OMAPDSS: add manager ops

The output drivers need some operations from the overlay managers, like
enable and set_timings. These will affect the dispc registers, and need
to be synchronized with the composition-side changes with overlays and
overlay managers.

We want to handle these calls in the apply.c in the compatibility mode,
but when in non-compat mode, the calls need to be handled by some other
component (e.g. omapdrm).

To make this possible, this patch creates a set of function pointers in
a dss_mgr_ops struct, that is used to redirect the calls into the
correct destination.

The non-compat users can install their mgr ops with
dss_install_mgr_ops() function.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/output.c b/drivers/video/omap2/dss/output.c
index 1a84b79..9527ee6 100644
--- a/drivers/video/omap2/dss/output.c
+++ b/drivers/video/omap2/dss/output.c
@@ -113,3 +113,47 @@
 
 	return NULL;
 }
+
+static const struct dss_mgr_ops *dss_mgr_ops;
+
+int dss_install_mgr_ops(const struct dss_mgr_ops *mgr_ops)
+{
+	if (dss_mgr_ops)
+		return -EBUSY;
+
+	dss_mgr_ops = mgr_ops;
+
+	return 0;
+}
+
+void dss_uninstall_mgr_ops(void)
+{
+	dss_mgr_ops = NULL;
+}
+
+void dss_mgr_set_timings(struct omap_overlay_manager *mgr,
+		const struct omap_video_timings *timings)
+{
+	dss_mgr_ops->set_timings(mgr, timings);
+}
+
+void dss_mgr_set_lcd_config(struct omap_overlay_manager *mgr,
+		const struct dss_lcd_mgr_config *config)
+{
+	dss_mgr_ops->set_lcd_config(mgr, config);
+}
+
+int dss_mgr_enable(struct omap_overlay_manager *mgr)
+{
+	return dss_mgr_ops->enable(mgr);
+}
+
+void dss_mgr_disable(struct omap_overlay_manager *mgr)
+{
+	dss_mgr_ops->disable(mgr);
+}
+
+void dss_mgr_start_update(struct omap_overlay_manager *mgr)
+{
+	dss_mgr_ops->start_update(mgr);
+}