1 files changed, 378 insertions, 296 deletions

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index a5a19ff10535..0743c6acd6e2 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * RTC class driver for "CMOS RTC":  PCs, ACPI, etc
  *
  * Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
  * Copyright (C) 2006 David Brownell (convert to new framework)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 /*
@@ -155,11 +151,6 @@ static inline int hpet_set_periodic_freq(unsigned long freq)
 	return 0;
 }
 
-static inline int hpet_rtc_dropped_irq(void)
-{
-	return 0;
-}
-
 static inline int hpet_rtc_timer_init(void)
 {
 	return 0;
@@ -226,6 +217,8 @@ 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.
@@ -233,61 +226,86 @@ static int cmos_read_time(struct device *dev, struct rtc_time *t)
 	if (!pm_trace_rtc_valid())
 		return -EIO;
 
-	/* REVISIT:  if the clock has a "century" register, use
-	 * that instead of the heuristic in mc146818_get_time().
-	 * That'll make Y3K compatility (year > 2070) easy!
-	 */
-	mc146818_get_time(t);
+	ret = mc146818_get_time(t, 1000);
+	if (ret < 0) {
+		dev_err_ratelimited(dev, "unable to read current time\n");
+		return ret;
+	}
+
 	return 0;
 }
 
 static int cmos_set_time(struct device *dev, struct rtc_time *t)
 {
-	/* REVISIT:  set the "century" register if available
-	 *
-	 * NOTE: this ignores the issue whereby updating the seconds
+	/* NOTE: this ignores the issue whereby updating the seconds
 	 * takes effect exactly 500ms after we write the register.
 	 * (Also queueing and other delays before we get this far.)
 	 */
 	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))
-		return -EIO;
+		return -ETIMEDOUT;
 
 	/* Basic alarms only support hour, minute, and seconds fields.
 	 * Some also support day and month, for alarms up to a year in
 	 * 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);
-
-	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);
+	/* 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, 10, &p))
+		return -EIO;
 
-	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
@@ -316,7 +334,7 @@ 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;
@@ -447,10 +465,57 @@ 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 */
@@ -461,52 +526,33 @@ 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;
+	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);
 	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".  */
-		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;
-	}
-
-	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);
+		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;
 	}
 
-	if (t->enabled)
-		cmos_irq_enable(cmos, RTC_AIE);
-
-	spin_unlock_irq(&rtc_lock);
+	/*
+	 * 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, 10, &p))
+		return -ETIMEDOUT;
 
 	cmos->alarm_expires = rtc_tm_to_time64(&t->time);
 
@@ -578,12 +624,6 @@ static const struct rtc_class_ops cmos_rtc_ops = {
 	.alarm_irq_enable	= cmos_alarm_irq_enable,
 };
 
-static const struct rtc_class_ops cmos_rtc_ops_no_alarm = {
-	.read_time		= cmos_read_time,
-	.set_time		= cmos_set_time,
-	.proc			= cmos_procfs,
-};
-
 /*----------------------------------------------------------------*/
 
 /*
@@ -598,21 +638,19 @@ static int cmos_nvram_read(void *priv, unsigned int off, void *val,
 			   size_t count)
 {
 	unsigned char *buf = val;
-	int	retval;
 
 	off += NVRAM_OFFSET;
-	spin_lock_irq(&rtc_lock);
-	for (retval = 0; count; count--, off++, retval++) {
+	for (; count; count--, off++, buf++) {
+		guard(spinlock_irq)(&rtc_lock);
 		if (off < 128)
-			*buf++ = CMOS_READ(off);
+			*buf = CMOS_READ(off);
 		else if (can_bank2)
-			*buf++ = cmos_read_bank2(off);
+			*buf = cmos_read_bank2(off);
 		else
-			break;
+			return -EIO;
 	}
-	spin_unlock_irq(&rtc_lock);
 
-	return retval;
+	return 0;
 }
 
 static int cmos_nvram_write(void *priv, unsigned int off, void *val,
@@ -620,7 +658,6 @@ static int cmos_nvram_write(void *priv, unsigned int off, void *val,
 {
 	struct cmos_rtc	*cmos = priv;
 	unsigned char	*buf = val;
-	int		retval;
 
 	/* NOTE:  on at least PCs and Ataris, the boot firmware uses a
 	 * checksum on part of the NVRAM data.  That's currently ignored
@@ -628,23 +665,23 @@ static int cmos_nvram_write(void *priv, unsigned int off, void *val,
 	 * NVRAM to update, updating checksums is also part of its job.
 	 */
 	off += NVRAM_OFFSET;
-	spin_lock_irq(&rtc_lock);
-	for (retval = 0; count; count--, off++, retval++) {
+	for (; count; count--, off++, buf++) {
 		/* don't trash RTC registers */
 		if (off == cmos->day_alrm
 				|| off == cmos->mon_alrm
 				|| off == cmos->century)
-			buf++;
-		else if (off < 128)
-			CMOS_WRITE(*buf++, off);
+			continue;
+
+		guard(spinlock_irq)(&rtc_lock);
+		if (off < 128)
+			CMOS_WRITE(*buf, off);
 		else if (can_bank2)
-			cmos_write_bank2(*buf++, off);
+			cmos_write_bank2(*buf, off);
 		else
-			break;
+			return -EIO;
 	}
-	spin_unlock_irq(&rtc_lock);
 
-	return retval;
+	return 0;
 }
 
 /*----------------------------------------------------------------*/
@@ -655,8 +692,12 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
 {
 	u8		irqstat;
 	u8		rtc_control;
+	unsigned long	flags;
 
-	spin_lock(&rtc_lock);
+	/* We cannot use spin_lock() here, as cmos_interrupt() is also called
+	 * in a non-irq context.
+	 */
+	spin_lock_irqsave(&rtc_lock, flags);
 
 	/* When the HPET interrupt handler calls us, the interrupt
 	 * status is passed as arg1 instead of the irq number.  But
@@ -690,7 +731,7 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
 			hpet_mask_rtc_irq_bit(RTC_AIE);
 		CMOS_READ(RTC_INTR_FLAGS);
 	}
-	spin_unlock(&rtc_lock);
+	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	if (is_intr(irqstat)) {
 		rtc_update_irq(p, 1, irqstat);
@@ -699,6 +740,174 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
 		return IRQ_NONE;
 }
 
+#ifdef	CONFIG_ACPI
+
+#include <linux/acpi.h>
+
+static u32 rtc_handler(void *context)
+{
+	struct device *dev = context;
+	struct cmos_rtc *cmos = dev_get_drvdata(dev);
+	unsigned char rtc_control = 0;
+	unsigned char rtc_intr;
+	unsigned long flags;
+
+
+	/*
+	 * Always update rtc irq when ACPI is used as RTC Alarm.
+	 * Or else, ACPI SCI is enabled during suspend/resume only,
+	 * update rtc irq in that case.
+	 */
+	if (cmos_use_acpi_alarm())
+		cmos_interrupt(0, (void *)cmos->rtc);
+	else {
+		/* Fix me: can we use cmos_interrupt() here as well? */
+		spin_lock_irqsave(&rtc_lock, flags);
+		if (cmos_rtc.suspend_ctrl)
+			rtc_control = CMOS_READ(RTC_CONTROL);
+		if (rtc_control & RTC_AIE) {
+			cmos_rtc.suspend_ctrl &= ~RTC_AIE;
+			CMOS_WRITE(rtc_control, RTC_CONTROL);
+			rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
+			rtc_update_irq(cmos->rtc, 1, rtc_intr);
+		}
+		spin_unlock_irqrestore(&rtc_lock, flags);
+	}
+
+	pm_wakeup_hard_event(dev);
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+	return ACPI_INTERRUPT_HANDLED;
+}
+
+static void acpi_rtc_event_setup(struct device *dev)
+{
+	if (acpi_disabled)
+		return;
+
+	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
+	/*
+	 * After the RTC handler is installed, the Fixed_RTC event should
+	 * be disabled. Only when the RTC alarm is set will it be enabled.
+	 */
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+}
+
+static void acpi_rtc_event_cleanup(void)
+{
+	if (acpi_disabled)
+		return;
+
+	acpi_remove_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler);
+}
+
+static void rtc_wake_on(struct device *dev)
+{
+	acpi_clear_event(ACPI_EVENT_RTC);
+	acpi_enable_event(ACPI_EVENT_RTC, 0);
+}
+
+static void rtc_wake_off(struct device *dev)
+{
+	acpi_disable_event(ACPI_EVENT_RTC, 0);
+}
+
+#ifdef CONFIG_X86
+static void use_acpi_alarm_quirks(void)
+{
+	switch (boot_cpu_data.x86_vendor) {
+	case X86_VENDOR_INTEL:
+		if (dmi_get_bios_year() < 2015)
+			return;
+		break;
+	case X86_VENDOR_AMD:
+	case X86_VENDOR_HYGON:
+		if (dmi_get_bios_year() < 2021)
+			return;
+		break;
+	default:
+		return;
+	}
+	if (!is_hpet_enabled())
+		return;
+
+	use_acpi_alarm = true;
+}
+#else
+static inline void use_acpi_alarm_quirks(void) { }
+#endif
+
+static void acpi_cmos_wake_setup(struct device *dev)
+{
+	if (acpi_disabled)
+		return;
+
+	use_acpi_alarm_quirks();
+
+	cmos_rtc.wake_on = rtc_wake_on;
+	cmos_rtc.wake_off = rtc_wake_off;
+
+	/* ACPI tables bug workaround. */
+	if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
+		dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
+			acpi_gbl_FADT.month_alarm);
+		acpi_gbl_FADT.month_alarm = 0;
+	}
+
+	cmos_rtc.day_alrm = acpi_gbl_FADT.day_alarm;
+	cmos_rtc.mon_alrm = acpi_gbl_FADT.month_alarm;
+	cmos_rtc.century = acpi_gbl_FADT.century;
+
+	if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
+		dev_info(dev, "RTC can wake from S4\n");
+
+	/* RTC always wakes from S1/S2/S3, and often S4/STD */
+	device_init_wakeup(dev, true);
+}
+
+static void cmos_check_acpi_rtc_status(struct device *dev,
+					      unsigned char *rtc_control)
+{
+	struct cmos_rtc *cmos = dev_get_drvdata(dev);
+	acpi_event_status rtc_status;
+	acpi_status status;
+
+	if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
+		return;
+
+	status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "Could not get RTC status\n");
+	} else if (rtc_status & ACPI_EVENT_FLAG_SET) {
+		unsigned char mask;
+		*rtc_control &= ~RTC_AIE;
+		CMOS_WRITE(*rtc_control, RTC_CONTROL);
+		mask = CMOS_READ(RTC_INTR_FLAGS);
+		rtc_update_irq(cmos->rtc, 1, mask);
+	}
+}
+
+#else /* !CONFIG_ACPI */
+
+static inline void acpi_rtc_event_setup(struct device *dev)
+{
+}
+
+static inline void acpi_rtc_event_cleanup(void)
+{
+}
+
+static inline void acpi_cmos_wake_setup(struct device *dev)
+{
+}
+
+static inline void cmos_check_acpi_rtc_status(struct device *dev,
+					      unsigned char *rtc_control)
+{
+}
+#endif /* CONFIG_ACPI */
+
 #ifdef	CONFIG_PNP
 #define	INITSECTION
 
@@ -706,6 +915,10 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
 #define	INITSECTION	__init
 #endif
 
+#define SECS_PER_DAY	(24 * 60 * 60)
+#define SECS_PER_MONTH	(28 * SECS_PER_DAY)
+#define SECS_PER_YEAR	(365 * SECS_PER_DAY)
+
 static int INITSECTION
 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 {
@@ -782,19 +995,27 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 		if (info->address_space)
 			address_space = info->address_space;
 
-		if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
-			cmos_rtc.day_alrm = info->rtc_day_alarm;
-		if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
-			cmos_rtc.mon_alrm = info->rtc_mon_alarm;
-		if (info->rtc_century && info->rtc_century < 128)
-			cmos_rtc.century = info->rtc_century;
+		cmos_rtc.day_alrm = info->rtc_day_alarm;
+		cmos_rtc.mon_alrm = info->rtc_mon_alarm;
+		cmos_rtc.century = info->rtc_century;
 
 		if (info->wake_on && info->wake_off) {
 			cmos_rtc.wake_on = info->wake_on;
 			cmos_rtc.wake_off = info->wake_off;
 		}
+	} else {
+		acpi_cmos_wake_setup(dev);
 	}
 
+	if (cmos_rtc.day_alrm >= 128)
+		cmos_rtc.day_alrm = 0;
+
+	if (cmos_rtc.mon_alrm >= 128)
+		cmos_rtc.mon_alrm = 0;
+
+	if (cmos_rtc.century >= 128)
+		cmos_rtc.century = 0;
+
 	cmos_rtc.dev = dev;
 	dev_set_drvdata(dev, &cmos_rtc);
 
@@ -804,8 +1025,21 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 		goto cleanup0;
 	}
 
+	if (cmos_rtc.mon_alrm)
+		cmos_rtc.rtc->alarm_offset_max = SECS_PER_YEAR - 1;
+	else if (cmos_rtc.day_alrm)
+		cmos_rtc.rtc->alarm_offset_max = SECS_PER_MONTH - 1;
+	else
+		cmos_rtc.rtc->alarm_offset_max = SECS_PER_DAY - 1;
+
 	rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
 
+	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)) {
@@ -854,27 +1088,35 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 			rtc_cmos_int_handler = cmos_interrupt;
 
 		retval = request_irq(rtc_irq, rtc_cmos_int_handler,
-				IRQF_SHARED, dev_name(&cmos_rtc.rtc->dev),
+				0, dev_name(&cmos_rtc.rtc->dev),
 				cmos_rtc.rtc);
 		if (retval < 0) {
 			dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 			goto cleanup1;
 		}
-
-		cmos_rtc.rtc->ops = &cmos_rtc_ops;
 	} else {
-		cmos_rtc.rtc->ops = &cmos_rtc_ops_no_alarm;
+		clear_bit(RTC_FEATURE_ALARM, cmos_rtc.rtc->features);
 	}
 
-	cmos_rtc.rtc->nvram_old_abi = true;
-	retval = rtc_register_device(cmos_rtc.rtc);
+	cmos_rtc.rtc->ops = &cmos_rtc_ops;
+
+	retval = devm_rtc_register_device(cmos_rtc.rtc);
 	if (retval)
 		goto cleanup2;
 
+	/* Set the sync offset for the periodic 11min update correct */
+	cmos_rtc.rtc->set_offset_nsec = NSEC_PER_SEC / 2;
+
 	/* export at least the first block of NVRAM */
 	nvmem_cfg.size = address_space - NVRAM_OFFSET;
-	if (rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg))
-		dev_err(dev, "nvmem registration failed\n");
+	devm_rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg);
+
+	/*
+	 * Everything has gone well so far, so by default register a handler for
+	 * the ACPI RTC fixed event.
+	 */
+	if (!info)
+		acpi_rtc_event_setup(dev);
 
 	dev_info(dev, "%s%s, %d bytes nvram%s\n",
 		 !is_valid_irq(rtc_irq) ? "no alarms" :
@@ -921,6 +1163,9 @@ static void cmos_do_remove(struct device *dev)
 			hpet_unregister_irq_handler(cmos_interrupt);
 	}
 
+	if (!dev_get_platdata(dev))
+		acpi_rtc_event_cleanup();
+
 	cmos->rtc = NULL;
 
 	ports = cmos->iomem;
@@ -1009,6 +1254,7 @@ static int cmos_suspend(struct device *dev)
 			enable_irq_wake(cmos->irq);
 	}
 
+	memset(&cmos->saved_wkalrm, 0, sizeof(struct rtc_wkalrm));
 	cmos_read_alarm(dev, &cmos->saved_wkalrm);
 
 	dev_dbg(dev, "suspend%s, ctrl %02x\n",
@@ -1057,6 +1303,7 @@ static void cmos_check_wkalrm(struct device *dev)
 		return;
 	}
 
+	memset(&current_alarm, 0, sizeof(struct rtc_wkalrm));
 	cmos_read_alarm(dev, &current_alarm);
 	t_current_expires = rtc_tm_to_time64(&current_alarm.time);
 	t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);
@@ -1066,9 +1313,6 @@ static void cmos_check_wkalrm(struct device *dev)
 	}
 }
 
-static void cmos_check_acpi_rtc_status(struct device *dev,
-				       unsigned char *rtc_control);
-
 static int __maybe_unused cmos_resume(struct device *dev)
 {
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
@@ -1135,189 +1379,29 @@ static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
  * predate even PNPBIOS should set up platform_bus devices.
  */
 
-#ifdef	CONFIG_ACPI
-
-#include <linux/acpi.h>
-
-static u32 rtc_handler(void *context)
-{
-	struct device *dev = context;
-	struct cmos_rtc *cmos = dev_get_drvdata(dev);
-	unsigned char rtc_control = 0;
-	unsigned char rtc_intr;
-	unsigned long flags;
-
-
-	/*
-	 * Always update rtc irq when ACPI is used as RTC Alarm.
-	 * Or else, ACPI SCI is enabled during suspend/resume only,
-	 * update rtc irq in that case.
-	 */
-	if (cmos_use_acpi_alarm())
-		cmos_interrupt(0, (void *)cmos->rtc);
-	else {
-		/* Fix me: can we use cmos_interrupt() here as well? */
-		spin_lock_irqsave(&rtc_lock, flags);
-		if (cmos_rtc.suspend_ctrl)
-			rtc_control = CMOS_READ(RTC_CONTROL);
-		if (rtc_control & RTC_AIE) {
-			cmos_rtc.suspend_ctrl &= ~RTC_AIE;
-			CMOS_WRITE(rtc_control, RTC_CONTROL);
-			rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
-			rtc_update_irq(cmos->rtc, 1, rtc_intr);
-		}
-		spin_unlock_irqrestore(&rtc_lock, flags);
-	}
-
-	pm_wakeup_hard_event(dev);
-	acpi_clear_event(ACPI_EVENT_RTC);
-	acpi_disable_event(ACPI_EVENT_RTC, 0);
-	return ACPI_INTERRUPT_HANDLED;
-}
-
-static inline void rtc_wake_setup(struct device *dev)
-{
-	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
-	/*
-	 * After the RTC handler is installed, the Fixed_RTC event should
-	 * be disabled. Only when the RTC alarm is set will it be enabled.
-	 */
-	acpi_clear_event(ACPI_EVENT_RTC);
-	acpi_disable_event(ACPI_EVENT_RTC, 0);
-}
-
-static void rtc_wake_on(struct device *dev)
-{
-	acpi_clear_event(ACPI_EVENT_RTC);
-	acpi_enable_event(ACPI_EVENT_RTC, 0);
-}
-
-static void rtc_wake_off(struct device *dev)
-{
-	acpi_disable_event(ACPI_EVENT_RTC, 0);
-}
-
-#ifdef CONFIG_X86
-/* Enable use_acpi_alarm mode for Intel platforms no earlier than 2015 */
-static void use_acpi_alarm_quirks(void)
-{
-	int year;
-
-	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
-		return;
-
-	if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
-		return;
-
-	if (!is_hpet_enabled())
-		return;
-
-	if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year >= 2015)
-		use_acpi_alarm = true;
-}
-#else
-static inline void use_acpi_alarm_quirks(void) { }
-#endif
-
-/* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
- * its device node and pass extra config data.  This helps its driver use
- * capabilities that the now-obsolete mc146818 didn't have, and informs it
- * that this board's RTC is wakeup-capable (per ACPI spec).
- */
-static struct cmos_rtc_board_info acpi_rtc_info;
-
-static void cmos_wake_setup(struct device *dev)
-{
-	if (acpi_disabled)
-		return;
-
-	use_acpi_alarm_quirks();
-
-	rtc_wake_setup(dev);
-	acpi_rtc_info.wake_on = rtc_wake_on;
-	acpi_rtc_info.wake_off = rtc_wake_off;
-
-	/* workaround bug in some ACPI tables */
-	if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
-		dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
-			acpi_gbl_FADT.month_alarm);
-		acpi_gbl_FADT.month_alarm = 0;
-	}
-
-	acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
-	acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
-	acpi_rtc_info.rtc_century = acpi_gbl_FADT.century;
-
-	/* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
-	if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
-		dev_info(dev, "RTC can wake from S4\n");
-
-	dev->platform_data = &acpi_rtc_info;
-
-	/* RTC always wakes from S1/S2/S3, and often S4/STD */
-	device_init_wakeup(dev, 1);
-}
-
-static void cmos_check_acpi_rtc_status(struct device *dev,
-				       unsigned char *rtc_control)
-{
-	struct cmos_rtc *cmos = dev_get_drvdata(dev);
-	acpi_event_status rtc_status;
-	acpi_status status;
-
-	if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
-		return;
-
-	status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
-	if (ACPI_FAILURE(status)) {
-		dev_err(dev, "Could not get RTC status\n");
-	} else if (rtc_status & ACPI_EVENT_FLAG_SET) {
-		unsigned char mask;
-		*rtc_control &= ~RTC_AIE;
-		CMOS_WRITE(*rtc_control, RTC_CONTROL);
-		mask = CMOS_READ(RTC_INTR_FLAGS);
-		rtc_update_irq(cmos->rtc, 1, mask);
-	}
-}
-
-#else
-
-static void cmos_wake_setup(struct device *dev)
-{
-}
-
-static void cmos_check_acpi_rtc_status(struct device *dev,
-				       unsigned char *rtc_control)
-{
-}
-
-#endif
-
 #ifdef	CONFIG_PNP
 
 #include <linux/pnp.h>
 
 static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 {
-	cmos_wake_setup(&pnp->dev);
+	int irq;
 
 	if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
-		unsigned int irq = 0;
+		irq = 0;
 #ifdef CONFIG_X86
 		/* Some machines contain a PNP entry for the RTC, but
 		 * don't define the IRQ. It should always be safe to
 		 * hardcode it on systems with a legacy PIC.
 		 */
 		if (nr_legacy_irqs())
-			irq = 8;
+			irq = RTC_IRQ;
 #endif
-		return cmos_do_probe(&pnp->dev,
-				pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
 	} else {
-		return cmos_do_probe(&pnp->dev,
-				pnp_get_resource(pnp, IORESOURCE_IO, 0),
-				pnp_irq(pnp, 0));
+		irq = pnp_irq(pnp, 0);
 	}
+
+	return cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
 }
 
 static void cmos_pnp_remove(struct pnp_dev *pnp)
@@ -1349,7 +1433,7 @@ static const struct pnp_device_id rtc_ids[] = {
 MODULE_DEVICE_TABLE(pnp, rtc_ids);
 
 static struct pnp_driver cmos_pnp_driver = {
-	.name		= (char *) driver_name,
+	.name		= driver_name,
 	.id_table	= rtc_ids,
 	.probe		= cmos_pnp_probe,
 	.remove		= cmos_pnp_remove,
@@ -1404,7 +1488,6 @@ static int __init cmos_platform_probe(struct platform_device *pdev)
 	int irq;
 
 	cmos_of_init(pdev);
-	cmos_wake_setup(&pdev->dev);
 
 	if (RTC_IOMAPPED)
 		resource = platform_get_resource(pdev, IORESOURCE_IO, 0);
@@ -1417,10 +1500,9 @@ static int __init cmos_platform_probe(struct platform_device *pdev)
 	return cmos_do_probe(&pdev->dev, resource, irq);
 }
 
-static int cmos_platform_remove(struct platform_device *pdev)
+static void cmos_platform_remove(struct platform_device *pdev)
 {
 	cmos_do_remove(&pdev->dev);
-	return 0;
 }
 
 static void cmos_platform_shutdown(struct platform_device *pdev)