drm/exynos: add TE handler to support LCD I80 interface

To support LCD I80 interface, the panel should generate
Tearing Effect synchronization signal between MCU and FB
to display video images.
And the display controller should trigger to transfer
video image at this signal.
So the panel receives the TE IRQ, then calls these handler
chains to notify it to the display controller.

Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.h b/drivers/gpu/drm/exynos/exynos_drm_crtc.h
index 9f74b10..690dcdd 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_crtc.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.h
@@ -36,4 +36,11 @@
 int exynos_drm_crtc_get_pipe_from_type(struct drm_device *drm_dev,
 					unsigned int out_type);
 
+/*
+ * This function calls the crtc device(manager)'s te_handler() callback
+ * to trigger to transfer video image at the tearing effect synchronization
+ * signal.
+ */
+void exynos_drm_crtc_te_handler(struct drm_crtc *crtc);
+
 #endif