diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 2c4e9cf2a1d2..1b79c953b4cc 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -3543,3 +3543,63 @@ int drm_format_plane_cpp(uint32_t format, int plane) } } EXPORT_SYMBOL(drm_format_plane_cpp); + +/** + * drm_format_horz_chroma_subsampling - get the horizontal chroma subsampling factor + * @format: pixel format (DRM_FORMAT_*) + * + * RETURNS: + * The horizontal chroma subsampling factor for the + * specified pixel format. + */ +int drm_format_horz_chroma_subsampling(uint32_t format) +{ + switch (format) { + case DRM_FORMAT_YUV411: + case DRM_FORMAT_YVU411: + case DRM_FORMAT_YUV410: + case DRM_FORMAT_YVU410: + return 4; + case DRM_FORMAT_YUYV: + case DRM_FORMAT_YVYU: + case DRM_FORMAT_UYVY: + case DRM_FORMAT_VYUY: + case DRM_FORMAT_NV12: + case DRM_FORMAT_NV21: + case DRM_FORMAT_NV16: + case DRM_FORMAT_NV61: + case DRM_FORMAT_YUV422: + case DRM_FORMAT_YVU422: + case DRM_FORMAT_YUV420: + case DRM_FORMAT_YVU420: + return 2; + default: + return 1; + } +} +EXPORT_SYMBOL(drm_format_horz_chroma_subsampling); + +/** + * drm_format_vert_chroma_subsampling - get the vertical chroma subsampling factor + * @format: pixel format (DRM_FORMAT_*) + * + * RETURNS: + * The vertical chroma subsampling factor for the + * specified pixel format. + */ +int drm_format_vert_chroma_subsampling(uint32_t format) +{ + switch (format) { + case DRM_FORMAT_YUV410: + case DRM_FORMAT_YVU410: + return 4; + case DRM_FORMAT_YUV420: + case DRM_FORMAT_YVU420: + case DRM_FORMAT_NV12: + case DRM_FORMAT_NV21: + return 2; + default: + return 1; + } +} +EXPORT_SYMBOL(drm_format_vert_chroma_subsampling); diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 2d128eb4293f..2d63a02571ff 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -1028,5 +1028,7 @@ extern void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth, int *bpp); extern int drm_format_num_planes(uint32_t format); extern int drm_format_plane_cpp(uint32_t format, int plane); +extern int drm_format_horz_chroma_subsampling(uint32_t format); +extern int drm_format_vert_chroma_subsampling(uint32_t format); #endif /* __DRM_CRTC_H__ */