diff options
Diffstat (limited to 'drivers/gpu/drm/drm_fourcc.c')
| -rw-r--r-- | drivers/gpu/drm/drm_fourcc.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index c81546c15c93..29c56b4331e0 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -36,6 +36,49 @@ static char printable_char(int c) } /** + * drm_mode_legacy_fb_format - compute drm fourcc code from legacy description + * @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(uint32_t bpp, uint32_t depth) +{ + uint32_t fmt; + + switch (bpp) { + case 8: + fmt = DRM_FORMAT_C8; + break; + case 16: + if (depth == 15) + fmt = DRM_FORMAT_XRGB1555; + else + fmt = DRM_FORMAT_RGB565; + break; + case 24: + fmt = DRM_FORMAT_RGB888; + break; + case 32: + if (depth == 24) + fmt = DRM_FORMAT_XRGB8888; + else if (depth == 30) + fmt = DRM_FORMAT_XRGB2101010; + else + fmt = DRM_FORMAT_ARGB8888; + break; + default: + DRM_ERROR("bad bpp, assuming x8r8g8b8 pixel format\n"); + fmt = DRM_FORMAT_XRGB8888; + break; + } + + return fmt; +} +EXPORT_SYMBOL(drm_mode_legacy_fb_format); + +/** * drm_get_format_name - return a string for drm fourcc format * @format: format to compute name of * |