diff --git a/drivers/renesas/rcar/common.c b/drivers/renesas/rcar/common.c
new file mode 100644
index 0000000..e82e8b5
--- /dev/null
+++ b/drivers/renesas/rcar/common.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2018, Renesas Electronics Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <mmio.h>
+#include "rcar_private.h"
+
+void
+#if IMAGE_BL31
+    __attribute__ ((section(".system_ram")))
+#endif
+    cpg_write(uintptr_t regadr, uint32_t regval)
+{
+	uint32_t value = (regval);
+	mmio_write_32((uintptr_t) RCAR_CPGWPR, ~value);
+	mmio_write_32(regadr, value);
+}
+
+void
+#if IMAGE_BL31
+    __attribute__ ((section(".system_ram")))
+#endif
+    mstpcr_write(uint32_t mstpcr, uint32_t mstpsr, uint32_t target_bit)
+{
+	uint32_t reg;
+	reg = mmio_read_32(mstpcr);
+	reg &= ~target_bit;
+	cpg_write(mstpcr, reg);
+	while ((mmio_read_32(mstpsr) & target_bit) != 0U) {
+	}
+}