diff --git a/plat/mediatek/drivers/apusys/mt8188/apusys_power.c b/plat/mediatek/drivers/apusys/mt8188/apusys_power.c
index ac62f2f..cdfc133 100644
--- a/plat/mediatek/drivers/apusys/mt8188/apusys_power.c
+++ b/plat/mediatek/drivers/apusys/mt8188/apusys_power.c
@@ -17,6 +17,7 @@
 /* Vendor header */
 #include "apusys.h"
 #include "apusys_power.h"
+#include "apusys_rv.h"
 #include <mtk_mmap_pool.h>
 
 static spinlock_t apu_lock;
@@ -47,6 +48,43 @@
 	return -1;
 }
 
+static void apu_backup_restore(enum APU_BACKUP_RESTORE_CTRL ctrl)
+{
+	int i;
+	static struct apu_restore_data apu_restore_data[] = {
+		{ UP_NORMAL_DOMAIN_NS, 0 },
+		{ UP_PRI_DOMAIN_NS, 0 },
+		{ UP_IOMMU_CTRL, 0 },
+		{ UP_CORE0_VABASE0, 0 },
+		{ UP_CORE0_MVABASE0, 0 },
+		{ UP_CORE0_VABASE1, 0 },
+		{ UP_CORE0_MVABASE1, 0 },
+		{ UP_CORE0_VABASE2, 0 },
+		{ UP_CORE0_MVABASE2, 0 },
+		{ UP_CORE0_VABASE3, 0 },
+		{ UP_CORE0_MVABASE3, 0 },
+		{ MD32_SYS_CTRL, 0 },
+		{ MD32_CLK_CTRL, 0 },
+		{ UP_WAKE_HOST_MASK0, 0 }
+	};
+
+	switch (ctrl) {
+	case APU_CTRL_BACKUP:
+		for (i = 0; i < ARRAY_SIZE(apu_restore_data); i++) {
+			apu_restore_data[i].data = mmio_read_32(apu_restore_data[i].reg);
+		}
+		break;
+	case APU_CTRL_RESTORE:
+		for (i = 0; i < ARRAY_SIZE(apu_restore_data); i++) {
+			mmio_write_32(apu_restore_data[i].reg, apu_restore_data[i].data);
+		}
+		break;
+	default:
+		ERROR(MODULE_TAG "%s invalid op: %d\n", __func__, ctrl);
+		break;
+	}
+}
+
 static void apu_xpu2apusys_d4_slv_en(enum APU_D4_SLV_CTRL en)
 {
 	switch (en) {
@@ -120,6 +158,8 @@
 
 	apu_xpu2apusys_d4_slv_en(D4_SLV_OFF);
 
+	apu_backup_restore(APU_CTRL_RESTORE);
+
 	apusys_top_on = true;
 
 	spin_unlock(&apu_lock);
@@ -153,6 +193,8 @@
 		return 0;
 	}
 
+	apu_backup_restore(APU_CTRL_BACKUP);
+
 	apu_xpu2apusys_d4_slv_en(D4_SLV_ON);
 
 	if (mmio_read_32(APU_MBOX0_BASE + PWR_FLOW_SYNC_REG) == 0) {
diff --git a/plat/mediatek/drivers/apusys/mt8188/apusys_power.h b/plat/mediatek/drivers/apusys/mt8188/apusys_power.h
index b4968d6..460cc50 100644
--- a/plat/mediatek/drivers/apusys/mt8188/apusys_power.h
+++ b/plat/mediatek/drivers/apusys/mt8188/apusys_power.h
@@ -29,6 +29,16 @@
 	D4_SLV_ON,
 };
 
+enum APU_BACKUP_RESTORE_CTRL {
+	APU_CTRL_BACKUP		= 0,
+	APU_CTRL_RESTORE	= 1,
+};
+
+struct apu_restore_data {
+	uint32_t reg;
+	uint32_t data;
+};
+
 #define APU_POLL_STEP_US			(5)
 
 #define OUT_CLK_FREQ_MIN			(1500)