diff --git a/plat/arm/css/drivers/mhu/css_mhu_doorbell.h b/plat/arm/css/drivers/mhu/css_mhu_doorbell.h
new file mode 100644
index 0000000..3c94536
--- /dev/null
+++ b/plat/arm/css/drivers/mhu/css_mhu_doorbell.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2014-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef CSS_MHU_DOORBELL_H
+#define CSS_MHU_DOORBELL_H
+
+#include <mmio.h>
+#include <stdint.h>
+
+/* MHUv2 Base Address */
+#define MHUV2_BASE_ADDR		PLAT_CSS_MHU_BASE
+
+/* MHUv2 Control Registers Offsets */
+#define MHU_V2_MSG_NO_CAP_OFFSET		0xF80
+#define MHU_V2_ACCESS_REQ_OFFSET		0xF88
+#define MHU_V2_ACCESS_READY_OFFSET		0xF8C
+
+#define SENDER_REG_STAT(CHANNEL)	(0x20 * (CHANNEL))
+#define SENDER_REG_SET(CHANNEL)		(0x20 * (CHANNEL)) + 0xC
+
+/* Helper macro to ring doorbell */
+#define MHU_RING_DOORBELL(addr, modify_mask, preserve_mask)	do {	\
+		uint32_t db = mmio_read_32(addr) & (preserve_mask);	\
+		mmio_write_32(addr, db | (modify_mask));		\
+	} while (0)
+
+#define MHU_V2_ACCESS_REQUEST(addr)	\
+	mmio_write_32((addr) + MHU_V2_ACCESS_REQ_OFFSET, 0x1)
+
+#define MHU_V2_CLEAR_REQUEST(addr)	\
+	mmio_write_32((addr) + MHU_V2_ACCESS_REQ_OFFSET, 0x0)
+
+#define MHU_V2_IS_ACCESS_READY(addr)	\
+	(mmio_read_32((addr) + MHU_V2_ACCESS_READY_OFFSET) & 0x1)
+
+struct scmi_channel_plat_info;
+void mhu_ring_doorbell(struct scmi_channel_plat_info *plat_info);
+void mhuv2_ring_doorbell(struct scmi_channel_plat_info *plat_info);
+
+#endif	/* CSS_MHU_DOORBELL_H */