Commit d405bc2c authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/ofdrm: Support big-endian scanout buffers 



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 endianness conversion to the format-helper
library. Also opt-in to allocated buffers in host format by default.

Suggested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-6-tzimmermann@suse.de
parent 4bbb9061

drivers/gpu/drm/drm_format_helper.c

+10 −0
Original line number Diff line number Diff line
@@ -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",

drivers/gpu/drm/tiny/ofdrm.c

+53 −2
Original line number Diff line number Diff line
@@ -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 */