drm/format-helper: Add conversion from XRGB8888 to ARGB2101010

Add dedicated helper to convert from XRGB8888 to ARGB2101010. Sets
all alpha bits to make pixels fully opaque.

v2:
	* set correct format in struct drm_framebuffer (Javier)
	* use cpubuf_to_le32()
	* type fixes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102112927.26565-9-tzimmermann@suse.de

3 files changed, 122 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 718e29341773..33780c9183bb 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -605,6 +605,59 @@ void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const unsigned int *d
 }
 EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010);
 
+static void drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	__le32 *dbuf32 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u32 val32;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		val32 = ((pix & 0x000000ff) << 2) |
+			((pix & 0x0000ff00) << 4) |
+			((pix & 0x00ff0000) << 6);
+		pix = GENMASK(31, 30) | /* set alpha bits */
+		      val32 | ((val32 >> 8) & 0x00300c03);
+		*dbuf32++ = cpu_to_le32(pix);
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_argb2101010 - Convert XRGB8888 to ARGB2101010 clip buffer
+ * @dst: Array of ARGB2101010 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
+ *
+ * This function copies parts of a framebuffer to display memory and converts
+ * the color format during the process. 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 ARGB2101010 devices that don't support XRGB8888
+ * natively.
+ */
+void drm_fb_xrgb8888_to_argb2101010(struct iosys_map *dst, const unsigned int *dst_pitch,
+				    const struct iosys_map *src, const struct drm_framebuffer *fb,
+				    const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		4,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_xrgb8888_to_argb2101010_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_argb2101010);
+
 static void drm_fb_xrgb8888_to_gray8_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
 	u8 *dbuf8 = dbuf;
@@ -696,8 +749,6 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
 		fb_format = DRM_FORMAT_XRGB8888;
 	if (fb_format == DRM_FORMAT_ARGB2101010)
 		fb_format = DRM_FORMAT_XRGB2101010;
-	if (dst_format == DRM_FORMAT_ARGB2101010)
-		dst_format = DRM_FORMAT_XRGB2101010;
 
 	if (fb_format == dst_format) {
 		drm_fb_memcpy(dst, dst_pitch, src, fb, clip);
@@ -721,6 +772,9 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
 		} else if (dst_format == DRM_FORMAT_XRGB2101010) {
 			drm_fb_xrgb8888_to_xrgb2101010(dst, dst_pitch, src, fb, clip);
 			return 0;
+		} else if (dst_format == DRM_FORMAT_ARGB2101010) {
+			drm_fb_xrgb8888_to_argb2101010(dst, dst_pitch, src, fb, clip);
+			return 0;
 		} else if (dst_format == DRM_FORMAT_BGRX8888) {
 			drm_fb_swab(dst, dst_pitch, src, fb, clip, false);
 			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 bc969413a412..de3aa252e8eb 100644
--- a/drivers/gpu/drm/tests/drm_format_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -47,6 +47,11 @@ struct convert_to_xrgb2101010_result {
 	const u32 expected[TEST_BUF_SIZE];
 };
 
+struct convert_to_argb2101010_result {
+	unsigned int dst_pitch;
+	const u32 expected[TEST_BUF_SIZE];
+};
+
 struct convert_xrgb8888_case {
 	const char *name;
 	unsigned int pitch;
@@ -58,6 +63,7 @@ struct convert_xrgb8888_case {
 	struct convert_to_rgb888_result rgb888_result;
 	struct convert_to_argb8888_result argb8888_result;
 	struct convert_to_xrgb2101010_result xrgb2101010_result;
+	struct convert_to_argb2101010_result argb2101010_result;
 };
 
 static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
@@ -91,6 +97,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0x3FF00000 },
 		},
+		.argb2101010_result = {
+			.dst_pitch = 0,
+			.expected = { 0xFFF00000 },
+		},
 	},
 	{
 		.name = "single_pixel_clip_rectangle",
@@ -125,6 +135,10 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 			.dst_pitch = 0,
 			.expected = { 0x3FF00000 },
 		},
+		.argb2101010_result = {
+			.dst_pitch = 0,
+			.expected = { 0xFFF00000 },
+		},
 	},
 	{
 		/* Well known colors: White, black, red, green, blue, magenta,
@@ -201,6 +215,15 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x3FFFFC00, 0x000FFFFF,
 			},
 		},
+		.argb2101010_result = {
+			.dst_pitch = 0,
+			.expected = {
+				0xFFFFFFFF, 0xC0000000,
+				0xFFF00000, 0xC00FFC00,
+				0xC00003FF, 0xFFF003FF,
+				0xFFFFFC00, 0xC00FFFFF,
+			},
+		},
 	},
 	{
 		/* Randomly picked colors. Full buffer within the clip area. */
@@ -268,6 +291,14 @@ static struct convert_xrgb8888_case convert_xrgb8888_cases[] = {
 				0x2A20300C, 0x1B1705CD, 0x03844672, 0x00000000, 0x00000000,
 			},
 		},
+		.argb2101010_result = {
+			.dst_pitch = 20,
+			.expected = {
+				0xC3844672, 0xC444D414, 0xEA20300C, 0x00000000, 0x00000000,
+				0xDB1705CD, 0xC3844672, 0xC444D414, 0x00000000, 0x00000000,
+				0xEA20300C, 0xDB1705CD, 0xC3844672, 0x00000000, 0x00000000,
+			},
+		},
 	},
 };
 
@@ -541,6 +572,37 @@ static void drm_test_fb_xrgb8888_to_xrgb2101010(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
 }
 
+static void drm_test_fb_xrgb8888_to_argb2101010(struct kunit *test)
+{
+	const struct convert_xrgb8888_case *params = test->param_value;
+	const struct convert_to_argb2101010_result *result = &params->argb2101010_result;
+	size_t dst_size;
+	u32 *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_ARGB2101010,
+				       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 = cpubuf_to_le32(test, params->xrgb8888, TEST_BUF_SIZE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xrgb8888);
+	iosys_map_set_vaddr(&src, xrgb8888);
+
+	drm_fb_xrgb8888_to_argb2101010(&dst, &result->dst_pitch, &src, &fb, &params->clip);
+	buf = le32buf_to_cpu(test, (__force const __le32 *)buf, dst_size / sizeof(u32));
+	KUNIT_EXPECT_EQ(test, memcmp(buf, result->expected, dst_size), 0);
+}
+
 static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_gray8, convert_xrgb8888_gen_params),
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb332, convert_xrgb8888_gen_params),
@@ -548,6 +610,7 @@ static struct kunit_case drm_format_helper_test_cases[] = {
 	KUNIT_CASE_PARAM(drm_test_fb_xrgb8888_to_rgb888, 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 3ce8129dfe43..10b2d19cdb66 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -39,6 +39,9 @@ void drm_fb_xrgb8888_to_argb8888(struct iosys_map *dst, const unsigned int *dst_
 void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const unsigned int *dst_pitch,
 				    const struct iosys_map *src, const struct drm_framebuffer *fb,
 				    const struct drm_rect *clip);
+void drm_fb_xrgb8888_to_argb2101010(struct iosys_map *dst, const unsigned int *dst_pitch,
+				    const struct iosys_map *src, const struct drm_framebuffer *fb,
+				    const struct drm_rect *clip);
 void drm_fb_xrgb8888_to_gray8(struct iosys_map *dst, const unsigned int *dst_pitch,
 			      const struct iosys_map *src, const struct drm_framebuffer *fb,
 			      const struct drm_rect *clip);