OMAPDSS: MANAGER: Create a function to check manager timings

Create a function dss_mgr_check_timings() which wraps around the function
dispc_mgr_timings_ok(). This is mainly a clean up to hide dispc functions
from interface drivers.

dss_mgr_check_timings() is added in the function dss_mgr_check(), it currently
takes the timings maintained in the omap_dss_device struct. This would be later
replaced by the timings stored in the manager's private data.

Make dss_mgr_check_timings() and dispc_mgr_timings_ok() take a const
omap_video_timings pointer since these functions just check the timings.

Signed-off-by: Archit Taneja <archit@ti.com>
diff --git a/drivers/video/omap2/dss/manager.c b/drivers/video/omap2/dss/manager.c
index e736460..566fbba 100644
--- a/drivers/video/omap2/dss/manager.c
+++ b/drivers/video/omap2/dss/manager.c
@@ -654,6 +654,17 @@
 	return 0;
 }
 
+int dss_mgr_check_timings(struct omap_overlay_manager *mgr,
+		const struct omap_video_timings *timings)
+{
+	if (!dispc_mgr_timings_ok(mgr->id, timings)) {
+		DSSERR("check_manager: invalid timings\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 int dss_mgr_check(struct omap_overlay_manager *mgr,
 		struct omap_dss_device *dssdev,
 		struct omap_overlay_manager_info *info,
@@ -668,6 +679,10 @@
 			return r;
 	}
 
+	r = dss_mgr_check_timings(mgr, &dssdev->panel.timings);
+	if (r)
+		return r;
+
 	list_for_each_entry(ovl, &mgr->overlays, list) {
 		struct omap_overlay_info *oi;
 		int r;