diff --git a/Documentation/devicetree/bindings/rtc/epson,rx8900.yaml b/Documentation/devicetree/bindings/rtc/epson,rx8900.yaml
index 29fe39bb08ad..d12855e7ffd7 100644
--- a/Documentation/devicetree/bindings/rtc/epson,rx8900.yaml
+++ b/Documentation/devicetree/bindings/rtc/epson,rx8900.yaml
@@ -15,6 +15,7 @@ allOf:
 properties:
   compatible:
     enum:
+      - epson,rx8804
       - epson,rx8900
       - microcrystal,rv8803
 
diff --git a/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml b/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
index 4fba6dba16f3..6fa7d9fc2dc7 100644
--- a/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
+++ b/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
@@ -19,7 +19,14 @@ properties:
       - qcom,pmk8350-rtc
 
   reg:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
+
+  reg-names:
+    minItems: 1
+    items:
+      - const: rtc
+      - const: alarm
 
   interrupts:
     maxItems: 1
diff --git a/Documentation/devicetree/bindings/rtc/sunplus,sp7021-rtc.yaml b/Documentation/devicetree/bindings/rtc/sunplus,sp7021-rtc.yaml
new file mode 100644
index 000000000000..fd1b3e71ff2c
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/sunplus,sp7021-rtc.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) Sunplus Co., Ltd. 2021
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/sunplus,sp7021-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sunplus SP7021 Real Time Clock controller
+
+maintainers:
+  - Vincent Shih <vincent.sunplus@gmail.com>
+
+properties:
+  compatible:
+    const: sunplus,sp7021-rtc
+
+  reg:
+    maxItems: 1
+
+  reg-names:
+    items:
+      - const: rtc
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - resets
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    rtc: serial@9c003a00 {
+        compatible = "sunplus,sp7021-rtc";
+        reg = <0x9c003a00 0x80>;
+        reg-names = "rtc";
+        clocks = <&clkc 0x12>;
+        resets = <&rstc 0x02>;
+        interrupt-parent = <&intc>;
+        interrupts = <163 IRQ_TYPE_EDGE_RISING>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 1630d899639d..6c08cbe953fe 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18491,6 +18491,13 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/dlink/sundance.c
 
+SUNPLUS RTC DRIVER
+M:	Vincent Shih <vincent.sunplus@gmail.com>
+L:	linux-rtc@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/rtc/sunplus,sp7021-rtc.yaml
+F:	drivers/rtc/rtc-sunplus.c
+
 SUPERH
 M:	Yoshinori Sato <ysato@users.sourceforge.jp>
 M:	Rich Felker <dalias@libc.org>
diff --git a/arch/alpha/kernel/rtc.c b/arch/alpha/kernel/rtc.c
index ce3077946e1d..fb3025396ac9 100644
--- a/arch/alpha/kernel/rtc.c
+++ b/arch/alpha/kernel/rtc.c
@@ -80,7 +80,12 @@ init_rtc_epoch(void)
 static int
 alpha_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
-	mc146818_get_time(tm);
+	int ret = mc146818_get_time(tm);
+
+	if (ret < 0) {
+		dev_err_ratelimited(dev, "unable to read current time\n");
+		return ret;
+	}
 
 	/* Adjust for non-default epochs.  It's easier to depend on the
 	   generic __get_rtc_time and adjust the epoch here than create
diff --git a/arch/powerpc/boot/dts/wii.dts b/arch/powerpc/boot/dts/wii.dts
index e9c945b123c6..e46143c32308 100644
--- a/arch/powerpc/boot/dts/wii.dts
+++ b/arch/powerpc/boot/dts/wii.dts
@@ -168,6 +168,11 @@
 			interrupts = <14>;
 		};
 
+		srnprot@d800060 {
+			compatible = "nintendo,hollywood-srnprot";
+			reg = <0x0d800060 0x4>;
+		};
+
 		GPIO: gpio@d8000c0 {
 			#gpio-cells = <2>;
 			compatible = "nintendo,hollywood-gpio";
diff --git a/arch/powerpc/configs/gamecube_defconfig b/arch/powerpc/configs/gamecube_defconfig
index 24c0e0ea5aeb..91a1b99f4e8f 100644
--- a/arch/powerpc/configs/gamecube_defconfig
+++ b/arch/powerpc/configs/gamecube_defconfig
@@ -68,7 +68,7 @@ CONFIG_SND_SEQUENCER=y
 CONFIG_SND_SEQUENCER_OSS=y
 # CONFIG_USB_SUPPORT is not set
 CONFIG_RTC_CLASS=y
-CONFIG_RTC_DRV_GENERIC=y
+CONFIG_RTC_DRV_GAMECUBE=y
 CONFIG_EXT2_FS=y
 CONFIG_EXT4_FS=y
 CONFIG_ISO9660_FS=y
diff --git a/arch/powerpc/configs/wii_defconfig b/arch/powerpc/configs/wii_defconfig
index a0c45bf2bfb1..0ab78c51455d 100644
--- a/arch/powerpc/configs/wii_defconfig
+++ b/arch/powerpc/configs/wii_defconfig
@@ -98,7 +98,7 @@ CONFIG_LEDS_TRIGGERS=y
 CONFIG_LEDS_TRIGGER_HEARTBEAT=y
 CONFIG_LEDS_TRIGGER_PANIC=y
 CONFIG_RTC_CLASS=y
-CONFIG_RTC_DRV_GENERIC=y
+CONFIG_RTC_DRV_GAMECUBE=y
 CONFIG_NVMEM_NINTENDO_OTP=y
 CONFIG_EXT2_FS=y
 CONFIG_EXT4_FS=y
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 882213df3713..71f336425e58 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -1435,8 +1435,12 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
 	hpet_rtc_timer_reinit();
 	memset(&curr_time, 0, sizeof(struct rtc_time));
 
-	if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
-		mc146818_get_time(&curr_time);
+	if (hpet_rtc_flags & (RTC_UIE | RTC_AIE)) {
+		if (unlikely(mc146818_get_time(&curr_time) < 0)) {
+			pr_err_ratelimited("unable to read current time from RTC\n");
+			return IRQ_HANDLED;
+		}
+	}
 
 	if (hpet_rtc_flags & RTC_UIE &&
 	    curr_time.tm_sec != hpet_prev_update_sec) {
diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
index 94665037f4a3..72b7a92337b1 100644
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -120,7 +120,11 @@ static unsigned int read_magic_time(void)
 	struct rtc_time time;
 	unsigned int val;
 
-	mc146818_get_time(&time);
+	if (mc146818_get_time(&time) < 0) {
+		pr_err("Unable to read current time from RTC\n");
+		return 0;
+	}
+
 	pr_info("RTC time: %ptRt, date: %ptRd\n", &time, &time);
 	val = time.tm_year;				/* 100 years */
 	if (val > 100)
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 058e56a10ab8..d85a3c31347c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1216,6 +1216,17 @@ config RTC_DRV_V3020
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-v3020.
 
+config RTC_DRV_GAMECUBE
+	tristate "Nintendo GameCube, Wii and Wii U RTC"
+	depends on GAMECUBE || WII || COMPILE_TEST
+	select REGMAP
+	help
+	  If you say yes here you will get support for the RTC subsystem
+	  of the Nintendo GameCube, Wii and Wii U.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called "rtc-gamecube".
+
 config RTC_DRV_WM831X
 	tristate "Wolfson Microelectronics WM831x RTC"
 	depends on MFD_WM831X
@@ -1444,6 +1455,19 @@ config RTC_DRV_SH
 	  To compile this driver as a module, choose M here: the
 	  module will be called rtc-sh.
 
+config RTC_DRV_SUNPLUS
+	tristate "Sunplus SP7021 RTC"
+	depends on SOC_SP7021
+	help
+	  Say 'yes' to get support for the real-time clock present in
+	  Sunplus SP7021 - a SoC for industrial applications. It provides
+	  RTC status check, timer/alarm functionalities, user data
+	  reservation with the battery over 2.5V, RTC power status check
+	  and battery charge.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-sunplus.
+
 config RTC_DRV_VR41XX
 	tristate "NEC VR41XX"
 	depends on CPU_VR41XX || COMPILE_TEST
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 678a8ef4abae..e92f3e943245 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -111,6 +111,7 @@ obj-$(CONFIG_RTC_DRV_MT7622)	+= rtc-mt7622.o
 obj-$(CONFIG_RTC_DRV_MV)	+= rtc-mv.o
 obj-$(CONFIG_RTC_DRV_MXC)	+= rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_MXC_V2)	+= rtc-mxc_v2.o
+obj-$(CONFIG_RTC_DRV_GAMECUBE)	+= rtc-gamecube.o
 obj-$(CONFIG_RTC_DRV_NTXEC)	+= rtc-ntxec.o
 obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
 obj-$(CONFIG_RTC_DRV_OPAL)	+= rtc-opal.o
@@ -165,6 +166,7 @@ obj-$(CONFIG_RTC_DRV_STM32) 	+= rtc-stm32.o
 obj-$(CONFIG_RTC_DRV_STMP)	+= rtc-stmp3xxx.o
 obj-$(CONFIG_RTC_DRV_SUN4V)	+= rtc-sun4v.o
 obj-$(CONFIG_RTC_DRV_SUN6I)	+= rtc-sun6i.o
+obj-$(CONFIG_RTC_DRV_SUNPLUS)	+= rtc-sunplus.o
 obj-$(CONFIG_RTC_DRV_SUNXI)	+= rtc-sunxi.o
 obj-$(CONFIG_RTC_DRV_TEGRA)	+= rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)	+= rtc-test.o
diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
index e104972a28fd..69325aeede1a 100644
--- a/drivers/rtc/dev.c
+++ b/drivers/rtc/dev.c
@@ -391,14 +391,14 @@ static long rtc_dev_ioctl(struct file *file,
 		}
 
 		switch(param.param) {
-			long offset;
 		case RTC_PARAM_FEATURES:
 			if (param.index != 0)
 				err = -EINVAL;
 			param.uvalue = rtc->features[0];
 			break;
 
-		case RTC_PARAM_CORRECTION:
+		case RTC_PARAM_CORRECTION: {
+			long offset;
 			mutex_unlock(&rtc->ops_lock);
 			if (param.index != 0)
 				return -EINVAL;
@@ -407,7 +407,7 @@ static long rtc_dev_ioctl(struct file *file,
 			if (err == 0)
 				param.svalue = offset;
 			break;
-
+		}
 		default:
 			if (rtc->ops->param_get)
 				err = rtc->ops->param_get(rtc->dev.parent, &param);
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 4eb53412b808..7c006c2b125f 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -222,6 +222,8 @@ static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
 
 static int cmos_read_time(struct device *dev, struct rtc_time *t)
 {
+	int ret;
+
 	/*
 	 * If pm_trace abused the RTC for storage, set the timespec to 0,
 	 * which tells the caller that this RTC value is unusable.
@@ -229,7 +231,12 @@ static int cmos_read_time(struct device *dev, struct rtc_time *t)
 	if (!pm_trace_rtc_valid())
 		return -EIO;
 
-	mc146818_get_time(t);
+	ret = mc146818_get_time(t);
+	if (ret < 0) {
+		dev_err_ratelimited(dev, "unable to read current time\n");
+		return ret;
+	}
+
 	return 0;
 }
 
@@ -242,10 +249,46 @@ static int cmos_set_time(struct device *dev, struct rtc_time *t)
 	return mc146818_set_time(t);
 }
 
+struct cmos_read_alarm_callback_param {
+	struct cmos_rtc *cmos;
+	struct rtc_time *time;
+	unsigned char	rtc_control;
+};
+
+static void cmos_read_alarm_callback(unsigned char __always_unused seconds,
+				     void *param_in)
+{
+	struct cmos_read_alarm_callback_param *p =
+		(struct cmos_read_alarm_callback_param *)param_in;
+	struct rtc_time *time = p->time;
+
+	time->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
+	time->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
+	time->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
+
+	if (p->cmos->day_alrm) {
+		/* ignore upper bits on readback per ACPI spec */
+		time->tm_mday = CMOS_READ(p->cmos->day_alrm) & 0x3f;
+		if (!time->tm_mday)
+			time->tm_mday = -1;
+
+		if (p->cmos->mon_alrm) {
+			time->tm_mon = CMOS_READ(p->cmos->mon_alrm);
+			if (!time->tm_mon)
+				time->tm_mon = -1;
+		}
+	}
+
+	p->rtc_control = CMOS_READ(RTC_CONTROL);
+}
+
 static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
-	unsigned char	rtc_control;
+	struct cmos_read_alarm_callback_param p = {
+		.cmos = cmos,
+		.time = &t->time,
+	};
 
 	/* This not only a rtc_op, but also called directly */
 	if (!is_valid_irq(cmos->irq))
@@ -256,28 +299,18 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 	 * the future.
 	 */
 
-	spin_lock_irq(&rtc_lock);
-	t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
-	t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
-	t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
+	/* Some Intel chipsets disconnect the alarm registers when the clock
+	 * update is in progress - during this time reads return bogus values
+	 * and writes may fail silently. See for example "7th Generation Intel®
+	 * Processor Family I/O for U/Y Platforms [...] Datasheet", section
+	 * 27.7.1
+	 *
+	 * Use the mc146818_avoid_UIP() function to avoid this.
+	 */
+	if (!mc146818_avoid_UIP(cmos_read_alarm_callback, &p))
+		return -EIO;
 
-	if (cmos->day_alrm) {
-		/* ignore upper bits on readback per ACPI spec */
-		t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
-		if (!t->time.tm_mday)
-			t->time.tm_mday = -1;
-
-		if (cmos->mon_alrm) {
-			t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
-			if (!t->time.tm_mon)
-				t->time.tm_mon = -1;
-		}
-	}
-
-	rtc_control = CMOS_READ(RTC_CONTROL);
-	spin_unlock_irq(&rtc_lock);
-
-	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+	if (!(p.rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 		if (((unsigned)t->time.tm_sec) < 0x60)
 			t->time.tm_sec = bcd2bin(t->time.tm_sec);
 		else
@@ -306,7 +339,7 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 		}
 	}
 
-	t->enabled = !!(rtc_control & RTC_AIE);
+	t->enabled = !!(p.rtc_control & RTC_AIE);
 	t->pending = 0;
 
 	return 0;
@@ -437,10 +470,57 @@ static int cmos_validate_alarm(struct device *dev, struct rtc_wkalrm *t)
 	return 0;
 }
 
+struct cmos_set_alarm_callback_param {
+	struct cmos_rtc *cmos;
+	unsigned char mon, mday, hrs, min, sec;
+	struct rtc_wkalrm *t;
+};
+
+/* Note: this function may be executed by mc146818_avoid_UIP() more then
+ *	 once
+ */
+static void cmos_set_alarm_callback(unsigned char __always_unused seconds,
+				    void *param_in)
+{
+	struct cmos_set_alarm_callback_param *p =
+		(struct cmos_set_alarm_callback_param *)param_in;
+
+	/* next rtc irq must not be from previous alarm setting */
+	cmos_irq_disable(p->cmos, RTC_AIE);
+
+	/* update alarm */
+	CMOS_WRITE(p->hrs, RTC_HOURS_ALARM);
+	CMOS_WRITE(p->min, RTC_MINUTES_ALARM);
+	CMOS_WRITE(p->sec, RTC_SECONDS_ALARM);
+
+	/* the system may support an "enhanced" alarm */
+	if (p->cmos->day_alrm) {
+		CMOS_WRITE(p->mday, p->cmos->day_alrm);
+		if (p->cmos->mon_alrm)
+			CMOS_WRITE(p->mon, p->cmos->mon_alrm);
+	}
+
+	if (use_hpet_alarm()) {
+		/*
+		 * FIXME the HPET alarm glue currently ignores day_alrm
+		 * and mon_alrm ...
+		 */
+		hpet_set_alarm_time(p->t->time.tm_hour, p->t->time.tm_min,
+				    p->t->time.tm_sec);
+	}
+
+	if (p->t->enabled)
+		cmos_irq_enable(p->cmos, RTC_AIE);
+}
+
 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
-	unsigned char mon, mday, hrs, min, sec, rtc_control;
+	struct cmos_set_alarm_callback_param p = {
+		.cmos = cmos,
+		.t = t
+	};
+	unsigned char rtc_control;
 	int ret;
 
 	/* This not only a rtc_op, but also called directly */
@@ -451,53 +531,34 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 	if (ret < 0)
 		return ret;
 
-	mon = t->time.tm_mon + 1;
-	mday = t->time.tm_mday;
-	hrs = t->time.tm_hour;
-	min = t->time.tm_min;
-	sec = t->time.tm_sec;
-
-	rtc_control = CMOS_READ(RTC_CONTROL);
-	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
-		/* Writing 0xff means "don't care" or "match all".  */
-		mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
-		mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
-		hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
-		min = (min < 60) ? bin2bcd(min) : 0xff;
-		sec = (sec < 60) ? bin2bcd(sec) : 0xff;
-	}
+	p.mon = t->time.tm_mon + 1;
+	p.mday = t->time.tm_mday;
+	p.hrs = t->time.tm_hour;
+	p.min = t->time.tm_min;
+	p.sec = t->time.tm_sec;
 
 	spin_lock_irq(&rtc_lock);
-
-	/* next rtc irq must not be from previous alarm setting */
-	cmos_irq_disable(cmos, RTC_AIE);
-
-	/* update alarm */
-	CMOS_WRITE(hrs, RTC_HOURS_ALARM);
-	CMOS_WRITE(min, RTC_MINUTES_ALARM);
-	CMOS_WRITE(sec, RTC_SECONDS_ALARM);
-
-	/* the system may support an "enhanced" alarm */
-	if (cmos->day_alrm) {
-		CMOS_WRITE(mday, cmos->day_alrm);
-		if (cmos->mon_alrm)
-			CMOS_WRITE(mon, cmos->mon_alrm);
-	}
-
-	if (use_hpet_alarm()) {
-		/*
-		 * FIXME the HPET alarm glue currently ignores day_alrm
-		 * and mon_alrm ...
-		 */
-		hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min,
-				    t->time.tm_sec);
-	}
-
-	if (t->enabled)
-		cmos_irq_enable(cmos, RTC_AIE);
-
+	rtc_control = CMOS_READ(RTC_CONTROL);
 	spin_unlock_irq(&rtc_lock);
 
+	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+		/* Writing 0xff means "don't care" or "match all".  */
+		p.mon = (p.mon <= 12) ? bin2bcd(p.mon) : 0xff;
+		p.mday = (p.mday >= 1 && p.mday <= 31) ? bin2bcd(p.mday) : 0xff;
+		p.hrs = (p.hrs < 24) ? bin2bcd(p.hrs) : 0xff;
+		p.min = (p.min < 60) ? bin2bcd(p.min) : 0xff;
+		p.sec = (p.sec < 60) ? bin2bcd(p.sec) : 0xff;
+	}
+
+	/*
+	 * Some Intel chipsets disconnect the alarm registers when the clock
+	 * update is in progress - during this time writes fail silently.
+	 *
+	 * Use mc146818_avoid_UIP() to avoid this.
+	 */
+	if (!mc146818_avoid_UIP(cmos_set_alarm_callback, &p))
+		return -EIO;
+
 	cmos->alarm_expires = rtc_tm_to_time64(&t->time);
 
 	return 0;
@@ -790,16 +851,14 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 
 	rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
 
-	spin_lock_irq(&rtc_lock);
-
-	/* Ensure that the RTC is accessible. Bit 6 must be 0! */
-	if ((CMOS_READ(RTC_VALID) & 0x40) != 0) {
-		spin_unlock_irq(&rtc_lock);
-		dev_warn(dev, "not accessible\n");
+	if (!mc146818_does_rtc_work()) {
+		dev_warn(dev, "broken or not accessible\n");
 		retval = -ENXIO;
 		goto cleanup1;
 	}
 
+	spin_lock_irq(&rtc_lock);
+
 	if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) {
 		/* force periodic irq to CMOS reset default of 1024Hz;
 		 *
diff --git a/drivers/rtc/rtc-da9063.c b/drivers/rtc/rtc-da9063.c
index d4b72a9fa2ba..ee2efb496174 100644
--- a/drivers/rtc/rtc-da9063.c
+++ b/drivers/rtc/rtc-da9063.c
@@ -475,12 +475,14 @@ static int da9063_rtc_probe(struct platform_device *pdev)
 	da9063_data_to_tm(data, &rtc->alarm_time, rtc);
 	rtc->rtc_sync = false;
 
-	/*
-	 * TODO: some models have alarms on a minute boundary but still support
-	 * real hardware interrupts. Add this once the core supports it.
-	 */
-	if (config->rtc_data_start != RTC_SEC)
-		rtc->rtc_dev->uie_unsupported = 1;
+	if (config->rtc_data_start != RTC_SEC) {
+		set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc_dev->features);
+		/*
+		 * TODO: some models have alarms on a minute boundary but still
+		 * support real hardware interrupts.
+		 */
+		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc_dev->features);
+	}
 
 	irq_alarm = platform_get_irq_byname(pdev, "ALARM");
 	if (irq_alarm < 0)
@@ -494,6 +496,8 @@ static int da9063_rtc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
 			irq_alarm, ret);
 
+	device_init_wakeup(&pdev->dev, true);
+
 	return devm_rtc_register_device(rtc->rtc_dev);
 }
 
diff --git a/drivers/rtc/rtc-ftrtc010.c b/drivers/rtc/rtc-ftrtc010.c
index ad3add5db4c8..53bb08fe1cd4 100644
--- a/drivers/rtc/rtc-ftrtc010.c
+++ b/drivers/rtc/rtc-ftrtc010.c
@@ -141,11 +141,9 @@ static int ftrtc010_rtc_probe(struct platform_device *pdev)
 		}
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!res)
-		return -ENODEV;
-
-	rtc->rtc_irq = res->start;
+	rtc->rtc_irq = platform_get_irq(pdev, 0);
+	if (rtc->rtc_irq < 0)
+		return rtc->rtc_irq;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
diff --git a/drivers/rtc/rtc-gamecube.c b/drivers/rtc/rtc-gamecube.c
new file mode 100644
index 000000000000..f717b36f4738
--- /dev/null
+++ b/drivers/rtc/rtc-gamecube.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nintendo GameCube, Wii and Wii U RTC driver
+ *
+ * This driver is for the MX23L4005, more specifically its real-time clock and
+ * SRAM storage.  The value returned by the RTC counter must be added with the
+ * offset stored in a bias register in SRAM (on the GameCube and Wii) or in
+ * /config/rtc.xml (on the Wii U).  The latter being very impractical to access
+ * from Linux, this driver assumes the bootloader has read it and stored it in
+ * SRAM like for the other two consoles.
+ *
+ * This device sits on a bus named EXI (which is similar to SPI), channel 0,
+ * device 1.  This driver assumes no other user of the EXI bus, which is
+ * currently the case but would have to be reworked to add support for other
+ * GameCube hardware exposed on this bus.
+ *
+ * References:
+ * - https://wiiubrew.org/wiki/Hardware/RTC
+ * - https://wiibrew.org/wiki/MX23L4005
+ *
+ * Copyright (C) 2018 rw-r-r-0644
+ * Copyright (C) 2021 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
+ *
+ * Based on rtc-gcn.c
+ * Copyright (C) 2004-2009 The GameCube Linux Team
+ * Copyright (C) 2005,2008,2009 Albert Herranz
+ * Based on gamecube_time.c from Torben Nielsen.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/time.h>
+
+/* EXI registers */
+#define EXICSR	0
+#define EXICR	12
+#define EXIDATA	16
+
+/* EXI register values */
+#define EXICSR_DEV		0x380
+	#define EXICSR_DEV1	0x100
+#define EXICSR_CLK		0x070
+	#define EXICSR_CLK_1MHZ	0x000
+	#define EXICSR_CLK_2MHZ	0x010
+	#define EXICSR_CLK_4MHZ	0x020
+	#define EXICSR_CLK_8MHZ	0x030
+	#define EXICSR_CLK_16MHZ 0x040
+	#define EXICSR_CLK_32MHZ 0x050
+#define EXICSR_INT		0x008
+	#define EXICSR_INTSET	0x008
+
+#define EXICR_TSTART		0x001
+#define EXICR_TRSMODE		0x002
+	#define EXICR_TRSMODE_IMM 0x000
+#define EXICR_TRSTYPE		0x00C
+	#define EXICR_TRSTYPE_R	0x000
+	#define EXICR_TRSTYPE_W	0x004
+#define EXICR_TLEN		0x030
+	#define EXICR_TLEN32	0x030
+
+/* EXI registers values to access the RTC */
+#define RTC_EXICSR	(EXICSR_DEV1 | EXICSR_CLK_8MHZ | EXICSR_INTSET)
+#define RTC_EXICR_W	(EXICR_TSTART | EXICR_TRSMODE_IMM | EXICR_TRSTYPE_W | EXICR_TLEN32)
+#define RTC_EXICR_R	(EXICR_TSTART | EXICR_TRSMODE_IMM | EXICR_TRSTYPE_R | EXICR_TLEN32)
+#define RTC_EXIDATA_W	0x80000000
+
+/* RTC registers */
+#define RTC_COUNTER	0x200000
+#define RTC_SRAM	0x200001
+#define RTC_SRAM_BIAS	0x200004
+#define RTC_SNAPSHOT	0x204000
+#define RTC_ONTMR	0x210000
+#define RTC_OFFTMR	0x210001
+#define RTC_TEST0	0x210004
+#define RTC_TEST1	0x210005
+#define RTC_TEST2	0x210006
+#define RTC_TEST3	0x210007
+#define RTC_CONTROL0	0x21000c
+#define RTC_CONTROL1	0x21000d
+
+/* RTC flags */
+#define RTC_CONTROL0_UNSTABLE_POWER	0x00000800
+#define RTC_CONTROL0_LOW_BATTERY	0x00000200
+
+struct priv {
+	struct regmap *regmap;
+	void __iomem *iob;
+	u32 rtc_bias;
+};
+
+static int exi_read(void *context, u32 reg, u32 *data)
+{
+	struct priv *d = (struct priv *)context;
+	void __iomem *iob = d->iob;
+
+	/* The spin loops here loop about 15~16 times each, so there is no need
+	 * to use a more expensive sleep method.
+	 */
+
+	/* Write register offset */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(reg << 8, iob + EXIDATA);
+	iowrite32be(RTC_EXICR_W, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+
+	/* Read data */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(RTC_EXICR_R, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+	*data = ioread32be(iob + EXIDATA);
+
+	/* Clear channel parameters */
+	iowrite32be(0, iob + EXICSR);
+
+	return 0;
+}
+
+static int exi_write(void *context, u32 reg, u32 data)
+{
+	struct priv *d = (struct priv *)context;
+	void __iomem *iob = d->iob;
+
+	/* The spin loops here loop about 15~16 times each, so there is no need
+	 * to use a more expensive sleep method.
+	 */
+
+	/* Write register offset */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(RTC_EXIDATA_W | (reg << 8), iob + EXIDATA);
+	iowrite32be(RTC_EXICR_W, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+
+	/* Write data */
+	iowrite32be(RTC_EXICSR, iob + EXICSR);
+	iowrite32be(data, iob + EXIDATA);
+	iowrite32be(RTC_EXICR_W, iob + EXICR);
+	while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
+		cpu_relax();
+
+	/* Clear channel parameters */
+	iowrite32be(0, iob + EXICSR);
+
+	return 0;
+}
+
+static const struct regmap_bus exi_bus = {
+	/* TODO: is that true?  Not that it matters here, but still. */
+	.fast_io = true,
+	.reg_read = exi_read,
+	.reg_write = exi_write,
+};
+
+static int gamecube_rtc_read_time(struct device *dev, struct rtc_time *t)
+{
+	struct priv *d = dev_get_drvdata(dev);
+	int ret;
+	u32 counter;
+	time64_t timestamp;
+
+	ret = regmap_read(d->regmap, RTC_COUNTER, &counter);
+	if (ret)
+		return ret;
+
+	/* Add the counter and the bias to obtain the timestamp */
+	timestamp = (time64_t)d->rtc_bias + counter;
+	rtc_time64_to_tm(timestamp, t);
+
+	return 0;
+}
+
+static int gamecube_rtc_set_time(struct device *dev, struct rtc_time *t)
+{
+	struct priv *d = dev_get_drvdata(dev);
+	time64_t timestamp;
+
+	/* Subtract the timestamp and the bias to obtain the counter value */
+	timestamp = rtc_tm_to_time64(t);
+	return regmap_write(d->regmap, RTC_COUNTER, timestamp - d->rtc_bias);
+}
+
+static int gamecube_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct priv *d = dev_get_drvdata(dev);
+	int value;
+	int control0;
+	int ret;
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = regmap_read(d->regmap, RTC_CONTROL0, &control0);
+		if (ret)
+			return ret;
+
+		value = 0;
+		if (control0 & RTC_CONTROL0_UNSTABLE_POWER)
+			value |= RTC_VL_DATA_INVALID;
+		if (control0 & RTC_CONTROL0_LOW_BATTERY)
+			value |= RTC_VL_BACKUP_LOW;
+		return put_user(value, (unsigned int __user *)arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static const struct rtc_class_ops gamecube_rtc_ops = {
+	.read_time	= gamecube_rtc_read_time,
+	.set_time	= gamecube_rtc_set_time,
+	.ioctl		= gamecube_rtc_ioctl,
+};
+
+static int gamecube_rtc_read_offset_from_sram(struct priv *d)
+{
+	struct device_node *np;
+	int ret;
+	struct resource res;
+	void __iomem *hw_srnprot;
+	u32 old;
+
+	np = of_find_compatible_node(NULL, NULL, "nintendo,latte-srnprot");
+	if (!np)
+		np = of_find_compatible_node(NULL, NULL,
+					     "nintendo,hollywood-srnprot");
+	if (!np) {
+		pr_info("HW_SRNPROT not found, assuming a GameCube\n");
+		return regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
+	}
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		pr_err("no io memory range found\n");
+		return -1;
+	}
+
+	hw_srnprot = ioremap(res.start, resource_size(&res));
+	old = ioread32be(hw_srnprot);
+
+	/* TODO: figure out why we use this magic constant.  I obtained it by
+	 * reading the leftover value after boot, after IOSU already ran.
+	 *
+	 * On my Wii U, setting this register to 1 prevents the console from
+	 * rebooting properly, so wiiubrew.org must be missing something.
+	 *
+	 * See https://wiiubrew.org/wiki/Hardware/Latte_registers
+	 */
+	if (old != 0x7bf)
+		iowrite32be(0x7bf, hw_srnprot);
+
+	/* Get the offset from RTC SRAM.
+	 *
+	 * Its default location on the GameCube and on the Wii is in the SRAM,
+	 * while on the Wii U the bootloader needs to fill it with the contents
+	 * of /config/rtc.xml on the SLC (the eMMC).  We don’t do that from
+	 * Linux since it requires implementing a proprietary filesystem and do
+	 * file decryption, instead we require the bootloader to fill the same
+	 * SRAM address as on previous consoles.
+	 */
+	ret = regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
+	if (ret) {
+		pr_err("failed to get the RTC bias\n");
+		return -1;
+	}
+
+	/* Reset SRAM access to how it was before, our job here is done. */
+	if (old != 0x7bf)
+		iowrite32be(old, hw_srnprot);
+	iounmap(hw_srnprot);
+
+	return 0;
+}
+
+static const struct regmap_range rtc_rd_ranges[] = {
+	regmap_reg_range(0x200000, 0x200010),
+	regmap_reg_range(0x204000, 0x204000),
+	regmap_reg_range(0x210000, 0x210001),
+	regmap_reg_range(0x210004, 0x210007),
+	regmap_reg_range(0x21000c, 0x21000d),
+};
+
+static const struct regmap_access_table rtc_rd_regs = {
+	.yes_ranges =	rtc_rd_ranges,
+	.n_yes_ranges =	ARRAY_SIZE(rtc_rd_ranges),
+};
+
+static const struct regmap_range rtc_wr_ranges[] = {
+	regmap_reg_range(0x200000, 0x200010),
+	regmap_reg_range(0x204000, 0x204000),
+	regmap_reg_range(0x210000, 0x210001),
+	regmap_reg_range(0x21000d, 0x21000d),
+};
+
+static const struct regmap_access_table rtc_wr_regs = {
+	.yes_ranges =	rtc_wr_ranges,
+	.n_yes_ranges =	ARRAY_SIZE(rtc_wr_ranges),
+};
+
+static const struct regmap_config gamecube_rtc_regmap_config = {
+	.reg_bits = 24,
+	.val_bits = 32,
+	.rd_table = &rtc_rd_regs,
+	.wr_table = &rtc_wr_regs,
+	.max_register = 0x21000d,
+	.name = "gamecube-rtc",
+};
+
+static int gamecube_rtc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rtc_device *rtc;
+	struct priv *d;
+	int ret;
+
+	d = devm_kzalloc(dev, sizeof(struct priv), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+
+	d->iob = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(d->iob))
+		return PTR_ERR(d->iob);
+
+	d->regmap = devm_regmap_init(dev, &exi_bus, d,
+				     &gamecube_rtc_regmap_config);
+	if (IS_ERR(d->regmap))
+		return PTR_ERR(d->regmap);
+
+	ret = gamecube_rtc_read_offset_from_sram(d);
+	if (ret)
+		return ret;
+	dev_dbg(dev, "SRAM bias: 0x%x", d->rtc_bias);
+
+	dev_set_drvdata(dev, d);
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	/* We can represent further than that, but it depends on the stored
+	 * bias and we can’t modify it persistently on all supported consoles,
+	 * so here we pretend to be limited to 2106.
+	 */
+	rtc->range_min = 0;
+	rtc->range_max = U32_MAX;
+	rtc->ops = &gamecube_rtc_ops;
+
+	devm_rtc_register_device(rtc);
+
+	return 0;
+}
+
+static const struct of_device_id gamecube_rtc_of_match[] = {
+	{.compatible = "nintendo,latte-exi" },
+	{.compatible = "nintendo,hollywood-exi" },
+	{.compatible = "nintendo,flipper-exi" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gamecube_rtc_of_match);
+
+static struct platform_driver gamecube_rtc_driver = {
+	.probe		= gamecube_rtc_probe,
+	.driver		= {
+		.name	= "rtc-gamecube",
+		.of_match_table	= gamecube_rtc_of_match,
+	},
+};
+module_platform_driver(gamecube_rtc_driver);
+
+MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>");
+MODULE_DESCRIPTION("Nintendo GameCube, Wii and Wii U RTC driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c
index dcfaf09946ee..ae9f131b43c0 100644
--- a/drivers/rtc/rtc-mc146818-lib.c
+++ b/drivers/rtc/rtc-mc146818-lib.c
@@ -8,48 +8,100 @@
 #include <linux/acpi.h>
 #endif
 
-unsigned int mc146818_get_time(struct rtc_time *time)
+/*
+ * Execute a function while the UIP (Update-in-progress) bit of the RTC is
+ * unset.
+ *
+ * Warning: callback may be executed more then once.
+ */
+bool mc146818_avoid_UIP(void (*callback)(unsigned char seconds, void *param),
+			void *param)
 {
-	unsigned char ctrl;
+	int i;
 	unsigned long flags;
-	unsigned char century = 0;
-	bool retry;
+	unsigned char seconds;
 
+	for (i = 0; i < 10; i++) {
+		spin_lock_irqsave(&rtc_lock, flags);
+
+		/*
+		 * Check whether there is an update in progress during which the
+		 * readout is unspecified. The maximum update time is ~2ms. Poll
+		 * every msec for completion.
+		 *
+		 * Store the second value before checking UIP so a long lasting
+		 * NMI which happens to hit after the UIP check cannot make
+		 * an update cycle invisible.
+		 */
+		seconds = CMOS_READ(RTC_SECONDS);
+
+		if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) {
+			spin_unlock_irqrestore(&rtc_lock, flags);
+			mdelay(1);
+			continue;
+		}
+
+		/* Revalidate the above readout */
+		if (seconds != CMOS_READ(RTC_SECONDS)) {
+			spin_unlock_irqrestore(&rtc_lock, flags);
+			continue;
+		}
+
+		if (callback)
+			callback(seconds, param);
+
+		/*
+		 * Check for the UIP bit again. If it is set now then
+		 * the above values may contain garbage.
+		 */
+		if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) {
+			spin_unlock_irqrestore(&rtc_lock, flags);
+			mdelay(1);
+			continue;
+		}
+
+		/*
+		 * A NMI might have interrupted the above sequence so check
+		 * whether the seconds value has changed which indicates that
+		 * the NMI took longer than the UIP bit was set. Unlikely, but
+		 * possible and there is also virt...
+		 */
+		if (seconds != CMOS_READ(RTC_SECONDS)) {
+			spin_unlock_irqrestore(&rtc_lock, flags);
+			continue;
+		}
+		spin_unlock_irqrestore(&rtc_lock, flags);
+
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(mc146818_avoid_UIP);
+
+/*
+ * If the UIP (Update-in-progress) bit of the RTC is set for more then
+ * 10ms, the RTC is apparently broken or not present.
+ */
+bool mc146818_does_rtc_work(void)
+{
+	return mc146818_avoid_UIP(NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(mc146818_does_rtc_work);
+
+struct mc146818_get_time_callback_param {
+	struct rtc_time *time;
+	unsigned char ctrl;
+#ifdef CONFIG_ACPI
+	unsigned char century;
+#endif
 #ifdef CONFIG_MACH_DECSTATION
 	unsigned int real_year;
 #endif
+};
 
-again:
-	spin_lock_irqsave(&rtc_lock, flags);
-	/* Ensure that the RTC is accessible. Bit 6 must be 0! */
-	if (WARN_ON_ONCE((CMOS_READ(RTC_VALID) & 0x40) != 0)) {
-		spin_unlock_irqrestore(&rtc_lock, flags);
-		memset(time, 0xff, sizeof(*time));
-		return 0;
-	}
-
-	/*
-	 * Check whether there is an update in progress during which the
-	 * readout is unspecified. The maximum update time is ~2ms. Poll
-	 * every msec for completion.
-	 *
-	 * Store the second value before checking UIP so a long lasting NMI
-	 * which happens to hit after the UIP check cannot make an update
-	 * cycle invisible.
-	 */
-	time->tm_sec = CMOS_READ(RTC_SECONDS);
-
-	if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) {
-		spin_unlock_irqrestore(&rtc_lock, flags);
-		mdelay(1);
-		goto again;
-	}
-
-	/* Revalidate the above readout */
-	if (time->tm_sec != CMOS_READ(RTC_SECONDS)) {
-		spin_unlock_irqrestore(&rtc_lock, flags);
-		goto again;
-	}
+static void mc146818_get_time_callback(unsigned char seconds, void *param_in)
+{
+	struct mc146818_get_time_callback_param *p = param_in;
 
 	/*
 	 * Only the values that we read from the RTC are set. We leave
@@ -57,39 +109,39 @@ again:
 	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
 	 * by the RTC when initially set to a non-zero value.
 	 */
-	time->tm_min = CMOS_READ(RTC_MINUTES);
-	time->tm_hour = CMOS_READ(RTC_HOURS);
-	time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
-	time->tm_mon = CMOS_READ(RTC_MONTH);
-	time->tm_year = CMOS_READ(RTC_YEAR);
+	p->time->tm_sec = seconds;
+	p->time->tm_min = CMOS_READ(RTC_MINUTES);
+	p->time->tm_hour = CMOS_READ(RTC_HOURS);
+	p->time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
+	p->time->tm_mon = CMOS_READ(RTC_MONTH);
+	p->time->tm_year = CMOS_READ(RTC_YEAR);
 #ifdef CONFIG_MACH_DECSTATION
-	real_year = CMOS_READ(RTC_DEC_YEAR);
+	p->real_year = CMOS_READ(RTC_DEC_YEAR);
 #endif
 #ifdef CONFIG_ACPI
 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
-	    acpi_gbl_FADT.century)
-		century = CMOS_READ(acpi_gbl_FADT.century);
+	    acpi_gbl_FADT.century) {
+		p->century = CMOS_READ(acpi_gbl_FADT.century);
+	} else {
+		p->century = 0;
+	}
 #endif
-	ctrl = CMOS_READ(RTC_CONTROL);
-	/*
-	 * Check for the UIP bit again. If it is set now then
-	 * the above values may contain garbage.
-	 */
-	retry = CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP;
-	/*
-	 * A NMI might have interrupted the above sequence so check whether
-	 * the seconds value has changed which indicates that the NMI took
-	 * longer than the UIP bit was set. Unlikely, but possible and
-	 * there is also virt...
-	 */
-	retry |= time->tm_sec != CMOS_READ(RTC_SECONDS);
 
-	spin_unlock_irqrestore(&rtc_lock, flags);
+	p->ctrl = CMOS_READ(RTC_CONTROL);
+}
 
-	if (retry)
-		goto again;
+int mc146818_get_time(struct rtc_time *time)
+{
+	struct mc146818_get_time_callback_param p = {
+		.time = time
+	};
 
-	if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
+	if (!mc146818_avoid_UIP(mc146818_get_time_callback, &p)) {
+		memset(time, 0, sizeof(*time));
+		return -EIO;
+	}
+
+	if (!(p.ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
 	{
 		time->tm_sec = bcd2bin(time->tm_sec);
 		time->tm_min = bcd2bin(time->tm_min);
@@ -97,15 +149,19 @@ again:
 		time->tm_mday = bcd2bin(time->tm_mday);
 		time->tm_mon = bcd2bin(time->tm_mon);
 		time->tm_year = bcd2bin(time->tm_year);
-		century = bcd2bin(century);
+#ifdef CONFIG_ACPI
+		p.century = bcd2bin(p.century);
+#endif
 	}
 
 #ifdef CONFIG_MACH_DECSTATION
-	time->tm_year += real_year - 72;
+	time->tm_year += p.real_year - 72;
 #endif
 
-	if (century > 20)
-		time->tm_year += (century - 19) * 100;
+#ifdef CONFIG_ACPI
+	if (p.century > 19)
+		time->tm_year += (p.century - 19) * 100;
+#endif
 
 	/*
 	 * Account for differences between how the RTC uses the values
@@ -116,7 +172,7 @@ again:
 
 	time->tm_mon--;
 
-	return RTC_24H;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mc146818_get_time);
 
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 56c58b055dff..81a5b1f2e68c 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -748,7 +748,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
 
 	/*
 	 * Enable timestamp function and store timestamp of first trigger
-	 * event until TSF1 and TFS2 interrupt flags are cleared.
+	 * event until TSF1 and TSF2 interrupt flags are cleared.
 	 */
 	ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,
 				 PCF2127_BIT_TS_CTRL_TSOFF |
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index 15e50bb10cf0..df2b072c394d 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -514,21 +514,56 @@ static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
 }
 #endif
 
-static const struct pcf85063_config pcf85063tp_config = {
-	.regmap = {
-		.reg_bits = 8,
-		.val_bits = 8,
-		.max_register = 0x0a,
+enum pcf85063_type {
+	PCF85063,
+	PCF85063TP,
+	PCF85063A,
+	RV8263,
+	PCF85063_LAST_ID
+};
+
+static struct pcf85063_config pcf85063_cfg[] = {
+	[PCF85063] = {
+		.regmap = {
+			.reg_bits = 8,
+			.val_bits = 8,
+			.max_register = 0x0a,
+		},
+	},
+	[PCF85063TP] = {
+		.regmap = {
+			.reg_bits = 8,
+			.val_bits = 8,
+			.max_register = 0x0a,
+		},
+	},
+	[PCF85063A] = {
+		.regmap = {
+			.reg_bits = 8,
+			.val_bits = 8,
+			.max_register = 0x11,
+		},
+		.has_alarms = 1,
+	},
+	[RV8263] = {
+		.regmap = {
+			.reg_bits = 8,
+			.val_bits = 8,
+			.max_register = 0x11,
+		},
+		.has_alarms = 1,
+		.force_cap_7000 = 1,
 	},
 };
 
+static const struct i2c_device_id pcf85063_ids[];
+
 static int pcf85063_probe(struct i2c_client *client)
 {
 	struct pcf85063 *pcf85063;
 	unsigned int tmp;
 	int err;
-	const struct pcf85063_config *config = &pcf85063tp_config;
-	const void *data = of_device_get_match_data(&client->dev);
+	const struct pcf85063_config *config;
 	struct nvmem_config nvmem_cfg = {
 		.name = "pcf85063_nvram",
 		.reg_read = pcf85063_nvmem_read,
@@ -544,8 +579,17 @@ static int pcf85063_probe(struct i2c_client *client)
 	if (!pcf85063)
 		return -ENOMEM;
 
-	if (data)
-		config = data;
+	if (client->dev.of_node) {
+		config = of_device_get_match_data(&client->dev);
+		if (!config)
+			return -ENODEV;
+	} else {
+		enum pcf85063_type type =
+			i2c_match_id(pcf85063_ids, client)->driver_data;
+		if (type >= PCF85063_LAST_ID)
+			return -ENODEV;
+		config = &pcf85063_cfg[type];
+	}
 
 	pcf85063->regmap = devm_regmap_init_i2c(client, &config->regmap);
 	if (IS_ERR(pcf85063->regmap))
@@ -604,31 +648,21 @@ static int pcf85063_probe(struct i2c_client *client)
 	return devm_rtc_register_device(pcf85063->rtc);
 }
 
+static const struct i2c_device_id pcf85063_ids[] = {
+	{ "pcf85063", PCF85063 },
+	{ "pcf85063tp", PCF85063TP },
+	{ "pcf85063a", PCF85063A },
+	{ "rv8263", RV8263 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, pcf85063_ids);
+
 #ifdef CONFIG_OF
-static const struct pcf85063_config pcf85063a_config = {
-	.regmap = {
-		.reg_bits = 8,
-		.val_bits = 8,
-		.max_register = 0x11,
-	},
-	.has_alarms = 1,
-};
-
-static const struct pcf85063_config rv8263_config = {
-	.regmap = {
-		.reg_bits = 8,
-		.val_bits = 8,
-		.max_register = 0x11,
-	},
-	.has_alarms = 1,
-	.force_cap_7000 = 1,
-};
-
 static const struct of_device_id pcf85063_of_match[] = {
-	{ .compatible = "nxp,pcf85063", .data = &pcf85063tp_config },
-	{ .compatible = "nxp,pcf85063tp", .data = &pcf85063tp_config },
-	{ .compatible = "nxp,pcf85063a", .data = &pcf85063a_config },
-	{ .compatible = "microcrystal,rv8263", .data = &rv8263_config },
+	{ .compatible = "nxp,pcf85063", .data = &pcf85063_cfg[PCF85063] },
+	{ .compatible = "nxp,pcf85063tp", .data = &pcf85063_cfg[PCF85063TP] },
+	{ .compatible = "nxp,pcf85063a", .data = &pcf85063_cfg[PCF85063A] },
+	{ .compatible = "microcrystal,rv8263", .data = &pcf85063_cfg[RV8263] },
 	{}
 };
 MODULE_DEVICE_TABLE(of, pcf85063_of_match);
@@ -640,6 +674,7 @@ static struct i2c_driver pcf85063_driver = {
 		.of_match_table = of_match_ptr(pcf85063_of_match),
 	},
 	.probe_new	= pcf85063_probe,
+	.id_table	= pcf85063_ids,
 };
 
 module_i2c_driver(pcf85063_driver);
diff --git a/drivers/rtc/rtc-pxa.c b/drivers/rtc/rtc-pxa.c
index d2f1d8f754bf..cf8119b6d320 100644
--- a/drivers/rtc/rtc-pxa.c
+++ b/drivers/rtc/rtc-pxa.c
@@ -330,6 +330,10 @@ static int __init pxa_rtc_probe(struct platform_device *pdev)
 	if (sa1100_rtc->irq_alarm < 0)
 		return -ENXIO;
 
+	sa1100_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(sa1100_rtc->rtc))
+		return PTR_ERR(sa1100_rtc->rtc);
+
 	pxa_rtc->base = devm_ioremap(dev, pxa_rtc->ress->start,
 				resource_size(pxa_rtc->ress));
 	if (!pxa_rtc->base) {
diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 80980414890c..cb15983383f5 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -28,8 +28,10 @@
 #define RS5C372_REG_MONTH	5
 #define RS5C372_REG_YEAR	6
 #define RS5C372_REG_TRIM	7
-#	define RS5C372_TRIM_XSL		0x80
+#	define RS5C372_TRIM_XSL		0x80		/* only if RS5C372[a|b] */
 #	define RS5C372_TRIM_MASK	0x7F
+#	define R2221TL_TRIM_DEV		(1 << 7)	/* only if R2221TL */
+#	define RS5C372_TRIM_DECR	(1 << 6)
 
 #define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
 #define RS5C_REG_ALARM_A_HOURS	9
@@ -324,8 +326,12 @@ static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 
-	if (osc)
-		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
+	if (osc) {
+		if (rs5c372->type == rtc_rs5c372a || rs5c372->type == rtc_rs5c372b)
+			*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
+		else
+			*osc = 32768;
+	}
 
 	if (trim) {
 		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
@@ -485,6 +491,176 @@ static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 #define	rs5c372_rtc_proc	NULL
 #endif
 
+#ifdef CONFIG_RTC_INTF_DEV
+static int rs5c372_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+	struct rs5c372	*rs5c = i2c_get_clientdata(to_i2c_client(dev));
+	unsigned char	ctrl2;
+	int		addr;
+	unsigned int	flags;
+
+	dev_dbg(dev, "%s: cmd=%x\n", __func__, cmd);
+
+	addr = RS5C_ADDR(RS5C_REG_CTRL2);
+	ctrl2 = i2c_smbus_read_byte_data(rs5c->client, addr);
+
+	switch (cmd) {
+	case RTC_VL_READ:
+		flags = 0;
+
+		switch (rs5c->type) {
+		case rtc_r2025sd:
+		case rtc_r2221tl:
+			if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) ||
+				(rs5c->type == rtc_r2221tl &&  (ctrl2 & R2x2x_CTRL2_XSTP))) {
+				flags |= RTC_VL_DATA_INVALID;
+			}
+			if (ctrl2 & R2x2x_CTRL2_VDET)
+				flags |= RTC_VL_BACKUP_LOW;
+			break;
+		default:
+			if (ctrl2 & RS5C_CTRL2_XSTP)
+				flags |= RTC_VL_DATA_INVALID;
+			break;
+		}
+
+		return put_user(flags, (unsigned int __user *)arg);
+	case RTC_VL_CLR:
+		/* clear VDET bit */
+		if (rs5c->type == rtc_r2025sd || rs5c->type == rtc_r2221tl) {
+			ctrl2 &= ~R2x2x_CTRL2_VDET;
+			if (i2c_smbus_write_byte_data(rs5c->client, addr, ctrl2) < 0) {
+				dev_dbg(&rs5c->client->dev, "%s: write error in line %i\n",
+						__func__, __LINE__);
+				return -EIO;
+			}
+		}
+		return 0;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+#else
+#define rs5c372_ioctl	NULL
+#endif
+
+static int rs5c372_read_offset(struct device *dev, long *offset)
+{
+	struct rs5c372 *rs5c = i2c_get_clientdata(to_i2c_client(dev));
+	u8 val = rs5c->regs[RS5C372_REG_TRIM];
+	long ppb_per_step = 0;
+	bool decr = val & RS5C372_TRIM_DECR;
+
+	switch (rs5c->type) {
+	case rtc_r2221tl:
+		ppb_per_step = val & R2221TL_TRIM_DEV ? 1017 : 3051;
+		break;
+	case rtc_rs5c372a:
+	case rtc_rs5c372b:
+		ppb_per_step = val & RS5C372_TRIM_XSL ? 3125 : 3051;
+		break;
+	default:
+		ppb_per_step = 3051;
+		break;
+	}
+
+	/* Only bits[0:5] repsents the time counts */
+	val &= 0x3F;
+
+	/* If bits[1:5] are all 0, it means no increment or decrement */
+	if (!(val & 0x3E)) {
+		*offset = 0;
+	} else {
+		if (decr)
+			*offset = -(((~val) & 0x3F) + 1) * ppb_per_step;
+		else
+			*offset = (val - 1) * ppb_per_step;
+	}
+
+	return 0;
+}
+
+static int rs5c372_set_offset(struct device *dev, long offset)
+{
+	struct rs5c372 *rs5c = i2c_get_clientdata(to_i2c_client(dev));
+	int addr = RS5C_ADDR(RS5C372_REG_TRIM);
+	u8 val = 0;
+	u8 tmp = 0;
+	long ppb_per_step = 3051;
+	long steps = LONG_MIN;
+
+	switch (rs5c->type) {
+	case rtc_rs5c372a:
+	case rtc_rs5c372b:
+		tmp = rs5c->regs[RS5C372_REG_TRIM];
+		if (tmp & RS5C372_TRIM_XSL) {
+			ppb_per_step = 3125;
+			val |= RS5C372_TRIM_XSL;
+		}
+		break;
+	case rtc_r2221tl:
+		/*
+		 * Check if it is possible to use high resolution mode (DEV=1).
+		 * In this mode, the minimum resolution is 2 / (32768 * 20 * 3),
+		 * which is about 1017 ppb.
+		 */
+		steps = DIV_ROUND_CLOSEST(offset, 1017);
+		if (steps >= -0x3E && steps <= 0x3E) {
+			ppb_per_step = 1017;
+			val |= R2221TL_TRIM_DEV;
+		} else {
+			/*
+			 * offset is out of the range of high resolution mode.
+			 * Try to use low resolution mode (DEV=0). In this mode,
+			 * the minimum resolution is 2 / (32768 * 20), which is
+			 * about 3051 ppb.
+			 */
+			steps = LONG_MIN;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (steps == LONG_MIN) {
+		steps = DIV_ROUND_CLOSEST(offset, ppb_per_step);
+		if (steps > 0x3E || steps < -0x3E)
+			return -ERANGE;
+	}
+
+	if (steps > 0) {
+		val |= steps + 1;
+	} else {
+		val |= RS5C372_TRIM_DECR;
+		val |= (~(-steps - 1)) & 0x3F;
+	}
+
+	if (!steps || !(val & 0x3E)) {
+		/*
+		 * if offset is too small, set oscillation adjustment register
+		 * or time trimming register with its default value whic means
+		 * no increment or decrement. But for rs5c372[a|b], the XSL bit
+		 * should be kept unchanged.
+		 */
+		if (rs5c->type == rtc_rs5c372a || rs5c->type == rtc_rs5c372b)
+			val &= RS5C372_TRIM_XSL;
+		else
+			val = 0;
+	}
+
+	dev_dbg(&rs5c->client->dev, "write 0x%x for offset %ld\n", val, offset);
+
+	if (i2c_smbus_write_byte_data(rs5c->client, addr, val) < 0) {
+		dev_err(&rs5c->client->dev, "failed to write 0x%x to reg %d\n", val, addr);
+		return -EIO;
+	}
+
+	rs5c->regs[RS5C372_REG_TRIM] = val;
+
+	return 0;
+}
+
 static const struct rtc_class_ops rs5c372_rtc_ops = {
 	.proc		= rs5c372_rtc_proc,
 	.read_time	= rs5c372_rtc_read_time,
@@ -492,6 +668,9 @@ static const struct rtc_class_ops rs5c372_rtc_ops = {
 	.read_alarm	= rs5c_read_alarm,
 	.set_alarm	= rs5c_set_alarm,
 	.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
+	.ioctl		= rs5c372_ioctl,
+	.read_offset    = rs5c372_read_offset,
+	.set_offset     = rs5c372_set_offset,
 };
 
 #if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index 0d5ed38bf60c..f69e0b1137cd 100644
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -55,6 +55,7 @@
 
 enum rv8803_type {
 	rv_8803,
+	rx_8804,
 	rx_8900
 };
 
@@ -601,6 +602,7 @@ static int rv8803_probe(struct i2c_client *client,
 
 static const struct i2c_device_id rv8803_id[] = {
 	{ "rv8803", rv_8803 },
+	{ "rv8804", rx_8804 },
 	{ "rx8803", rv_8803 },
 	{ "rx8900", rx_8900 },
 	{ }
@@ -616,6 +618,10 @@ static const __maybe_unused struct of_device_id rv8803_of_match[] = {
 		.compatible = "epson,rx8803",
 		.data = (void *)rv_8803
 	},
+	{
+		.compatible = "epson,rx8804",
+		.data = (void *)rx_8804
+	},
 	{
 		.compatible = "epson,rx8900",
 		.data = (void *)rx_8900
diff --git a/drivers/rtc/rtc-sunplus.c b/drivers/rtc/rtc-sunplus.c
new file mode 100644
index 000000000000..e8e2ab1103fc
--- /dev/null
+++ b/drivers/rtc/rtc-sunplus.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * The RTC driver for Sunplus	SP7021
+ *
+ * Copyright (C) 2019 Sunplus Technology Inc., All rights reseerved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/rtc.h>
+
+#define RTC_REG_NAME			"rtc"
+
+#define RTC_CTRL			0x40
+#define TIMER_FREEZE_MASK_BIT		BIT(5 + 16)
+#define TIMER_FREEZE			BIT(5)
+#define DIS_SYS_RST_RTC_MASK_BIT	BIT(4 + 16)
+#define DIS_SYS_RST_RTC			BIT(4)
+#define RTC32K_MODE_RESET_MASK_BIT	BIT(3 + 16)
+#define RTC32K_MODE_RESET		BIT(3)
+#define ALARM_EN_OVERDUE_MASK_BIT	BIT(2 + 16)
+#define ALARM_EN_OVERDUE		BIT(2)
+#define ALARM_EN_PMC_MASK_BIT		BIT(1 + 16)
+#define ALARM_EN_PMC			BIT(1)
+#define ALARM_EN_MASK_BIT		BIT(0 + 16)
+#define ALARM_EN			BIT(0)
+#define RTC_TIMER_OUT			0x44
+#define RTC_DIVIDER			0x48
+#define RTC_TIMER_SET			0x4c
+#define RTC_ALARM_SET			0x50
+#define RTC_USER_DATA			0x54
+#define RTC_RESET_RECORD		0x58
+#define RTC_BATT_CHARGE_CTRL		0x5c
+#define BAT_CHARGE_RSEL_MASK_BIT	GENMASK(3 + 16, 2 + 16)
+#define BAT_CHARGE_RSEL_MASK		GENMASK(3, 2)
+#define BAT_CHARGE_RSEL_2K_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 0)
+#define BAT_CHARGE_RSEL_250_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 1)
+#define BAT_CHARGE_RSEL_50_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 2)
+#define BAT_CHARGE_RSEL_0_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 3)
+#define BAT_CHARGE_DSEL_MASK_BIT	BIT(1 + 16)
+#define BAT_CHARGE_DSEL_MASK		GENMASK(1, 1)
+#define BAT_CHARGE_DSEL_ON		FIELD_PREP(BAT_CHARGE_DSEL_MASK, 0)
+#define BAT_CHARGE_DSEL_OFF		FIELD_PREP(BAT_CHARGE_DSEL_MASK, 1)
+#define BAT_CHARGE_EN_MASK_BIT		BIT(0 + 16)
+#define BAT_CHARGE_EN			BIT(0)
+#define RTC_TRIM_CTRL			0x60
+
+struct sunplus_rtc {
+	struct rtc_device *rtc;
+	struct resource *res;
+	struct clk *rtcclk;
+	struct reset_control *rstc;
+	void __iomem *reg_base;
+	int irq;
+};
+
+static void sp_get_seconds(struct device *dev, unsigned long *secs)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+
+	*secs = (unsigned long)readl(sp_rtc->reg_base + RTC_TIMER_OUT);
+}
+
+static void sp_set_seconds(struct device *dev, unsigned long secs)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+
+	writel((u32)secs, sp_rtc->reg_base + RTC_TIMER_SET);
+}
+
+static int sp_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long secs;
+
+	sp_get_seconds(dev, &secs);
+	rtc_time64_to_tm(secs, tm);
+
+	return 0;
+}
+
+static int sp_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long secs;
+
+	secs = rtc_tm_to_time64(tm);
+	dev_dbg(dev, "%s, secs = %lu\n", __func__, secs);
+	sp_set_seconds(dev, secs);
+
+	return 0;
+}
+
+static int sp_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+	unsigned long alarm_time;
+
+	alarm_time = rtc_tm_to_time64(&alrm->time);
+	dev_dbg(dev, "%s, alarm_time: %u\n", __func__, (u32)(alarm_time));
+	writel((u32)alarm_time, sp_rtc->reg_base + RTC_ALARM_SET);
+
+	return 0;
+}
+
+static int sp_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+	unsigned int alarm_time;
+
+	alarm_time = readl(sp_rtc->reg_base + RTC_ALARM_SET);
+	dev_dbg(dev, "%s, alarm_time: %u\n", __func__, alarm_time);
+
+	if (alarm_time == 0)
+		alrm->enabled = 0;
+	else
+		alrm->enabled = 1;
+
+	rtc_time64_to_tm((unsigned long)(alarm_time), &alrm->time);
+
+	return 0;
+}
+
+static int sp_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+
+	if (enabled)
+		writel((TIMER_FREEZE_MASK_BIT | DIS_SYS_RST_RTC_MASK_BIT |
+			RTC32K_MODE_RESET_MASK_BIT | ALARM_EN_OVERDUE_MASK_BIT |
+			ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) |
+			(DIS_SYS_RST_RTC | ALARM_EN_OVERDUE | ALARM_EN_PMC | ALARM_EN),
+			sp_rtc->reg_base + RTC_CTRL);
+	else
+		writel((ALARM_EN_OVERDUE_MASK_BIT | ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) |
+			0x0, sp_rtc->reg_base + RTC_CTRL);
+
+	return 0;
+}
+
+static const struct rtc_class_ops sp_rtc_ops = {
+	.read_time =		sp_rtc_read_time,
+	.set_time =		sp_rtc_set_time,
+	.set_alarm =		sp_rtc_set_alarm,
+	.read_alarm =		sp_rtc_read_alarm,
+	.alarm_irq_enable =	sp_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t sp_rtc_irq_handler(int irq, void *dev_id)
+{
+	struct platform_device *plat_dev = dev_id;
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev);
+
+	rtc_update_irq(sp_rtc->rtc, 1, RTC_IRQF | RTC_AF);
+	dev_dbg(&plat_dev->dev, "[RTC] ALARM INT\n");
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * -------------------------------------------------------------------------------------
+ * bat_charge_rsel   bat_charge_dsel   bat_charge_en     Remarks
+ *         x              x                 0            Disable
+ *         0              0                 1            0.86mA (2K Ohm with diode)
+ *         1              0                 1            1.81mA (250 Ohm with diode)
+ *         2              0                 1            2.07mA (50 Ohm with diode)
+ *         3              0                 1            16.0mA (0 Ohm with diode)
+ *         0              1                 1            1.36mA (2K Ohm without diode)
+ *         1              1                 1            3.99mA (250 Ohm without diode)
+ *         2              1                 1            4.41mA (50 Ohm without diode)
+ *         3              1                 1            16.0mA (0 Ohm without diode)
+ * -------------------------------------------------------------------------------------
+ */
+static void sp_rtc_set_trickle_charger(struct device dev)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(&dev);
+	u32 ohms, rsel;
+	u32 chargeable;
+
+	if (of_property_read_u32(dev.of_node, "trickle-resistor-ohms", &ohms) ||
+	    of_property_read_u32(dev.of_node, "aux-voltage-chargeable", &chargeable)) {
+		dev_warn(&dev, "battery charger disabled\n");
+		return;
+	}
+
+	switch (ohms) {
+	case 2000:
+		rsel = BAT_CHARGE_RSEL_2K_OHM;
+		break;
+	case 250:
+		rsel = BAT_CHARGE_RSEL_250_OHM;
+		break;
+	case 50:
+		rsel = BAT_CHARGE_RSEL_50_OHM;
+		break;
+	case 0:
+		rsel = BAT_CHARGE_RSEL_0_OHM;
+		break;
+	default:
+		dev_err(&dev, "invalid charger resistor value (%d)\n", ohms);
+		return;
+	}
+
+	writel(BAT_CHARGE_RSEL_MASK_BIT | rsel, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
+
+	switch (chargeable) {
+	case 0:
+		writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_OFF,
+		       sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
+		break;
+	case 1:
+		writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_ON,
+		       sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
+		break;
+	default:
+		dev_err(&dev, "invalid aux-voltage-chargeable value (%d)\n", chargeable);
+		return;
+	}
+
+	writel(BAT_CHARGE_EN_MASK_BIT | BAT_CHARGE_EN, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
+}
+
+static int sp_rtc_probe(struct platform_device *plat_dev)
+{
+	struct sunplus_rtc *sp_rtc;
+	int ret;
+
+	sp_rtc = devm_kzalloc(&plat_dev->dev, sizeof(*sp_rtc), GFP_KERNEL);
+	if (!sp_rtc)
+		return -ENOMEM;
+
+	sp_rtc->res = platform_get_resource_byname(plat_dev, IORESOURCE_MEM, RTC_REG_NAME);
+	sp_rtc->reg_base = devm_ioremap_resource(&plat_dev->dev, sp_rtc->res);
+	if (IS_ERR(sp_rtc->reg_base))
+		return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->reg_base),
+					    "%s devm_ioremap_resource fail\n", RTC_REG_NAME);
+	dev_dbg(&plat_dev->dev, "res = 0x%x, reg_base = 0x%lx\n",
+		sp_rtc->res->start, (unsigned long)sp_rtc->reg_base);
+
+	sp_rtc->irq = platform_get_irq(plat_dev, 0);
+	if (sp_rtc->irq < 0)
+		return dev_err_probe(&plat_dev->dev, sp_rtc->irq, "platform_get_irq failed\n");
+
+	ret = devm_request_irq(&plat_dev->dev, sp_rtc->irq, sp_rtc_irq_handler,
+			       IRQF_TRIGGER_RISING, "rtc irq", plat_dev);
+	if (ret)
+		return dev_err_probe(&plat_dev->dev, ret, "devm_request_irq failed:\n");
+
+	sp_rtc->rtcclk = devm_clk_get(&plat_dev->dev, NULL);
+	if (IS_ERR(sp_rtc->rtcclk))
+		return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rtcclk),
+					    "devm_clk_get fail\n");
+
+	sp_rtc->rstc = devm_reset_control_get_exclusive(&plat_dev->dev, NULL);
+	if (IS_ERR(sp_rtc->rstc))
+		return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rstc),
+					    "failed to retrieve reset controller\n");
+
+	ret = clk_prepare_enable(sp_rtc->rtcclk);
+	if (ret)
+		goto free_clk;
+
+	ret = reset_control_deassert(sp_rtc->rstc);
+	if (ret)
+		goto free_reset_assert;
+
+	device_init_wakeup(&plat_dev->dev, 1);
+	dev_set_drvdata(&plat_dev->dev, sp_rtc);
+
+	sp_rtc->rtc = devm_rtc_allocate_device(&plat_dev->dev);
+	if (IS_ERR(sp_rtc->rtc)) {
+		ret = PTR_ERR(sp_rtc->rtc);
+		goto free_reset_assert;
+	}
+
+	sp_rtc->rtc->range_max = U32_MAX;
+	sp_rtc->rtc->range_min = 0;
+	sp_rtc->rtc->ops = &sp_rtc_ops;
+
+	ret = devm_rtc_register_device(sp_rtc->rtc);
+	if (ret)
+		goto free_reset_assert;
+
+	/* Setup trickle charger */
+	if (plat_dev->dev.of_node)
+		sp_rtc_set_trickle_charger(plat_dev->dev);
+
+	/* Keep RTC from system reset */
+	writel(DIS_SYS_RST_RTC_MASK_BIT | DIS_SYS_RST_RTC, sp_rtc->reg_base + RTC_CTRL);
+
+	return 0;
+
+free_reset_assert:
+	reset_control_assert(sp_rtc->rstc);
+free_clk:
+	clk_disable_unprepare(sp_rtc->rtcclk);
+
+	return ret;
+}
+
+static int sp_rtc_remove(struct platform_device *plat_dev)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev);
+
+	device_init_wakeup(&plat_dev->dev, 0);
+	reset_control_assert(sp_rtc->rstc);
+	clk_disable_unprepare(sp_rtc->rtcclk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int sp_rtc_suspend(struct device *dev)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(sp_rtc->irq);
+
+	return 0;
+}
+
+static int sp_rtc_resume(struct device *dev)
+{
+	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(sp_rtc->irq);
+
+	return 0;
+}
+#endif
+
+static const struct of_device_id sp_rtc_of_match[] = {
+	{ .compatible = "sunplus,sp7021-rtc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sp_rtc_of_match);
+
+static SIMPLE_DEV_PM_OPS(sp_rtc_pm_ops, sp_rtc_suspend, sp_rtc_resume);
+
+static struct platform_driver sp_rtc_driver = {
+	.probe   = sp_rtc_probe,
+	.remove  = sp_rtc_remove,
+	.driver  = {
+		.name	= "sp7021-rtc",
+		.of_match_table = sp_rtc_of_match,
+		.pm	= &sp_rtc_pm_ops,
+	},
+};
+module_platform_driver(sp_rtc_driver);
+
+MODULE_AUTHOR("Vincent Shih <vincent.sunplus@gmail.com>");
+MODULE_DESCRIPTION("Sunplus RTC driver");
+MODULE_LICENSE("GPL v2");
+
diff --git a/include/linux/mc146818rtc.h b/include/linux/mc146818rtc.h
index 0661af17a758..808bb4cee230 100644
--- a/include/linux/mc146818rtc.h
+++ b/include/linux/mc146818rtc.h
@@ -123,7 +123,11 @@ struct cmos_rtc_board_info {
 #define RTC_IO_EXTENT_USED      RTC_IO_EXTENT
 #endif /* ARCH_RTC_LOCATION */
 
-unsigned int mc146818_get_time(struct rtc_time *time);
+bool mc146818_does_rtc_work(void);
+int mc146818_get_time(struct rtc_time *time);
 int mc146818_set_time(struct rtc_time *time);
 
+bool mc146818_avoid_UIP(void (*callback)(unsigned char seconds, void *param),
+			void *param);
+
 #endif /* _MC146818RTC_H */