Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 654 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
new file mode 100644
index 000000000..fe396d27e
--- /dev/null
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -0,0 +1,654 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Real Time Clock interface for Linux on Atmel AT91RM9200
+ *
+ *	Copyright (C) 2002 Rick Bronson
+ *
+ *	Converted to RTC class model by Andrew Victor
+ *
+ *	Ported to Linux 2.6 by Steven Scholz
+ *	Based on s3c2410-rtc.c Simtec Electronics
+ *
+ *	Based on sa1100-rtc.c by Nils Faerber
+ *	Based on rtc.c by Paul Gortmaker
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/spinlock.h>
+#include <linux/suspend.h>
+#include <linux/time.h>
+#include <linux/uaccess.h>
+
+#define	AT91_RTC_CR		0x00			/* Control Register */
+#define		AT91_RTC_UPDTIM		BIT(0)		/* Update Request Time Register */
+#define		AT91_RTC_UPDCAL		BIT(1)		/* Update Request Calendar Register */
+
+#define	AT91_RTC_MR		0x04			/* Mode Register */
+#define		AT91_RTC_HRMOD		BIT(0)		/* 12/24 hour mode */
+#define		AT91_RTC_NEGPPM		BIT(4)		/* Negative PPM correction */
+#define		AT91_RTC_CORRECTION	GENMASK(14, 8)	/* Slow clock correction */
+#define		AT91_RTC_HIGHPPM	BIT(15)		/* High PPM correction */
+
+#define	AT91_RTC_TIMR		0x08			/* Time Register */
+#define		AT91_RTC_SEC		GENMASK(6, 0)	/* Current Second */
+#define		AT91_RTC_MIN		GENMASK(14, 8)	/* Current Minute */
+#define		AT91_RTC_HOUR		GENMASK(21, 16)	/* Current Hour */
+#define		AT91_RTC_AMPM		BIT(22)		/* Ante Meridiem Post Meridiem Indicator */
+
+#define	AT91_RTC_CALR		0x0c			/* Calendar Register */
+#define		AT91_RTC_CENT		GENMASK(6, 0)	/* Current Century */
+#define		AT91_RTC_YEAR		GENMASK(15, 8)	/* Current Year */
+#define		AT91_RTC_MONTH		GENMASK(20, 16)	/* Current Month */
+#define		AT91_RTC_DAY		GENMASK(23, 21)	/* Current Day */
+#define		AT91_RTC_DATE		GENMASK(29, 24)	/* Current Date */
+
+#define	AT91_RTC_TIMALR		0x10			/* Time Alarm Register */
+#define		AT91_RTC_SECEN		BIT(7)		/* Second Alarm Enable */
+#define		AT91_RTC_MINEN		BIT(15)		/* Minute Alarm Enable */
+#define		AT91_RTC_HOUREN		BIT(23)		/* Hour Alarm Enable */
+
+#define	AT91_RTC_CALALR		0x14			/* Calendar Alarm Register */
+#define		AT91_RTC_MTHEN		BIT(23)		/* Month Alarm Enable */
+#define		AT91_RTC_DATEEN		BIT(31)		/* Date Alarm Enable */
+
+#define	AT91_RTC_SR		0x18			/* Status Register */
+#define		AT91_RTC_ACKUPD		BIT(0)		/* Acknowledge for Update */
+#define		AT91_RTC_ALARM		BIT(1)		/* Alarm Flag */
+#define		AT91_RTC_SECEV		BIT(2)		/* Second Event */
+#define		AT91_RTC_TIMEV		BIT(3)		/* Time Event */
+#define		AT91_RTC_CALEV		BIT(4)		/* Calendar Event */
+
+#define	AT91_RTC_SCCR		0x1c			/* Status Clear Command Register */
+#define	AT91_RTC_IER		0x20			/* Interrupt Enable Register */
+#define	AT91_RTC_IDR		0x24			/* Interrupt Disable Register */
+#define	AT91_RTC_IMR		0x28			/* Interrupt Mask Register */
+
+#define	AT91_RTC_VER		0x2c			/* Valid Entry Register */
+#define		AT91_RTC_NVTIM		BIT(0)		/* Non valid Time */
+#define		AT91_RTC_NVCAL		BIT(1)		/* Non valid Calendar */
+#define		AT91_RTC_NVTIMALR	BIT(2)		/* Non valid Time Alarm */
+#define		AT91_RTC_NVCALALR	BIT(3)		/* Non valid Calendar Alarm */
+
+#define AT91_RTC_CORR_DIVIDEND		3906000
+#define AT91_RTC_CORR_LOW_RATIO		20
+
+#define at91_rtc_read(field) \
+	readl_relaxed(at91_rtc_regs + field)
+#define at91_rtc_write(field, val) \
+	writel_relaxed((val), at91_rtc_regs + field)
+
+struct at91_rtc_config {
+	bool use_shadow_imr;
+	bool has_correction;
+};
+
+static const struct at91_rtc_config *at91_rtc_config;
+static DECLARE_COMPLETION(at91_rtc_updated);
+static DECLARE_COMPLETION(at91_rtc_upd_rdy);
+static void __iomem *at91_rtc_regs;
+static int irq;
+static DEFINE_SPINLOCK(at91_rtc_lock);
+static u32 at91_rtc_shadow_imr;
+static bool suspended;
+static DEFINE_SPINLOCK(suspended_lock);
+static unsigned long cached_events;
+static u32 at91_rtc_imr;
+static struct clk *sclk;
+
+static void at91_rtc_write_ier(u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&at91_rtc_lock, flags);
+	at91_rtc_shadow_imr |= mask;
+	at91_rtc_write(AT91_RTC_IER, mask);
+	spin_unlock_irqrestore(&at91_rtc_lock, flags);
+}
+
+static void at91_rtc_write_idr(u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&at91_rtc_lock, flags);
+	at91_rtc_write(AT91_RTC_IDR, mask);
+	/*
+	 * Register read back (of any RTC-register) needed to make sure
+	 * IDR-register write has reached the peripheral before updating
+	 * shadow mask.
+	 *
+	 * Note that there is still a possibility that the mask is updated
+	 * before interrupts have actually been disabled in hardware. The only
+	 * way to be certain would be to poll the IMR-register, which is is
+	 * the very register we are trying to emulate. The register read back
+	 * is a reasonable heuristic.
+	 */
+	at91_rtc_read(AT91_RTC_SR);
+	at91_rtc_shadow_imr &= ~mask;
+	spin_unlock_irqrestore(&at91_rtc_lock, flags);
+}
+
+static u32 at91_rtc_read_imr(void)
+{
+	unsigned long flags;
+	u32 mask;
+
+	if (at91_rtc_config->use_shadow_imr) {
+		spin_lock_irqsave(&at91_rtc_lock, flags);
+		mask = at91_rtc_shadow_imr;
+		spin_unlock_irqrestore(&at91_rtc_lock, flags);
+	} else {
+		mask = at91_rtc_read(AT91_RTC_IMR);
+	}
+
+	return mask;
+}
+
+/*
+ * Decode time/date into rtc_time structure
+ */
+static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
+				struct rtc_time *tm)
+{
+	unsigned int time, date;
+
+	/* must read twice in case it changes */
+	do {
+		time = at91_rtc_read(timereg);
+		date = at91_rtc_read(calreg);
+	} while ((time != at91_rtc_read(timereg)) ||
+			(date != at91_rtc_read(calreg)));
+
+	tm->tm_sec  = bcd2bin(FIELD_GET(AT91_RTC_SEC, time));
+	tm->tm_min  = bcd2bin(FIELD_GET(AT91_RTC_MIN, time));
+	tm->tm_hour = bcd2bin(FIELD_GET(AT91_RTC_HOUR, time));
+
+	/*
+	 * The Calendar Alarm register does not have a field for
+	 * the year - so these will return an invalid value.
+	 */
+	tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;	/* century */
+	tm->tm_year += bcd2bin(FIELD_GET(AT91_RTC_YEAR, date));	/* year */
+
+	tm->tm_wday = bcd2bin(FIELD_GET(AT91_RTC_DAY, date)) - 1;	/* day of the week [0-6], Sunday=0 */
+	tm->tm_mon  = bcd2bin(FIELD_GET(AT91_RTC_MONTH, date)) - 1;
+	tm->tm_mday = bcd2bin(FIELD_GET(AT91_RTC_DATE, date));
+}
+
+/*
+ * Read current time and date in RTC
+ */
+static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+	at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
+	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+	tm->tm_year = tm->tm_year - 1900;
+
+	dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
+
+	return 0;
+}
+
+/*
+ * Set current time and date in RTC
+ */
+static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long cr;
+
+	dev_dbg(dev, "%s(): %ptR\n", __func__, tm);
+
+	wait_for_completion(&at91_rtc_upd_rdy);
+
+	/* Stop Time/Calendar from counting */
+	cr = at91_rtc_read(AT91_RTC_CR);
+	at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
+
+	at91_rtc_write_ier(AT91_RTC_ACKUPD);
+	wait_for_completion(&at91_rtc_updated);	/* wait for ACKUPD interrupt */
+	at91_rtc_write_idr(AT91_RTC_ACKUPD);
+
+	at91_rtc_write(AT91_RTC_TIMR,
+			  FIELD_PREP(AT91_RTC_SEC, bin2bcd(tm->tm_sec))
+			| FIELD_PREP(AT91_RTC_MIN, bin2bcd(tm->tm_min))
+			| FIELD_PREP(AT91_RTC_HOUR, bin2bcd(tm->tm_hour)));
+
+	at91_rtc_write(AT91_RTC_CALR,
+			  FIELD_PREP(AT91_RTC_CENT,
+				     bin2bcd((tm->tm_year + 1900) / 100))
+			| FIELD_PREP(AT91_RTC_YEAR, bin2bcd(tm->tm_year % 100))
+			| FIELD_PREP(AT91_RTC_MONTH, bin2bcd(tm->tm_mon + 1))
+			| FIELD_PREP(AT91_RTC_DAY, bin2bcd(tm->tm_wday + 1))
+			| FIELD_PREP(AT91_RTC_DATE, bin2bcd(tm->tm_mday)));
+
+	/* Restart Time/Calendar */
+	cr = at91_rtc_read(AT91_RTC_CR);
+	at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
+	at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
+	at91_rtc_write_ier(AT91_RTC_SECEV);
+
+	return 0;
+}
+
+/*
+ * Read alarm time and date in RTC
+ */
+static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_time *tm = &alrm->time;
+
+	at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
+	tm->tm_year = -1;
+
+	alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
+			? 1 : 0;
+
+	dev_dbg(dev, "%s(): %ptR %sabled\n", __func__, tm,
+		alrm->enabled ? "en" : "dis");
+
+	return 0;
+}
+
+/*
+ * Set alarm time and date in RTC
+ */
+static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rtc_time tm = alrm->time;
+
+	at91_rtc_write_idr(AT91_RTC_ALARM);
+	at91_rtc_write(AT91_RTC_TIMALR,
+		  FIELD_PREP(AT91_RTC_SEC, bin2bcd(alrm->time.tm_sec))
+		| FIELD_PREP(AT91_RTC_MIN, bin2bcd(alrm->time.tm_min))
+		| FIELD_PREP(AT91_RTC_HOUR, bin2bcd(alrm->time.tm_hour))
+		| AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
+	at91_rtc_write(AT91_RTC_CALALR,
+		  FIELD_PREP(AT91_RTC_MONTH, bin2bcd(alrm->time.tm_mon + 1))
+		| FIELD_PREP(AT91_RTC_DATE, bin2bcd(alrm->time.tm_mday))
+		| AT91_RTC_DATEEN | AT91_RTC_MTHEN);
+
+	if (alrm->enabled) {
+		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
+		at91_rtc_write_ier(AT91_RTC_ALARM);
+	}
+
+	dev_dbg(dev, "%s(): %ptR\n", __func__, &tm);
+
+	return 0;
+}
+
+static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
+
+	if (enabled) {
+		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
+		at91_rtc_write_ier(AT91_RTC_ALARM);
+	} else
+		at91_rtc_write_idr(AT91_RTC_ALARM);
+
+	return 0;
+}
+
+static int at91_rtc_readoffset(struct device *dev, long *offset)
+{
+	u32 mr = at91_rtc_read(AT91_RTC_MR);
+	long val = FIELD_GET(AT91_RTC_CORRECTION, mr);
+
+	if (!val) {
+		*offset = 0;
+		return 0;
+	}
+
+	val++;
+
+	if (!(mr & AT91_RTC_NEGPPM))
+		val = -val;
+
+	if (!(mr & AT91_RTC_HIGHPPM))
+		val *= AT91_RTC_CORR_LOW_RATIO;
+
+	*offset = DIV_ROUND_CLOSEST(AT91_RTC_CORR_DIVIDEND, val);
+
+	return 0;
+}
+
+static int at91_rtc_setoffset(struct device *dev, long offset)
+{
+	long corr;
+	u32 mr;
+
+	if (offset > AT91_RTC_CORR_DIVIDEND / 2)
+		return -ERANGE;
+	if (offset < -AT91_RTC_CORR_DIVIDEND / 2)
+		return -ERANGE;
+
+	mr = at91_rtc_read(AT91_RTC_MR);
+	mr &= ~(AT91_RTC_NEGPPM | AT91_RTC_CORRECTION | AT91_RTC_HIGHPPM);
+
+	if (offset > 0)
+		mr |= AT91_RTC_NEGPPM;
+	else
+		offset = -offset;
+
+	/* offset less than 764 ppb, disable correction*/
+	if (offset < 764) {
+		at91_rtc_write(AT91_RTC_MR, mr & ~AT91_RTC_NEGPPM);
+
+		return 0;
+	}
+
+	/*
+	 * 29208 ppb is the perfect cutoff between low range and high range
+	 * low range values are never better than high range value after that.
+	 */
+	if (offset < 29208) {
+		corr = DIV_ROUND_CLOSEST(AT91_RTC_CORR_DIVIDEND, offset * AT91_RTC_CORR_LOW_RATIO);
+	} else {
+		corr = DIV_ROUND_CLOSEST(AT91_RTC_CORR_DIVIDEND, offset);
+		mr |= AT91_RTC_HIGHPPM;
+	}
+
+	if (corr > 128)
+		corr = 128;
+
+	mr |= FIELD_PREP(AT91_RTC_CORRECTION, corr - 1);
+
+	at91_rtc_write(AT91_RTC_MR, mr);
+
+	return 0;
+}
+
+/*
+ * IRQ handler for the RTC
+ */
+static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
+{
+	struct platform_device *pdev = dev_id;
+	struct rtc_device *rtc = platform_get_drvdata(pdev);
+	unsigned int rtsr;
+	unsigned long events = 0;
+	int ret = IRQ_NONE;
+
+	spin_lock(&suspended_lock);
+	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
+	if (rtsr) {		/* this interrupt is shared!  Is it ours? */
+		if (rtsr & AT91_RTC_ALARM)
+			events |= (RTC_AF | RTC_IRQF);
+		if (rtsr & AT91_RTC_SECEV) {
+			complete(&at91_rtc_upd_rdy);
+			at91_rtc_write_idr(AT91_RTC_SECEV);
+		}
+		if (rtsr & AT91_RTC_ACKUPD)
+			complete(&at91_rtc_updated);
+
+		at91_rtc_write(AT91_RTC_SCCR, rtsr);	/* clear status reg */
+
+		if (!suspended) {
+			rtc_update_irq(rtc, 1, events);
+
+			dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
+				__func__, events >> 8, events & 0x000000FF);
+		} else {
+			cached_events |= events;
+			at91_rtc_write_idr(at91_rtc_imr);
+			pm_system_wakeup();
+		}
+
+		ret = IRQ_HANDLED;
+	}
+	spin_unlock(&suspended_lock);
+
+	return ret;
+}
+
+static const struct at91_rtc_config at91rm9200_config = {
+};
+
+static const struct at91_rtc_config at91sam9x5_config = {
+	.use_shadow_imr	= true,
+};
+
+static const struct at91_rtc_config sama5d4_config = {
+	.has_correction = true,
+};
+
+static const struct of_device_id at91_rtc_dt_ids[] = {
+	{
+		.compatible = "atmel,at91rm9200-rtc",
+		.data = &at91rm9200_config,
+	}, {
+		.compatible = "atmel,at91sam9x5-rtc",
+		.data = &at91sam9x5_config,
+	}, {
+		.compatible = "atmel,sama5d4-rtc",
+		.data = &sama5d4_config,
+	}, {
+		.compatible = "atmel,sama5d2-rtc",
+		.data = &sama5d4_config,
+	}, {
+		.compatible = "microchip,sam9x60-rtc",
+		.data = &sama5d4_config,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
+
+static const struct rtc_class_ops at91_rtc_ops = {
+	.read_time	= at91_rtc_readtime,
+	.set_time	= at91_rtc_settime,
+	.read_alarm	= at91_rtc_readalarm,
+	.set_alarm	= at91_rtc_setalarm,
+	.alarm_irq_enable = at91_rtc_alarm_irq_enable,
+};
+
+static const struct rtc_class_ops sama5d4_rtc_ops = {
+	.read_time	= at91_rtc_readtime,
+	.set_time	= at91_rtc_settime,
+	.read_alarm	= at91_rtc_readalarm,
+	.set_alarm	= at91_rtc_setalarm,
+	.alarm_irq_enable = at91_rtc_alarm_irq_enable,
+	.set_offset	= at91_rtc_setoffset,
+	.read_offset	= at91_rtc_readoffset,
+};
+
+/*
+ * Initialize and install RTC driver
+ */
+static int __init at91_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	struct resource *regs;
+	int ret = 0;
+
+	at91_rtc_config = of_device_get_match_data(&pdev->dev);
+	if (!at91_rtc_config)
+		return -ENODEV;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "no mmio resource defined\n");
+		return -ENXIO;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENXIO;
+
+	at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
+				     resource_size(regs));
+	if (!at91_rtc_regs) {
+		dev_err(&pdev->dev, "failed to map registers, aborting.\n");
+		return -ENOMEM;
+	}
+
+	rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+	platform_set_drvdata(pdev, rtc);
+
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
+	at91_rtc_write(AT91_RTC_CR, 0);
+	at91_rtc_write(AT91_RTC_MR, at91_rtc_read(AT91_RTC_MR) & ~AT91_RTC_HRMOD);
+
+	/* Disable all interrupts */
+	at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+					AT91_RTC_SECEV | AT91_RTC_TIMEV |
+					AT91_RTC_CALEV);
+
+	ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
+			       IRQF_SHARED | IRQF_COND_SUSPEND,
+			       "at91_rtc", pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
+		goto err_clk;
+	}
+
+	/* cpu init code should really have flagged this device as
+	 * being wake-capable; if it didn't, do that here.
+	 */
+	if (!device_can_wakeup(&pdev->dev))
+		device_init_wakeup(&pdev->dev, 1);
+
+	if (at91_rtc_config->has_correction)
+		rtc->ops = &sama5d4_rtc_ops;
+	else
+		rtc->ops = &at91_rtc_ops;
+
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
+	ret = devm_rtc_register_device(rtc);
+	if (ret)
+		goto err_clk;
+
+	/* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
+	 * completion.
+	 */
+	at91_rtc_write_ier(AT91_RTC_SECEV);
+
+	dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(sclk);
+
+	return ret;
+}
+
+/*
+ * Disable and remove the RTC driver
+ */
+static int __exit at91_rtc_remove(struct platform_device *pdev)
+{
+	/* Disable all interrupts */
+	at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+					AT91_RTC_SECEV | AT91_RTC_TIMEV |
+					AT91_RTC_CALEV);
+
+	clk_disable_unprepare(sclk);
+
+	return 0;
+}
+
+static void at91_rtc_shutdown(struct platform_device *pdev)
+{
+	/* Disable all interrupts */
+	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
+					AT91_RTC_SECEV | AT91_RTC_TIMEV |
+					AT91_RTC_CALEV);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+/* AT91RM9200 RTC Power management control */
+
+static int at91_rtc_suspend(struct device *dev)
+{
+	/* this IRQ is shared with DBGU and other hardware which isn't
+	 * necessarily doing PM like we are...
+	 */
+	at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
+
+	at91_rtc_imr = at91_rtc_read_imr()
+			& (AT91_RTC_ALARM|AT91_RTC_SECEV);
+	if (at91_rtc_imr) {
+		if (device_may_wakeup(dev)) {
+			unsigned long flags;
+
+			enable_irq_wake(irq);
+
+			spin_lock_irqsave(&suspended_lock, flags);
+			suspended = true;
+			spin_unlock_irqrestore(&suspended_lock, flags);
+		} else {
+			at91_rtc_write_idr(at91_rtc_imr);
+		}
+	}
+	return 0;
+}
+
+static int at91_rtc_resume(struct device *dev)
+{
+	struct rtc_device *rtc = dev_get_drvdata(dev);
+
+	if (at91_rtc_imr) {
+		if (device_may_wakeup(dev)) {
+			unsigned long flags;
+
+			spin_lock_irqsave(&suspended_lock, flags);
+
+			if (cached_events) {
+				rtc_update_irq(rtc, 1, cached_events);
+				cached_events = 0;
+			}
+
+			suspended = false;
+			spin_unlock_irqrestore(&suspended_lock, flags);
+
+			disable_irq_wake(irq);
+		}
+		at91_rtc_write_ier(at91_rtc_imr);
+	}
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
+
+static struct platform_driver at91_rtc_driver = {
+	.remove		= __exit_p(at91_rtc_remove),
+	.shutdown	= at91_rtc_shutdown,
+	.driver		= {
+		.name	= "at91_rtc",
+		.pm	= &at91_rtc_pm_ops,
+		.of_match_table = of_match_ptr(at91_rtc_dt_ids),
+	},
+};
+
+module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
+
+MODULE_AUTHOR("Rick Bronson");
+MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:at91_rtc");