[PATCH 4/6] drm/format-helper: Support the AB24 format

[Thierry Reding <thierry.reding@gmail.com>]

From: Thierry Reding <treding@nvidia.com>

Add a conversion helper for the AB24 format to use in drm_fb_blit().

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_format_helper.c | 35 +++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 56642816fdff..d564412a816b 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -503,6 +503,36 @@ static void drm_fb_rgb888_to_xrgb8888(struct iosys_map *dst, const unsigned int
 		    drm_fb_rgb888_to_xrgb8888_line);
 }
 
+static void drm_fb_xrgb8888_to_abgr8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	__le32 *dbuf32 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		pix = ((pix & 0xff000000) >> 24) << 24 |
+		      ((pix & 0x00ff0000) >> 16) <<  0 |
+		      ((pix & 0x0000ff00) >>  8) <<  8 |
+		      ((pix & 0x000000ff) >>  0) << 16;
+		*dbuf32++ = cpu_to_le32(pix);
+	}
+}
+
+static void drm_fb_xrgb8888_to_abgr8888(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_abgr8888_line);
+}
+
 static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
 	__le32 *dbuf32 = dbuf;
@@ -672,6 +702,11 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
 			drm_fb_rgb565_to_xrgb8888(dst, dst_pitch, src, fb, clip);
 			return 0;
 		}
+	} else if (dst_format == DRM_FORMAT_ABGR8888) {
+		if (fb_format == DRM_FORMAT_XRGB8888) {
+			drm_fb_xrgb8888_to_abgr8888(dst, dst_pitch, src, fb, clip);
+			return 0;
+		}
 	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
 		if (fb_format == DRM_FORMAT_XRGB8888) {
 			drm_fb_xrgb8888_to_xrgb2101010(dst, dst_pitch, src, fb, clip);
-- 
2.37.2