YCBCR_BT709,
+		.range = DRM_COLOR_YCBCR_FULL_RANGE,
+		.n_colors = 6,
+		.colors = {
+			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x36, 0x63, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xb6, 0x1e, 0x0c }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x12, 0xff, 0x74 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		},
+	},
+	/*
+	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
+	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.709"],
+	 *                     in_bits = 16,
+	 *                     int_legal = False,
+	 *                     in_int = True,
+	 *                     out_bits = 8,
+	 *                     out_legal = True,
+	 *                     out_int = True)
+	 * Tests cases for color conversion generated by converting RGB
+	 * values to YUV BT709 limited range using the ITU-R BT.709 weights.
+	 */
+	{
+		.encoding = DRM_COLOR_YCBCR_BT709,
+		.range = DRM_COLOR_YCBCR_LIMITED_RANGE,
+		.n_colors = 6,
+		.colors = {
+			{ "white", { 0xeb, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x7e, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x10, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x3f, 0x66, 0xf0 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xad, 0x2a, 0x1a }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x20, 0xf0, 0x76 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		},
+	},
+	/*
+	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
+	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.2020"],
+	 *                     in_bits = 16,
+	 *                     in_legal = False,
+	 *                     in_int = True,
+	 *                     out_bits = 8,
+	 *                     out_legal = False,
+	 *                     out_int = True)
+	 * Tests cases for color conversion generated by converting RGB
+	 * values to YUV BT2020 full range using the ITU-R BT.2020 weights.
+	 */
+	{
+		.encoding = DRM_COLOR_YCBCR_BT2020,
+		.range = DRM_COLOR_YCBCR_FULL_RANGE,
+		.n_colors = 6,
+		.colors = {
+			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x43, 0x5c, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xad, 0x24, 0x0b }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x0f, 0xff, 0x76 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		},
+	},
+	/*
+	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
+	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.2020"],
+	 *                     in_bits = 16,
+	 *                     in_legal = False,
+	 *                     in_int = True,
+	 *                     out_bits = 8,
+	 *                     out_legal = True,
+	 *                     out_int = True)
+	 * Tests cases for color conversion generated by converting RGB
+	 * values to YUV BT2020 limited range using the ITU-R BT.2020 weights.
+	 */
+	{
+		.encoding = DRM_COLOR_YCBCR_BT2020,
+		.range = DRM_COLOR_YCBCR_LIMITED_RANGE,
+		.n_colors = 6,
+		.colors = {
+			{ "white", { 0xeb, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x7e, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x10, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x4a, 0x61, 0xf0 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xa4, 0x2f, 0x19 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x1d, 0xf0, 0x77 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		},
+	},
+};
+
+/*
+ * vkms_format_test_yuv_u8_to_argb_u16 - Testing the conversion between YUV
+ * colors to ARGB colors in VKMS
+ *
+ * This test will use the functions get_conversion_matrix_to_argb_u16 and
+ * argb_u16_from_yuv888 to convert YUV colors (stored in
+ * yuv_u8_to_argb_u16_cases) into ARGB colors.
+ *
+ * The conversion between YUV and RGB is not totally reversible, so there may be
+ * some difference between the expected value and the result.
+ * In addition, there may be some rounding error as the input color is 8 bits
+ * and output color is 16 bits.
+ */
+static void vkms_format_test_yuv_u8_to_argb_u16(struct kunit *test)
+{
+	const struct yuv_u8_to_argb_u16_case *param = test->param_value;
+	struct pixel_argb_u16 argb;
+
+	for (size_t i = 0; i < param->n_colors; i++) {
+		const struct format_pair *color = &param->colors[i];
+		struct conversion_matrix matrix;
+
+		get_conversion_matrix_to_argb_u16
+			(DRM_FORMAT_NV12, param->encoding, param->range, &matrix);
+
+		argb = argb_u16_from_yuv888(color->yuv.y, color->yuv.u, color->yuv.v, &matrix);
+
+		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.a, color->argb.a), 0x1ff,
+				    "On the A channel of the color %s expected 0x%04x, got 0x%04x",
+				    color->name, color->argb.a, argb.a);
+		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.r, color->argb.r), 0x1ff,
+				    "On the R channel of the color %s expected 0x%04x, got 0x%04x",
+				    color->name, color->argb.r, argb.r);
+		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.g, color->argb.g), 0x1ff,
+				    "On the G channel of the color %s expected 0x%04x, got 0x%04x",
+				    color->name, color->argb.g, argb.g);
+		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.b, color->argb.b), 0x1ff,
+				    "On the B channel of the color %s expected 0x%04x, got 0x%04x",
+				    color->name, color->argb.b, argb.b);
+	}
+}
+
+static void vkms_format_test_yuv_u8_to_argb_u16_case_desc(struct yuv_u8_to_argb_u16_case *t,
+							  char *desc)
+{
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "%s - %s",
+		 drm_get_color_encoding_name(t->encoding), drm_get_color_range_name(t->range));
+}
+
+KUNIT_ARRAY_PARAM(yuv_u8_to_argb_u16, yuv_u8_to_argb_u16_cases,
+		  vkms_format_test_yuv_u8_to_argb_u16_case_desc
+);
+
+static struct kunit_case vkms_format_test_cases[] = {
+	KUNIT_CASE_PARAM(vkms_format_test_yuv_u8_to_argb_u16, yuv_u8_to_argb_u16_gen_params),
+	{}
+};
+
+static struct kunit_suite vkms_format_test_suite = {
+	.name = "vkms-format",
+	.test_cases = vkms_format_test_cases,
+};
+
+kunit_test_suite(vkms_format_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Kunit test for vkms format conversion");
diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 8f7a5d54a076..9972780f3fa9 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -7,6 +7,8 @@
 #include <drm/drm_rect.h>
 #include <drm/drm_fixed.h>
 
+#include <kunit/visibility.h>
+
 #include "vkms_formats.h"
 
 /**
@@ -247,8 +249,8 @@ static struct pixel_argb_u16 argb_u16_from_RGB565(const __le16 *pixel)
 	return out_pixel;
 }
 
-static struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
-						  const struct conversion_matrix *matrix)
+VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
+							    const struct conversion_matrix *matrix)
 {
 	u16 r, g, b;
 	s64 fp_y, fp_channel_1, fp_channel_2;
@@ -278,6 +280,7 @@ static struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel
 
 	return argb_u16_from_u16161616(0xffff, r, g, b);
 }
+EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
 
 /*
  * The following functions are read_line function for each pixel format supported by VKMS.
diff --git a/drivers/gpu/drm/vkms/vkms_formats.h b/drivers/gpu/drm/vkms/vkms_formats.h
index d583855cb320..b4fe62ab9c65 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.h
+++ b/drivers/gpu/drm/vkms/vkms_formats.h
@@ -13,4 +13,9 @@ void get_conversion_matrix_to_argb_u16(u32 format, enum drm_color_encoding encod
 				       enum drm_color_range range,
 				       struct conversion_matrix *matrix);
 
+#if IS_ENABLED(CONFIG_KUNIT)
+struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
+					   const struct conversion_matrix *matrix);
+#endif
+
 #endif /* _VKMS_FORMATS_H_ */

-- 
2.49.0

Re: [PATCH v18 6/8] drm/vkms: Create KUnit tests for YUV conversions

[Louis Chauvet]

Hi Maxime,

Did you have the time to look at this patch?

Pekka added his Acked-by, but as you made some remarks about this patch, 
I would like to have your validation before applying it.

Thanks a lot,
Louis Chauvet

Le 15/04/2025 à 15:55, Louis Chauvet a écrit :
> From: Arthur Grillo <arthurgrillo@riseup.net>
> 
> Create KUnit tests to test the conversion between YUV and RGB. Test each
> conversion and range combination with some common colors.
> 
> The code used to compute the expected result can be found in comment.
> 
> [Louis Chauvet:
> - fix minor formating issues (whitespace, double line)
> - change expected alpha from 0x0000 to 0xffff
> - adapt to the new get_conversion_matrix usage
> - apply the changes from Arthur
> - move struct pixel_yuv_u8 to the test itself]
> 
> Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
> Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
>   drivers/gpu/drm/vkms/tests/Makefile           |   1 +
>   drivers/gpu/drm/vkms/tests/vkms_format_test.c | 280 ++++++++++++++++++++++++++
>   drivers/gpu/drm/vkms/vkms_formats.c           |   7 +-
>   drivers/gpu/drm/vkms/vkms_formats.h           |   5 +
>   4 files changed, 291 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/tests/Makefile b/drivers/gpu/drm/vkms/tests/Makefile
> index 9ded37b67a46..0ee077942ae2 100644
> --- a/drivers/gpu/drm/vkms/tests/Makefile
> +++ b/drivers/gpu/drm/vkms/tests/Makefile
> @@ -1,3 +1,4 @@
>   # SPDX-License-Identifier: GPL-2.0-only
>   
>   obj-$(CONFIG_DRM_VKMS_KUNIT_TEST) += vkms_config_test.o
> +obj-$(CONFIG_DRM_VKMS_KUNIT_TESTS) += vkms_format_test.o
> diff --git a/drivers/gpu/drm/vkms/tests/vkms_format_test.c b/drivers/gpu/drm/vkms/tests/vkms_format_test.c
> new file mode 100644
> index 000000000000..2e1daef94831
> --- /dev/null
> +++ b/drivers/gpu/drm/vkms/tests/vkms_format_test.c
> @@ -0,0 +1,280 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +#include <kunit/test.h>
> +
> +#include <drm/drm_fixed.h>
> +#include <drm/drm_fourcc.h>
> +
> +#include "../../drm_crtc_internal.h"
> +
> +#include "../vkms_formats.h"
> +
> +#define TEST_BUFF_SIZE 50
> +
> +MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
> +
> +/**
> + * struct pixel_yuv_u8 - Internal representation of a pixel color.
> + * @y: Luma value, stored in 8 bits, without padding, using
> + *     machine endianness
> + * @u: Blue difference chroma value, stored in 8 bits, without padding, using
> + *     machine endianness
> + * @v: Red difference chroma value, stored in 8 bits, without padding, using
> + *     machine endianness
> + */
> +struct pixel_yuv_u8 {
> +	u8 y, u, v;
> +};
> +
> +/*
> + * struct yuv_u8_to_argb_u16_case - Reference values to test the color
> + * conversions in VKMS between YUV to ARGB
> + *
> + * @encoding: Encoding used to convert RGB to YUV
> + * @range: Range used to convert RGB to YUV
> + * @n_colors: Count of test colors in this case
> + * @format_pair.name: Name used for this color conversion, used to
> + *                    clarify the test results
> + * @format_pair.rgb: RGB color tested
> + * @format_pair.yuv: Same color as @format_pair.rgb, but converted to
> + *                   YUV using @encoding and @range.
> + */
> +struct yuv_u8_to_argb_u16_case {
> +	enum drm_color_encoding encoding;
> +	enum drm_color_range range;
> +	size_t n_colors;
> +	struct format_pair {
> +		char *name;
> +		struct pixel_yuv_u8 yuv;
> +		struct pixel_argb_u16 argb;
> +	} colors[TEST_BUFF_SIZE];
> +};
> +
> +/*
> + * The YUV color representation were acquired via the colour python framework.
> + * Below are the function calls used for generating each case.
> + *
> + * For more information got to the docs:
> + * https://colour.readthedocs.io/en/master/generated/colour.RGB_to_YCbCr.html
> + */
> +static struct yuv_u8_to_argb_u16_case yuv_u8_to_argb_u16_cases[] = {
> +	/*
> +	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
> +	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
> +	 *                     in_bits = 16,
> +	 *                     in_legal = False,
> +	 *                     in_int = True,
> +	 *                     out_bits = 8,
> +	 *                     out_legal = False,
> +	 *                     out_int = True)
> +	 *
> +	 * Tests cases for color conversion generated by converting RGB
> +	 * values to YUV BT601 full range using the ITU-R BT.601 weights.
> +	 */
> +	{
> +		.encoding = DRM_COLOR_YCBCR_BT601,
> +		.range = DRM_COLOR_YCBCR_FULL_RANGE,
> +		.n_colors = 6,
> +		.colors = {
> +			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",   { 0x4c, 0x55, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green", { 0x96, 0x2c, 0x15 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",  { 0x1d, 0xff, 0x6b }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> +		},
> +	},
> +	/*
> +	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
> +	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.601"],
> +	 *                     in_bits = 16,
> +	 *                     in_legal = False,
> +	 *                     in_int = True,
> +	 *                     out_bits = 8,
> +	 *                     out_legal = True,
> +	 *                     out_int = True)
> +	 * Tests cases for color conversion generated by converting RGB
> +	 * values to YUV BT601 limited range using the ITU-R BT.601 weights.
> +	 */
> +	{
> +		.encoding = DRM_COLOR_YCBCR_BT601,
> +		.range = DRM_COLOR_YCBCR_LIMITED_RANGE,
> +		.n_colors = 6,
> +		.colors = {
> +			{ "white", { 0xeb, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",  { 0x7e, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black", { 0x10, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",   { 0x51, 0x5a, 0xf0 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green", { 0x91, 0x36, 0x22 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",  { 0x29, 0xf0, 0x6e }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> +		},
> +	},
> +	/*
> +	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
> +	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.709"],
> +	 *                     in_bits = 16,
> +	 *                     in_legal = False,
> +	 *                     in_int = True,
> +	 *                     out_bits = 8,
> +	 *                     out_legal = False,
> +	 *                     out_int = True)
> +	 * Tests cases for color conversion generated by converting RGB
> +	 * values to YUV BT709 full range using the ITU-R BT.709 weights.
> +	 */
> +	{
> +		.encoding = DRM_COLOR_YCBCR_BT709,
> +		.range = DRM_COLOR_YCBCR_FULL_RANGE,
> +		.n_colors = 6,
> +		.colors = {
> +			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",   { 0x36, 0x63, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green", { 0xb6, 0x1e, 0x0c }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",  { 0x12, 0xff, 0x74 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> +		},
> +	},
> +	/*
> +	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
> +	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.709"],
> +	 *                     in_bits = 16,
> +	 *                     int_legal = False,
> +	 *                     in_int = True,
> +	 *                     out_bits = 8,
> +	 *                     out_legal = True,
> +	 *                     out_int = True)
> +	 * Tests cases for color conversion generated by converting RGB
> +	 * values to YUV BT709 limited range using the ITU-R BT.709 weights.
> +	 */
> +	{
> +		.encoding = DRM_COLOR_YCBCR_BT709,
> +		.range = DRM_COLOR_YCBCR_LIMITED_RANGE,
> +		.n_colors = 6,
> +		.colors = {
> +			{ "white", { 0xeb, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",  { 0x7e, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black", { 0x10, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",   { 0x3f, 0x66, 0xf0 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green", { 0xad, 0x2a, 0x1a }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",  { 0x20, 0xf0, 0x76 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> +		},
> +	},
> +	/*
> +	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
> +	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.2020"],
> +	 *                     in_bits = 16,
> +	 *                     in_legal = False,
> +	 *                     in_int = True,
> +	 *                     out_bits = 8,
> +	 *                     out_legal = False,
> +	 *                     out_int = True)
> +	 * Tests cases for color conversion generated by converting RGB
> +	 * values to YUV BT2020 full range using the ITU-R BT.2020 weights.
> +	 */
> +	{
> +		.encoding = DRM_COLOR_YCBCR_BT2020,
> +		.range = DRM_COLOR_YCBCR_FULL_RANGE,
> +		.n_colors = 6,
> +		.colors = {
> +			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",   { 0x43, 0x5c, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green", { 0xad, 0x24, 0x0b }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",  { 0x0f, 0xff, 0x76 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> +		},
> +	},
> +	/*
> +	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
> +	 *                     K=colour.WEIGHTS_YCBCR["ITU-R BT.2020"],
> +	 *                     in_bits = 16,
> +	 *                     in_legal = False,
> +	 *                     in_int = True,
> +	 *                     out_bits = 8,
> +	 *                     out_legal = True,
> +	 *                     out_int = True)
> +	 * Tests cases for color conversion generated by converting RGB
> +	 * values to YUV BT2020 limited range using the ITU-R BT.2020 weights.
> +	 */
> +	{
> +		.encoding = DRM_COLOR_YCBCR_BT2020,
> +		.range = DRM_COLOR_YCBCR_LIMITED_RANGE,
> +		.n_colors = 6,
> +		.colors = {
> +			{ "white", { 0xeb, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",  { 0x7e, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black", { 0x10, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",   { 0x4a, 0x61, 0xf0 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green", { 0xa4, 0x2f, 0x19 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",  { 0x1d, 0xf0, 0x77 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> +		},
> +	},
> +};
> +
> +/*
> + * vkms_format_test_yuv_u8_to_argb_u16 - Testing the conversion between YUV
> + * colors to ARGB colors in VKMS
> + *
> + * This test will use the functions get_conversion_matrix_to_argb_u16 and
> + * argb_u16_from_yuv888 to convert YUV colors (stored in
> + * yuv_u8_to_argb_u16_cases) into ARGB colors.
> + *
> + * The conversion between YUV and RGB is not totally reversible, so there may be
> + * some difference between the expected value and the result.
> + * In addition, there may be some rounding error as the input color is 8 bits
> + * and output color is 16 bits.
> + */
> +static void vkms_format_test_yuv_u8_to_argb_u16(struct kunit *test)
> +{
> +	const struct yuv_u8_to_argb_u16_case *param = test->param_value;
> +	struct pixel_argb_u16 argb;
> +
> +	for (size_t i = 0; i < param->n_colors; i++) {
> +		const struct format_pair *color = &param->colors[i];
> +		struct conversion_matrix matrix;
> +
> +		get_conversion_matrix_to_argb_u16
> +			(DRM_FORMAT_NV12, param->encoding, param->range, &matrix);
> +
> +		argb = argb_u16_from_yuv888(color->yuv.y, color->yuv.u, color->yuv.v, &matrix);
> +
> +		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.a, color->argb.a), 0x1ff,
> +				    "On the A channel of the color %s expected 0x%04x, got 0x%04x",
> +				    color->name, color->argb.a, argb.a);
> +		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.r, color->argb.r), 0x1ff,
> +				    "On the R channel of the color %s expected 0x%04x, got 0x%04x",
> +				    color->name, color->argb.r, argb.r);
> +		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.g, color->argb.g), 0x1ff,
> +				    "On the G channel of the color %s expected 0x%04x, got 0x%04x",
> +				    color->name, color->argb.g, argb.g);
> +		KUNIT_EXPECT_LE_MSG(test, abs_diff(argb.b, color->argb.b), 0x1ff,
> +				    "On the B channel of the color %s expected 0x%04x, got 0x%04x",
> +				    color->name, color->argb.b, argb.b);
> +	}
> +}
> +
> +static void vkms_format_test_yuv_u8_to_argb_u16_case_desc(struct yuv_u8_to_argb_u16_case *t,
> +							  char *desc)
> +{
> +	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "%s - %s",
> +		 drm_get_color_encoding_name(t->encoding), drm_get_color_range_name(t->range));
> +}
> +
> +KUNIT_ARRAY_PARAM(yuv_u8_to_argb_u16, yuv_u8_to_argb_u16_cases,
> +		  vkms_format_test_yuv_u8_to_argb_u16_case_desc
> +);
> +
> +static struct kunit_case vkms_format_test_cases[] = {
> +	KUNIT_CASE_PARAM(vkms_format_test_yuv_u8_to_argb_u16, yuv_u8_to_argb_u16_gen_params),
> +	{}
> +};
> +
> +static struct kunit_suite vkms_format_test_suite = {
> +	.name = "vkms-format",
> +	.test_cases = vkms_format_test_cases,
> +};
> +
> +kunit_test_suite(vkms_format_test_suite);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Kunit test for vkms format conversion");
> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> index 8f7a5d54a076..9972780f3fa9 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.c
> +++ b/drivers/gpu/drm/vkms/vkms_formats.c
> @@ -7,6 +7,8 @@
>   #include <drm/drm_rect.h>
>   #include <drm/drm_fixed.h>
>   
> +#include <kunit/visibility.h>
> +
>   #include "vkms_formats.h"
>   
>   /**
> @@ -247,8 +249,8 @@ static struct pixel_argb_u16 argb_u16_from_RGB565(const __le16 *pixel)
>   	return out_pixel;
>   }
>   
> -static struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
> -						  const struct conversion_matrix *matrix)
> +VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
> +							    const struct conversion_matrix *matrix)
>   {
>   	u16 r, g, b;
>   	s64 fp_y, fp_channel_1, fp_channel_2;
> @@ -278,6 +280,7 @@ static struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel
>   
>   	return argb_u16_from_u16161616(0xffff, r, g, b);
>   }
> +EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
>   
>   /*
>    * The following functions are read_line function for each pixel format supported by VKMS.
> diff --git a/drivers/gpu/drm/vkms/vkms_formats.h b/drivers/gpu/drm/vkms/vkms_formats.h
> index d583855cb320..b4fe62ab9c65 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.h
> +++ b/drivers/gpu/drm/vkms/vkms_formats.h
> @@ -13,4 +13,9 @@ void get_conversion_matrix_to_argb_u16(u32 format, enum drm_color_encoding encod
>   				       enum drm_color_range range,
>   				       struct conversion_matrix *matrix);
>   
> +#if IS_ENABLED(CONFIG_KUNIT)
> +struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
> +					   const struct conversion_matrix *matrix);
> +#endif
> +
>   #endif /* _VKMS_FORMATS_H_ */
> 

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v18 6/8] drm/vkms: Create KUnit tests for YUV conversions

[Maxime Ripard]

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On Mon, May 12, 2025 at 03:07:55PM +0200, Louis Chauvet wrote:
> Hi Maxime,
> 
> Did you have the time to look at this patch?
> 
> Pekka added his Acked-by, but as you made some remarks about this patch, I
> would like to have your validation before applying it.

Yep, thank you

Acked-by: Maxime Ripard <mripard@kernel.org>


Maxime

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Re: [PATCH v18 6/8] drm/vkms: Create KUnit tests for YUV conversions

[Louis Chauvet]

Le 22/05/2025 à 17:39, Maxime Ripard a écrit :
> On Mon, May 12, 2025 at 03:07:55PM +0200, Louis Chauvet wrote:
>> Hi Maxime,
>>
>> Did you have the time to look at this patch?
>>
>> Pekka added his Acked-by, but as you made some remarks about this patch, I
>> would like to have your validation before applying it.
> 
> Yep, thank you
> 
> Acked-by: Maxime Ripard <mripard@kernel.org>
> 

Hi Maxime,

Some time ago you told me "The rest looked good to me the last time I 
looked." [1]

Does it mean that I can add your ack on the rest of the series?

Thanks a lot for your reviews,
Louis Chauvet

[1]:https://lore.kernel.org/all/20250205-pristine-perch-of-abundance-7abac1@houat/

> Maxime

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v18 6/8] drm/vkms: Create KUnit tests for YUV conversions

[Maxime Ripard]

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On Tue, May 27, 2025 at 03:36:16PM +0200, Louis Chauvet wrote:
> 
> 
> Le 22/05/2025 à 17:39, Maxime Ripard a écrit :
> > On Mon, May 12, 2025 at 03:07:55PM +0200, Louis Chauvet wrote:
> > > Hi Maxime,
> > > 
> > > Did you have the time to look at this patch?
> > > 
> > > Pekka added his Acked-by, but as you made some remarks about this patch, I
> > > would like to have your validation before applying it.
> > 
> > Yep, thank you
> > 
> > Acked-by: Maxime Ripard <mripard@kernel.org>
> > 
> 
> Hi Maxime,
> 
> Some time ago you told me "The rest looked good to me the last time I
> looked." [1]
> 
> Does it mean that I can add your ack on the rest of the series?

Yes

Maxime

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[PATCH v18 7/8] drm/vkms: Add how to run the Kunit tests

[Louis Chauvet]

From: Arthur Grillo <arthurgrillo@riseup.net>

Now that we have KUnit tests, add instructions on how to run them.

Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 Documentation/gpu/vkms.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
index 88e0913ca33a..8a8b1002931f 100644
--- a/Documentation/gpu/vkms.rst
+++ b/Documentation/gpu/vkms.rst
@@ -89,6 +89,17 @@ You can also run subtests if you do not want to run the entire test::
   sudo ./build/tests/kms_flip --run-subtest basic-plain-flip --device "sys:/sys/devices/platform/vkms"
   sudo IGT_DEVICE="sys:/sys/devices/platform/vkms" ./build/tests/kms_flip --run-subtest basic-plain-flip
 
+Testing With KUnit
+==================
+
+KUnit (Kernel unit testing framework) provides a common framework for unit tests
+within the Linux kernel.
+More information in ../dev-tools/kunit/index.rst .
+
+To run the VKMS KUnit tests::
+
+  tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/vkms/tests
+
 TODO
 ====
 

-- 
2.49.0

[PATCH v18 8/8] drm/vkms: Add support for DRM_FORMAT_R*

[Louis Chauvet]

This add the support for:
- R1/R2/R4/R8

R1 format was tested with [1] and [2].

[1]: https://lore.kernel.org/r/20240313-new_rotation-v2-0-6230fd5cae59@bootlin.com
[2]: https://lore.kernel.org/igt-dev/20240306-b4-kms_tests-v1-0-8fe451efd2ac@bootlin.com/

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_formats.c | 110 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/vkms/vkms_plane.c   |   4 ++
 2 files changed, 113 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 9972780f3fa9..6d0227c6635a 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -249,6 +249,16 @@ static struct pixel_argb_u16 argb_u16_from_RGB565(const __le16 *pixel)
 	return out_pixel;
 }
 
+static struct pixel_argb_u16 argb_u16_from_gray8(u8 gray)
+{
+	return argb_u16_from_u8888(255, gray, gray, gray);
+}
+
+static struct pixel_argb_u16 argb_u16_from_grayu16(u16 gray)
+{
+	return argb_u16_from_u16161616(0xFFFF, gray, gray, gray);
+}
+
 VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
 							    const struct conversion_matrix *matrix)
 {
@@ -286,7 +296,7 @@ EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
  * The following functions are read_line function for each pixel format supported by VKMS.
  *
  * They read a line starting at the point @x_start,@y_start following the @direction. The result
- * is stored in @out_pixel and in the format ARGB16161616.
+ * is stored in @out_pixel and in a 64 bits format, see struct pixel_argb_u16.
  *
  * These functions are very repetitive, but the innermost pixel loops must be kept inside these
  * functions for performance reasons. Some benchmarking was done in [1] where having the innermost
@@ -295,6 +305,96 @@ EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
  * [1]: https://lore.kernel.org/dri-devel/d258c8dc-78e9-4509-9037-a98f7f33b3a3@riseup.net/
  */
 
+static void Rx_read_line(const struct vkms_plane_state *plane, int x_start,
+			 int y_start, enum pixel_read_direction direction, int count,
+			 struct pixel_argb_u16 out_pixel[])
+{
+	struct pixel_argb_u16 *end = out_pixel + count;
+	int bits_per_pixel = drm_format_info_bpp(plane->frame_info->fb->format, 0);
+	u8 *src_pixels;
+	int rem_x, rem_y;
+
+	WARN_ONCE(drm_format_info_block_height(plane->frame_info->fb->format, 0) != 1,
+		  "%s() only support formats with block_h == 1", __func__);
+
+	packed_pixels_addr(plane->frame_info, x_start, y_start, 0, &src_pixels, &rem_x, &rem_y);
+	int bit_offset = (8 - bits_per_pixel) - rem_x * bits_per_pixel;
+	int step = get_block_step_bytes(plane->frame_info->fb, direction, 0);
+	int mask = (0x1 << bits_per_pixel) - 1;
+	int lum_per_level = 0xFFFF / mask;
+
+	if (direction == READ_LEFT_TO_RIGHT || direction == READ_RIGHT_TO_LEFT) {
+		int restart_bit_offset;
+		int step_bit_offset;
+
+		if (direction == READ_LEFT_TO_RIGHT) {
+			restart_bit_offset = 8 - bits_per_pixel;
+			step_bit_offset = -bits_per_pixel;
+		} else {
+			restart_bit_offset = 0;
+			step_bit_offset = bits_per_pixel;
+		}
+
+		while (out_pixel < end) {
+			u8 val = ((*src_pixels) >> bit_offset) & mask;
+
+			*out_pixel = argb_u16_from_grayu16((int)val * lum_per_level);
+
+			bit_offset += step_bit_offset;
+			if (bit_offset < 0 || 8 <= bit_offset) {
+				bit_offset = restart_bit_offset;
+				src_pixels += step;
+			}
+			out_pixel += 1;
+		}
+	} else if (direction == READ_TOP_TO_BOTTOM || direction == READ_BOTTOM_TO_TOP) {
+		while (out_pixel < end) {
+			u8 val = (*src_pixels >> bit_offset) & mask;
+			*out_pixel = argb_u16_from_grayu16((int)val * lum_per_level);
+			src_pixels += step;
+			out_pixel += 1;
+		}
+	}
+}
+
+static void R1_read_line(const struct vkms_plane_state *plane, int x_start,
+			 int y_start, enum pixel_read_direction direction, int count,
+			 struct pixel_argb_u16 out_pixel[])
+{
+	Rx_read_line(plane, x_start, y_start, direction, count, out_pixel);
+}
+
+static void R2_read_line(const struct vkms_plane_state *plane, int x_start,
+			 int y_start, enum pixel_read_direction direction, int count,
+			 struct pixel_argb_u16 out_pixel[])
+{
+	Rx_read_line(plane, x_start, y_start, direction, count, out_pixel);
+}
+
+static void R4_read_line(const struct vkms_plane_state *plane, int x_start,
+			 int y_start, enum pixel_read_direction direction, int count,
+			 struct pixel_argb_u16 out_pixel[])
+{
+	Rx_read_line(plane, x_start, y_start, direction, count, out_pixel);
+}
+
+static void R8_read_line(const struct vkms_plane_state *plane, int x_start,
+			 int y_start, enum pixel_read_direction direction, int count,
+			 struct pixel_argb_u16 out_pixel[])
+{
+	struct pixel_argb_u16 *end = out_pixel + count;
+	u8 *src_pixels;
+	int step = get_block_step_bytes(plane->frame_info->fb, direction, 0);
+
+	packed_pixels_addr_1x1(plane->frame_info, x_start, y_start, 0, &src_pixels);
+
+	while (out_pixel < end) {
+		*out_pixel = argb_u16_from_gray8(*src_pixels);
+		src_pixels += step;
+		out_pixel += 1;
+	}
+}
+
 static void ARGB8888_read_line(const struct vkms_plane_state *plane, int x_start, int y_start,
 			       enum pixel_read_direction direction, int count,
 			       struct pixel_argb_u16 out_pixel[])
@@ -636,6 +736,14 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
 	case DRM_FORMAT_YVU422:
 	case DRM_FORMAT_YVU444:
 		return &planar_yuv_read_line;
+	case DRM_FORMAT_R1:
+		return &R1_read_line;
+	case DRM_FORMAT_R2:
+		return &R2_read_line;
+	case DRM_FORMAT_R4:
+		return &R4_read_line;
+	case DRM_FORMAT_R8:
+		return &R8_read_line;
 	default:
 		/*
 		 * This is a bug in vkms_plane_atomic_check(). All the supported
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index fbfbe424e558..e3fdd161d0f0 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -31,6 +31,10 @@ static const u32 vkms_formats[] = {
 	DRM_FORMAT_YVU420,
 	DRM_FORMAT_YVU422,
 	DRM_FORMAT_YVU444,
+	DRM_FORMAT_R1,
+	DRM_FORMAT_R2,
+	DRM_FORMAT_R4,
+	DRM_FORMAT_R8,
 };
 
 static struct drm_plane_state *

-- 
2.49.0

Re: [PATCH v18 0/8] drm/vkms: Add support for YUV and DRM_FORMAT_R*

[Louis Chauvet]

On Tue, 15 Apr 2025 15:55:31 +0200, Louis Chauvet wrote:
> This patchset is extracted from [1]. The goal is to introduce the YUV
> support, thanks to Arthur's work.
> 
> - PATCH 2: Document pixel_arbg_u16
> - PATCH 3: Add the support of YUV formats
> - PATCH 4: Add some drm properties to expose more YUV features
> - PATCH 5: Cleanup the todo
> - PATCH 6..7: Add some kunit tests
> - PATCH 8: Add the support of DRM_FORMAT_R1/2/4/8
> 
> [...]

Applied, thanks!

[1/8] drm/vkms: Document pixel_argb_u16
      commit: c76e2c78bc2a35ca04eead275f14b6d23ae9a89f
[2/8] drm/vkms: Add YUV support
      commit: fe22d21e93426294eb0ebdb0bf5f6d6b77481ecc
[3/8] drm/vkms: Add range and encoding properties to the plane
      commit: 81dbec07197678fc2d86f1494dfaf44023864842
[4/8] drm/vkms: Drop YUV formats TODO
      commit: f776e5cef757927b038a9c07c0c68f34d35f7787
[5/8] drm: Export symbols to use in tests
      commit: 11d435b81e5dd2cc48daa2d3d71a19bcbc46e807
[6/8] drm/vkms: Create KUnit tests for YUV conversions
      commit: 3e897853debde269ab01f0d3d28c3e7b37bf2c39
[7/8] drm/vkms: Add how to run the Kunit tests
      commit: c59176cbca1188b906a36f06004a98a6264a8008
[8/8] drm/vkms: Add support for DRM_FORMAT_R*
      commit: ef818481d9fbaf3483dde0d1faa565a016810de3

Best regards,
-- 
Louis Chauvet <louis.chauvet@bootlin.com>