[PATCH v2 4/4] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb565()

José Expósito
2022-07-09T11:59:03Z

Extend the existing test cases to test the conversion from XRGB8888 to
RGB565.

The documentation and the color picker available on [1] are useful
resources to understand this patch and validate the values returned by
the conversion function.

Tested-by: Tales L. Aparecida <tales.aparecida@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: http://www.barth-dev.de/online/rgb565-color-picker/ # [1]
---
.../gpu/drm/tests/drm_format_helper_test.c | 76 ++++++++++++++++++-
1 file changed, 75 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index 0a490ad4fd32..c0592c1235cf 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -21,12 +21,19 @@ struct convert_to_rgb332_result {
const u8 expected[TEST_BUF_SIZE];
};

+struct convert_to_rgb565_result {
+ unsigned int dst_pitch;
+ const u16 expected[TEST_BUF_SIZE];
+ const u16 expected_swab[TEST_BUF_SIZE];
+};
+
struct convert_xrgb8888_case {
const char *name;
unsigned int pitch;
struct drm_rect clip;
const u32 xrgb8888[TEST_BUF_SIZE];
struct convert_to_rgb332_result rgb332_result;
+ struct convert_to_rgb565_result rgb565_result;
};

static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -39,6 +46,11 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
.dst_pitch = 0,
.expected = { 0xE0 },
},
+ .rgb565_result = {
+ .dst_pitch = 0,
+ .expected = { 0xF800 },
+ .expected_swab = { 0x00F8 },
+ },
},
{
.name = "single_pixel_clip_rectangle",
@@ -52,6 +64,11 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
.dst_pitch = 0,
.expected = { 0xE0 },
},
+ .rgb565_result = {
+ .dst_pitch = 0,
+ .expected = { 0xF800 },
+ .expected_swab = { 0x00F8 },
+ },
},
{
/* Well known colors: White, black, red, green, blue, magenta,
@@ -77,6 +94,21 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
0xFC, 0x1F,
},
},
+ .rgb565_result = {
+ .dst_pitch = 0,
+ .expected = {
+ 0xFFFF, 0x0000,
+ 0xF800, 0x07E0,
+ 0x001F, 0xF81F,
+ 0xFFE0, 0x07FF,
+ },
+ .expected_swab = {
+ 0xFFFF, 0x0000,
+ 0x00F8, 0xE007,
+ 0x1F00, 0x1FF8,
+ 0xE0FF, 0xFF07,
+ },
+ },
},
{
/* Randomly picked colors. Full buffer within the clip area. */
@@ -96,6 +128,19 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
0xA0, 0x6D, 0x0A, 0x00, 0x00,
},
},
+ .rgb565_result = {
+ .dst_pitch = 10,
+ .expected = {
+ 0x0A33, 0x1260, 0xA800, 0x0000, 0x0000,
+ 0x6B8E, 0x0A33, 0x1260, 0x0000, 0x0000,
+ 0xA800, 0x6B8E, 0x0A33, 0x0000, 0x0000,
+ },
+ .expected_swab = {
+ 0x330A, 0x6012, 0x00A8, 0x0000, 0x0000,
+ 0x8E6B, 0x330A, 0x6012, 0x0000, 0x0000,
+ 0x00A8, 0x8E6B, 0x330A, 0x0000, 0x0000,
+ },
+ },
},
};

@@ -120,7 +165,7 @@ static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
if (!dst_pitch)
dst_pitch = drm_rect_width(clip) * dst_fi->cpp[0];

- return dst_pitch * drm_rect_height(clip);
+ return (dst_pitch * drm_rect_height(clip)) / (dst_fi->depth / 8);
}

static u32 *le32buf_to_cpu(struct kunit *test, const u32 *buf, size_t buf_size)
@@ -175,8 +220,37 @@ static void xrgb8888_to_rgb332_test(struct kunit *test)
KUNIT_EXPECT_EQ(test, memcmp(dst, result->expected, dst_size), 0);
}

+static void xrgb8888_to_rgb565_test(struct kunit *test)
+{
+ const struct convert_xrgb8888_case *params = test->param_value;
+ const struct convert_to_rgb565_result *result = &params->rgb565_result;
+ size_t dst_size;
+ __u16 *dst = NULL;
+
+ struct drm_framebuffer fb = {
+ .format = drm_format_info(DRM_FORMAT_XRGB8888),
+ .pitches = { params->pitch, 0, 0 },
+ };
+
+ dst_size = conversion_buf_size(DRM_FORMAT_RGB565, result->dst_pitch,
+ &params->clip);
+ KUNIT_ASSERT_GT(test, dst_size, 0);
+
+ dst = kunit_kzalloc(test, dst_size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dst);
+
+ drm_fb_xrgb8888_to_rgb565(dst, result->dst_pitch, params->xrgb8888, &fb,
+ &params->clip, false);
+ KUNIT_EXPECT_EQ(test, memcmp(dst, result->expected, dst_size), 0);
+
+ drm_fb_xrgb8888_to_rgb565(dst, result->dst_pitch, params->xrgb8888, &fb,
+ &params->clip, true);
+ KUNIT_EXPECT_EQ(test, memcmp(dst, result->expected_swab, 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),
{}
};

--
2.25.1