[PATCH v5 5/5] drm/ofdrm: Support big-endian scanout buffers
Thomas Zimmermann
tzimmermann at suse.de
Tue Oct 11 15:07:12 UTC 2022
All DRM formats assume little-endian byte order. On big-endian systems,
it is likely that the scanout buffer is in big endian as well. Update
the format accordingly and add endianess conversion to the format-helper
library. Also opt-in to allocated buffers in host format by default.
Suggested-by: Geert Uytterhoeven <geert at linux-m68k.org>
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Javier Martinez Canillas <javierm at redhat.com>
---
drivers/gpu/drm/drm_format_helper.c | 10 ++++++
drivers/gpu/drm/tiny/ofdrm.c | 55 +++++++++++++++++++++++++++--
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index e2f76621453c..653a5821dd53 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -660,6 +660,11 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
drm_fb_xrgb8888_to_rgb565(dst, dst_pitch, src, fb, clip, false);
return 0;
}
+ } else if (dst_format == (DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN)) {
+ if (fb_format == DRM_FORMAT_RGB565) {
+ drm_fb_swab(dst, dst_pitch, src, fb, clip, false);
+ return 0;
+ }
} else if (dst_format == DRM_FORMAT_RGB888) {
if (fb_format == DRM_FORMAT_XRGB8888) {
drm_fb_xrgb8888_to_rgb888(dst, dst_pitch, src, fb, clip);
@@ -678,6 +683,11 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
drm_fb_xrgb8888_to_xrgb2101010(dst, dst_pitch, src, fb, clip);
return 0;
}
+ } else if (dst_format == DRM_FORMAT_BGRX8888) {
+ if (fb_format == DRM_FORMAT_XRGB8888) {
+ drm_fb_swab(dst, dst_pitch, src, fb, clip, false);
+ return 0;
+ }
}
drm_warn_once(fb->dev, "No conversion helper from %p4cc to %p4cc found.\n",
diff --git a/drivers/gpu/drm/tiny/ofdrm.c b/drivers/gpu/drm/tiny/ofdrm.c
index 3b0eaebd86f9..0e1cc2369afc 100644
--- a/drivers/gpu/drm/tiny/ofdrm.c
+++ b/drivers/gpu/drm/tiny/ofdrm.c
@@ -94,7 +94,7 @@ static int display_get_validated_int0(struct drm_device *dev, const char *name,
}
static const struct drm_format_info *display_get_validated_format(struct drm_device *dev,
- u32 depth)
+ u32 depth, bool big_endian)
{
const struct drm_format_info *info;
u32 format;
@@ -115,6 +115,29 @@ static const struct drm_format_info *display_get_validated_format(struct drm_dev
return ERR_PTR(-EINVAL);
}
+ /*
+ * DRM formats assume little-endian byte order. Update the format
+ * if the scanout buffer uses big-endian ordering.
+ */
+ if (big_endian) {
+ switch (format) {
+ case DRM_FORMAT_XRGB8888:
+ format = DRM_FORMAT_BGRX8888;
+ break;
+ case DRM_FORMAT_ARGB8888:
+ format = DRM_FORMAT_BGRA8888;
+ break;
+ case DRM_FORMAT_RGB565:
+ format = DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN;
+ break;
+ case DRM_FORMAT_XRGB1555:
+ format = DRM_FORMAT_XRGB1555 | DRM_FORMAT_BIG_ENDIAN;
+ break;
+ default:
+ break;
+ }
+ }
+
info = drm_format_info(format);
if (!info) {
drm_err(dev, "cannot find framebuffer format for depth %u\n", depth);
@@ -134,6 +157,23 @@ static int display_read_u32_of(struct drm_device *dev, struct device_node *of_no
return ret;
}
+static bool display_get_big_endian_of(struct drm_device *dev, struct device_node *of_node)
+{
+ bool big_endian;
+
+#ifdef __BIG_ENDIAN
+ big_endian = true;
+ if (of_get_property(of_node, "little-endian", NULL))
+ big_endian = false;
+#else
+ big_endian = false;
+ if (of_get_property(of_node, "big-endian", NULL))
+ big_endian = true;
+#endif
+
+ return big_endian;
+}
+
static int display_get_width_of(struct drm_device *dev, struct device_node *of_node)
{
u32 width;
@@ -613,6 +653,7 @@ static void ofdrm_device_set_gamma_linear(struct ofdrm_device *odev,
switch (format->format) {
case DRM_FORMAT_RGB565:
+ case DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN:
/* Use better interpolation, to take 32 values from 0 to 255 */
for (i = 0; i < OFDRM_GAMMA_LUT_SIZE / 8; i++) {
unsigned char r = i * 8 + i / 4;
@@ -631,6 +672,7 @@ static void ofdrm_device_set_gamma_linear(struct ofdrm_device *odev,
}
break;
case DRM_FORMAT_XRGB8888:
+ case DRM_FORMAT_BGRX8888:
for (i = 0; i < OFDRM_GAMMA_LUT_SIZE; i++)
odev->funcs->cmap_write(odev, i, i, i, i);
break;
@@ -650,6 +692,7 @@ static void ofdrm_device_set_gamma(struct ofdrm_device *odev,
switch (format->format) {
case DRM_FORMAT_RGB565:
+ case DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN:
/* Use better interpolation, to take 32 values from lut[0] to lut[255] */
for (i = 0; i < OFDRM_GAMMA_LUT_SIZE / 8; i++) {
unsigned char r = lut[i * 8 + i / 4].red >> 8;
@@ -668,6 +711,7 @@ static void ofdrm_device_set_gamma(struct ofdrm_device *odev,
}
break;
case DRM_FORMAT_XRGB8888:
+ case DRM_FORMAT_BGRX8888:
for (i = 0; i < OFDRM_GAMMA_LUT_SIZE; i++) {
unsigned char r = lut[i].red >> 8;
unsigned char g = lut[i].green >> 8;
@@ -718,6 +762,9 @@ static const uint32_t ofdrm_primary_plane_formats[] = {
DRM_FORMAT_RGB565,
//DRM_FORMAT_XRGB1555,
//DRM_FORMAT_C8,
+ /* Big-endian formats below */
+ DRM_FORMAT_BGRX8888,
+ DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN,
};
static const uint64_t ofdrm_primary_plane_format_modifiers[] = {
@@ -1051,6 +1098,7 @@ static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
struct ofdrm_device *odev;
struct drm_device *dev;
enum ofdrm_model model;
+ bool big_endian;
int width, height, depth, linebytes;
const struct drm_format_info *format;
u64 address;
@@ -1112,6 +1160,8 @@ static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
break;
}
+ big_endian = display_get_big_endian_of(dev, of_node);
+
width = display_get_width_of(dev, of_node);
if (width < 0)
return ERR_PTR(width);
@@ -1125,7 +1175,7 @@ static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
if (linebytes < 0)
return ERR_PTR(linebytes);
- format = display_get_validated_format(dev, depth);
+ format = display_get_validated_format(dev, depth, big_endian);
if (IS_ERR(format))
return ERR_CAST(format);
if (!linebytes) {
@@ -1237,6 +1287,7 @@ static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
dev->mode_config.preferred_depth = depth;
break;
}
+ dev->mode_config.quirk_addfb_prefer_host_byte_order = true;
/* Primary plane */
--
2.37.3
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