Add XRGB8888 emulation support for devices that can only do RGB332.
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
---
drivers/gpu/drm/drm_format_helper.c | 47 +++++++++++++++++++++++++++++
include/drm/drm_format_helper.h | 2 ++
2 files changed, 49 insertions(+)
diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 5231104b1498..53b426da7467 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -135,6 +135,53 @@ void drm_fb_swab(void *dst, void *src, struct drm_framebuffer *fb,
}
EXPORT_SYMBOL(drm_fb_swab);
+static void drm_fb_xrgb8888_to_rgb332_line(u8 *dbuf, u32 *sbuf, unsigned int pixels)
+{
+ unsigned int x;
+
+ for (x = 0; x < pixels; x++)
+ dbuf[x] = ((sbuf[x] & 0x00e00000) >> 16) |
+ ((sbuf[x] & 0x0000e000) >> 11) |
+ ((sbuf[x] & 0x000000c0) >> 6);
+}
+
+/**
+ * drm_fb_xrgb8888_to_rgb332 - Convert XRGB8888 to RGB332 clip buffer
+ * @dst: RGB332 destination buffer
+ * @src: XRGB8888 source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * Drivers can use this function for RGB332 devices that don't natively support XRGB8888.
+ *
+ * This function does not apply clipping on dst, i.e. the destination is a small buffer
+ * containing the clip rect only.
+ */
+void drm_fb_xrgb8888_to_rgb332(void *dst, void *src, struct drm_framebuffer *fb,
+ struct drm_rect *clip)
+{
+ size_t width = drm_rect_width(clip);
+ size_t src_len = width * sizeof(u32);
+ unsigned int y;
+ void *sbuf;
+
+ /* Use a buffer to speed up access on buffers with uncached read mapping (i.e. WC) */
+ sbuf = kmalloc(src_len, GFP_KERNEL);
+ if (!sbuf)
+ return;
+
+ src += clip_offset(clip, fb->pitches[0], sizeof(u32));
+ for (y = 0; y < drm_rect_height(clip); y++) {
+ memcpy(sbuf, src, src_len);
+ drm_fb_xrgb8888_to_rgb332_line(dst, sbuf, width);
+ src += fb->pitches[0];
+ dst += width;
+ }
+
+ kfree(sbuf);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb332);
+
static void drm_fb_xrgb8888_to_rgb565_line(u16 *dbuf, u32 *sbuf,
unsigned int pixels,
bool swab)
diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index 4e0258a61311..d0809aff5cf8 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -16,6 +16,8 @@ void drm_fb_memcpy_dstclip(void __iomem *dst, unsigned int dst_pitch, void *vadd
struct drm_rect *clip);
void drm_fb_swab(void *dst, void *src, struct drm_framebuffer *fb,
struct drm_rect *clip, bool cached);
+void drm_fb_xrgb8888_to_rgb332(void *dst, void *vaddr, struct drm_framebuffer *fb,
+ struct drm_rect *clip);
void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr,
struct drm_framebuffer *fb,
struct drm_rect *clip, bool swab);
--
2.32.0
