drm: add crtc helper drm_crtc_from_index()
It adds a crtc helper drm_crtc_from_index() to find the registered CRTC
with a given index, just like drm_plane_from_index().
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1483015290-16660-2-git-send-email-shawnguo@kernel.org
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 080c8d3..75e0bee 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -47,6 +47,26 @@
#include "drm_internal.h"
/**
+ * drm_crtc_from_index - find the registered CRTC at an index
+ * @dev: DRM device
+ * @idx: index of registered CRTC to find for
+ *
+ * Given a CRTC index, return the registered CRTC from DRM device's
+ * list of CRTCs with matching index.
+ */
+struct drm_crtc *drm_crtc_from_index(struct drm_device *dev, int idx)
+{
+ struct drm_crtc *crtc;
+
+ drm_for_each_crtc(crtc, dev)
+ if (idx == crtc->index)
+ return crtc;
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_crtc_from_index);
+
+/**
* drm_crtc_force_disable - Forcibly turn off a CRTC
* @crtc: CRTC to turn off
*