[2/3] drm/format-helper: Add RGB888-to-XRGB8888 conversion

Commit Message

Thomas Zimmermann April 21, 2022, 6:17 p.m. UTC

Add a format helper that converts RGB888 to XRGB8888. Use this
function in drm_fb_blit_toio(). Fixes simpledrm output for this
combination of formats.

Signed-off-by: Thomas Zimmermann <[e-mail]>
---
 drivers/gpu/drm/drm_format_helper.c | 46 +++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

Comments

Javier Martinez Canillas April 22, 2022, 12:26 p.m. UTC | #1

On 4/21/22 20:17, Thomas Zimmermann wrote:
> Add a format helper that converts RGB888 to XRGB8888. Use this
> function in drm_fb_blit_toio(). Fixes simpledrm output for this
> combination of formats.
>

I think the examples you have in the cover letter are quite illustrative,
maybe I would mention an example in the commit description as well.

> Signed-off-by: Thomas Zimmermann <[e-mail]>
> ---

[snip]

> +
> +static void drm_fb_rgb888_to_xrgb8888_toio(void __iomem *dst, unsigned int dst_pitch,
> +					   const void *vaddr, const struct drm_framebuffer *fb,
> +					   const struct drm_rect *clip)
> +{
> +	size_t linepixels = clip->x2 - clip->x1;

drm_rect_width(clip) instead ?

> +	size_t dst_len = linepixels * 4;
> +	unsigned int y, lines = clip->y2 - clip->y1;
and drm_rect_height(clip) ?

> +	void *dbuf;
> +
Reviewed-by: Javier Martinez Canillas <[e-mail]>

Patch

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index b648f29b21b6..c107ff75ef78 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -411,6 +411,47 @@  void drm_fb_xrgb8888_to_rgb888_toio(void __iomem *dst, unsigned int dst_pitch,
 }
 EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888_toio);
 
+static void drm_fb_rgb888_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u32 *dbuf32 = dbuf;
+	const u8 *sbuf8 = sbuf;
+	unsigned int x;
+
+	for (x = 0; x < pixels; x++) {
+		u8 r = *sbuf8++;
+		u8 g = *sbuf8++;
+		u8 b = *sbuf8++;
+		*dbuf32++ = 0xff000000 | (r << 16) | (g << 8) | b;
+	}
+}
+
+static void drm_fb_rgb888_to_xrgb8888_toio(void __iomem *dst, unsigned int dst_pitch,
+					   const void *vaddr, const struct drm_framebuffer *fb,
+					   const struct drm_rect *clip)
+{
+	size_t linepixels = clip->x2 - clip->x1;
+	size_t dst_len = linepixels * 4;
+	unsigned int y, lines = clip->y2 - clip->y1;
+	void *dbuf;
+
+	if (!dst_pitch)
+		dst_pitch = dst_len;
+
+	dbuf = kmalloc(dst_len, GFP_KERNEL);
+	if (!dbuf)
+		return;
+
+	vaddr += clip_offset(clip, fb->pitches[0], 3);
+	for (y = 0; y < lines; y++) {
+		drm_fb_rgb888_to_xrgb8888_line(dbuf, vaddr, linepixels);
+		memcpy_toio(dst, dbuf, dst_len);
+		vaddr += fb->pitches[0];
+		dst += dst_pitch;
+	}
+
+	kfree(dbuf);
+}
+
 static void drm_fb_xrgb8888_to_xrgb2101010_line(u32 *dbuf, const u32 *sbuf,
 						unsigned int pixels)
 {
@@ -583,6 +624,11 @@  int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for
 			drm_fb_xrgb8888_to_rgb888_toio(dst, dst_pitch, vmap, fb, clip);
 			return 0;
 		}
+	} else if (dst_format == DRM_FORMAT_XRGB8888) {
+		if (fb_format == DRM_FORMAT_RGB888) {
+			drm_fb_rgb888_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
+			return 0;
+		}
 	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
 		if (fb_format == DRM_FORMAT_XRGB8888) {
 			drm_fb_xrgb8888_to_xrgb2101010_toio(dst, dst_pitch, vmap, fb, clip);