diff --git a/plat/socionext/synquacer/drivers/scpi/sq_scpi.c b/plat/socionext/synquacer/drivers/scpi/sq_scpi.c
new file mode 100644
index 0000000000000000000000000000000000000000..a6924e2e28e36af7772cbcd74fee60b71c6a0de8
--- /dev/null
+++ b/plat/socionext/synquacer/drivers/scpi/sq_scpi.c
@@ -0,0 +1,170 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <assert.h>
+#include <platform_def.h>
+#include <sq_common.h>
+#include <debug.h>
+#include <string.h>
+#include "sq_mhu.h"
+#include "sq_scpi.h"
+
+#define SCPI_SHARED_MEM_SCP_TO_AP	PLAT_SQ_SCP_COM_SHARED_MEM_BASE
+#define SCPI_SHARED_MEM_AP_TO_SCP	(PLAT_SQ_SCP_COM_SHARED_MEM_BASE \
+								 + 0x100)
+
+#define SCPI_CMD_HEADER_AP_TO_SCP		\
+	((scpi_cmd_t *) SCPI_SHARED_MEM_AP_TO_SCP)
+#define SCPI_CMD_PAYLOAD_AP_TO_SCP		\
+	((void *) (SCPI_SHARED_MEM_AP_TO_SCP + sizeof(scpi_cmd_t)))
+
+/* ID of the MHU slot used for the SCPI protocol */
+#define SCPI_MHU_SLOT_ID		0
+
+static void scpi_secure_message_start(void)
+{
+	mhu_secure_message_start(SCPI_MHU_SLOT_ID);
+}
+
+static void scpi_secure_message_send(size_t payload_size)
+{
+	/*
+	 * Ensure that any write to the SCPI payload area is seen by SCP before
+	 * we write to the MHU register. If these 2 writes were reordered by
+	 * the CPU then SCP would read stale payload data
+	 */
+	dmbst();
+
+	mhu_secure_message_send(SCPI_MHU_SLOT_ID);
+}
+
+static void scpi_secure_message_receive(scpi_cmd_t *cmd)
+{
+	uint32_t mhu_status;
+
+	assert(cmd != NULL);
+
+	mhu_status = mhu_secure_message_wait();
+
+	/* Expect an SCPI message, reject any other protocol */
+	if (mhu_status != (1 << SCPI_MHU_SLOT_ID)) {
+		ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
+			mhu_status);
+		panic();
+	}
+
+	/*
+	 * Ensure that any read to the SCPI payload area is done after reading
+	 * the MHU register. If these 2 reads were reordered then the CPU would
+	 * read invalid payload data
+	 */
+	dmbld();
+
+	memcpy(cmd, (void *) SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd));
+}
+
+static void scpi_secure_message_end(void)
+{
+	mhu_secure_message_end(SCPI_MHU_SLOT_ID);
+}
+
+int scpi_wait_ready(void)
+{
+	scpi_cmd_t scpi_cmd;
+	scpi_status_t status = SCP_OK;
+
+	VERBOSE("Waiting for SCP_READY command...\n");
+
+	/* Get a message from the SCP */
+	scpi_secure_message_start();
+	scpi_secure_message_receive(&scpi_cmd);
+	scpi_secure_message_end();
+
+	/* We are expecting 'SCP Ready', produce correct error if it's not */
+	if (scpi_cmd.id != SCPI_CMD_SCP_READY) {
+		ERROR("Unexpected SCP command: expected command #%u,"
+		      "got command #%u\n", SCPI_CMD_SCP_READY, scpi_cmd.id);
+		status = SCP_E_SUPPORT;
+	} else if (scpi_cmd.size != 0) {
+		ERROR("SCP_READY command has incorrect size: expected 0,"
+		      "got %u\n", scpi_cmd.size);
+		status = SCP_E_SIZE;
+	}
+
+	VERBOSE("Sending response for SCP_READY command\n");
+
+	/*
+	 * Send our response back to SCP.
+	 * We are using the same SCPI header, just update the status field.
+	 */
+	scpi_cmd.status = status;
+	scpi_secure_message_start();
+	memcpy((void *) SCPI_SHARED_MEM_AP_TO_SCP, &scpi_cmd, sizeof(scpi_cmd));
+	scpi_secure_message_send(0);
+	scpi_secure_message_end();
+
+	return status == SCP_OK ? 0 : -1;
+}
+
+void scpi_set_sq_power_state(unsigned int mpidr, scpi_power_state_t cpu_state,
+		scpi_power_state_t cluster_state, scpi_power_state_t sq_state)
+{
+	scpi_cmd_t *cmd;
+	uint32_t state = 0;
+	uint32_t *payload_addr;
+
+	state |= mpidr & 0x0f;	/* CPU ID */
+	state |= (mpidr & 0xf00) >> 4;	/* Cluster ID */
+	state |= cpu_state << 8;
+	state |= cluster_state << 12;
+	state |= sq_state << 16;
+
+	scpi_secure_message_start();
+
+	/* Populate the command header */
+	cmd = SCPI_CMD_HEADER_AP_TO_SCP;
+	cmd->id = SCPI_CMD_SET_POWER_STATE;
+	cmd->set = SCPI_SET_NORMAL;
+	cmd->sender = 0;
+	cmd->size = sizeof(state);
+	/* Populate the command payload */
+	payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
+	*payload_addr = state;
+	scpi_secure_message_send(sizeof(state));
+
+	/*
+	 * SCP does not reply to this command in order to avoid MHU interrupts
+	 * from the sender, which could interfere with its power state request.
+	 */
+	scpi_secure_message_end();
+}
+
+uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
+{
+	scpi_cmd_t *cmd;
+	uint8_t *payload_addr;
+	scpi_cmd_t response;
+
+	scpi_secure_message_start();
+
+	/* Populate the command header */
+	cmd = SCPI_CMD_HEADER_AP_TO_SCP;
+	cmd->id = SCPI_CMD_SYS_POWER_STATE;
+	cmd->set = 0;
+	cmd->sender = 0;
+	cmd->size = sizeof(*payload_addr);
+	/* Populate the command payload */
+	payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
+	*payload_addr = system_state & 0xff;
+	scpi_secure_message_send(sizeof(*payload_addr));
+
+	scpi_secure_message_receive(&response);
+
+	scpi_secure_message_end();
+
+	return response.status;
+}
diff --git a/plat/socionext/synquacer/drivers/scpi/sq_scpi.h b/plat/socionext/synquacer/drivers/scpi/sq_scpi.h
new file mode 100644
index 0000000000000000000000000000000000000000..30fa5c72d44e77f9cdb188a892e3d83afb87339f
--- /dev/null
+++ b/plat/socionext/synquacer/drivers/scpi/sq_scpi.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __SQ_SCPI_H__
+#define __SQ_SCPI_H__
+
+#include <stddef.h>
+#include <stdint.h>
+
+/*
+ * An SCPI command consists of a header and a payload.
+ * The following structure describes the header. It is 64-bit long.
+ */
+typedef struct {
+	/* Command ID */
+	uint32_t id		: 7;
+	/* Set ID. Identifies whether this is a standard or extended command. */
+	uint32_t set		: 1;
+	/* Sender ID to match a reply. The value is sender specific. */
+	uint32_t sender		: 8;
+	/* Size of the payload in bytes (0 - 511) */
+	uint32_t size		: 9;
+	uint32_t reserved	: 7;
+	/*
+	 * Status indicating the success of a command.
+	 * See the enum below.
+	 */
+	uint32_t status;
+} scpi_cmd_t;
+
+typedef enum {
+	SCPI_SET_NORMAL = 0,	/* Normal SCPI commands */
+	SCPI_SET_EXTENDED	/* Extended SCPI commands */
+} scpi_set_t;
+
+enum {
+	SCP_OK = 0,	/* Success */
+	SCP_E_PARAM,	/* Invalid parameter(s) */
+	SCP_E_ALIGN,	/* Invalid alignment */
+	SCP_E_SIZE,	/* Invalid size */
+	SCP_E_HANDLER,	/* Invalid handler or callback */
+	SCP_E_ACCESS,	/* Invalid access or permission denied */
+	SCP_E_RANGE,	/* Value out of range */
+	SCP_E_TIMEOUT,	/* Time out has ocurred */
+	SCP_E_NOMEM,	/* Invalid memory area or pointer */
+	SCP_E_PWRSTATE,	/* Invalid power state */
+	SCP_E_SUPPORT,	/* Feature not supported or disabled */
+	SCPI_E_DEVICE,	/* Device error */
+	SCPI_E_BUSY,	/* Device is busy */
+};
+
+typedef uint32_t scpi_status_t;
+
+typedef enum {
+	SCPI_CMD_SCP_READY = 0x01,
+	SCPI_CMD_SET_POWER_STATE = 0x03,
+	SCPI_CMD_SYS_POWER_STATE = 0x05
+} scpi_command_t;
+
+typedef enum {
+	scpi_power_on = 0,
+	scpi_power_retention = 1,
+	scpi_power_off = 3,
+} scpi_power_state_t;
+
+typedef enum {
+	scpi_system_shutdown = 0,
+	scpi_system_reboot = 1,
+	scpi_system_reset = 2
+} scpi_system_state_t;
+
+extern int scpi_wait_ready(void);
+extern void scpi_set_sq_power_state(unsigned int mpidr,
+					scpi_power_state_t cpu_state,
+					scpi_power_state_t cluster_state,
+					scpi_power_state_t css_state);
+uint32_t scpi_sys_power_state(scpi_system_state_t system_state);
+
+#endif	/* __SQ_SCPI_H__ */
diff --git a/plat/socionext/synquacer/include/platform_def.h b/plat/socionext/synquacer/include/platform_def.h
index 07db2b6de016b07a46d245b11bc319aec9af3cbd..f9bc4022ca301d8c9f11c946e7e38a72b15badd1 100644
--- a/plat/socionext/synquacer/include/platform_def.h
+++ b/plat/socionext/synquacer/include/platform_def.h
@@ -56,6 +56,9 @@
 
 #define PLAT_SQ_MHU_BASE		0x45000000
 
+#define PLAT_SQ_SCP_COM_SHARED_MEM_BASE		0x45400000
+#define SCPI_CMD_GET_DRAMINFO			0x1
+
 #define SQ_BOOT_CFG_ADDR			0x45410000
 #define PLAT_SQ_PRIMARY_CPU_SHIFT		8
 #define PLAT_SQ_PRIMARY_CPU_BIT_WIDTH		6