[mirror_ubuntu-artful-kernel.git] / drivers / rtc / rtc-ds1553.c

/*
 * An rtc driver for the Dallas DS1553
 *
 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>

#define DRV_VERSION "0.3"

#define RTC_REG_SIZE		0x2000
#define RTC_OFFSET		0x1ff0

#define RTC_FLAGS		(RTC_OFFSET + 0)
#define RTC_SECONDS_ALARM	(RTC_OFFSET + 2)
#define RTC_MINUTES_ALARM	(RTC_OFFSET + 3)
#define RTC_HOURS_ALARM		(RTC_OFFSET + 4)
#define RTC_DATE_ALARM		(RTC_OFFSET + 5)
#define RTC_INTERRUPTS		(RTC_OFFSET + 6)
#define RTC_WATCHDOG		(RTC_OFFSET + 7)
#define RTC_CONTROL		(RTC_OFFSET + 8)
#define RTC_CENTURY		(RTC_OFFSET + 8)
#define RTC_SECONDS		(RTC_OFFSET + 9)
#define RTC_MINUTES		(RTC_OFFSET + 10)
#define RTC_HOURS		(RTC_OFFSET + 11)
#define RTC_DAY			(RTC_OFFSET + 12)
#define RTC_DATE		(RTC_OFFSET + 13)
#define RTC_MONTH		(RTC_OFFSET + 14)
#define RTC_YEAR		(RTC_OFFSET + 15)

#define RTC_CENTURY_MASK	0x3f
#define RTC_SECONDS_MASK	0x7f
#define RTC_DAY_MASK		0x07

/* Bits in the Control/Century register */
#define RTC_WRITE		0x80
#define RTC_READ		0x40

/* Bits in the Seconds register */
#define RTC_STOP		0x80

/* Bits in the Flags register */
#define RTC_FLAGS_AF		0x40
#define RTC_FLAGS_BLF		0x10

/* Bits in the Interrupts register */
#define RTC_INTS_AE		0x80

struct rtc_plat_data {
	struct rtc_device *rtc;
	void __iomem *ioaddr;
	unsigned long last_jiffies;
	int irq;
	unsigned int irqen;
	int alrm_sec;
	int alrm_min;
	int alrm_hour;
	int alrm_mday;
	spinlock_t lock;
};

static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	u8 century;

	century = bin2bcd((tm->tm_year + 1900) / 100);

	writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);

	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);

	/* RTC_CENTURY and RTC_CONTROL share same register */
	writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	return 0;
}

static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned int year, month, day, hour, minute, second, week;
	unsigned int century;

	/* give enough time to update RTC in case of continuous read */
	if (pdata->last_jiffies == jiffies)
		msleep(1);
	pdata->last_jiffies = jiffies;
	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	minute = readb(ioaddr + RTC_MINUTES);
	hour = readb(ioaddr + RTC_HOURS);
	day = readb(ioaddr + RTC_DATE);
	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	month = readb(ioaddr + RTC_MONTH);
	year = readb(ioaddr + RTC_YEAR);
	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	writeb(0, ioaddr + RTC_CONTROL);
	tm->tm_sec = bcd2bin(second);
	tm->tm_min = bcd2bin(minute);
	tm->tm_hour = bcd2bin(hour);
	tm->tm_mday = bcd2bin(day);
	tm->tm_wday = bcd2bin(week);
	tm->tm_mon = bcd2bin(month) - 1;
	/* year is 1900 + tm->tm_year */
	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;

	if (rtc_valid_tm(tm) < 0) {
		dev_err(dev, "retrieved date/time is not valid.\n");
		rtc_time_to_tm(0, tm);
	}
	return 0;
}

static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
{
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned long flags;

	spin_lock_irqsave(&pdata->lock, flags);
	writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_mday),
	       ioaddr + RTC_DATE_ALARM);
	writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_hour),
	       ioaddr + RTC_HOURS_ALARM);
	writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_min),
	       ioaddr + RTC_MINUTES_ALARM);
	writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_sec),
	       ioaddr + RTC_SECONDS_ALARM);
	writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
	spin_unlock_irqrestore(&pdata->lock, flags);
}

static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	if (pdata->irq <= 0)
		return -EINVAL;
	pdata->alrm_mday = alrm->time.tm_mday;
	pdata->alrm_hour = alrm->time.tm_hour;
	pdata->alrm_min = alrm->time.tm_min;
	pdata->alrm_sec = alrm->time.tm_sec;
	if (alrm->enabled)
		pdata->irqen |= RTC_AF;
	ds1553_rtc_update_alarm(pdata);
	return 0;
}

static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	if (pdata->irq <= 0)
		return -EINVAL;
	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	return 0;
}

static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
{
	struct platform_device *pdev = dev_id;
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned long events = 0;

	spin_lock(&pdata->lock);
	/* read and clear interrupt */
	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
		events = RTC_IRQF;
		if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
			events |= RTC_UF;
		else
			events |= RTC_AF;
		if (likely(pdata->rtc))
			rtc_update_irq(pdata->rtc, 1, events);
	}
	spin_unlock(&pdata->lock);
	return events ? IRQ_HANDLED : IRQ_NONE;
}

static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	if (pdata->irq <= 0)
		return -EINVAL;
	if (enabled)
		pdata->irqen |= RTC_AF;
	else
		pdata->irqen &= ~RTC_AF;
	ds1553_rtc_update_alarm(pdata);
	return 0;
}

static int ds1553_rtc_update_irq_enable(struct device *dev,
	unsigned int enabled)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	if (pdata->irq <= 0)
		return -EINVAL;
	if (enabled)
		pdata->irqen |= RTC_UF;
	else
		pdata->irqen &= ~RTC_UF;
	ds1553_rtc_update_alarm(pdata);
	return 0;
}

static const struct rtc_class_ops ds1553_rtc_ops = {
	.read_time		= ds1553_rtc_read_time,
	.set_time		= ds1553_rtc_set_time,
	.read_alarm		= ds1553_rtc_read_alarm,
	.set_alarm		= ds1553_rtc_set_alarm,
	.alarm_irq_enable	= ds1553_rtc_alarm_irq_enable,
	.update_irq_enable	= ds1553_rtc_update_irq_enable,
};

static ssize_t ds1553_nvram_read(struct kobject *kobj,
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	ssize_t count;

	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
		*buf++ = readb(ioaddr + pos++);
	return count;
}

static ssize_t ds1553_nvram_write(struct kobject *kobj,
				  struct bin_attribute *bin_attr,
				  char *buf, loff_t pos, size_t size)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	ssize_t count;

	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
		writeb(*buf++, ioaddr + pos++);
	return count;
}

static struct bin_attribute ds1553_nvram_attr = {
	.attr = {
		.name = "nvram",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = RTC_OFFSET,
	.read = ds1553_nvram_read,
	.write = ds1553_nvram_write,
};

static int __devinit ds1553_rtc_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	struct resource *res;
	unsigned int cen, sec;
	struct rtc_plat_data *pdata;
	void __iomem *ioaddr;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;
	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
	if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
			pdev->name))
		return -EBUSY;

	ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
	if (!ioaddr)
		return -ENOMEM;
	pdata->ioaddr = ioaddr;
	pdata->irq = platform_get_irq(pdev, 0);

	/* turn RTC on if it was not on */
	sec = readb(ioaddr + RTC_SECONDS);
	if (sec & RTC_STOP) {
		sec &= RTC_SECONDS_MASK;
		cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
		writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
		writeb(sec, ioaddr + RTC_SECONDS);
		writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	}
	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
		dev_warn(&pdev->dev, "voltage-low detected.\n");

	spin_lock_init(&pdata->lock);
	pdata->last_jiffies = jiffies;
	platform_set_drvdata(pdev, pdata);
	if (pdata->irq > 0) {
		writeb(0, ioaddr + RTC_INTERRUPTS);
		if (devm_request_irq(&pdev->dev, pdata->irq,
				ds1553_rtc_interrupt,
				IRQF_DISABLED, pdev->name, pdev) < 0) {
			dev_warn(&pdev->dev, "interrupt not available.\n");
			pdata->irq = 0;
		}
	}

	rtc = rtc_device_register(pdev->name, &pdev->dev,
				  &ds1553_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);
	pdata->rtc = rtc;

	ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
	if (ret)
		rtc_device_unregister(rtc);
	return ret;
}

static int __devexit ds1553_rtc_remove(struct platform_device *pdev)
{
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
	rtc_device_unregister(pdata->rtc);
	if (pdata->irq > 0)
		writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
	return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:rtc-ds1553");

static struct platform_driver ds1553_rtc_driver = {
	.probe		= ds1553_rtc_probe,
	.remove		= __devexit_p(ds1553_rtc_remove),
	.driver		= {
		.name	= "rtc-ds1553",
		.owner	= THIS_MODULE,
	},
};

static __init int ds1553_init(void)
{
	return platform_driver_register(&ds1553_rtc_driver);
}

static __exit void ds1553_exit(void)
{
	platform_driver_unregister(&ds1553_rtc_driver);
}

module_init(ds1553_init);
module_exit(ds1553_exit);

MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
Commit	Line	Data
9bf5b4f5 AN	1	/*
	2	* An rtc driver for the Dallas DS1553
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/bcd.h>
	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
5a0e3ad6	14	#include <linux/gfp.h>
9bf5b4f5 AN	15	#include <linux/delay.h>
	16	#include <linux/jiffies.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/rtc.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/io.h>
	21
618161f7	22	#define DRV_VERSION "0.3"
9bf5b4f5 AN	23
	24	#define RTC_REG_SIZE 0x2000
	25	#define RTC_OFFSET 0x1ff0
	26
	27	#define RTC_FLAGS (RTC_OFFSET + 0)
	28	#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
	29	#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
	30	#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
	31	#define RTC_DATE_ALARM (RTC_OFFSET + 5)
	32	#define RTC_INTERRUPTS (RTC_OFFSET + 6)
	33	#define RTC_WATCHDOG (RTC_OFFSET + 7)
	34	#define RTC_CONTROL (RTC_OFFSET + 8)
	35	#define RTC_CENTURY (RTC_OFFSET + 8)
	36	#define RTC_SECONDS (RTC_OFFSET + 9)
	37	#define RTC_MINUTES (RTC_OFFSET + 10)
	38	#define RTC_HOURS (RTC_OFFSET + 11)
	39	#define RTC_DAY (RTC_OFFSET + 12)
	40	#define RTC_DATE (RTC_OFFSET + 13)
	41	#define RTC_MONTH (RTC_OFFSET + 14)
	42	#define RTC_YEAR (RTC_OFFSET + 15)
	43
	44	#define RTC_CENTURY_MASK 0x3f
	45	#define RTC_SECONDS_MASK 0x7f
	46	#define RTC_DAY_MASK 0x07
	47
	48	/* Bits in the Control/Century register */
	49	#define RTC_WRITE 0x80
	50	#define RTC_READ 0x40
	51
	52	/* Bits in the Seconds register */
	53	#define RTC_STOP 0x80
	54
	55	/* Bits in the Flags register */
	56	#define RTC_FLAGS_AF 0x40
	57	#define RTC_FLAGS_BLF 0x10
	58
	59	/* Bits in the Interrupts register */
	60	#define RTC_INTS_AE 0x80
	61
	62	struct rtc_plat_data {
	63	struct rtc_device *rtc;
	64	void __iomem *ioaddr;
9bf5b4f5 AN	65	unsigned long last_jiffies;
	66	int irq;
	67	unsigned int irqen;
	68	int alrm_sec;
	69	int alrm_min;
	70	int alrm_hour;
	71	int alrm_mday;
618161f7	72	spinlock_t lock;
9bf5b4f5 AN	73	};
	74
	75	static int ds1553_rtc_set_time(struct device dev, struct rtc_time tm)
	76	{
	77	struct platform_device *pdev = to_platform_device(dev);
	78	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	79	void __iomem *ioaddr = pdata->ioaddr;
	80	u8 century;
	81
fe20ba70	82	century = bin2bcd((tm->tm_year + 1900) / 100);
9bf5b4f5 AN	83
	84	writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
	85
fe20ba70 AB	86	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	87	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	88	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	89	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	90	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	91	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	92	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
9bf5b4f5 AN	93
	94	/* RTC_CENTURY and RTC_CONTROL share same register */
	95	writeb(RTC_WRITE \| (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	96	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	97	return 0;
	98	}
	99
	100	static int ds1553_rtc_read_time(struct device dev, struct rtc_time tm)
	101	{
	102	struct platform_device *pdev = to_platform_device(dev);
	103	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	104	void __iomem *ioaddr = pdata->ioaddr;
	105	unsigned int year, month, day, hour, minute, second, week;
	106	unsigned int century;
	107
	108	/* give enough time to update RTC in case of continuous read */
	109	if (pdata->last_jiffies == jiffies)
	110	msleep(1);
	111	pdata->last_jiffies = jiffies;
	112	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	113	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	114	minute = readb(ioaddr + RTC_MINUTES);
	115	hour = readb(ioaddr + RTC_HOURS);
	116	day = readb(ioaddr + RTC_DATE);
	117	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	118	month = readb(ioaddr + RTC_MONTH);
	119	year = readb(ioaddr + RTC_YEAR);
	120	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	121	writeb(0, ioaddr + RTC_CONTROL);
fe20ba70 AB	122	tm->tm_sec = bcd2bin(second);
	123	tm->tm_min = bcd2bin(minute);
	124	tm->tm_hour = bcd2bin(hour);
	125	tm->tm_mday = bcd2bin(day);
	126	tm->tm_wday = bcd2bin(week);
	127	tm->tm_mon = bcd2bin(month) - 1;
9bf5b4f5	128	/* year is 1900 + tm->tm_year */
fe20ba70	129	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
9bf5b4f5 AN	130
	131	if (rtc_valid_tm(tm) < 0) {
	132	dev_err(dev, "retrieved date/time is not valid.\n");
	133	rtc_time_to_tm(0, tm);
	134	}
	135	return 0;
	136	}
	137
	138	static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
	139	{
	140	void __iomem *ioaddr = pdata->ioaddr;
	141	unsigned long flags;
	142
618161f7	143	spin_lock_irqsave(&pdata->lock, flags);
9bf5b4f5	144	writeb(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	145	0x80 : bin2bcd(pdata->alrm_mday),
9bf5b4f5 AN	146	ioaddr + RTC_DATE_ALARM);
9bf5b4f5 AN	147	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	148	0x80 : bin2bcd(pdata->alrm_hour),
9bf5b4f5 AN	149	ioaddr + RTC_HOURS_ALARM);
9bf5b4f5 AN	150	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	151	0x80 : bin2bcd(pdata->alrm_min),
9bf5b4f5 AN	152	ioaddr + RTC_MINUTES_ALARM);
9bf5b4f5 AN	153	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	154	0x80 : bin2bcd(pdata->alrm_sec),
9bf5b4f5 AN	155	ioaddr + RTC_SECONDS_ALARM);
	156	writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
	157	readb(ioaddr + RTC_FLAGS); /* clear interrupts */
618161f7	158	spin_unlock_irqrestore(&pdata->lock, flags);
9bf5b4f5 AN	159	}
	160
	161	static int ds1553_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	162	{
	163	struct platform_device *pdev = to_platform_device(dev);
	164	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	165
2fac6674	166	if (pdata->irq <= 0)
9bf5b4f5 AN	167	return -EINVAL;
	168	pdata->alrm_mday = alrm->time.tm_mday;
	169	pdata->alrm_hour = alrm->time.tm_hour;
	170	pdata->alrm_min = alrm->time.tm_min;
	171	pdata->alrm_sec = alrm->time.tm_sec;
	172	if (alrm->enabled)
	173	pdata->irqen \|= RTC_AF;
	174	ds1553_rtc_update_alarm(pdata);
	175	return 0;
	176	}
	177
	178	static int ds1553_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	179	{
	180	struct platform_device *pdev = to_platform_device(dev);
	181	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	182
2fac6674	183	if (pdata->irq <= 0)
9bf5b4f5 AN	184	return -EINVAL;
	185	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	186	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	187	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	188	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	189	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	190	return 0;
	191	}
	192
7d12e780	193	static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
9bf5b4f5 AN	194	{
	195	struct platform_device *pdev = dev_id;
	196	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	197	void __iomem *ioaddr = pdata->ioaddr;
618161f7	198	unsigned long events = 0;
9bf5b4f5	199
618161f7	200	spin_lock(&pdata->lock);
9bf5b4f5	201	/* read and clear interrupt */
618161f7 AN	202	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
	203	events = RTC_IRQF;
	204	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
	205	events \|= RTC_UF;
	206	else
	207	events \|= RTC_AF;
	208	if (likely(pdata->rtc))
	209	rtc_update_irq(pdata->rtc, 1, events);
	210	}
	211	spin_unlock(&pdata->lock);
	212	return events ? IRQ_HANDLED : IRQ_NONE;
9bf5b4f5 AN	213	}
9bf5b4f5 AN	214
618161f7	215	static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
9bf5b4f5 AN	216	{
	217	struct platform_device *pdev = to_platform_device(dev);
	218	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	219
2fac6674	220	if (pdata->irq <= 0)
618161f7 AN	221	return -EINVAL;
618161f7 AN	222	if (enabled)
9bf5b4f5	223	pdata->irqen \|= RTC_AF;
618161f7 AN	224	else
	225	pdata->irqen &= ~RTC_AF;
	226	ds1553_rtc_update_alarm(pdata);
	227	return 0;
	228	}
	229
	230	static int ds1553_rtc_update_irq_enable(struct device *dev,
	231	unsigned int enabled)
	232	{
	233	struct platform_device *pdev = to_platform_device(dev);
	234	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	235
	236	if (pdata->irq <= 0)
	237	return -EINVAL;
	238	if (enabled)
9bf5b4f5	239	pdata->irqen \|= RTC_UF;
618161f7 AN	240	else
	241	pdata->irqen &= ~RTC_UF;
	242	ds1553_rtc_update_alarm(pdata);
9bf5b4f5 AN	243	return 0;
	244	}
	245
ff8371ac	246	static const struct rtc_class_ops ds1553_rtc_ops = {
618161f7 AN	247	.read_time = ds1553_rtc_read_time,
	248	.set_time = ds1553_rtc_set_time,
	249	.read_alarm = ds1553_rtc_read_alarm,
	250	.set_alarm = ds1553_rtc_set_alarm,
	251	.alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
	252	.update_irq_enable = ds1553_rtc_update_irq_enable,
9bf5b4f5 AN	253	};
9bf5b4f5 AN	254
91a69029 ZR	255	static ssize_t ds1553_nvram_read(struct kobject *kobj,
	256	struct bin_attribute *bin_attr,
	257	char *buf, loff_t pos, size_t size)
9bf5b4f5	258	{
50e49bee AN	259	struct device *dev = container_of(kobj, struct device, kobj);
50e49bee AN	260	struct platform_device *pdev = to_platform_device(dev);
9bf5b4f5 AN	261	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	262	void __iomem *ioaddr = pdata->ioaddr;
	263	ssize_t count;
	264
	265	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
	266	*buf++ = readb(ioaddr + pos++);
	267	return count;
	268	}
	269
91a69029 ZR	270	static ssize_t ds1553_nvram_write(struct kobject *kobj,
	271	struct bin_attribute *bin_attr,
	272	char *buf, loff_t pos, size_t size)
9bf5b4f5	273	{
50e49bee AN	274	struct device *dev = container_of(kobj, struct device, kobj);
50e49bee AN	275	struct platform_device *pdev = to_platform_device(dev);
9bf5b4f5 AN	276	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	277	void __iomem *ioaddr = pdata->ioaddr;
	278	ssize_t count;
	279
	280	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
	281	writeb(*buf++, ioaddr + pos++);
	282	return count;
	283	}
	284
	285	static struct bin_attribute ds1553_nvram_attr = {
	286	.attr = {
	287	.name = "nvram",
a4b1d50e	288	.mode = S_IRUGO \| S_IWUSR,
9bf5b4f5 AN	289	},
	290	.size = RTC_OFFSET,
	291	.read = ds1553_nvram_read,
	292	.write = ds1553_nvram_write,
	293	};
	294
c239122d	295	static int __devinit ds1553_rtc_probe(struct platform_device *pdev)
9bf5b4f5 AN	296	{
	297	struct rtc_device *rtc;
	298	struct resource *res;
	299	unsigned int cen, sec;
618161f7 AN	300	struct rtc_plat_data *pdata;
618161f7 AN	301	void __iomem *ioaddr;
9bf5b4f5 AN	302	int ret = 0;
	303
	304	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	305	if (!res)
	306	return -ENODEV;
618161f7	307	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
9bf5b4f5 AN	308	if (!pdata)
9bf5b4f5 AN	309	return -ENOMEM;
618161f7 AN	310	if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
	311	pdev->name))
	312	return -EBUSY;
	313
	314	ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
	315	if (!ioaddr)
	316	return -ENOMEM;
9bf5b4f5 AN	317	pdata->ioaddr = ioaddr;
	318	pdata->irq = platform_get_irq(pdev, 0);
	319
	320	/* turn RTC on if it was not on */
	321	sec = readb(ioaddr + RTC_SECONDS);
	322	if (sec & RTC_STOP) {
	323	sec &= RTC_SECONDS_MASK;
	324	cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	325	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	326	writeb(sec, ioaddr + RTC_SECONDS);
	327	writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	328	}
	329	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
	330	dev_warn(&pdev->dev, "voltage-low detected.\n");
	331
618161f7 AN	332	spin_lock_init(&pdata->lock);
	333	pdata->last_jiffies = jiffies;
	334	platform_set_drvdata(pdev, pdata);
2fac6674	335	if (pdata->irq > 0) {
9bf5b4f5	336	writeb(0, ioaddr + RTC_INTERRUPTS);
618161f7 AN	337	if (devm_request_irq(&pdev->dev, pdata->irq,
618161f7 AN	338	ds1553_rtc_interrupt,
014b6e90	339	IRQF_DISABLED, pdev->name, pdev) < 0) {
9bf5b4f5	340	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	341	pdata->irq = 0;
9bf5b4f5 AN	342	}
	343	}
	344
	345	rtc = rtc_device_register(pdev->name, &pdev->dev,
	346	&ds1553_rtc_ops, THIS_MODULE);
618161f7 AN	347	if (IS_ERR(rtc))
618161f7 AN	348	return PTR_ERR(rtc);
9bf5b4f5	349	pdata->rtc = rtc;
618161f7	350
391b1fe6 AN	351	ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
391b1fe6 AN	352	if (ret)
618161f7	353	rtc_device_unregister(rtc);
9bf5b4f5 AN	354	return ret;
	355	}
	356
	357	static int __devexit ds1553_rtc_remove(struct platform_device *pdev)
	358	{
	359	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	360
	361	sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
	362	rtc_device_unregister(pdata->rtc);
618161f7	363	if (pdata->irq > 0)
9bf5b4f5	364	writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
9bf5b4f5 AN	365	return 0;
	366	}
	367
ad28a07b KS	368	/* work with hotplug and coldplug */
	369	MODULE_ALIAS("platform:rtc-ds1553");
	370
9bf5b4f5 AN	371	static struct platform_driver ds1553_rtc_driver = {
	372	.probe = ds1553_rtc_probe,
	373	.remove = __devexit_p(ds1553_rtc_remove),
	374	.driver = {
e7634c27	375	.name = "rtc-ds1553",
9bf5b4f5 AN	376	.owner = THIS_MODULE,
	377	},
	378	};
	379
	380	static __init int ds1553_init(void)
	381	{
	382	return platform_driver_register(&ds1553_rtc_driver);
	383	}
	384
	385	static __exit void ds1553_exit(void)
	386	{
ef154ec6	387	platform_driver_unregister(&ds1553_rtc_driver);
9bf5b4f5 AN	388	}
	389
	390	module_init(ds1553_init);
	391	module_exit(ds1553_exit);
	392
	393	MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
	394	MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
	395	MODULE_LICENSE("GPL");
	396	MODULE_VERSION(DRV_VERSION);