Re: [PATCH 2/3] drm/format-helper: Add drm_fb_xrgb8888_to_xrgb2101010_dstclip()

From: Thomas Zimmermann
Date: Thu Nov 18 2021 - 04:16:57 EST


Hi

Am 17.11.21 um 15:58 schrieb Hector Martin:
Add XRGB8888 emulation support for devices that can only do XRGB2101010.

This is chiefly useful for simpledrm on Apple devices where the
bootloader-provided framebuffer is 10-bit, which already works fine with
simplefb. This is required to make simpledrm support this too.

As mentioned in the other review, this requires a rebase onto the latest DRM tree; preferably drm-tip.

Best regards
Thomas


Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
drivers/gpu/drm/drm_format_helper.c | 64 +++++++++++++++++++++++++++++
include/drm/drm_format_helper.h | 4 ++
2 files changed, 68 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 69fde60e36b3..5998e57d6ff2 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -378,6 +378,60 @@ void drm_fb_xrgb8888_to_rgb888_dstclip(void __iomem *dst, unsigned int dst_pitch
}
EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888_dstclip);
+static void drm_fb_xrgb8888_to_xrgb2101010_line(u32 *dbuf, u32 *sbuf,
+ unsigned int pixels)
+{
+ unsigned int x;
+
+ for (x = 0; x < pixels; x++) {
+ *dbuf++ = ((sbuf[x] & 0x000000FF) << 2) |
+ ((sbuf[x] & 0x0000FF00) << 4) |
+ ((sbuf[x] & 0x00FF0000) << 6);
+ }
+}
+
+/**
+ * drm_fb_xrgb8888_to_xrgb2101010_dstclip - Convert XRGB8888 to XRGB2101010 clip
+ * buffer
+ * @dst: XRGB2101010 destination buffer (iomem)
+ * @dst_pitch: destination buffer pitch
+ * @vaddr: XRGB8888 source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * Drivers can use this function for XRGB2101010 devices that don't natively
+ * support XRGB8888.
+ *
+ * This function applies clipping on dst, i.e. the destination is a
+ * full (iomem) framebuffer but only the clip rect content is copied over.
+ */
+void drm_fb_xrgb8888_to_xrgb2101010_dstclip(void __iomem *dst,
+ unsigned int dst_pitch, void *vaddr,
+ struct drm_framebuffer *fb,
+ 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;
+
+ dbuf = kmalloc(dst_len, GFP_KERNEL);
+ if (!dbuf)
+ return;
+
+ vaddr += clip_offset(clip, fb->pitches[0], sizeof(u32));
+ dst += clip_offset(clip, dst_pitch, sizeof(u32));
+ for (y = 0; y < lines; y++) {
+ drm_fb_xrgb8888_to_xrgb2101010_line(dbuf, vaddr, linepixels);
+ memcpy_toio(dst, dbuf, dst_len);
+ vaddr += fb->pitches[0];
+ dst += dst_pitch;
+ }
+
+ kfree(dbuf);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010_dstclip);
+
/**
* drm_fb_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale
* @dst: 8-bit grayscale destination buffer
@@ -464,6 +518,10 @@ int drm_fb_blit_rect_dstclip(void __iomem *dst, unsigned int dst_pitch,
fb_format = DRM_FORMAT_XRGB8888;
if (dst_format == DRM_FORMAT_ARGB8888)
dst_format = DRM_FORMAT_XRGB8888;
+ if (fb_format == DRM_FORMAT_ARGB2101010)
+ fb_format = DRM_FORMAT_XRGB2101010;
+ if (dst_format == DRM_FORMAT_ARGB2101010)
+ dst_format = DRM_FORMAT_XRGB2101010;
if (dst_format == fb_format) {
drm_fb_memcpy_dstclip(dst, dst_pitch, vmap, fb, clip);
@@ -482,6 +540,12 @@ int drm_fb_blit_rect_dstclip(void __iomem *dst, unsigned int 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_dstclip(dst, dst_pitch,
+ vmap, fb, clip);
+ return 0;
+ }
}
return -EINVAL;
diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index e86925cf07b9..a0faa710878b 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -29,6 +29,10 @@ void drm_fb_xrgb8888_to_rgb888(void *dst, void *src, struct drm_framebuffer *fb,
void drm_fb_xrgb8888_to_rgb888_dstclip(void __iomem *dst, unsigned int dst_pitch,
void *vaddr, struct drm_framebuffer *fb,
struct drm_rect *clip);
+void drm_fb_xrgb8888_to_xrgb2101010_dstclip(void __iomem *dst,
+ unsigned int dst_pitch, void *vaddr,
+ struct drm_framebuffer *fb,
+ struct drm_rect *clip);
void drm_fb_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
struct drm_rect *clip);


--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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