On Tue, Aug 17, 2021 at 02:29:12PM +0200, Noralf Trønnes wrote:
Add XRGB8888 emulation support for devices that can only do RGB332.
Cc: Thomas Zimmermann tzimmermann@suse.de Signed-off-by: Noralf Trønnes noralf@tronnes.org
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) |
I think for 2/3 bits correct rounding would be useful, not just masking. i.e. before you shift add 0x00100000 here, and similar below.
Also I just realized we've totally ignored endianess on these, which is not great, because strictly speaking all the drm_fourcc codes should be little endian. But I'm also not sure that's worth fixing ...
Either way, lgtm:
Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
((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