diff --git a/plat/mediatek/drivers/rtc/rtc_common.c b/plat/mediatek/drivers/rtc/rtc_common.c
new file mode 100644
index 0000000..4efddff
--- /dev/null
+++ b/plat/mediatek/drivers/rtc/rtc_common.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2019-2022, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+
+#include <pmic_wrap_init.h>
+#include <rtc.h>
+
+/* RTC busy status polling interval and retry count */
+enum {
+	RTC_WRTGR_POLLING_DELAY_MS	= 10,
+	RTC_WRTGR_POLLING_CNT		= 100
+};
+
+uint16_t RTC_Read(uint32_t addr)
+{
+	uint32_t rdata = 0;
+
+	pwrap_read((uint32_t)addr, &rdata);
+	return (uint16_t)rdata;
+}
+
+void RTC_Write(uint32_t addr, uint16_t data)
+{
+	pwrap_write((uint32_t)addr, (uint32_t)data);
+}
+
+int32_t rtc_busy_wait(void)
+{
+	uint64_t retry = RTC_WRTGR_POLLING_CNT;
+
+	do {
+		mdelay(RTC_WRTGR_POLLING_DELAY_MS);
+		if (!(RTC_Read(RTC_BBPU) & RTC_BBPU_CBUSY))
+			return 1;
+		retry--;
+	} while (retry);
+
+	ERROR("[RTC] rtc cbusy time out!\n");
+	return 0;
+}
+
+int32_t RTC_Write_Trigger(void)
+{
+	RTC_Write(RTC_WRTGR, 1);
+	return rtc_busy_wait();
+}
+
+int32_t Writeif_unlock(void)
+{
+	RTC_Write(RTC_PROT, RTC_PROT_UNLOCK1);
+	if (!RTC_Write_Trigger())
+		return 0;
+	RTC_Write(RTC_PROT, RTC_PROT_UNLOCK2);
+	if (!RTC_Write_Trigger())
+		return 0;
+
+	return 1;
+}
+