drm/format-helper: Add drm_fb_xrgb8888_to_gray8_line()

Pull the per-line conversion logic into a separate helper function.

This will allow to do line-by-line conversion in other helpers that
convert to a gray8 format.
Suggested-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-2-javierm@redhat.com
parent b3d9f59f
......@@ -464,6 +464,21 @@ void drm_fb_xrgb8888_to_xrgb2101010_toio(void __iomem *dst,
}
EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010_toio);
static void drm_fb_xrgb8888_to_gray8_line(u8 *dst, const u32 *src, unsigned int pixels)
{
unsigned int x;
for (x = 0; x < pixels; x++) {
u8 r = (*src & 0x00ff0000) >> 16;
u8 g = (*src & 0x0000ff00) >> 8;
u8 b = *src & 0x000000ff;
/* ITU BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
*dst++ = (3 * r + 6 * g + b) / 10;
src++;
}
}
/**
* drm_fb_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale
* @dst: 8-bit grayscale destination buffer
......@@ -484,8 +499,9 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010_toio);
void drm_fb_xrgb8888_to_gray8(void *dst, unsigned int dst_pitch, const void *vaddr,
const struct drm_framebuffer *fb, const struct drm_rect *clip)
{
unsigned int len = (clip->x2 - clip->x1) * sizeof(u32);
unsigned int x, y;
unsigned int linepixels = clip->x2 - clip->x1;
unsigned int len = linepixels * sizeof(u32);
unsigned int y;
void *buf;
u8 *dst8;
u32 *src32;
......@@ -508,16 +524,7 @@ void drm_fb_xrgb8888_to_gray8(void *dst, unsigned int dst_pitch, const void *vad
for (y = clip->y1; y < clip->y2; y++) {
dst8 = dst;
src32 = memcpy(buf, vaddr, len);
for (x = clip->x1; x < clip->x2; x++) {
u8 r = (*src32 & 0x00ff0000) >> 16;
u8 g = (*src32 & 0x0000ff00) >> 8;
u8 b = *src32 & 0x000000ff;
/* ITU BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
*dst8++ = (3 * r + 6 * g + b) / 10;
src32++;
}
drm_fb_xrgb8888_to_gray8_line(dst8, src32, linepixels);
vaddr += fb->pitches[0];
dst += dst_pitch;
}
......
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