Add a common helper to check if the given CRTC state is in clone mode.
This can be used by drivers to help detect if a CRTC is being shared by
multiple encoders

Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
---

NOTE: The appropriate KUnit tests will be added in a separate series
---
 drivers/gpu/drm/drm_crtc.c | 20 ++++++++++++++++++++
 include/drm/drm_crtc.h     |  2 +-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 3488ff067c69bb820b36177c97bc9fe5d5cbfea1..46655339003db2a1b43441434839e26f61d79b4e 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -939,3 +939,23 @@ int drm_crtc_create_scaling_filter_property(struct drm_crtc *crtc,
 	return 0;
 }
 EXPORT_SYMBOL(drm_crtc_create_scaling_filter_property);
+
+/**
+ * drm_crtc_in_clone_mode - check if the given CRTC state is in clone mode
+ *
+ * @crtc_state: CRTC state to check
+ *
+ * This function determines if the given CRTC state is being cloned by multiple
+ * encoders.
+ *
+ * RETURNS:
+ * True if the CRTC state is in clone mode. False otherwise
+ */
+bool drm_crtc_in_clone_mode(struct drm_crtc_state *crtc_state)
+{
+	if (!crtc_state)
+		return false;
+
+	return hweight32(crtc_state->encoder_mask) > 1;
+}
+EXPORT_SYMBOL(drm_crtc_in_clone_mode);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 8b48a1974da3143c7de176e6fe3e01da9c8fc9d8..caa56e039da2a748cf40ebf45b37158acda439d9 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1323,5 +1323,5 @@ static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev,
 
 int drm_crtc_create_scaling_filter_property(struct drm_crtc *crtc,
 					    unsigned int supported_filters);
-
+bool drm_crtc_in_clone_mode(struct drm_crtc_state *crtc_state);
 #endif /* __DRM_CRTC_H__ */

-- 
2.34.1