[PATCH 3/3] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_gray8()

[José Expósito]

Extend the existing test cases to test the conversion from XRGB8888 to
grayscale.

Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>
---
 .../gpu/drm/tests/drm_format_helper_test.c    | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index d8536db4de1e..2f548aa51a30 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -37,6 +37,11 @@ struct convert_to_xrgb2101010_result {
 	const u32 expected[TEST_BUF_SIZE];
 };
 
+struct convert_to_gray8_result {
+	unsigned int dst_pitch;
+	const u8 expected[TEST_BUF_SIZE];
+};
+
 struct convert_xrgb8888_case {
 	const char *name;
 	unsigned int pitch;
@@ -46,6 +51,7 @@ struct convert_xrgb8888_case {
 	struct convert_to_rgb565_result rgb565_result;
 	struct convert_to_rgb888_result rgb888_result;
 	struct convert_to_xrgb2101010_result xrgb2101010_result;
+	struct convert_to_gray8_result gray8_result;
 };
 
 static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -71,6 +77,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0x3FF00000 },
 		},
+		.gray8_result = {
+			.dst_pitch = 0,
+			.expected = { 0x4C },
+		},
 	},
 	{
 		.name = "single_pixel_clip_rectangle",
@@ -97,6 +107,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0x3FF00000 },
 		},
+		.gray8_result = {
+			.dst_pitch = 0,
+			.expected = { 0x4C },
+		},
 	},
 	{
 		/* Well known colors: White, black, red, green, blue, magenta,
@@ -155,6 +169,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x3FFFFC00, 0x000FFFFF,
 			},
 		},
+		.gray8_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0xFF, 0x00,
+				0x4C, 0x99,
+				0x19, 0x66,
+				0xE5, 0xB2,
+			},
+		},
 	},
 	{
 		/* Randomly picked colors. Full buffer within the clip area. */
@@ -206,6 +229,14 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x2A20300C, 0x1B1705CD, 0x03844672, 0x00000000, 0x00000000,
 			},
 		},
+		.gray8_result = {
+			.dst_pitch = 5,
+			.expected = {
+				0x3C, 0x33, 0x34, 0x00, 0x00,
+				0x6F, 0x3C, 0x33, 0x00, 0x00,
+				0x34, 0x6F, 0x3C, 0x00, 0x00,
+			},
+		},
 	},
 };
 
@@ -381,11 +412,42 @@ static void xrgb8888_to_xrgb2101010_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
 }
 
+static void xrgb8888_to_gray8_test(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_gray8_result *result = &params->gray8_result;
+	size_t dst_size;
+	__u8 *buf = NULL;
+	__u32 *xrgb8888 = NULL;
+	struct iosys_map dst, src;
+
+	struct drm_framebuffer fb = {
+		.format = drm_format_info(DRM_FORMAT_XRGB8888),
+		.pitches = { params->pitch, 0, 0 },
+	};
+
+	dst_size = conversion_buf_size(DRM_FORMAT_R8, result->dst_pitch,
+				       &params->clip);
+	KUNIT_ASSERT_GT(test, dst_size, 0);
+
+	buf = kunit_kzalloc(test, dst_size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf);
+	iosys_map_set_vaddr(&dst, buf);
+
+	xrgb8888 = le32buf_to_cpu(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	drm_fb_xrgb8888_to_gray8(&dst, &result->dst_pitch, &src, &fb, &params->clip);
+	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+}
+
 static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(xrgb8888_to_rgb332_test, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(xrgb8888_to_rgb565_test, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(xrgb8888_to_rgb888_test, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(xrgb8888_to_xrgb2101010_test, convert_xrgb8888_gen_params),
+	KUNIT_CASE_PARAM(xrgb8888_to_gray8_test, convert_xrgb8888_gen_params),
 	{}
 };
 
-- 
2.25.1