drm: Add drm_format_num_planes() utility function
This function returns the number of planes used by a specific pixel
format.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Rob Clark <rob.clark@linaro.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h
index e88b7d7..37515d1 100644
--- a/include/drm/drm_crtc_helper.h
+++ b/include/drm/drm_crtc_helper.h
@@ -144,4 +144,7 @@
extern void drm_kms_helper_poll_disable(struct drm_device *dev);
extern void drm_kms_helper_poll_enable(struct drm_device *dev);
+
+extern int drm_format_num_planes(uint32_t format);
+
#endif