soc / drm: mediatek: Move routing control to mmsys device

Provide a mtk_mmsys_ddp_connect() and mtk_mmsys_disconnect() functions to
replace mtk_ddp_add_comp_to_path() and mtk_ddp_remove_comp_from_path().
Those functions will allow DRM driver and others to control the data
path routing.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Acked-by: CK Hu <ck.hu@mediatek.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

include/linux/soc/mediatek/mtk-mmsys.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ */
+
+#ifndef __MTK_MMSYS_H
+#define __MTK_MMSYS_H
+
+enum mtk_ddp_comp_id;
+struct device;
+
+void mtk_mmsys_ddp_connect(struct device *dev,
+			   enum mtk_ddp_comp_id cur,
+			   enum mtk_ddp_comp_id next);
+
+void mtk_mmsys_ddp_disconnect(struct device *dev,
+			      enum mtk_ddp_comp_id cur,
+			      enum mtk_ddp_comp_id next);
+
+#endif /* __MTK_MMSYS_H */