[mirror_ubuntu-artful-kernel.git] / drivers / rtc / rtc-at91rm9200.c

/*
 *	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");
Commit	Line	Data
788b1fc6 AV	1	/*
	2	* Real Time Clock interface for Linux on Atmel AT91RM9200
	3	*
	4	* Copyright (C) 2002 Rick Bronson
	5	*
	6	* Converted to RTC class model by Andrew Victor
	7	*
	8	* Ported to Linux 2.6 by Steven Scholz
	9	* Based on s3c2410-rtc.c Simtec Electronics
	10	*
	11	* Based on sa1100-rtc.c by Nils Faerber
	12	* Based on rtc.c by Paul Gortmaker
	13	*
	14	* This program is free software; you can redistribute it and/or
	15	* modify it under the terms of the GNU General Public License
	16	* as published by the Free Software Foundation; either version
	17	* 2 of the License, or (at your option) any later version.
	18	*
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/kernel.h>
	23	#include <linux/platform_device.h>
	24	#include <linux/time.h>
	25	#include <linux/rtc.h>
	26	#include <linux/bcd.h>
	27	#include <linux/interrupt.h>
e9f08bbe	28	#include <linux/spinlock.h>
788b1fc6 AV	29	#include <linux/ioctl.h>
788b1fc6 AV	30	#include <linux/completion.h>
14070ade	31	#include <linux/io.h>
7c1b68d4 JE	32	#include <linux/of.h>
7c1b68d4 JE	33	#include <linux/of_device.h>
dd1f1f39	34	#include <linux/suspend.h>
8ecc0bf4	35	#include <linux/uaccess.h>
fb0d4ec4	36
75984df0	37	#include "rtc-at91rm9200.h"
d73e3cd7	38
d28bdfc5	39	#define at91_rtc_read(field) \
6da7bb1e	40	readl_relaxed(at91_rtc_regs + field)
d28bdfc5	41	#define at91_rtc_write(field, val) \
6da7bb1e	42	writel_relaxed((val), at91_rtc_regs + field)
788b1fc6	43
788b1fc6 AV	44	#define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */
788b1fc6 AV	45
de645475	46	struct at91_rtc_config {
e9f08bbe	47	bool use_shadow_imr;
de645475 JH	48	};
	49
	50	static const struct at91_rtc_config *at91_rtc_config;
788b1fc6	51	static DECLARE_COMPLETION(at91_rtc_updated);
2fe121e1	52	static DECLARE_COMPLETION(at91_rtc_upd_rdy);
788b1fc6	53	static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
d28bdfc5 JCPV	54	static void __iomem *at91_rtc_regs;
d28bdfc5 JCPV	55	static int irq;
e9f08bbe JH	56	static DEFINE_SPINLOCK(at91_rtc_lock);
e9f08bbe JH	57	static u32 at91_rtc_shadow_imr;
dd1f1f39 BB	58	static bool suspended;
	59	static DEFINE_SPINLOCK(suspended_lock);
	60	static unsigned long cached_events;
	61	static u32 at91_rtc_imr;
788b1fc6	62
e304fcd0 JH	63	static void at91_rtc_write_ier(u32 mask)
e304fcd0 JH	64	{
e9f08bbe JH	65	unsigned long flags;
	66
	67	spin_lock_irqsave(&at91_rtc_lock, flags);
	68	at91_rtc_shadow_imr \|= mask;
e304fcd0	69	at91_rtc_write(AT91_RTC_IER, mask);
e9f08bbe	70	spin_unlock_irqrestore(&at91_rtc_lock, flags);
e304fcd0 JH	71	}
	72
	73	static void at91_rtc_write_idr(u32 mask)
	74	{
e9f08bbe JH	75	unsigned long flags;
	76
	77	spin_lock_irqsave(&at91_rtc_lock, flags);
e304fcd0	78	at91_rtc_write(AT91_RTC_IDR, mask);
e9f08bbe JH	79	/*
	80	* Register read back (of any RTC-register) needed to make sure
	81	* IDR-register write has reached the peripheral before updating
	82	* shadow mask.
	83	*
	84	* Note that there is still a possibility that the mask is updated
	85	* before interrupts have actually been disabled in hardware. The only
	86	* way to be certain would be to poll the IMR-register, which is is
	87	* the very register we are trying to emulate. The register read back
	88	* is a reasonable heuristic.
	89	*/
	90	at91_rtc_read(AT91_RTC_SR);
	91	at91_rtc_shadow_imr &= ~mask;
	92	spin_unlock_irqrestore(&at91_rtc_lock, flags);
e304fcd0 JH	93	}
	94
	95	static u32 at91_rtc_read_imr(void)
	96	{
e9f08bbe JH	97	unsigned long flags;
	98	u32 mask;
	99
	100	if (at91_rtc_config->use_shadow_imr) {
	101	spin_lock_irqsave(&at91_rtc_lock, flags);
	102	mask = at91_rtc_shadow_imr;
	103	spin_unlock_irqrestore(&at91_rtc_lock, flags);
	104	} else {
	105	mask = at91_rtc_read(AT91_RTC_IMR);
	106	}
	107
	108	return mask;
e304fcd0 JH	109	}
e304fcd0 JH	110
788b1fc6 AV	111	/*
	112	* Decode time/date into rtc_time structure
	113	*/
e7a8bb12 AM	114	static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
e7a8bb12 AM	115	struct rtc_time *tm)
788b1fc6 AV	116	{
	117	unsigned int time, date;
	118
	119	/* must read twice in case it changes */
	120	do {
d28bdfc5 JCPV	121	time = at91_rtc_read(timereg);
	122	date = at91_rtc_read(calreg);
	123	} while ((time != at91_rtc_read(timereg)) \|\|
	124	(date != at91_rtc_read(calreg)));
788b1fc6	125
fe20ba70 AB	126	tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0);
	127	tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8);
	128	tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
788b1fc6 AV	129
	130	/*
	131	* The Calendar Alarm register does not have a field for
	132	* the year - so these will return an invalid value. When an
25985edc	133	* alarm is set, at91_alarm_year will store the current year.
788b1fc6	134	*/
fe20ba70 AB	135	tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */
fe20ba70 AB	136	tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */
788b1fc6	137
fe20ba70 AB	138	tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
	139	tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
	140	tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
788b1fc6 AV	141	}
	142
	143	/*
	144	* Read current time and date in RTC
	145	*/
	146	static int at91_rtc_readtime(struct device dev, struct rtc_time tm)
	147	{
	148	at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
	149	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
	150	tm->tm_year = tm->tm_year - 1900;
	151
6588208c	152	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
e7a8bb12 AM	153	1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
e7a8bb12 AM	154	tm->tm_hour, tm->tm_min, tm->tm_sec);
788b1fc6 AV	155
	156	return 0;
	157	}
	158
	159	/*
	160	* Set current time and date in RTC
	161	*/
	162	static int at91_rtc_settime(struct device dev, struct rtc_time tm)
	163	{
	164	unsigned long cr;
	165
6588208c	166	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
e7a8bb12 AM	167	1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
e7a8bb12 AM	168	tm->tm_hour, tm->tm_min, tm->tm_sec);
788b1fc6	169
2fe121e1 BB	170	wait_for_completion(&at91_rtc_upd_rdy);
2fe121e1 BB	171
788b1fc6	172	/* Stop Time/Calendar from counting */
d28bdfc5 JCPV	173	cr = at91_rtc_read(AT91_RTC_CR);
d28bdfc5 JCPV	174	at91_rtc_write(AT91_RTC_CR, cr \| AT91_RTC_UPDCAL \| AT91_RTC_UPDTIM);
788b1fc6	175
e304fcd0	176	at91_rtc_write_ier(AT91_RTC_ACKUPD);
e7a8bb12	177	wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
e304fcd0	178	at91_rtc_write_idr(AT91_RTC_ACKUPD);
788b1fc6	179
d28bdfc5	180	at91_rtc_write(AT91_RTC_TIMR,
fe20ba70 AB	181	bin2bcd(tm->tm_sec) << 0
	182	\| bin2bcd(tm->tm_min) << 8
	183	\| bin2bcd(tm->tm_hour) << 16);
788b1fc6	184
d28bdfc5	185	at91_rtc_write(AT91_RTC_CALR,
fe20ba70 AB	186	bin2bcd((tm->tm_year + 1900) / 100) /* century */
	187	\| bin2bcd(tm->tm_year % 100) << 8 /* year */
	188	\| bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */
	189	\| bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */
	190	\| bin2bcd(tm->tm_mday) << 24);
788b1fc6 AV	191
788b1fc6 AV	192	/* Restart Time/Calendar */
d28bdfc5	193	cr = at91_rtc_read(AT91_RTC_CR);
2fe121e1	194	at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
d28bdfc5	195	at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL \| AT91_RTC_UPDTIM));
2fe121e1	196	at91_rtc_write_ier(AT91_RTC_SECEV);
788b1fc6 AV	197
	198	return 0;
	199	}
	200
	201	/*
	202	* Read alarm time and date in RTC
	203	*/
	204	static int at91_rtc_readalarm(struct device dev, struct rtc_wkalrm alrm)
	205	{
	206	struct rtc_time *tm = &alrm->time;
	207
	208	at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
	209	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
	210	tm->tm_year = at91_alarm_year - 1900;
	211
e304fcd0	212	alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM)
a2db8dfc DB	213	? 1 : 0;
a2db8dfc DB	214
6588208c	215	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
e7a8bb12 AM	216	1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
e7a8bb12 AM	217	tm->tm_hour, tm->tm_min, tm->tm_sec);
788b1fc6 AV	218
	219	return 0;
	220	}
	221
	222	/*
	223	* Set alarm time and date in RTC
	224	*/
	225	static int at91_rtc_setalarm(struct device dev, struct rtc_wkalrm alrm)
	226	{
	227	struct rtc_time tm;
	228
	229	at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
	230
	231	at91_alarm_year = tm.tm_year;
	232
eb3c2272 LP	233	tm.tm_mon = alrm->time.tm_mon;
eb3c2272 LP	234	tm.tm_mday = alrm->time.tm_mday;
788b1fc6 AV	235	tm.tm_hour = alrm->time.tm_hour;
	236	tm.tm_min = alrm->time.tm_min;
	237	tm.tm_sec = alrm->time.tm_sec;
	238
e304fcd0	239	at91_rtc_write_idr(AT91_RTC_ALARM);
d28bdfc5	240	at91_rtc_write(AT91_RTC_TIMALR,
fe20ba70 AB	241	bin2bcd(tm.tm_sec) << 0
	242	\| bin2bcd(tm.tm_min) << 8
	243	\| bin2bcd(tm.tm_hour) << 16
788b1fc6	244	\| AT91_RTC_HOUREN \| AT91_RTC_MINEN \| AT91_RTC_SECEN);
d28bdfc5	245	at91_rtc_write(AT91_RTC_CALALR,
fe20ba70 AB	246	bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */
fe20ba70 AB	247	\| bin2bcd(tm.tm_mday) << 24
788b1fc6 AV	248	\| AT91_RTC_DATEEN \| AT91_RTC_MTHEN);
788b1fc6 AV	249
449321b3	250	if (alrm->enabled) {
d28bdfc5	251	at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
e304fcd0	252	at91_rtc_write_ier(AT91_RTC_ALARM);
449321b3	253	}
5d4675a8	254
6588208c	255	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
e7a8bb12 AM	256	at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
e7a8bb12 AM	257	tm.tm_min, tm.tm_sec);
788b1fc6 AV	258
	259	return 0;
	260	}
	261
16380c15 JS	262	static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
16380c15 JS	263	{
6588208c	264	dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
16380c15 JS	265
16380c15 JS	266	if (enabled) {
d28bdfc5	267	at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
e304fcd0	268	at91_rtc_write_ier(AT91_RTC_ALARM);
e24b0bfa	269	} else
e304fcd0	270	at91_rtc_write_idr(AT91_RTC_ALARM);
16380c15 JS	271
	272	return 0;
	273	}
788b1fc6 AV	274	/*
	275	* Provide additional RTC information in /proc/driver/rtc
	276	*/
	277	static int at91_rtc_proc(struct device dev, struct seq_file seq)
	278	{
e304fcd0	279	unsigned long imr = at91_rtc_read_imr();
e24b0bfa	280
e7a8bb12	281	seq_printf(seq, "update_IRQ\t: %s\n",
e24b0bfa	282	(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
e7a8bb12	283	seq_printf(seq, "periodic_IRQ\t: %s\n",
e24b0bfa	284	(imr & AT91_RTC_SECEV) ? "yes" : "no");
788b1fc6 AV	285
	286	return 0;
	287	}
	288
	289	/*
	290	* IRQ handler for the RTC
	291	*/
7d12e780	292	static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
788b1fc6	293	{
e7a8bb12	294	struct platform_device *pdev = dev_id;
788b1fc6 AV	295	struct rtc_device *rtc = platform_get_drvdata(pdev);
	296	unsigned int rtsr;
	297	unsigned long events = 0;
dd1f1f39	298	int ret = IRQ_NONE;
788b1fc6	299
dd1f1f39	300	spin_lock(&suspended_lock);
e304fcd0	301	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
788b1fc6 AV	302	if (rtsr) { /* this interrupt is shared! Is it ours? */
	303	if (rtsr & AT91_RTC_ALARM)
	304	events \|= (RTC_AF \| RTC_IRQF);
2fe121e1 BB	305	if (rtsr & AT91_RTC_SECEV) {
	306	complete(&at91_rtc_upd_rdy);
	307	at91_rtc_write_idr(AT91_RTC_SECEV);
	308	}
788b1fc6 AV	309	if (rtsr & AT91_RTC_ACKUPD)
	310	complete(&at91_rtc_updated);
	311
d28bdfc5	312	at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
788b1fc6	313
dd1f1f39 BB	314	if (!suspended) {
dd1f1f39 BB	315	rtc_update_irq(rtc, 1, events);
788b1fc6	316
dd1f1f39 BB	317	dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
	318	__func__, events >> 8, events & 0x000000FF);
	319	} else {
	320	cached_events \|= events;
	321	at91_rtc_write_idr(at91_rtc_imr);
	322	pm_system_wakeup();
	323	}
788b1fc6	324
dd1f1f39	325	ret = IRQ_HANDLED;
788b1fc6	326	}
88601683	327	spin_unlock(&suspended_lock);
dd1f1f39 BB	328
dd1f1f39 BB	329	return ret;
788b1fc6 AV	330	}
788b1fc6 AV	331
de645475 JH	332	static const struct at91_rtc_config at91rm9200_config = {
	333	};
	334
bba00e59 JH	335	static const struct at91_rtc_config at91sam9x5_config = {
	336	.use_shadow_imr = true,
	337	};
	338
de645475 JH	339	#ifdef CONFIG_OF
	340	static const struct of_device_id at91_rtc_dt_ids[] = {
	341	{
	342	.compatible = "atmel,at91rm9200-rtc",
	343	.data = &at91rm9200_config,
bba00e59 JH	344	}, {
	345	.compatible = "atmel,at91sam9x5-rtc",
	346	.data = &at91sam9x5_config,
de645475 JH	347	}, {
	348	/* sentinel */
	349	}
	350	};
	351	MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
	352	#endif
	353
	354	static const struct at91_rtc_config *
	355	at91_rtc_get_config(struct platform_device *pdev)
	356	{
	357	const struct of_device_id *match;
	358
	359	if (pdev->dev.of_node) {
	360	match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
	361	if (!match)
	362	return NULL;
	363	return (const struct at91_rtc_config *)match->data;
	364	}
	365
	366	return &at91rm9200_config;
	367	}
	368
ff8371ac	369	static const struct rtc_class_ops at91_rtc_ops = {
788b1fc6 AV	370	.read_time = at91_rtc_readtime,
	371	.set_time = at91_rtc_settime,
	372	.read_alarm = at91_rtc_readalarm,
	373	.set_alarm = at91_rtc_setalarm,
	374	.proc = at91_rtc_proc,
16380c15	375	.alarm_irq_enable = at91_rtc_alarm_irq_enable,
788b1fc6 AV	376	};
	377
	378	/*
	379	* Initialize and install RTC driver
	380	*/
	381	static int __init at91_rtc_probe(struct platform_device *pdev)
	382	{
	383	struct rtc_device *rtc;
d28bdfc5 JCPV	384	struct resource *regs;
d28bdfc5 JCPV	385	int ret = 0;
788b1fc6	386
de645475 JH	387	at91_rtc_config = at91_rtc_get_config(pdev);
	388	if (!at91_rtc_config)
	389	return -ENODEV;
	390
d28bdfc5 JCPV	391	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	392	if (!regs) {
	393	dev_err(&pdev->dev, "no mmio resource defined\n");
	394	return -ENXIO;
	395	}
	396
	397	irq = platform_get_irq(pdev, 0);
	398	if (irq < 0) {
	399	dev_err(&pdev->dev, "no irq resource defined\n");
	400	return -ENXIO;
	401	}
	402
f3766250 SK	403	at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start,
f3766250 SK	404	resource_size(regs));
d28bdfc5 JCPV	405	if (!at91_rtc_regs) {
	406	dev_err(&pdev->dev, "failed to map registers, aborting.\n");
	407	return -ENOMEM;
	408	}
	409
	410	at91_rtc_write(AT91_RTC_CR, 0);
	411	at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
788b1fc6 AV	412
788b1fc6 AV	413	/* Disable all interrupts */
e304fcd0	414	at91_rtc_write_idr(AT91_RTC_ACKUPD \| AT91_RTC_ALARM \|
e7a8bb12 AM	415	AT91_RTC_SECEV \| AT91_RTC_TIMEV \|
e7a8bb12 AM	416	AT91_RTC_CALEV);
788b1fc6	417
f3766250	418	ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
dd1f1f39 BB	419	IRQF_SHARED \| IRQF_COND_SUSPEND,
dd1f1f39 BB	420	"at91_rtc", pdev);
788b1fc6	421	if (ret) {
6588208c	422	dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
f3766250	423	return ret;
788b1fc6 AV	424	}
788b1fc6 AV	425
5d4675a8 DB	426	/* cpu init code should really have flagged this device as
	427	* being wake-capable; if it didn't, do that here.
	428	*/
	429	if (!device_can_wakeup(&pdev->dev))
	430	device_init_wakeup(&pdev->dev, 1);
	431
f3766250	432	rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
e7a8bb12	433	&at91_rtc_ops, THIS_MODULE);
f3766250 SK	434	if (IS_ERR(rtc))
f3766250 SK	435	return PTR_ERR(rtc);
788b1fc6 AV	436	platform_set_drvdata(pdev, rtc);
788b1fc6 AV	437
2fe121e1 BB	438	/* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
	439	* completion.
	440	*/
	441	at91_rtc_write_ier(AT91_RTC_SECEV);
	442
6588208c	443	dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
788b1fc6 AV	444	return 0;
	445	}
	446
	447	/*
	448	* Disable and remove the RTC driver
	449	*/
5d4675a8	450	static int __exit at91_rtc_remove(struct platform_device *pdev)
788b1fc6	451	{
788b1fc6	452	/* Disable all interrupts */
e304fcd0	453	at91_rtc_write_idr(AT91_RTC_ACKUPD \| AT91_RTC_ALARM \|
e7a8bb12 AM	454	AT91_RTC_SECEV \| AT91_RTC_TIMEV \|
e7a8bb12 AM	455	AT91_RTC_CALEV);
788b1fc6 AV	456
	457	return 0;
	458	}
	459
51a0d036 JH	460	static void at91_rtc_shutdown(struct platform_device *pdev)
	461	{
	462	/* Disable all interrupts */
	463	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD \| AT91_RTC_ALARM \|
	464	AT91_RTC_SECEV \| AT91_RTC_TIMEV \|
	465	AT91_RTC_CALEV);
	466	}
	467
6975a9c1	468	#ifdef CONFIG_PM_SLEEP
788b1fc6 AV	469
	470	/* AT91RM9200 RTC Power management control */
	471
dac94d9e	472	static int at91_rtc_suspend(struct device *dev)
788b1fc6	473	{
90b4d648 DB	474	/* this IRQ is shared with DBGU and other hardware which isn't
	475	* necessarily doing PM like we are...
	476	*/
e304fcd0	477	at91_rtc_imr = at91_rtc_read_imr()
e24b0bfa JH	478	& (AT91_RTC_ALARM\|AT91_RTC_SECEV);
e24b0bfa JH	479	if (at91_rtc_imr) {
dd1f1f39 BB	480	if (device_may_wakeup(dev)) {
	481	unsigned long flags;
	482
d28bdfc5	483	enable_irq_wake(irq);
dd1f1f39 BB	484
	485	spin_lock_irqsave(&suspended_lock, flags);
	486	suspended = true;
	487	spin_unlock_irqrestore(&suspended_lock, flags);
	488	} else {
e304fcd0	489	at91_rtc_write_idr(at91_rtc_imr);
dd1f1f39	490	}
e24b0bfa	491	}
788b1fc6 AV	492	return 0;
	493	}
	494
dac94d9e	495	static int at91_rtc_resume(struct device *dev)
788b1fc6	496	{
dd1f1f39 BB	497	struct rtc_device *rtc = dev_get_drvdata(dev);
dd1f1f39 BB	498
e24b0bfa	499	if (at91_rtc_imr) {
dd1f1f39 BB	500	if (device_may_wakeup(dev)) {
	501	unsigned long flags;
	502
	503	spin_lock_irqsave(&suspended_lock, flags);
	504
	505	if (cached_events) {
	506	rtc_update_irq(rtc, 1, cached_events);
	507	cached_events = 0;
	508	}
	509
	510	suspended = false;
	511	spin_unlock_irqrestore(&suspended_lock, flags);
	512
d28bdfc5	513	disable_irq_wake(irq);
dd1f1f39 BB	514	}
dd1f1f39 BB	515	at91_rtc_write_ier(at91_rtc_imr);
90b4d648	516	}
788b1fc6 AV	517	return 0;
788b1fc6 AV	518	}
788b1fc6 AV	519	#endif
788b1fc6 AV	520
6975a9c1 JH	521	static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
6975a9c1 JH	522
788b1fc6	523	static struct platform_driver at91_rtc_driver = {
5d4675a8	524	.remove = __exit_p(at91_rtc_remove),
51a0d036	525	.shutdown = at91_rtc_shutdown,
788b1fc6 AV	526	.driver = {
788b1fc6 AV	527	.name = "at91_rtc",
6975a9c1	528	.pm = &at91_rtc_pm_ops,
7c1b68d4	529	.of_match_table = of_match_ptr(at91_rtc_dt_ids),
788b1fc6 AV	530	},
	531	};
	532
ac36960f	533	module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
788b1fc6 AV	534
	535	MODULE_AUTHOR("Rick Bronson");
	536	MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
	537	MODULE_LICENSE("GPL");
ad28a07b	538	MODULE_ALIAS("platform:at91_rtc");