drm/vkms: Change YUV helpers to support u16 inputs for conversion

Some YUV format uses 16 bit values, so change the helper function for
conversion to support those new formats.

Reviewed-by: Maíra Canal <[e-mail]>
Acked-by: Daniel Stone <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Louis Chauvet <[e-mail]>

drivers/gpu/drm/vkms/tests/vkms_format_test.c

···
 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
+ * struct pixel_yuv_u16 - Internal representation of a pixel color.
+ * @y: Luma value, stored in 16 bits, without padding, using
  *     machine endianness
- * @u: Blue difference chroma value, stored in 8 bits, without padding, using
+ * @u: Blue difference chroma value, stored in 16 bits, without padding, using
  *     machine endianness
- * @v: Red difference chroma value, stored in 8 bits, without padding, using
+ * @v: Red difference chroma value, stored in 16 bits, without padding, using
  *     machine endianness
  */
-struct pixel_yuv_u8 {
-	u8 y, u, v;
+struct pixel_yuv_u16 {
+	u16 y, u, v;
 };
 
 /*
- * struct yuv_u8_to_argb_u16_case - Reference values to test the color
+ * struct yuv_u16_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
···
  * @format_pair.yuv: Same color as @format_pair.rgb, but converted to
  *                   YUV using @encoding and @range.
  */
-struct yuv_u8_to_argb_u16_case {
+struct yuv_u16_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_yuv_u16 yuv;
 		struct pixel_argb_u16 argb;
 	} colors[TEST_BUFF_SIZE];
 };
···
  * 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[] = {
+static struct yuv_u16_to_argb_u16_case yuv_u16_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_bits = 16,
 	 *                     out_legal = False,
 	 *                     out_int = True)
 	 *
···
 		.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 }},
-		},
+			{ "white", { 0xffff, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x8080, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x0000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x4c8b, 0x54ce, 0xffff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0x9645, 0x2b33, 0x14d1 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x1d2f, 0xffff, 0x6b2f }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		}
 	},
 	/*
 	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
···
 	 *                     in_bits = 16,
 	 *                     in_legal = False,
 	 *                     in_int = True,
-	 *                     out_bits = 8,
+	 *                     out_bits = 16,
 	 *                     out_legal = True,
 	 *                     out_int = True)
 	 * Tests cases for color conversion generated by converting RGB
···
 		.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 }},
-		},
+			{ "white", { 0xeb00, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x7dee, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x1000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x517b, 0x5a34, 0xf000 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0x908e, 0x35cc, 0x2237 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x28f7, 0xf000, 0x6dc9 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		}
 	},
 	/*
 	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
···
 	 *                     in_bits = 16,
 	 *                     in_legal = False,
 	 *                     in_int = True,
-	 *                     out_bits = 8,
+	 *                     out_bits = 16,
 	 *                     out_legal = False,
 	 *                     out_int = True)
 	 * Tests cases for color conversion generated by converting RGB
···
 		.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 }},
-		},
+			{ "white", { 0xffff, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x8080, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x0000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x366d, 0x62ac, 0xffff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xb717, 0x1d55, 0x0bbd }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x127c, 0xffff, 0x7443 }, { 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_legal = False,
 	 *                     in_int = True,
-	 *                     out_bits = 8,
+	 *                     out_bits = 16,
 	 *                     out_legal = True,
 	 *                     out_int = True)
 	 * Tests cases for color conversion generated by converting RGB
···
 		.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 }},
-		},
+			{ "white", { 0xeb00, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x7dee, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x1000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x3e8f, 0x6656, 0xf000 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xaca1, 0x29aa, 0x1a45 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x1fd0, 0xf000, 0x75bb }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		}
 	},
 	/*
 	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
···
 	 *                     in_bits = 16,
 	 *                     in_legal = False,
 	 *                     in_int = True,
-	 *                     out_bits = 8,
+	 *                     out_bits = 16,
 	 *                     out_legal = False,
 	 *                     out_int = True)
 	 * Tests cases for color conversion generated by converting RGB
···
 		.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 }},
-		},
+			{ "white", { 0xffff, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x8080, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x0000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x4340, 0x5c41, 0xffff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xad91, 0x23bf, 0x0a4c }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x0f2e, 0xffff, 0x75b5 }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		}
 	},
 	/*
 	 * colour.RGB_to_YCbCr(<rgb color in 16 bit form>,
···
 	 *                     in_bits = 16,
 	 *                     in_legal = False,
 	 *                     in_int = True,
-	 *                     out_bits = 8,
+	 *                     out_bits = 16,
 	 *                     out_legal = True,
 	 *                     out_int = True)
 	 * Tests cases for color conversion generated by converting RGB
···
 		.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 }},
-		},
+			{ "white", { 0xeb00, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
+			{ "gray",  { 0x7dee, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
+			{ "black", { 0x1000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
+			{ "red",   { 0x4988, 0x60b9, 0xf000 }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
+			{ "green", { 0xa47b, 0x2f47, 0x1902 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
+			{ "blue",  { 0x1cfd, 0xf000, 0x76fe }, { 0xffff, 0x0000, 0x0000, 0xffff }},
+		}
 	},
 };
 
 /*
- * vkms_format_test_yuv_u8_to_argb_u16 - Testing the conversion between YUV
+ * vkms_format_test_yuv_u16_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.
+ * argb_u16_from_yuv161616 to convert YUV colors (stored in
+ * yuv_u16_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)
+static void vkms_format_test_yuv_u16_to_argb_u16(struct kunit *test)
 {
-	const struct yuv_u8_to_argb_u16_case *param = test->param_value;
+	const struct yuv_u16_to_argb_u16_case *param = test->param_value;
 	struct pixel_argb_u16 argb;
 
 	for (size_t i = 0; i < param->n_colors; i++) {
···
 		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);
+		argb = argb_u16_from_yuv161616(&matrix, color->yuv.y, color->yuv.u,
+					       color->yuv.v);
 
 		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",
···
 	}
 }
 
-static void vkms_format_test_yuv_u8_to_argb_u16_case_desc(struct yuv_u8_to_argb_u16_case *t,
-							  char *desc)
+static void vkms_format_test_yuv_u16_to_argb_u16_case_desc(struct yuv_u16_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
+KUNIT_ARRAY_PARAM(yuv_u16_to_argb_u16, yuv_u16_to_argb_u16_cases,
+		  vkms_format_test_yuv_u16_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),
+	KUNIT_CASE_PARAM(vkms_format_test_yuv_u16_to_argb_u16, yuv_u16_to_argb_u16_gen_params),
 	{}
 };
 

drivers/gpu/drm/vkms/vkms_formats.c

···
 	return out_pixel;
 }
 
-VISIBLE_IF_KUNIT 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_yuv161616(const struct conversion_matrix *matrix,
+					      u16 y, u16 channel_1, u16 channel_2)
 {
 	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_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) +
···
 
 	return argb_u16_from_u16161616(0xffff, r, g, b);
 }
-EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
+EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv161616);
 
 /**
  * READ_LINE() - Generic generator for a read_line function which can be used for format with one
···
 	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 = argb_u16_from_yuv161616(conversion_matrix, y_plane[0] * 257,
+						     uv_plane[0] * 257, uv_plane[1] * 257);
 		out_pixel += 1;
 		y_plane += step_y;
 		if ((i + subsampling_offset + 1) % subsampling == 0)
···
 	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 = argb_u16_from_yuv161616(conversion_matrix,
+						     *y_plane * 257, *channel_1_plane * 257,
+						     *channel_2_plane * 257);
 		out_pixel += 1;
 		y_plane += step_y;
 		if ((i + subsampling_offset + 1) % subsampling == 0) {

drivers/gpu/drm/vkms/vkms_formats.h

···
 				       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);
+struct pixel_argb_u16 argb_u16_from_yuv161616(const struct conversion_matrix *matrix,
+					      u16 y, u16 channel_1, u16 channel_2);
 #endif
 
 #endif /* _VKMS_FORMATS_H_ */