[PATCH v3 8/9] drm/format-helper: Add conversion from XRGB8888 to BGR888

[Aditya Garg <gargaditya08@live.com>]

From: Kerem Karabay <kekrby@gmail.com>

Add XRGB8888 emulation helper for devices that only support BGR888.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/gpu/drm/drm_format_helper.c           | 54 +++++++++++++
 .../gpu/drm/tests/drm_format_helper_test.c    | 81 +++++++++++++++++++
 include/drm/drm_format_helper.h               |  3 +
 3 files changed, 138 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index b1be458ed..28c0e76a1 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -702,6 +702,57 @@ void drm_fb_xrgb8888_to_rgb888(struct iosys_map *dst, const unsigned int *dst_pi
 }
 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888);
 
+static void drm_fb_xrgb8888_to_bgr888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u8 *dbuf8 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		/* write red-green-blue to output in little endianness */
+		*dbuf8++ = (pix & 0x00FF0000) >> 16;
+		*dbuf8++ = (pix & 0x0000FF00) >> 8;
+		*dbuf8++ = (pix & 0x000000FF) >> 0;
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_bgr888 - Convert XRGB8888 to BGR888 clip buffer
+ * @dst: Array of BGR888 destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ * @state: Transform and conversion state
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Drivers can use this function for BGR888 devices that don't natively
+ * support XRGB8888.
+ */
+void drm_fb_xrgb8888_to_bgr888(struct iosys_map *dst, const unsigned int *dst_pitch,
+			       const struct iosys_map *src, const struct drm_framebuffer *fb,
+			       const struct drm_rect *clip, struct drm_format_conv_state *state)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		3,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false, state,
+		    drm_fb_xrgb8888_to_bgr888_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_bgr888);
+
 static void drm_fb_xrgb8888_to_argb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
 	__le32 *dbuf32 = dbuf;
@@ -1035,6 +1086,9 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
 		} else if (dst_format == DRM_FORMAT_RGB888) {
 			drm_fb_xrgb8888_to_rgb888(dst, dst_pitch, src, fb, clip, state);
 			return 0;
+		} else if (dst_format == DRM_FORMAT_BGR888) {
+			drm_fb_xrgb8888_to_bgr888(dst, dst_pitch, src, fb, clip, state);
+			return 0;
 		} else if (dst_format == DRM_FORMAT_ARGB8888) {
 			drm_fb_xrgb8888_to_argb8888(dst, dst_pitch, src, fb, clip, state);
 			return 0;
diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
index 08992636e..35cd3405d 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -60,6 +60,11 @@ struct convert_to_rgb888_result {
 	const u8 expected[TEST_BUF_SIZE];
 };
 
+struct convert_to_bgr888_result {
+	unsigned int dst_pitch;
+	const u8 expected[TEST_BUF_SIZE];
+};
+
 struct convert_to_argb8888_result {
 	unsigned int dst_pitch;
 	const u32 expected[TEST_BUF_SIZE];
@@ -107,6 +112,7 @@ struct convert_xrgb8888_case {
 	struct convert_to_argb1555_result argb1555_result;
 	struct convert_to_rgba5551_result rgba5551_result;
 	struct convert_to_rgb888_result rgb888_result;
+	struct convert_to_bgr888_result bgr888_result;
 	struct convert_to_argb8888_result argb8888_result;
 	struct convert_to_xrgb2101010_result xrgb2101010_result;
 	struct convert_to_argb2101010_result argb2101010_result;
@@ -151,6 +157,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = TEST_USE_DEFAULT_PITCH,
 			.expected = { 0x00, 0x00, 0xFF },
 		},
+		.bgr888_result = {
+			.dst_pitch = TEST_USE_DEFAULT_PITCH,
+			.expected = { 0xFF, 0x00, 0x00 },
+		},
 		.argb8888_result = {
 			.dst_pitch = TEST_USE_DEFAULT_PITCH,
 			.expected = { 0xFFFF0000 },
@@ -217,6 +227,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = TEST_USE_DEFAULT_PITCH,
 			.expected = { 0x00, 0x00, 0xFF },
 		},
+		.bgr888_result = {
+			.dst_pitch = TEST_USE_DEFAULT_PITCH,
+			.expected = { 0xFF, 0x00, 0x00 },
+		},
 		.argb8888_result = {
 			.dst_pitch = TEST_USE_DEFAULT_PITCH,
 			.expected = { 0xFFFF0000 },
@@ -330,6 +344,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00,
 			},
 		},
+		.bgr888_result = {
+			.dst_pitch = TEST_USE_DEFAULT_PITCH,
+			.expected = {
+				0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00,
+				0xFF, 0x00, 0x00, 0x00, 0xFF, 0x00,
+				0x00, 0x00, 0xFF, 0xFF, 0x00, 0xFF,
+				0xFF, 0xFF, 0x00, 0x00, 0xFF, 0xFF,
+			},
+		},
 		.argb8888_result = {
 			.dst_pitch = TEST_USE_DEFAULT_PITCH,
 			.expected = {
@@ -468,6 +491,17 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 			},
 		},
+		.bgr888_result = {
+			.dst_pitch = 15,
+			.expected = {
+				0x0E, 0x44, 0x9C, 0x11, 0x4D, 0x05, 0xA8, 0xF3, 0x03,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0x6C, 0xF0, 0x73, 0x0E, 0x44, 0x9C, 0x11, 0x4D, 0x05,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+				0xA8, 0x03, 0x03, 0x6C, 0xF0, 0x73, 0x0E, 0x44, 0x9C,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+		},
 		.argb8888_result = {
 			.dst_pitch = 20,
 			.expected = {
@@ -914,6 +948,52 @@ static void drm_test_fb_xrgb8888_to_rgb888(struct kunit *test)
 	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
 }
 
+static void drm_test_fb_xrgb8888_to_bgr888(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_bgr888_result *result = &params->bgr888_result;
+	size_t dst_size;
+	u8 *buf = NULL;
+	__le32 *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_BGR888, result->dst_pitch,
+				       &params->clip, 0);
+	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 = cpubuf_to_le32(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	/*
+	 * BGR888 expected results are already in little-endian
+	 * order, so there's no need to convert the test output.
+	 */
+	drm_fb_xrgb8888_to_bgr888(&dst, &result->dst_pitch, &src, &fb, &params->clip,
+				  &fmtcnv_state);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
+
+	buf = dst.vaddr; /* restore original value of buf */
+	memset(buf, 0, dst_size);
+
+	int blit_result = 0;
+
+	blit_result = drm_fb_blit(&dst, &result->dst_pitch, DRM_FORMAT_BGR888, &src, &fb, &params->clip,
+				  &fmtcnv_state);
+
+	KUNIT_EXPECT_FALSE(test, blit_result);
+	KUNIT_EXPECT_MEMEQ(test, buf, result->expected, dst_size);
+}
+
 static void drm_test_fb_xrgb8888_to_argb8888(struct kunit *test)
 {
 	const struct convert_xrgb8888_case *params = test->param_value;
@@ -1851,6 +1931,7 @@ static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_argb1555, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgba5551, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb888, convert_xrgb8888_gen_params),
+	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_bgr888, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_argb8888, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_xrgb2101010, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_argb2101010, convert_xrgb8888_gen_params),
diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index 428d81afe..aa1604d92 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -96,6 +96,9 @@ void drm_fb_xrgb8888_to_rgba5551(struct iosys_map *dst, const unsigned int *dst_
 void drm_fb_xrgb8888_to_rgb888(struct iosys_map *dst, const unsigned int *dst_pitch,
 			       const struct iosys_map *src, const struct drm_framebuffer *fb,
 			       const struct drm_rect *clip, struct drm_format_conv_state *state);
+void drm_fb_xrgb8888_to_bgr888(struct iosys_map *dst, const unsigned int *dst_pitch,
+			       const struct iosys_map *src, const struct drm_framebuffer *fb,
+			       const struct drm_rect *clip, struct drm_format_conv_state *state);
 void drm_fb_xrgb8888_to_argb8888(struct iosys_map *dst, const unsigned int *dst_pitch,
 				 const struct iosys_map *src, const struct drm_framebuffer *fb,
 				 const struct drm_rect *clip, struct drm_format_conv_state *state);
-- 
2.43.0