[net-next-2.6.git] / drivers / rtc / rtc-stk17ta8.c

/*
 * A RTC driver for the Simtek STK17TA8
 *
 * By Thomas Hommel <thomas.hommel@gefanuc.com>
 *
 * Based on the DS1553 driver from
 * 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/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 "0.1"

#define RTC_REG_SIZE		0x20000
#define RTC_OFFSET		0x1fff0

#define RTC_FLAGS		(RTC_OFFSET + 0)
#define RTC_CENTURY		(RTC_OFFSET + 1)
#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_CALIBRATION		(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_SECONDS_MASK	0x7f
#define RTC_DAY_MASK		0x07
#define RTC_CAL_MASK		0x3f

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

/* Bits in the Flags register */
#define RTC_FLAGS_AF		0x40
#define RTC_FLAGS_PF		0x20
#define RTC_WRITE		0x02
#define RTC_READ		0x01

/* Bits in the Interrupts register */
#define RTC_INTS_AIE		0x40

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 stk17ta8_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 flags;

	flags = readb(pdata->ioaddr + RTC_FLAGS);
	writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);

	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);
	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);

	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	return 0;
}

static int stk17ta8_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;
	u8 flags;

	/* give enough time to update RTC in case of continuous read */
	if (pdata->last_jiffies == jiffies)
		msleep(1);
	pdata->last_jiffies = jiffies;

	flags = readb(pdata->ioaddr + RTC_FLAGS);
	writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
	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);
	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
	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 stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
{
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned long irqflags;
	u8 flags;

	spin_lock_irqsave(&pdata->lock, irqflags);

	flags = readb(ioaddr + RTC_FLAGS);
	writeb(flags | RTC_WRITE, ioaddr + RTC_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_AIE : 0, ioaddr + RTC_INTERRUPTS);
	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	spin_unlock_irqrestore(&pdata->lock, irqflags);
}

static int stk17ta8_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;
	stk17ta8_rtc_update_alarm(pdata);
	return 0;
}

static int stk17ta8_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 stk17ta8_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 stk17ta8_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;
	stk17ta8_rtc_update_alarm(pdata);
	return 0;
}

static const struct rtc_class_ops stk17ta8_rtc_ops = {
	.read_time		= stk17ta8_rtc_read_time,
	.set_time		= stk17ta8_rtc_set_time,
	.read_alarm		= stk17ta8_rtc_read_alarm,
	.set_alarm		= stk17ta8_rtc_set_alarm,
	.alarm_irq_enable	= stk17ta8_rtc_alarm_irq_enable,
};

static ssize_t stk17ta8_nvram_read(struct kobject *kobj,
				 struct bin_attribute *attr, char *buf,
				 loff_t pos, size_t size)
{
	struct platform_device *pdev =
		to_platform_device(container_of(kobj, struct device, kobj));
	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 stk17ta8_nvram_write(struct kobject *kobj,
				  struct bin_attribute *attr, char *buf,
				  loff_t pos, size_t size)
{
	struct platform_device *pdev =
		to_platform_device(container_of(kobj, struct device, kobj));
	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 stk17ta8_nvram_attr = {
	.attr = {
		.name = "nvram",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = RTC_OFFSET,
	.read = stk17ta8_nvram_read,
	.write = stk17ta8_nvram_write,
};

static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
{
	struct resource *res;
	unsigned int cal;
	unsigned int flags;
	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 */
	cal = readb(ioaddr + RTC_CALIBRATION);
	if (cal & RTC_STOP) {
		cal &= RTC_CAL_MASK;
		flags = readb(ioaddr + RTC_FLAGS);
		writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
		writeb(cal, ioaddr + RTC_CALIBRATION);
		writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	}
	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
		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,
				stk17ta8_rtc_interrupt,
				IRQF_DISABLED | IRQF_SHARED,
				pdev->name, pdev) < 0) {
			dev_warn(&pdev->dev, "interrupt not available.\n");
			pdata->irq = 0;
		}
	}

	pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
				  &stk17ta8_rtc_ops, THIS_MODULE);
	if (IS_ERR(pdata->rtc))
		return PTR_ERR(pdata->rtc);

	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
	if (ret)
		rtc_device_unregister(pdata->rtc);
	return ret;
}

static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
{
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_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:stk17ta8");

static struct platform_driver stk17ta8_rtc_driver = {
	.probe		= stk17ta8_rtc_probe,
	.remove		= __devexit_p(stk17ta8_rtc_remove),
	.driver		= {
		.name	= "stk17ta8",
		.owner	= THIS_MODULE,
	},
};

static __init int stk17ta8_init(void)
{
	return platform_driver_register(&stk17ta8_rtc_driver);
}

static __exit void stk17ta8_exit(void)
{
	platform_driver_unregister(&stk17ta8_rtc_driver);
}

module_init(stk17ta8_init);
module_exit(stk17ta8_exit);

MODULE_AUTHOR("Thomas Hommel <thomas.hommel@gefanuc.com>");
MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
Commit	Line	Data
02964115 TH	1	/*
	2	* A RTC driver for the Simtek STK17TA8
	3	*
	4	* By Thomas Hommel <thomas.hommel@gefanuc.com>
	5	*
	6	* Based on the DS1553 driver from
	7	* Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/bcd.h>
	15	#include <linux/init.h>
	16	#include <linux/kernel.h>
	17	#include <linux/delay.h>
	18	#include <linux/jiffies.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/rtc.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/io.h>
	23
	24	#define DRV_VERSION "0.1"
	25
	26	#define RTC_REG_SIZE 0x20000
	27	#define RTC_OFFSET 0x1fff0
	28
	29	#define RTC_FLAGS (RTC_OFFSET + 0)
	30	#define RTC_CENTURY (RTC_OFFSET + 1)
	31	#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
	32	#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
	33	#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
	34	#define RTC_DATE_ALARM (RTC_OFFSET + 5)
	35	#define RTC_INTERRUPTS (RTC_OFFSET + 6)
	36	#define RTC_WATCHDOG (RTC_OFFSET + 7)
	37	#define RTC_CALIBRATION (RTC_OFFSET + 8)
	38	#define RTC_SECONDS (RTC_OFFSET + 9)
	39	#define RTC_MINUTES (RTC_OFFSET + 10)
	40	#define RTC_HOURS (RTC_OFFSET + 11)
	41	#define RTC_DAY (RTC_OFFSET + 12)
	42	#define RTC_DATE (RTC_OFFSET + 13)
	43	#define RTC_MONTH (RTC_OFFSET + 14)
	44	#define RTC_YEAR (RTC_OFFSET + 15)
	45
	46	#define RTC_SECONDS_MASK 0x7f
	47	#define RTC_DAY_MASK 0x07
	48	#define RTC_CAL_MASK 0x3f
	49
	50	/* Bits in the Calibration register */
	51	#define RTC_STOP 0x80
	52
	53	/* Bits in the Flags register */
	54	#define RTC_FLAGS_AF 0x40
	55	#define RTC_FLAGS_PF 0x20
	56	#define RTC_WRITE 0x02
	57	#define RTC_READ 0x01
	58
	59	/* Bits in the Interrupts register */
	60	#define RTC_INTS_AIE 0x40
	61
	62	struct rtc_plat_data {
	63	struct rtc_device *rtc;
	64	void __iomem *ioaddr;
02964115 TH	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;
3151520d	72	spinlock_t lock;
02964115 TH	73	};
	74
	75	static int stk17ta8_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 flags;
	81
	82	flags = readb(pdata->ioaddr + RTC_FLAGS);
	83	writeb(flags \| RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	84
fe20ba70 AB	85	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	86	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	87	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	88	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	89	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	90	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	91	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
	92	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
02964115 TH	93
	94	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	95	return 0;
	96	}
	97
	98	static int stk17ta8_rtc_read_time(struct device dev, struct rtc_time tm)
	99	{
	100	struct platform_device *pdev = to_platform_device(dev);
	101	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	102	void __iomem *ioaddr = pdata->ioaddr;
	103	unsigned int year, month, day, hour, minute, second, week;
	104	unsigned int century;
	105	u8 flags;
	106
	107	/* give enough time to update RTC in case of continuous read */
	108	if (pdata->last_jiffies == jiffies)
	109	msleep(1);
	110	pdata->last_jiffies = jiffies;
	111
	112	flags = readb(pdata->ioaddr + RTC_FLAGS);
	113	writeb(flags \| RTC_READ, ioaddr + RTC_FLAGS);
	114	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	115	minute = readb(ioaddr + RTC_MINUTES);
	116	hour = readb(ioaddr + RTC_HOURS);
	117	day = readb(ioaddr + RTC_DATE);
	118	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	119	month = readb(ioaddr + RTC_MONTH);
	120	year = readb(ioaddr + RTC_YEAR);
	121	century = readb(ioaddr + RTC_CENTURY);
	122	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
fe20ba70 AB	123	tm->tm_sec = bcd2bin(second);
	124	tm->tm_min = bcd2bin(minute);
	125	tm->tm_hour = bcd2bin(hour);
	126	tm->tm_mday = bcd2bin(day);
	127	tm->tm_wday = bcd2bin(week);
	128	tm->tm_mon = bcd2bin(month) - 1;
02964115	129	/* year is 1900 + tm->tm_year */
fe20ba70	130	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
02964115 TH	131
	132	if (rtc_valid_tm(tm) < 0) {
	133	dev_err(dev, "retrieved date/time is not valid.\n");
	134	rtc_time_to_tm(0, tm);
	135	}
	136	return 0;
	137	}
	138
	139	static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
	140	{
	141	void __iomem *ioaddr = pdata->ioaddr;
	142	unsigned long irqflags;
	143	u8 flags;
	144
3151520d	145	spin_lock_irqsave(&pdata->lock, irqflags);
02964115 TH	146
	147	flags = readb(ioaddr + RTC_FLAGS);
	148	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
	149
	150	writeb(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	151	0x80 : bin2bcd(pdata->alrm_mday),
02964115 TH	152	ioaddr + RTC_DATE_ALARM);
02964115 TH	153	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	154	0x80 : bin2bcd(pdata->alrm_hour),
02964115 TH	155	ioaddr + RTC_HOURS_ALARM);
02964115 TH	156	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	157	0x80 : bin2bcd(pdata->alrm_min),
02964115 TH	158	ioaddr + RTC_MINUTES_ALARM);
02964115 TH	159	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	160	0x80 : bin2bcd(pdata->alrm_sec),
02964115 TH	161	ioaddr + RTC_SECONDS_ALARM);
	162	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
	163	readb(ioaddr + RTC_FLAGS); /* clear interrupts */
	164	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
3151520d	165	spin_unlock_irqrestore(&pdata->lock, irqflags);
02964115 TH	166	}
	167
	168	static int stk17ta8_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	169	{
	170	struct platform_device *pdev = to_platform_device(dev);
	171	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	172
2fac6674	173	if (pdata->irq <= 0)
02964115 TH	174	return -EINVAL;
	175	pdata->alrm_mday = alrm->time.tm_mday;
	176	pdata->alrm_hour = alrm->time.tm_hour;
	177	pdata->alrm_min = alrm->time.tm_min;
	178	pdata->alrm_sec = alrm->time.tm_sec;
	179	if (alrm->enabled)
	180	pdata->irqen \|= RTC_AF;
	181	stk17ta8_rtc_update_alarm(pdata);
	182	return 0;
	183	}
	184
	185	static int stk17ta8_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	186	{
	187	struct platform_device *pdev = to_platform_device(dev);
	188	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	189
2fac6674	190	if (pdata->irq <= 0)
02964115 TH	191	return -EINVAL;
	192	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	193	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	194	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	195	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	196	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	197	return 0;
	198	}
	199
	200	static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
	201	{
	202	struct platform_device *pdev = dev_id;
	203	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	204	void __iomem *ioaddr = pdata->ioaddr;
3151520d	205	unsigned long events = 0;
02964115	206
3151520d	207	spin_lock(&pdata->lock);
02964115	208	/* read and clear interrupt */
3151520d AN	209	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
	210	events = RTC_IRQF;
	211	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
	212	events \|= RTC_UF;
	213	else
	214	events \|= RTC_AF;
	215	if (likely(pdata->rtc))
	216	rtc_update_irq(pdata->rtc, 1, events);
	217	}
	218	spin_unlock(&pdata->lock);
	219	return events ? IRQ_HANDLED : IRQ_NONE;
02964115 TH	220	}
02964115 TH	221
3151520d AN	222	static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
3151520d AN	223	unsigned int enabled)
02964115 TH	224	{
	225	struct platform_device *pdev = to_platform_device(dev);
	226	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	227
2fac6674	228	if (pdata->irq <= 0)
3151520d AN	229	return -EINVAL;
3151520d AN	230	if (enabled)
02964115	231	pdata->irqen \|= RTC_AF;
3151520d AN	232	else
	233	pdata->irqen &= ~RTC_AF;
	234	stk17ta8_rtc_update_alarm(pdata);
02964115 TH	235	return 0;
	236	}
	237
	238	static const struct rtc_class_ops stk17ta8_rtc_ops = {
3151520d AN	239	.read_time = stk17ta8_rtc_read_time,
	240	.set_time = stk17ta8_rtc_set_time,
	241	.read_alarm = stk17ta8_rtc_read_alarm,
	242	.set_alarm = stk17ta8_rtc_set_alarm,
	243	.alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable,
02964115 TH	244	};
02964115 TH	245
c98dbe59 AV	246	static ssize_t stk17ta8_nvram_read(struct kobject *kobj,
c98dbe59 AV	247	struct bin_attribute attr, char buf,
02964115 TH	248	loff_t pos, size_t size)
	249	{
	250	struct platform_device *pdev =
	251	to_platform_device(container_of(kobj, struct device, kobj));
	252	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	253	void __iomem *ioaddr = pdata->ioaddr;
	254	ssize_t count;
	255
	256	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
	257	*buf++ = readb(ioaddr + pos++);
	258	return count;
	259	}
	260
c98dbe59 AV	261	static ssize_t stk17ta8_nvram_write(struct kobject *kobj,
c98dbe59 AV	262	struct bin_attribute attr, char buf,
02964115 TH	263	loff_t pos, size_t size)
	264	{
	265	struct platform_device *pdev =
	266	to_platform_device(container_of(kobj, struct device, kobj));
	267	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	268	void __iomem *ioaddr = pdata->ioaddr;
	269	ssize_t count;
	270
	271	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
	272	writeb(*buf++, ioaddr + pos++);
	273	return count;
	274	}
	275
	276	static struct bin_attribute stk17ta8_nvram_attr = {
	277	.attr = {
	278	.name = "nvram",
a4b1d50e	279	.mode = S_IRUGO \| S_IWUSR,
02964115 TH	280	},
	281	.size = RTC_OFFSET,
	282	.read = stk17ta8_nvram_read,
	283	.write = stk17ta8_nvram_write,
	284	};
	285
81e627e0	286	static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
02964115	287	{
02964115 TH	288	struct resource *res;
	289	unsigned int cal;
	290	unsigned int flags;
	291	struct rtc_plat_data *pdata;
3151520d	292	void __iomem *ioaddr;
02964115 TH	293	int ret = 0;
	294
	295	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	296	if (!res)
	297	return -ENODEV;
	298
3151520d	299	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
02964115 TH	300	if (!pdata)
02964115 TH	301	return -ENOMEM;
3151520d AN	302	if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
	303	pdev->name))
	304	return -EBUSY;
	305	ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
	306	if (!ioaddr)
	307	return -ENOMEM;
02964115 TH	308	pdata->ioaddr = ioaddr;
	309	pdata->irq = platform_get_irq(pdev, 0);
	310
	311	/* turn RTC on if it was not on */
	312	cal = readb(ioaddr + RTC_CALIBRATION);
	313	if (cal & RTC_STOP) {
	314	cal &= RTC_CAL_MASK;
	315	flags = readb(ioaddr + RTC_FLAGS);
	316	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
	317	writeb(cal, ioaddr + RTC_CALIBRATION);
	318	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	319	}
	320	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
	321	dev_warn(&pdev->dev, "voltage-low detected.\n");
	322
3151520d AN	323	spin_lock_init(&pdata->lock);
	324	pdata->last_jiffies = jiffies;
	325	platform_set_drvdata(pdev, pdata);
2fac6674	326	if (pdata->irq > 0) {
02964115	327	writeb(0, ioaddr + RTC_INTERRUPTS);
3151520d AN	328	if (devm_request_irq(&pdev->dev, pdata->irq,
3151520d AN	329	stk17ta8_rtc_interrupt,
02964115 TH	330	IRQF_DISABLED \| IRQF_SHARED,
	331	pdev->name, pdev) < 0) {
	332	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	333	pdata->irq = 0;
02964115 TH	334	}
	335	}
	336
b74d2caa	337	pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
02964115	338	&stk17ta8_rtc_ops, THIS_MODULE);
3151520d AN	339	if (IS_ERR(pdata->rtc))
3151520d AN	340	return PTR_ERR(pdata->rtc);
b74d2caa	341
02964115	342	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
3151520d	343	if (ret)
b74d2caa	344	rtc_device_unregister(pdata->rtc);
02964115 TH	345	return ret;
	346	}
	347
	348	static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
	349	{
	350	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	351
	352	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
	353	rtc_device_unregister(pdata->rtc);
3151520d	354	if (pdata->irq > 0)
02964115	355	writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
02964115 TH	356	return 0;
	357	}
	358
ad28a07b KS	359	/* work with hotplug and coldplug */
	360	MODULE_ALIAS("platform:stk17ta8");
	361
02964115 TH	362	static struct platform_driver stk17ta8_rtc_driver = {
	363	.probe = stk17ta8_rtc_probe,
	364	.remove = __devexit_p(stk17ta8_rtc_remove),
	365	.driver = {
	366	.name = "stk17ta8",
	367	.owner = THIS_MODULE,
	368	},
	369	};
	370
	371	static __init int stk17ta8_init(void)
	372	{
	373	return platform_driver_register(&stk17ta8_rtc_driver);
	374	}
	375
	376	static __exit void stk17ta8_exit(void)
	377	{
277835ad	378	platform_driver_unregister(&stk17ta8_rtc_driver);
02964115 TH	379	}
	380
	381	module_init(stk17ta8_init);
	382	module_exit(stk17ta8_exit);
	383
	384	MODULE_AUTHOR("Thomas Hommel <thomas.hommel@gefanuc.com>");
	385	MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
	386	MODULE_LICENSE("GPL");
	387	MODULE_VERSION(DRV_VERSION);