drm/vc4: crtc: Create vblank reporting function

We'll need that code in the HVS driver, so let's create a shared function
to reuse it.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-15-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -544,6 +544,20 @@ int vc4_crtc_disable_at_boot(struct drm_crtc *crtc)
 	return 0;
 }
 
+void vc4_crtc_send_vblank(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	unsigned long flags;
+
+	if (!crtc->state || !crtc->state->event)
+		return;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	drm_crtc_send_vblank_event(crtc, crtc->state->event);
+	crtc->state->event = NULL;
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
 static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
 				    struct drm_atomic_state *state)
 {
@@ -567,14 +581,7 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
 	 * Make sure we issue a vblank event after disabling the CRTC if
 	 * someone was waiting it.
 	 */
-	if (crtc->state->event) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&dev->event_lock, flags);
-		drm_crtc_send_vblank_event(crtc, crtc->state->event);
-		crtc->state->event = NULL;
-		spin_unlock_irqrestore(&dev->event_lock, flags);
-	}
+	vc4_crtc_send_vblank(crtc);
 }
 
 static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,

drivers/gpu/drm/vc4/vc4_drv.h

@@ -862,6 +862,7 @@ void vc4_crtc_destroy_state(struct drm_crtc *crtc,
 			    struct drm_crtc_state *state);
 void vc4_crtc_reset(struct drm_crtc *crtc);
 void vc4_crtc_handle_vblank(struct vc4_crtc *crtc);
+void vc4_crtc_send_vblank(struct drm_crtc *crtc);
 void vc4_crtc_get_margins(struct drm_crtc_state *state,
 			  unsigned int *left, unsigned int *right,
 			  unsigned int *top, unsigned int *bottom);