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

[José Expósito]

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.

[1] http://www.barth-dev.de/online/rgb565-color-picker/

Signed-off-by: José Expósito <jose.exposito89 at gmail.com>
---
 .../gpu/drm/tests/drm_format_helper_test.c    | 100 +++++++++++++++++-
 1 file changed, 99 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 52dc41cc7c60..3fbe8026bccc 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -48,7 +48,7 @@ struct convert_xrgb8888_case {
 	unsigned int pitch;
 	struct drm_rect clip;
 	const u32 xrgb8888[TEST_BUF_SIZE];
-	struct convert_xrgb8888_result results[1];
+	struct convert_xrgb8888_result results[3];
 };
 
 static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -64,6 +64,26 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				.dst_pitch = 0,
 				.expected = { 0xE0 },
 			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = false,
+				},
+				.dst_pitch = 0,
+				.expected = { 0x00, 0xF8 },
+			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = true,
+				},
+				.dst_pitch = 0,
+				.expected = { 0xF8, 0x00 },
+			},
 		},
 	},
 	{
@@ -81,6 +101,26 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				.dst_pitch = 0,
 				.expected = { 0xE0 },
 			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = false,
+				},
+				.dst_pitch = 0,
+				.expected = { 0x00, 0xF8 },
+			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = true,
+				},
+				.dst_pitch = 0,
+				.expected = { 0xF8, 0x00 },
+			},
 		},
 	},
 	{
@@ -110,6 +150,36 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 					0xFC, 0x1F,
 				},
 			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = false,
+				},
+				.dst_pitch = 0,
+				.expected = {
+					0xFF, 0xFF, 0x00, 0x00,
+					0x00, 0xF8, 0xE0, 0x07,
+					0x1F, 0x00, 0x1F, 0xF8,
+					0xE0, 0xFF, 0xFF, 0x07,
+				},
+			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = true,
+				},
+				.dst_pitch = 0,
+				.expected = {
+					0xFF, 0xFF, 0x00, 0x00,
+					0xF8, 0x00, 0x07, 0xE0,
+					0x00, 0x1F, 0xF8, 0x1F,
+					0xFF, 0xE0, 0x07, 0xFF,
+				},
+			},
 		},
 	},
 	{
@@ -133,6 +203,34 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 					0xA0, 0x6D, 0x0A, 0x00, 0x00,
 				},
 			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = false,
+				},
+				.dst_pitch = 10,
+				.expected = {
+					0x33, 0x0A, 0x60, 0x12, 0x00, 0xA8, 0x00, 0x00, 0x00, 0x00,
+					0x8E, 0x6B, 0x33, 0x0A, 0x60, 0x12, 0x00, 0x00, 0x00, 0x00,
+					0x00, 0xA8, 0x8E, 0x6B, 0x33, 0x0A, 0x00, 0x00, 0x00, 0x00,
+				},
+			},
+			{
+				.dst_format = DRM_FORMAT_RGB565,
+				.has_swab = true,
+				.conv_swab = {
+					.func = drm_fb_xrgb8888_to_rgb565,
+					.swab = true,
+				},
+				.dst_pitch = 10,
+				.expected = {
+					0x0A, 0x33, 0x12, 0x60, 0xA8, 0x00, 0x00, 0x00, 0x00, 0x00,
+					0x6B, 0x8E, 0x0A, 0x33, 0x12, 0x60, 0x00, 0x00, 0x00, 0x00,
+					0xA8, 0x00, 0x6B, 0x8E, 0x0A, 0x33, 0x00, 0x00, 0x00, 0x00,
+				},
+			},
 		},
 	},
 };
-- 
2.25.1