Initial import

1 files changed, 538 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
new file mode 100644
index 000000000..35efd3f75
--- /dev/null
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -0,0 +1,538 @@
+/*
+ *	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
+ *
+ *	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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/ioctl.h>
+#include <linux/completion.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/suspend.h>
+#include <linux/uaccess.h>
+
+#include "rtc-at91rm9200.h"
+
+#define at91_rtc_read(field) \
+	readl_relaxed(at91_rtc_regs + field)
+#define at91_rtc_write(field, val) \
+	writel_relaxed((val), at91_rtc_regs + field)
+
+#define AT91_RTC_EPOCH		1900UL	/* just like arch/arm/common/rtctime.c */
+
+struct at91_rtc_config {
+	bool use_shadow_imr;
+};
+
+static const struct at91_rtc_config *at91_rtc_config;
+static DECLARE_COMPLETION(at91_rtc_updated);
+static DECLARE_COMPLETION(at91_rtc_upd_rdy);
+static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
+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 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((time & AT91_RTC_SEC) >> 0);
+	tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
+	tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
+
+	/*
+	 * The Calendar Alarm register does not have a field for
+	 * the year - so these will return an invalid value.  When an
+	 * alarm is set, at91_alarm_year will store the current year.
+	 */
+	tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;	/* century */
+	tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);	/* year */
+
+	tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1;	/* day of the week [0-6], Sunday=0 */
+	tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
+	tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
+}
+
+/*
+ * 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(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
+		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	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(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
+		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	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,
+			  bin2bcd(tm->tm_sec) << 0
+			| bin2bcd(tm->tm_min) << 8
+			| bin2bcd(tm->tm_hour) << 16);
+
+	at91_rtc_write(AT91_RTC_CALR,
+			  bin2bcd((tm->tm_year + 1900) / 100)	/* century */
+			| bin2bcd(tm->tm_year % 100) << 8	/* year */
+			| bin2bcd(tm->tm_mon + 1) << 16		/* tm_mon starts at zero */
+			| bin2bcd(tm->tm_wday + 1) << 21	/* day of the week [0-6], Sunday=0 */
+			| bin2bcd(tm->tm_mday) << 24);
+
+	/* 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_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+	tm->tm_year = at91_alarm_year - 1900;
+
+	alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
+			? 1 : 0;
+
+	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
+		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
+		tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	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;
+
+	at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
+
+	at91_alarm_year = tm.tm_year;
+
+	tm.tm_mon = alrm->time.tm_mon;
+	tm.tm_mday = alrm->time.tm_mday;
+	tm.tm_hour = alrm->time.tm_hour;
+	tm.tm_min = alrm->time.tm_min;
+	tm.tm_sec = alrm->time.tm_sec;
+
+	at91_rtc_write_idr(AT91_RTC_ALARM);
+	at91_rtc_write(AT91_RTC_TIMALR,
+		  bin2bcd(tm.tm_sec) << 0
+		| bin2bcd(tm.tm_min) << 8
+		| bin2bcd(tm.tm_hour) << 16
+		| AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
+	at91_rtc_write(AT91_RTC_CALALR,
+		  bin2bcd(tm.tm_mon + 1) << 16		/* tm_mon starts at zero */
+		| bin2bcd(tm.tm_mday) << 24
+		| 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(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
+		at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
+		tm.tm_min, tm.tm_sec);
+
+	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;
+}
+/*
+ * Provide additional RTC information in /proc/driver/rtc
+ */
+static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+	unsigned long imr = at91_rtc_read_imr();
+
+	seq_printf(seq, "update_IRQ\t: %s\n",
+			(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
+	seq_printf(seq, "periodic_IRQ\t: %s\n",
+			(imr & AT91_RTC_SECEV) ? "yes" : "no");
+
+	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,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id at91_rtc_dt_ids[] = {
+	{
+		.compatible = "atmel,at91rm9200-rtc",
+		.data = &at91rm9200_config,
+	}, {
+		.compatible = "atmel,at91sam9x5-rtc",
+		.data = &at91sam9x5_config,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
+#endif
+
+static const struct at91_rtc_config *
+at91_rtc_get_config(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+
+	if (pdev->dev.of_node) {
+		match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
+		if (!match)
+			return NULL;
+		return (const struct at91_rtc_config *)match->data;
+	}
+
+	return &at91rm9200_config;
+}
+
+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,
+	.proc		= at91_rtc_proc,
+	.alarm_irq_enable = at91_rtc_alarm_irq_enable,
+};
+
+/*
+ * 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 = at91_rtc_get_config(pdev);
+	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) {
+		dev_err(&pdev->dev, "no irq resource defined\n");
+		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;
+	}
+
+	at91_rtc_write(AT91_RTC_CR, 0);
+	at91_rtc_write(AT91_RTC_MR, 0);		/* 24 hour mode */
+
+	/* 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);
+		return ret;
+	}
+
+	/* 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);
+
+	rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+				&at91_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+	platform_set_drvdata(pdev, rtc);
+
+	/* 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;
+}
+
+/*
+ * 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);
+
+	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_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");