[PATCH v2 0/3] drm/format-helper: Support conversion to XRGB8888

[PATCH v2 0/3] drm/format-helper: Support conversion to XRGB8888

[Thomas Zimmermann]

Support conversion from RGB565 and RGB888 to XRGB8888. This enables
simpledrm to work with framebuffers of such formats.

UEFI and/or Grub will usually set 32-bit output in XRGB8888 format.
The issue can be reproduced by enabling simpledrm and requesting a
console framebuffer of different format on the kernel command line;
for example

  nomodeset video=1024x768-16

  or

  nomodeset video=1024x768-24

Conversion helpers will do nothing in this case.

Make this work by implementing the rsp conversion helpers. Also add
a warning about unsupported format conversions. The patchset should
also enable odd userspace configurations, such as running Xorg with
16- or 24-bit color depth.

v2:
	* use helpers for struct drm_rect (Javier)
	* improve commit messages (Javier)

Thomas Zimmermann (3):
  drm/format-helper: Print warning on missing format conversion
  drm/format-helper: Add RGB888-to-XRGB8888 conversion
  drm/format-helper: Add RGB565-to-XRGB8888 conversion

 drivers/gpu/drm/drm_format_helper.c | 95 +++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)


base-commit: 0e7deff6446a4ba2c75f499a0bfa80cd6a15c129
prerequisite-patch-id: c2b2f08f0eccc9f5df0c0da49fa1d36267deb11d
prerequisite-patch-id: c67e5d886a47b7d0266d81100837557fda34cb24
-- 
2.36.0

[PATCH v2 1/3] drm/format-helper: Print warning on missing format conversion

[Thomas Zimmermann]

Not all possible format conversions are supported yet. Print a
warning on unsupported combinations.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
---
 drivers/gpu/drm/drm_format_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 0e7135114728..b648f29b21b6 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -590,6 +590,9 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for
 		}
 	}
 
+	drm_warn_once(fb->dev, "No conversion helper from %p4cc to %p4cc found.\n",
+		      &fb_format, &dst_format);
+
 	return -EINVAL;
 }
 EXPORT_SYMBOL(drm_fb_blit_toio);
-- 
2.36.0

[PATCH v2 2/3] drm/format-helper: Add RGB888-to-XRGB8888 conversion

[Thomas Zimmermann]

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.

UEFI and/or Grub will usually set 32-bit output in XRGB8888 format.
The issue can be reproduced by enabling simpledrm and requesting a
console framebuffer of different format on the kernel command line;
for example

  nomodeset video=1024x768-24

In this case, conversion helpers will display nothing on the console.
The patch makes this work by implementing the rsp conversion helpers.
It also enables odd userspace configurations, such as running Xorg
with 24-bit color depth on a 32-bit output buffer.

v2:
	* use helpers for struct drm_rect (Javier)
	* improve commit message (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
---
 drivers/gpu/drm/drm_format_helper.c | 46 +++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index b648f29b21b6..c83e0bb2e8c7 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 = drm_rect_width(clip);
+	size_t dst_len = linepixels * 4;
+	unsigned int y, lines = drm_rect_height(clip);
+	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);
-- 
2.36.0

[PATCH v2 3/3] drm/format-helper: Add RGB565-to-XRGB8888 conversion

[Thomas Zimmermann]

Add a format helper that converts RGB565 to XRGB8888. Use this
function in drm_fb_blit_toio(). Fixes simpledrm output for this
combination of formats.

UEFI and/or Grub will usually set 32-bit output in XRGB8888 format.
The issue can be reproduced by enabling simpledrm and requesting a
console framebuffer of different format on the kernel command line;
for example

  nomodeset video=1024x768-16

In this case, conversion helpers will display nothing on the console.
The patch makes this work by implementing the rsp conversion helpers.
It also enables odd userspace configurations, such as running Xorg
with 16-bit color depth on a 32-bit output buffer.

v2:
	* use helpers for struct drm_rect (Javier)
	* improve commit message (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
---
 drivers/gpu/drm/drm_format_helper.c | 46 +++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index c83e0bb2e8c7..34b7ef443ad2 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -411,6 +411,49 @@ 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_rgb565_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u32 *dbuf32 = dbuf;
+	const u16 *sbuf16 = sbuf;
+	unsigned int x;
+
+	for (x = 0; x < pixels; x++, ++sbuf16, ++dbuf32) {
+		u32 val32 = ((*sbuf16 & 0xf800) << 8) |
+			    ((*sbuf16 & 0x07e0) << 5) |
+			    ((*sbuf16 & 0x001f) << 3);
+		*dbuf32 = 0xff000000 | val32 |
+			  ((val32 >> 3) & 0x00070007) |
+			  ((val32 >> 2) & 0x00000300);
+	}
+}
+
+static void drm_fb_rgb565_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 = drm_rect_width(clip);
+	size_t dst_len = linepixels * 4;
+	unsigned int y, lines = drm_rect_height(clip);
+	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], 2);
+	for (y = 0; y < lines; y++) {
+		drm_fb_rgb565_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_rgb888_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
 	u32 *dbuf32 = dbuf;
@@ -628,6 +671,9 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for
 		if (fb_format == DRM_FORMAT_RGB888) {
 			drm_fb_rgb888_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
 			return 0;
+		} else if (fb_format == DRM_FORMAT_RGB565) {
+			drm_fb_rgb565_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
+			return 0;
 		}
 	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
 		if (fb_format == DRM_FORMAT_XRGB8888) {
-- 
2.36.0