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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/rtc/rtc-at91rm9200.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/rtc/rtc-at91rm9200.c')
-rw-r--r--drivers/rtc/rtc-at91rm9200.c654
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");