drm/irq: Add drm_crtc_vblank_count_and_time()

This function is the KMS native variant of drm_vblank_count_and_time().
It takes a struct drm_crtc * instead of a struct drm_device * and an
index of the CRTC.

Eventually the goal is to access vblank data through the CRTC only so
that the per-CRTC data can be moved to struct drm_crtc.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_irq.c

@@ -917,6 +917,8 @@ EXPORT_SYMBOL(drm_crtc_vblank_count);
  * vblank events since the system was booted, including lost events due to
  * modesetting activity. Returns corresponding system timestamp of the time
  * of the vblank interval that corresponds to the current vblank counter value.
+ *
+ * This is the legacy version of drm_crtc_vblank_count_and_time().
  */
 u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
 			      struct timeval *vblanktime)
@@ -944,6 +946,27 @@ u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
 }
 EXPORT_SYMBOL(drm_vblank_count_and_time);
 
+/**
+ * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
+ *     and the system timestamp corresponding to that vblank counter value
+ * @crtc: which counter to retrieve
+ * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
+ *
+ * Fetches the "cooked" vblank count value that represents the number of
+ * vblank events since the system was booted, including lost events due to
+ * modesetting activity. Returns corresponding system timestamp of the time
+ * of the vblank interval that corresponds to the current vblank counter value.
+ *
+ * This is the native KMS version of drm_vblank_count_and_time().
+ */
+u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
+				   struct timeval *vblanktime)
+{
+	return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
+					 vblanktime);
+}
+EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
+
 static void send_vblank_event(struct drm_device *dev,
 		struct drm_pending_vblank_event *e,
 		unsigned long seq, struct timeval *now)

include/drm/drmP.h

@@ -932,6 +932,8 @@ extern u32 drm_vblank_count(struct drm_device *dev, int pipe);
 extern u32 drm_crtc_vblank_count(struct drm_crtc *crtc);
 extern u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
 				     struct timeval *vblanktime);
+extern u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
+					  struct timeval *vblanktime);
 extern void drm_send_vblank_event(struct drm_device *dev, unsigned int pipe,
 				  struct drm_pending_vblank_event *e);
 extern void drm_crtc_send_vblank_event(struct drm_crtc *crtc,