From: Ville Syrjälä ville.syrjala@linux.intel.com
These functions return the chroma subsampling factors for the specified pixel format.
Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_crtc_helper.c | 60 +++++++++++++++++++++++++++++++++++++ include/drm/drm_crtc_helper.h | 2 + 2 files changed, 62 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 507c3fe..00d1218 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -1057,3 +1057,63 @@ 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_helper.h b/include/drm/drm_crtc_helper.h index 13f6145..30a6610 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -147,5 +147,7 @@ extern void drm_kms_helper_poll_enable(struct drm_device *dev);
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