diff --git a/plat/mediatek/mt8183/bl31_plat_setup.c b/plat/mediatek/mt8183/bl31_plat_setup.c
index fd3a5b0..ec387f4 100644
--- a/plat/mediatek/mt8183/bl31_plat_setup.c
+++ b/plat/mediatek/mt8183/bl31_plat_setup.c
@@ -16,6 +16,7 @@
 #include <mt_gic_v3.h>
 #include <lib/coreboot.h>
 #include <lib/mmio.h>
+#include <mtk_mcdi.h>
 #include <mtk_plat_common.h>
 #include <mtspmc.h>
 #include <plat_debug.h>
@@ -148,6 +149,7 @@
 	spmc_init();
 #endif
 	spm_boot_init();
+	mcdi_init();
 }
 
 /*******************************************************************************
diff --git a/plat/mediatek/mt8183/drivers/mcdi/mtk_mcdi.c b/plat/mediatek/mt8183/drivers/mcdi/mtk_mcdi.c
new file mode 100644
index 0000000..29eebcb
--- /dev/null
+++ b/plat/mediatek/mt8183/drivers/mcdi/mtk_mcdi.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <lib/mmio.h>
+#include <sspm_reg.h>
+#include <mtk_mcdi.h>
+
+static inline uint32_t mcdi_mbox_read(uint32_t id)
+{
+	return mmio_read_32(SSPM_MBOX_3_BASE + (id << 2));
+}
+
+static inline void mcdi_mbox_write(uint32_t id, uint32_t val)
+{
+	mmio_write_32(SSPM_MBOX_3_BASE + (id << 2), val);
+}
+
+void sspm_set_bootaddr(uint32_t bootaddr)
+{
+	mcdi_mbox_write(MCDI_MBOX_BOOTADDR, bootaddr);
+}
+
+void sspm_cluster_pwr_off_notify(uint32_t cluster)
+{
+	mcdi_mbox_write(MCDI_MBOX_CLUSTER_0_ATF_ACTION_DONE + cluster, 1);
+}
+
+void sspm_cluster_pwr_on_notify(uint32_t cluster)
+{
+	mcdi_mbox_write(MCDI_MBOX_CLUSTER_0_ATF_ACTION_DONE + cluster, 0);
+}
+
+void sspm_standbywfi_irq_enable(uint32_t cpu_idx)
+{
+	mmio_write_32(SSPM_CFGREG_ACAO_INT_SET, STANDBYWFI_EN(cpu_idx));
+}
+
+uint32_t mcdi_avail_cpu_mask_read(void)
+{
+	return mcdi_mbox_read(MCDI_MBOX_AVAIL_CPU_MASK);
+}
+
+uint32_t mcdi_avail_cpu_mask_write(uint32_t mask)
+{
+	mcdi_mbox_write(MCDI_MBOX_AVAIL_CPU_MASK, mask);
+
+	return mask;
+}
+
+uint32_t mcdi_avail_cpu_mask_set(uint32_t mask)
+{
+	uint32_t m;
+
+	m = mcdi_mbox_read(MCDI_MBOX_AVAIL_CPU_MASK);
+	m |= mask;
+	mcdi_mbox_write(MCDI_MBOX_AVAIL_CPU_MASK, m);
+
+	return m;
+}
+
+uint32_t mcdi_avail_cpu_mask_clr(uint32_t mask)
+{
+	uint32_t m;
+
+	m = mcdi_mbox_read(MCDI_MBOX_AVAIL_CPU_MASK);
+	m &= ~mask;
+	mcdi_mbox_write(MCDI_MBOX_AVAIL_CPU_MASK, m);
+
+	return m;
+}
+
+uint32_t mcdi_cpu_cluster_pwr_stat_read(void)
+{
+	return mcdi_mbox_read(MCDI_MBOX_CPU_CLUSTER_PWR_STAT);
+}
+
+#define PAUSE_BIT		1
+#define CLUSTER_OFF_OFS		20
+#define CPU_OFF_OFS		24
+#define CLUSTER_ON_OFS		4
+#define CPU_ON_OFS		8
+
+static uint32_t target_mask(int cluster, int cpu_idx, bool on)
+{
+	uint32_t t = 0;
+
+	if (on) {
+		if (cluster >= 0)
+			t |= BIT(cluster + CLUSTER_ON_OFS);
+
+		if (cpu_idx >= 0)
+			t |= BIT(cpu_idx + CPU_ON_OFS);
+	} else {
+		if (cluster >= 0)
+			t |= BIT(cluster + CLUSTER_OFF_OFS);
+
+		if (cpu_idx >= 0)
+			t |= BIT(cpu_idx + CPU_OFF_OFS);
+	}
+
+	return t;
+}
+
+void mcdi_pause_clr(int cluster, int cpu_idx, bool on)
+{
+	uint32_t tgt = target_mask(cluster, cpu_idx, on);
+	uint32_t m = mcdi_mbox_read(MCDI_MBOX_PAUSE_ACTION);
+
+	m &= ~tgt;
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+}
+
+void mcdi_pause_set(int cluster, int cpu_idx, bool on)
+{
+	uint32_t tgt = target_mask(cluster, cpu_idx, on);
+	uint32_t m = mcdi_mbox_read(MCDI_MBOX_PAUSE_ACTION);
+	uint32_t tgtn = target_mask(-1, cpu_idx, !on);
+
+	/* request on and off at the same time to ensure it can be paused */
+	m |= tgt | tgtn;
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+
+	/* wait pause_ack */
+	while (!mcdi_mbox_read(MCDI_MBOX_PAUSE_ACK))
+		;
+
+	/* clear non-requested operation */
+	m &= ~tgtn;
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+}
+
+void mcdi_pause(void)
+{
+	uint32_t m = mcdi_mbox_read(MCDI_MBOX_PAUSE_ACTION) | BIT(PAUSE_BIT);
+
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+
+	/* wait pause_ack */
+	while (!mcdi_mbox_read(MCDI_MBOX_PAUSE_ACK))
+		;
+}
+
+void mcdi_unpause(void)
+{
+	uint32_t m = mcdi_mbox_read(MCDI_MBOX_PAUSE_ACTION) & ~BIT(PAUSE_BIT);
+
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+}
+
+void mcdi_hotplug_wait_ack(int cluster, int cpu_idx, bool on)
+{
+	uint32_t tgt = target_mask(cluster, cpu_idx, on);
+	uint32_t ack = mcdi_mbox_read(MCDI_MBOX_HP_ACK);
+
+	/* wait until ack */
+	while (!(ack & tgt))
+		ack = mcdi_mbox_read(MCDI_MBOX_HP_ACK);
+}
+
+void mcdi_hotplug_clr(int cluster, int cpu_idx, bool on)
+{
+	uint32_t tgt = target_mask(cluster, cpu_idx, on);
+	uint32_t tgt_cpu = target_mask(-1, cpu_idx, on);
+	uint32_t cmd = mcdi_mbox_read(MCDI_MBOX_HP_CMD);
+	uint32_t ack = mcdi_mbox_read(MCDI_MBOX_HP_ACK);
+
+	if (!(cmd & tgt))
+		return;
+
+	/* wait until ack */
+	while (!(ack & tgt_cpu))
+		ack = mcdi_mbox_read(MCDI_MBOX_HP_ACK);
+
+	cmd &= ~tgt;
+	mcdi_mbox_write(MCDI_MBOX_HP_CMD, cmd);
+}
+
+void mcdi_hotplug_set(int cluster, int cpu_idx, bool on)
+{
+	uint32_t tgt = target_mask(cluster, cpu_idx, on);
+	uint32_t tgt_cpu = target_mask(-1, cpu_idx, on);
+	uint32_t cmd = mcdi_mbox_read(MCDI_MBOX_HP_CMD);
+	uint32_t ack = mcdi_mbox_read(MCDI_MBOX_HP_ACK);
+
+	if ((cmd & tgt) == tgt)
+		return;
+
+	/* wait until ack clear */
+	while (ack & tgt_cpu)
+		ack = mcdi_mbox_read(MCDI_MBOX_HP_ACK);
+
+	cmd |= tgt;
+	mcdi_mbox_write(MCDI_MBOX_HP_CMD, cmd);
+}
+
+bool check_mcdi_ctl_stat(void)
+{
+	uint32_t clk_regs[] = {0x100010ac, 0x100010c8};
+	uint32_t clk_mask[] = {0x00028000, 0x00000018};
+	uint32_t tgt = target_mask(0, 0, true);
+	uint32_t m;
+	int i;
+
+	/* check clk status */
+	for (i = 0; i < ARRAY_SIZE(clk_regs); i++) {
+		if (mmio_read_32(clk_regs[i]) & clk_mask[i]) {
+			WARN("mcdi: clk check fail.\n");
+			return false;
+		}
+	}
+
+	/* check mcdi cmd handling */
+	m = mcdi_mbox_read(MCDI_MBOX_PAUSE_ACTION) | BIT(PAUSE_BIT);
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+
+	i = 500;
+	while (!mcdi_mbox_read(MCDI_MBOX_PAUSE_ACK) && --i > 0)
+		udelay(10);
+
+	m = mcdi_mbox_read(MCDI_MBOX_PAUSE_ACTION) & ~BIT(PAUSE_BIT);
+	mcdi_mbox_write(MCDI_MBOX_PAUSE_ACTION, m);
+
+	if (i == 0) {
+		WARN("mcdi: pause_action fail.\n");
+		return false;
+	}
+
+	/* check mcdi cmd handling */
+	if (mcdi_mbox_read(MCDI_MBOX_HP_CMD) ||
+			mcdi_mbox_read(MCDI_MBOX_HP_ACK)) {
+		WARN("mcdi: hp_cmd fail.\n");
+		return false;
+	}
+
+	mcdi_mbox_write(MCDI_MBOX_HP_CMD, tgt);
+
+	i = 500;
+	while ((mcdi_mbox_read(MCDI_MBOX_HP_ACK) & tgt) != tgt && --i > 0)
+		udelay(10);
+
+	mcdi_mbox_write(MCDI_MBOX_HP_CMD, 0);
+
+	if (i == 0) {
+		WARN("mcdi: hp_ack fail.\n");
+		return false;
+	}
+
+	return true;
+}
+
+void mcdi_init(void)
+{
+	mcdi_avail_cpu_mask_write(0x01); /* cpu0 default on */
+}
diff --git a/plat/mediatek/mt8183/drivers/mcdi/mtk_mcdi.h b/plat/mediatek/mt8183/drivers/mcdi/mtk_mcdi.h
new file mode 100644
index 0000000..9a40df1
--- /dev/null
+++ b/plat/mediatek/mt8183/drivers/mcdi/mtk_mcdi.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __MTK_MCDI_H__
+#define __MTK_MCDI_H__
+
+#include <stdbool.h>
+
+void sspm_set_bootaddr(uint32_t bootaddr);
+void sspm_standbywfi_irq_enable(uint32_t cpu_idx);
+void sspm_cluster_pwr_off_notify(uint32_t cluster);
+void sspm_cluster_pwr_on_notify(uint32_t cluster);
+
+uint32_t mcdi_avail_cpu_mask_read(void);
+uint32_t mcdi_avail_cpu_mask_write(uint32_t mask);
+uint32_t mcdi_avail_cpu_mask_set(uint32_t mask);
+uint32_t mcdi_avail_cpu_mask_clr(uint32_t mask);
+uint32_t mcdi_cpu_cluster_pwr_stat_read(void);
+
+void mcdi_pause(void);
+void mcdi_unpause(void);
+void mcdi_pause_set(int cluster, int cpu_idx, bool on);
+void mcdi_pause_clr(int cluster, int cpu_idx, bool on);
+void mcdi_hotplug_set(int cluster, int cpu_idx, bool on);
+void mcdi_hotplug_clr(int cluster, int cpu_idx, bool on);
+void mcdi_hotplug_wait_ack(int cluster, int cpu_idx, bool on);
+
+bool check_mcdi_ctl_stat(void);
+void mcdi_init(void);
+
+#endif /* __MTK_MCDI_H__ */
diff --git a/plat/mediatek/mt8183/include/sspm_reg.h b/plat/mediatek/mt8183/include/sspm_reg.h
new file mode 100644
index 0000000..3f1ac86
--- /dev/null
+++ b/plat/mediatek/mt8183/include/sspm_reg.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __SSPM_REG_H__
+#define __SSPM_REG_H__
+
+#include "platform_def.h"
+
+#define SSPM_CFGREG_RSV_RW_REG0        (SSPM_CFGREG_BASE + 0x0100)
+#define SSPM_CFGREG_ACAO_INT_SET       (SSPM_CFGREG_BASE + 0x00D8)
+#define SSPM_CFGREG_ACAO_INT_CLR       (SSPM_CFGREG_BASE + 0x00DC)
+#define SSPM_CFGREG_ACAO_WAKEUP_EN     (SSPM_CFGREG_BASE + 0x0204)
+
+#define STANDBYWFI_EN(n)               (1 << (n +  8))
+#define GIC_IRQOUT_EN(n)               (1 << (n +  0))
+
+#define NF_MCDI_MBOX                            19
+#define MCDI_MBOX_CLUSTER_0_CAN_POWER_OFF       0
+#define MCDI_MBOX_CLUSTER_1_CAN_POWER_OFF       1
+#define MCDI_MBOX_BUCK_POWER_OFF_MASK           2
+#define MCDI_MBOX_CLUSTER_0_ATF_ACTION_DONE     3
+#define MCDI_MBOX_CLUSTER_1_ATF_ACTION_DONE     4
+#define MCDI_MBOX_BOOTADDR                      5
+#define MCDI_MBOX_PAUSE_ACTION                  6
+#define MCDI_MBOX_AVAIL_CPU_MASK                7
+#define MCDI_MBOX_CPU_CLUSTER_PWR_STAT          8
+#define MCDI_MBOX_ACTION_STAT                   9
+#define MCDI_MBOX_CLUSTER_0_CNT                 10
+#define MCDI_MBOX_CLUSTER_1_CNT                 11
+#define MCDI_MBOX_CPU_ISOLATION_MASK            12
+#define MCDI_MBOX_PAUSE_ACK                     13
+#define MCDI_MBOX_PENDING_ON_EVENT              14
+#define MCDI_MBOX_PROF_CMD                      15
+#define MCDI_MBOX_DRCC_CALI_DONE                16
+#define MCDI_MBOX_HP_CMD                        17
+#define MCDI_MBOX_HP_ACK                        18
+
+#endif /* __SSPM_REG_H__ */
diff --git a/plat/mediatek/mt8183/plat_pm.c b/plat/mediatek/mt8183/plat_pm.c
index 9e0a920..555b389 100644
--- a/plat/mediatek/mt8183/plat_pm.c
+++ b/plat/mediatek/mt8183/plat_pm.c
@@ -16,6 +16,7 @@
 #include <platform_def.h>
 #include <scu.h>
 #include <mt_gic_v3.h>
+#include <mtk_mcdi.h>
 #include <mtk_plat_common.h>
 #include <mtgpio.h>
 #include <mtspmc.h>
@@ -27,9 +28,101 @@
 #include <pmic.h>
 #include <spm.h>
 #include <spm_suspend.h>
+#include <sspm.h>
 #include <rtc.h>
 
-#define MTK_LOCAL_STATE_OFF     2
+/* Local power state for power domains in Run state. */
+#define MTK_LOCAL_STATE_RUN	0
+/* Local power state for retention. */
+#define MTK_LOCAL_STATE_RET	1
+/* Local power state for OFF/power-down. */
+#define MTK_LOCAL_STATE_OFF	2
+
+#if PSCI_EXTENDED_STATE_ID
+/*
+ * Macros used to parse state information from State-ID if it is using the
+ * recommended encoding for State-ID.
+ */
+#define MTK_LOCAL_PSTATE_WIDTH		4
+#define MTK_LOCAL_PSTATE_MASK		((1 << MTK_LOCAL_PSTATE_WIDTH) - 1)
+
+/* Macros to construct the composite power state */
+
+/* Make composite power state parameter till power level 0 */
+
+#define mtk_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
+	(((lvl0_state) << PSTATE_ID_SHIFT) | ((type) << PSTATE_TYPE_SHIFT))
+
+#else /* !PSCI_EXTENDED_STATE_ID */
+
+#define mtk_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
+		(((lvl0_state) << PSTATE_ID_SHIFT) | \
+		((pwr_lvl) << PSTATE_PWR_LVL_SHIFT) | \
+		((type) << PSTATE_TYPE_SHIFT))
+
+#endif /* PSCI_EXTENDED_STATE_ID */
+
+/* Make composite power state parameter till power level 1 */
+#define mtk_make_pwrstate_lvl1(lvl1_state, lvl0_state, pwr_lvl, type) \
+		(((lvl1_state) << MTK_LOCAL_PSTATE_WIDTH) | \
+		mtk_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type))
+
+/* Make composite power state parameter till power level 2 */
+#define mtk_make_pwrstate_lvl2( \
+		lvl2_state, lvl1_state, lvl0_state, pwr_lvl, type) \
+		(((lvl2_state) << (MTK_LOCAL_PSTATE_WIDTH * 2)) | \
+		mtk_make_pwrstate_lvl1(lvl1_state, lvl0_state, pwr_lvl, type))
+
+#define MTK_PWR_LVL0	0
+#define MTK_PWR_LVL1	1
+#define MTK_PWR_LVL2	2
+
+/* Macros to read the MTK power domain state */
+#define MTK_CORE_PWR_STATE(state)	(state)->pwr_domain_state[MTK_PWR_LVL0]
+#define MTK_CLUSTER_PWR_STATE(state)	(state)->pwr_domain_state[MTK_PWR_LVL1]
+#define MTK_SYSTEM_PWR_STATE(state)	((PLAT_MAX_PWR_LVL > MTK_PWR_LVL1) ? \
+			(state)->pwr_domain_state[MTK_PWR_LVL2] : 0)
+
+#if PSCI_EXTENDED_STATE_ID
+/*
+ *  The table storing the valid idle power states. Ensure that the
+ *  array entries are populated in ascending order of state-id to
+ *  enable us to use binary search during power state validation.
+ *  The table must be terminated by a NULL entry.
+ */
+const unsigned int mtk_pm_idle_states[] = {
+	/* State-id - 0x001 */
+	mtk_make_pwrstate_lvl2(MTK_LOCAL_STATE_RUN, MTK_LOCAL_STATE_RUN,
+		MTK_LOCAL_STATE_RET, MTK_PWR_LVL0, PSTATE_TYPE_STANDBY),
+	/* State-id - 0x002 */
+	mtk_make_pwrstate_lvl2(MTK_LOCAL_STATE_RUN, MTK_LOCAL_STATE_RUN,
+		MTK_LOCAL_STATE_OFF, MTK_PWR_LVL0, PSTATE_TYPE_POWERDOWN),
+	/* State-id - 0x022 */
+	mtk_make_pwrstate_lvl2(MTK_LOCAL_STATE_RUN, MTK_LOCAL_STATE_OFF,
+		MTK_LOCAL_STATE_OFF, MTK_PWR_LVL1, PSTATE_TYPE_POWERDOWN),
+#if PLAT_MAX_PWR_LVL > MTK_PWR_LVL1
+	/* State-id - 0x222 */
+	mtk_make_pwrstate_lvl2(MTK_LOCAL_STATE_OFF, MTK_LOCAL_STATE_OFF,
+		MTK_LOCAL_STATE_OFF, MTK_PWR_LVL2, PSTATE_TYPE_POWERDOWN),
+#endif
+	0,
+};
+#endif
+
+#define CPU_IDX(cluster, cpu)		((cluster << 2) + cpu)
+#define ON	true
+#define OFF	false
+
+/* Pause MCDI when CPU hotplug */
+static bool HP_SSPM_PAUSE;
+/* CPU Hotplug by SSPM */
+static bool HP_SSPM_CTRL = true;
+/* Turn off cluster when CPU hotplug off */
+static bool HP_CLUSTER_OFF = true;
+/* Turn off cluster when CPU MCDI off */
+static bool MCDI_C2 = true;
+/* Enable MCDI */
+static bool MCDI_SSPM = true;
 
 static uintptr_t secure_entrypoint;
 
@@ -40,30 +133,171 @@
 	dsb();
 }
 
+static bool clst_single_pwr(int cluster, int cpu)
+{
+	uint32_t cpu_mask[2] = {0x00001e00, 0x000f0000};
+	uint32_t cpu_pwr_bit[] = {9, 10, 11, 12, 16, 17, 18, 19};
+	int my_idx = (cluster << 2) + cpu;
+	uint32_t pwr_stat = mmio_read_32(0x10006180);
+
+	return !(pwr_stat & (cpu_mask[cluster] & ~BIT(cpu_pwr_bit[my_idx])));
+}
+
+static bool clst_single_on(int cluster, int cpu)
+{
+	uint32_t cpu_mask[2] = {0x0f, 0xf0};
+	int my_idx = (cluster << 2) + cpu;
+	uint32_t on_stat = mcdi_avail_cpu_mask_read();
+
+	return !(on_stat & (cpu_mask[cluster] & ~BIT(my_idx)));
+}
+
+static void plat_cluster_pwrdwn_common(uint64_t mpidr, int cluster)
+{
+	if (cluster > 0)
+		mt_gic_sync_dcm_enable();
+
+	/* Disable coherency */
+	plat_mtk_cci_disable();
+	disable_scu(mpidr);
+}
+
+static void plat_cluster_pwron_common(uint64_t mpidr, int cluster)
+{
+	if (cluster > 0) {
+		l2c_parity_check_setup();
+		circular_buffer_setup();
+		mp1_L2_desel_config();
+		mt_gic_sync_dcm_disable();
+	}
+
+	/* Enable coherency */
+	enable_scu(mpidr);
+	plat_mtk_cci_enable();
+	/* Enable big core dcm */
+	plat_dcm_restore_cluster_on(mpidr);
+	/* Enable rgu dcm */
+	plat_dcm_rgu_enable();
+}
+
+static void plat_cpu_standby(plat_local_state_t cpu_state)
+{
+	unsigned int scr;
+
+	scr = read_scr_el3();
+	write_scr_el3(scr | SCR_IRQ_BIT | SCR_FIQ_BIT);
+
+	isb();
+	dsb();
+	wfi();
+
+	write_scr_el3(scr);
+}
+
+static void mcdi_ctrl_before_hotplug_on(int cluster, int cpu)
+{
+	if (!HP_SSPM_CTRL && HP_SSPM_PAUSE && MCDI_SSPM) {
+		mcdi_pause_clr(cluster, CPU_IDX(cluster, cpu), OFF);
+		mcdi_pause_set(cluster, CPU_IDX(cluster, cpu), ON);
+	}
+}
+
+static void mcdi_ctrl_before_hotplug_off(int cluster, int cpu, bool cluster_off)
+{
+	if (!HP_SSPM_CTRL && HP_SSPM_PAUSE && MCDI_SSPM)
+		mcdi_pause_set(cluster_off ? cluster : -1,
+				CPU_IDX(cluster, cpu), OFF);
+}
+
+static void mcdi_ctrl_cluster_cpu_off(int cluster, int cpu, bool cluster_off)
+{
+	if (MCDI_SSPM) {
+		sspm_set_bootaddr(secure_entrypoint);
+
+		sspm_standbywfi_irq_enable(CPU_IDX(cluster, cpu));
+
+		if (cluster_off)
+			sspm_cluster_pwr_off_notify(cluster);
+		else
+			sspm_cluster_pwr_on_notify(cluster);
+	}
+}
+
+static void mcdi_ctrl_suspend(void)
+{
+	if (MCDI_SSPM)
+		mcdi_pause();
+}
+
+static void mcdi_ctrl_resume(void)
+{
+	if (MCDI_SSPM)
+		mcdi_unpause();
+}
+
+static void hotplug_ctrl_cluster_on(int cluster, int cpu)
+{
+	if (HP_SSPM_CTRL && MCDI_SSPM) {
+		mcdi_hotplug_clr(cluster, CPU_IDX(cluster, cpu), OFF);
+		mcdi_hotplug_set(cluster, -1, ON);
+		mcdi_hotplug_wait_ack(cluster, -1, ON);
+	} else {
+		/* power on cluster */
+		if (!spm_get_cluster_powerstate(cluster))
+			spm_poweron_cluster(cluster);
+	}
+}
+
+static void hotplug_ctrl_cpu_on(int cluster, int cpu)
+{
+	if (HP_SSPM_CTRL && MCDI_SSPM)
+		mcdi_hotplug_set(cluster, CPU_IDX(cluster, cpu), ON);
+	else
+		spm_poweron_cpu(cluster, cpu);
+}
+
+static void hotplug_ctrl_cpu_on_finish(int cluster, int cpu)
+{
+	spm_disable_cpu_auto_off(cluster, cpu);
+
+	if (HP_SSPM_CTRL && MCDI_SSPM)
+		mcdi_hotplug_clr(cluster, CPU_IDX(cluster, cpu), ON);
+	else if (HP_SSPM_PAUSE && MCDI_SSPM)
+		mcdi_pause_clr(cluster, CPU_IDX(cluster, cpu), ON);
+
+	mcdi_avail_cpu_mask_set(BIT(CPU_IDX(cluster, cpu)));
+}
+
+static void hotplug_ctrl_cluster_cpu_off(int cluster, int cpu, bool cluster_off)
+{
+	mcdi_avail_cpu_mask_clr(BIT(CPU_IDX(cluster, cpu)));
+
+	if (HP_SSPM_CTRL && MCDI_SSPM) {
+		mcdi_hotplug_set(cluster_off ? cluster : -1,
+				CPU_IDX(cluster, cpu), OFF);
+	} else {
+		spm_enable_cpu_auto_off(cluster, cpu);
+
+		if (cluster_off)
+			spm_enable_cluster_auto_off(cluster);
+
+		spm_set_cpu_power_off(cluster, cpu);
+	}
+}
+
 static int plat_mtk_power_domain_on(unsigned long mpidr)
 {
 	int cpu = MPIDR_AFFLVL0_VAL(mpidr);
 	int cluster = MPIDR_AFFLVL1_VAL(mpidr);
 
-	INFO("%s():%d: mpidr: %lx, c.c: %d.%d\n",
-		__func__, __LINE__, mpidr, cluster, cpu);
-
-	/* power on cluster */
-	if (!spm_get_cluster_powerstate(cluster)) {
-		spm_poweron_cluster(cluster);
-		if (cluster == 1) {
-			l2c_parity_check_setup();
-			circular_buffer_setup();
-			mp1_L2_desel_config();
-			mt_gic_sync_dcm_disable();
-		}
-	}
+	mcdi_ctrl_before_hotplug_on(cluster, cpu);
+	hotplug_ctrl_cluster_on(cluster, cpu);
 
 	/* init cpu reset arch as AARCH64 */
 	mcucfg_init_archstate(cluster, cpu, 1);
 	mcucfg_set_bootaddr(cluster, cpu, secure_entrypoint);
 
-	spm_poweron_cpu(cluster, cpu);
+	hotplug_ctrl_cpu_on(cluster, cpu);
 
 	return PSCI_E_SUCCESS;
 }
@@ -73,23 +307,18 @@
 	uint64_t mpidr = read_mpidr();
 	int cpu = MPIDR_AFFLVL0_VAL(mpidr);
 	int cluster = MPIDR_AFFLVL1_VAL(mpidr);
+	const plat_local_state_t *pds = state->pwr_domain_state;
+	bool afflvl1 = (pds[MPIDR_AFFLVL1] == MTK_LOCAL_STATE_OFF);
+	bool cluster_off = (HP_CLUSTER_OFF && afflvl1 &&
+					clst_single_on(cluster, cpu));
 
-	INFO("%s():%d: c.c: %d.%d\n", __func__, __LINE__, cluster, cpu);
-
-	/* Prevent interrupts from spuriously waking up this cpu */
 	mt_gic_cpuif_disable();
 
-	spm_enable_cpu_auto_off(cluster, cpu);
+	if (cluster_off)
+		plat_cluster_pwrdwn_common(mpidr, cluster);
 
-	if (state->pwr_domain_state[MPIDR_AFFLVL1] == MTK_LOCAL_STATE_OFF) {
-		if (cluster == 1)
-			mt_gic_sync_dcm_enable();
-
-		plat_mtk_cci_disable();
-		spm_enable_cluster_auto_off(cluster);
-	}
-
-	spm_set_cpu_power_off(cluster, cpu);
+	mcdi_ctrl_before_hotplug_off(cluster, cpu, cluster_off);
+	hotplug_ctrl_cluster_cpu_off(cluster, cpu, cluster_off);
 }
 
 static void plat_mtk_power_domain_on_finish(const psci_power_state_t *state)
@@ -97,29 +326,170 @@
 	uint64_t mpidr = read_mpidr();
 	int cpu = MPIDR_AFFLVL0_VAL(mpidr);
 	int cluster = MPIDR_AFFLVL1_VAL(mpidr);
+	const plat_local_state_t *pds = state->pwr_domain_state;
+	bool afflvl1 = (pds[MPIDR_AFFLVL1] == MTK_LOCAL_STATE_OFF);
 
-	INFO("%s():%d: c.c: %d.%d\n", __func__, __LINE__, cluster, cpu);
+	if (afflvl1)
+		plat_cluster_pwron_common(mpidr, cluster);
 
-	assert(state->pwr_domain_state[MPIDR_AFFLVL0] == MTK_LOCAL_STATE_OFF);
-
-	if (state->pwr_domain_state[MPIDR_AFFLVL1] == MTK_LOCAL_STATE_OFF) {
-		enable_scu(mpidr);
-
-		/* Enable coherency if this cluster was off */
-		plat_mtk_cci_enable();
-		/* Enable big core dcm if this cluster was on */
-		plat_dcm_restore_cluster_on(mpidr);
-		/* Enable rgu dcm if this cluster was off */
-		plat_dcm_rgu_enable();
-	}
-
-	spm_disable_cpu_auto_off(cluster, cpu);
-
-	/* Enable the gic cpu interface */
 	mt_gic_pcpu_init();
 	mt_gic_cpuif_enable();
+
+	hotplug_ctrl_cpu_on_finish(cluster, cpu);
 }
 
+static void plat_mtk_power_domain_suspend(const psci_power_state_t *state)
+{
+	uint64_t mpidr = read_mpidr();
+	int cpu = MPIDR_AFFLVL0_VAL(mpidr);
+	int cluster = MPIDR_AFFLVL1_VAL(mpidr);
+	const plat_local_state_t *pds = state->pwr_domain_state;
+	bool afflvl1 = (pds[MPIDR_AFFLVL1] == MTK_LOCAL_STATE_OFF);
+	bool afflvl2 = (pds[MPIDR_AFFLVL2] == MTK_LOCAL_STATE_OFF);
+	bool cluster_off = MCDI_C2 && afflvl1 && clst_single_pwr(cluster, cpu);
+
+	/* init cpu reset arch as AARCH64 */
+	mcucfg_init_archstate(cluster, cpu, 1);
+	mcucfg_set_bootaddr(cluster, cpu, secure_entrypoint);
+
+	mt_gic_cpuif_disable();
+	mt_gic_irq_save();
+	plat_dcm_mcsi_a_backup();
+
+	if (cluster_off || afflvl2)
+		plat_cluster_pwrdwn_common(mpidr, cluster);
+
+	if (afflvl2) {
+		spm_data_t spm_d = { .cmd = SPM_SUSPEND };
+		uint32_t *d = (uint32_t *)&spm_d;
+		uint32_t l = sizeof(spm_d) / sizeof(uint32_t);
+
+		mcdi_ctrl_suspend();
+
+		spm_set_bootaddr(secure_entrypoint);
+
+		if (MCDI_SSPM)
+			sspm_ipi_send_non_blocking(IPI_ID_SUSPEND, d);
+
+		spm_system_suspend();
+
+		if (MCDI_SSPM)
+			while (sspm_ipi_recv_non_blocking(IPI_ID_SUSPEND, d, l))
+				;
+	} else {
+		mcdi_ctrl_cluster_cpu_off(cluster, cpu, cluster_off);
+	}
+}
+
+static void plat_mtk_power_domain_suspend_finish(const psci_power_state_t *state)
+{
+	uint64_t mpidr = read_mpidr();
+	int cluster = MPIDR_AFFLVL1_VAL(mpidr);
+	const plat_local_state_t *pds = state->pwr_domain_state;
+	bool afflvl2 = (pds[MPIDR_AFFLVL2] == MTK_LOCAL_STATE_OFF);
+
+	if (afflvl2) {
+		spm_data_t spm_d = { .cmd = SPM_RESUME };
+		uint32_t *d = (uint32_t *)&spm_d;
+		uint32_t l = sizeof(spm_d) / sizeof(uint32_t);
+
+		mt_gic_init();
+		mt_gic_irq_restore();
+		mmio_write_32(EMI_WFIFO, 0xf);
+
+		if (MCDI_SSPM)
+			sspm_ipi_send_non_blocking(IPI_ID_SUSPEND, d);
+
+		spm_system_suspend_finish();
+
+		if (MCDI_SSPM)
+			while (sspm_ipi_recv_non_blocking(IPI_ID_SUSPEND, d, l))
+				;
+
+		mcdi_ctrl_resume();
+	}
+
+	plat_cluster_pwron_common(mpidr, cluster);
+
+	plat_dcm_mcsi_a_restore();
+}
+
+#if PSCI_EXTENDED_STATE_ID
+
+static int plat_mtk_validate_power_state(unsigned int power_state,
+				psci_power_state_t *req_state)
+{
+	unsigned int state_id;
+	int i;
+
+	assert(req_state);
+
+	if (!MCDI_SSPM)
+		return PSCI_E_INVALID_PARAMS;
+
+	/*
+	 *  Currently we are using a linear search for finding the matching
+	 *  entry in the idle power state array. This can be made a binary
+	 *  search if the number of entries justify the additional complexity.
+	 */
+	for (i = 0; !!mtk_pm_idle_states[i]; i++) {
+		if (power_state == mtk_pm_idle_states[i])
+			break;
+	}
+
+	/* Return error if entry not found in the idle state array */
+	if (!mtk_pm_idle_states[i])
+		return PSCI_E_INVALID_PARAMS;
+
+	i = 0;
+	state_id = psci_get_pstate_id(power_state);
+
+	/* Parse the State ID and populate the state info parameter */
+	while (state_id) {
+		req_state->pwr_domain_state[i++] = state_id &
+						MTK_LOCAL_PSTATE_MASK;
+		state_id >>= MTK_LOCAL_PSTATE_WIDTH;
+	}
+
+	return PSCI_E_SUCCESS;
+}
+
+#else /* if !PSCI_EXTENDED_STATE_ID */
+
+static int plat_mtk_validate_power_state(unsigned int power_state,
+					psci_power_state_t *req_state)
+{
+	int pstate = psci_get_pstate_type(power_state);
+	int pwr_lvl = psci_get_pstate_pwrlvl(power_state);
+	int i;
+
+	assert(req_state);
+
+	if (pwr_lvl > PLAT_MAX_PWR_LVL)
+		return PSCI_E_INVALID_PARAMS;
+
+	/* Sanity check the requested state */
+	if (pstate == PSTATE_TYPE_STANDBY) {
+		/*
+		 * It's possible to enter standby only on power level 0
+		 * Ignore any other power level.
+		 */
+		if (pwr_lvl != 0)
+			return PSCI_E_INVALID_PARAMS;
+
+		req_state->pwr_domain_state[MTK_PWR_LVL0] = MTK_LOCAL_STATE_RET;
+	} else if (!MCDI_SSPM) {
+		return PSCI_E_INVALID_PARAMS;
+	} else {
+		for (i = 0; i <= pwr_lvl; i++)
+			req_state->pwr_domain_state[i] = MTK_LOCAL_STATE_OFF;
+	}
+
+	return PSCI_E_SUCCESS;
+}
+
+#endif /* PSCI_EXTENDED_STATE_ID */
+
 /*******************************************************************************
  * MTK handlers to shutdown/reboot the system
  ******************************************************************************/
@@ -149,46 +519,6 @@
 	panic();
 }
 
-static void plat_mtk_power_domain_suspend(const psci_power_state_t *state)
-{
-	uint64_t mpidr = read_mpidr();
-	int cpu = MPIDR_AFFLVL0_VAL(mpidr);
-	int cluster = MPIDR_AFFLVL1_VAL(mpidr);
-
-	spm_system_suspend();
-
-	/* init cpu reset arch as AARCH64 */
-	mcucfg_init_archstate(cluster, cpu, 1);
-	mcucfg_set_bootaddr(cluster, cpu, secure_entrypoint);
-	spm_set_bootaddr(secure_entrypoint);
-
-	/* Prevent interrupts from spuriously waking up this cpu */
-	mt_gic_cpuif_disable();
-	mt_gic_irq_save();
-
-	if (state->pwr_domain_state[MPIDR_AFFLVL2] == MTK_LOCAL_STATE_OFF) {
-		plat_mtk_cci_disable();
-		disable_scu(mpidr);
-	}
-}
-
-static void plat_mtk_power_domain_suspend_finish(const psci_power_state_t *state)
-{
-	uint64_t mpidr = read_mpidr();
-
-	mt_gic_init();
-	mt_gic_irq_restore();
-
-	if (state->pwr_domain_state[MPIDR_AFFLVL2] == MTK_LOCAL_STATE_OFF) {
-		enable_scu(mpidr);
-		plat_mtk_cci_enable();
-		plat_dcm_restore_cluster_on(mpidr);
-	}
-
-	mmio_write_32(EMI_WFIFO, 0xf);
-	spm_system_suspend_finish();
-}
-
 static void plat_mtk_get_sys_suspend_power_state(psci_power_state_t *req_state)
 {
 	assert(PLAT_MAX_PWR_LVL >= 2);
@@ -202,7 +532,7 @@
  * on. The level and mpidr determine the affinity instance.
  ******************************************************************************/
 static const plat_psci_ops_t plat_plat_pm_ops = {
-	.cpu_standby			= NULL,
+	.cpu_standby			= plat_cpu_standby,
 	.pwr_domain_on			= plat_mtk_power_domain_on,
 	.pwr_domain_on_finish		= plat_mtk_power_domain_on_finish,
 	.pwr_domain_off			= plat_mtk_power_domain_off,
@@ -210,7 +540,7 @@
 	.pwr_domain_suspend_finish	= plat_mtk_power_domain_suspend_finish,
 	.system_off			= plat_mtk_system_off,
 	.system_reset			= plat_mtk_system_reset,
-	.validate_power_state		= NULL,
+	.validate_power_state		= plat_mtk_validate_power_state,
 	.get_sys_suspend_power_state	= plat_mtk_get_sys_suspend_power_state,
 };
 
@@ -219,5 +549,11 @@
 {
 	*psci_ops = &plat_plat_pm_ops;
 	secure_entrypoint = sec_entrypoint;
+
+	if (!check_mcdi_ctl_stat()) {
+		HP_SSPM_CTRL = false;
+		MCDI_SSPM = false;
+	}
+
 	return 0;
 }
diff --git a/plat/mediatek/mt8183/platform.mk b/plat/mediatek/mt8183/platform.mk
index 5bf504b..efa7e9e 100644
--- a/plat/mediatek/mt8183/platform.mk
+++ b/plat/mediatek/mt8183/platform.mk
@@ -9,6 +9,7 @@
 
 PLAT_INCLUDES := -I${MTK_PLAT}/common/                            \
                  -I${MTK_PLAT_SOC}/drivers/                       \
+                 -I${MTK_PLAT_SOC}/drivers/mcdi/                  \
                  -I${MTK_PLAT_SOC}/drivers/spmc/                  \
                  -I${MTK_PLAT_SOC}/drivers/gpio/                  \
                  -I${MTK_PLAT_SOC}/drivers/pmic/                  \
@@ -48,6 +49,7 @@
                    ${MTK_PLAT_SOC}/drivers/mcsi/mcsi.c                   \
                    ${MTK_PLAT_SOC}/drivers/pmic/pmic.c                   \
                    ${MTK_PLAT_SOC}/drivers/rtc/rtc.c                     \
+                   ${MTK_PLAT_SOC}/drivers/mcdi/mtk_mcdi.c               \
                    ${MTK_PLAT_SOC}/drivers/spmc/mtspmc.c                 \
                    ${MTK_PLAT_SOC}/drivers/spm/spm.c                     \
                    ${MTK_PLAT_SOC}/drivers/spm/spm_pmic_wrap.c           \