drm: add clone mode check for CRTC

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>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241216-concurrent-wb-v4-1-fe220297a7f0@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 3488ff0..4665533 100644 (file)
--- 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 8b48a19..caa56e0 100644 (file)
--- 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__ */