Add drm_mode_legacy_fb_format variant which returns fourcc codes for framebuffer format in host byte order.
Signed-off-by: Gerd Hoffmann kraxel@redhat.com --- include/drm/drm_fourcc.h | 3 +++ drivers/gpu/drm/drm_fourcc.c | 54 +++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 56 insertions(+), 1 deletion(-)
diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h index cae05153e8..729e9d1b11 100644 --- a/include/drm/drm_fourcc.h +++ b/include/drm/drm_fourcc.h @@ -73,7 +73,10 @@ const struct drm_format_info *drm_format_info(u32 format); const struct drm_format_info * drm_get_format_info(struct drm_device *dev, const struct drm_mode_fb_cmd2 *mode_cmd); + uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth); +uint32_t drm_mode_legacy_fb_format_he(uint32_t bpp, uint32_t depth); + int drm_format_num_planes(uint32_t format); int drm_format_plane_cpp(uint32_t format, int plane); int drm_format_horz_chroma_subsampling(uint32_t format); diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index adb3ff59a4..97ff2cdf4e 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -36,12 +36,24 @@ static char printable_char(int c) }
/** - * drm_mode_legacy_fb_format - compute drm fourcc code from legacy description + * drm_mode_legacy_fb_format - compute drm fourcc code from legacy description, + * little endian. * @bpp: bits per pixels * @depth: bit depth per pixel * + * Deprecated, use drm_mode_legacy_fb_format_he instead. + * * Computes a drm fourcc pixel format code for the given @bpp/@depth values. * Useful in fbdev emulation code, since that deals in those values. + * + * Note that drm_mode_addfb (DRM_IOCTL_MODE_ADDFB implementation) uses this + * too. + * + * For historical reasons, this function returns fourcc codes for framebuffer + * formats in little endian byte order unconditinally, even though fbdev + * emulation expects the framebuffer in host byte order (i.e. big endian on + * big endian machines). Ideally we would simply fix this function, but that + * would break drivers expecting the broken behavior ... */ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth) { @@ -79,6 +91,46 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth) EXPORT_SYMBOL(drm_mode_legacy_fb_format);
/** + * drm_mode_legacy_fb_format_he - compute drm fourcc code from legacy + * description, host endian. + * @bpp: bits per pixels + * @depth: bit depth per pixel + * + * Computes a drm fourcc pixel format code for the given @bpp/@depth values. + * Useful in fbdev emulation code, since that deals in those values. + */ +uint32_t drm_mode_legacy_fb_format_he(uint32_t bpp, uint32_t depth) +{ +#ifdef __BIG_ENDIAN + uint32_t fmt; + + switch (bpp) { + case 8: + fmt = DRM_FORMAT_C8; + break; + case 24: + fmt = DRM_FORMAT_BGR888; + break; + case 32: + if (depth == 24) + fmt = DRM_FORMAT_BGRX8888; + else + fmt = DRM_FORMAT_BGRA8888; + break; + default: + DRM_ERROR("bad bpp, assuming b8g8r8x8 pixel format\n"); + fmt = DRM_FORMAT_BGRX8888; + break; + } + + return fmt; +#else + return drm_mode_legacy_fb_format(bpp, depth); +#endif +} +EXPORT_SYMBOL(drm_mode_legacy_fb_format_he); + +/** * drm_get_format_name - fill a string with a drm fourcc format's name * @format: format to compute name of * @buf: caller-supplied buffer