[deliverable/linux.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 baseaddr;
	unsigned long last_jiffies;
	int irq;
	unsigned int irqen;
	int alrm_sec;
	int alrm_min;
	int alrm_hour;
	int alrm_mday;
};

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->rtc->irq_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->rtc->irq_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 = RTC_IRQF;

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

static void stk17ta8_rtc_release(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	if (pdata->irq >= 0) {
		pdata->irqen = 0;
		stk17ta8_rtc_update_alarm(pdata);
	}
}

static int stk17ta8_rtc_ioctl(struct device *dev, unsigned int cmd,
			    unsigned long arg)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	if (pdata->irq < 0)
		return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
	switch (cmd) {
	case RTC_AIE_OFF:
		pdata->irqen &= ~RTC_AF;
		stk17ta8_rtc_update_alarm(pdata);
		break;
	case RTC_AIE_ON:
		pdata->irqen |= RTC_AF;
		stk17ta8_rtc_update_alarm(pdata);
		break;
	default:
		return -ENOIOCTLCMD;
	}
	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,
	.release	= stk17ta8_rtc_release,
	.ioctl		= stk17ta8_rtc_ioctl,
};

static ssize_t stk17ta8_nvram_read(struct kobject *kobj, 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, 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_IWUGO,
		.owner = THIS_MODULE,
	},
	.size = RTC_OFFSET,
	.read = stk17ta8_nvram_read,
	.write = stk17ta8_nvram_write,
};

static int __init stk17ta8_rtc_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	struct resource *res;
	unsigned int cal;
	unsigned int flags;
	struct rtc_plat_data *pdata;
	void __iomem *ioaddr = NULL;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
	pdata->irq = -1;
	if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
		ret = -EBUSY;
		goto out;
	}
	pdata->baseaddr = res->start;
	ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
	if (!ioaddr) {
		ret = -ENOMEM;
		goto out;
	}
	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");

	if (pdata->irq >= 0) {
		writeb(0, ioaddr + RTC_INTERRUPTS);
		if (request_irq(pdata->irq, stk17ta8_rtc_interrupt,
				IRQF_DISABLED | IRQF_SHARED,
				pdev->name, pdev) < 0) {
			dev_warn(&pdev->dev, "interrupt not available.\n");
			pdata->irq = -1;
		}
	}

	rtc = rtc_device_register(pdev->name, &pdev->dev,
				  &stk17ta8_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc)) {
		ret = PTR_ERR(rtc);
		goto out;
	}
	pdata->rtc = rtc;
	pdata->last_jiffies = jiffies;
	platform_set_drvdata(pdev, pdata);
	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
	if (ret)
		goto out;
	return 0;
 out:
	if (pdata->rtc)
		rtc_device_unregister(pdata->rtc);
	if (pdata->irq >= 0)
		free_irq(pdata->irq, pdev);
	if (ioaddr)
		iounmap(ioaddr);
	if (pdata->baseaddr)
		release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
	kfree(pdata);
	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);
		free_irq(pdata->irq, pdev);
	}
	iounmap(pdata->ioaddr);
	release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
	kfree(pdata);
	return 0;
}

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)
{
	return 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;
65	unsigned long baseaddr;
66	unsigned long last_jiffies;
67	int irq;
68	unsigned int irqen;
69	int alrm_sec;
70	int alrm_min;
71	int alrm_hour;
72	int alrm_mday;
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
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);
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);
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;
129	/* year is 1900 + tm->tm_year */
130	tm->tm_year = BCD2BIN(year) + BCD2BIN(century) * 100 - 1900;
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
145	spin_lock_irqsave(&pdata->rtc->irq_lock, irqflags);
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) ?
151	0x80 : BIN2BCD(pdata->alrm_mday),
152	ioaddr + RTC_DATE_ALARM);
153	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
154	0x80 : BIN2BCD(pdata->alrm_hour),
155	ioaddr + RTC_HOURS_ALARM);
156	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
157	0x80 : BIN2BCD(pdata->alrm_min),
158	ioaddr + RTC_MINUTES_ALARM);
159	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
160	0x80 : BIN2BCD(pdata->alrm_sec),
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);
165	spin_unlock_irqrestore(&pdata->rtc->irq_lock, irqflags);
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
173	if (pdata->irq < 0)
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
190	if (pdata->irq < 0)
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;
205	unsigned long events = RTC_IRQF;
206
207	/* read and clear interrupt */
208	if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF))
209	return IRQ_NONE;
210	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
211	events \|= RTC_UF;
212	else
213	events \|= RTC_AF;
214	rtc_update_irq(pdata->rtc, 1, events);
215	return IRQ_HANDLED;
216	}
217
218	static void stk17ta8_rtc_release(struct device *dev)
219	{
220	struct platform_device *pdev = to_platform_device(dev);
221	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
222
223	if (pdata->irq >= 0) {
224	pdata->irqen = 0;
225	stk17ta8_rtc_update_alarm(pdata);
226	}
227	}
228
229	static int stk17ta8_rtc_ioctl(struct device *dev, unsigned int cmd,
230	unsigned long arg)
231	{
232	struct platform_device *pdev = to_platform_device(dev);
233	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
234
235	if (pdata->irq < 0)
236	return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
237	switch (cmd) {
238	case RTC_AIE_OFF:
239	pdata->irqen &= ~RTC_AF;
240	stk17ta8_rtc_update_alarm(pdata);
241	break;
242	case RTC_AIE_ON:
243	pdata->irqen \|= RTC_AF;
244	stk17ta8_rtc_update_alarm(pdata);
245	break;
246	default:
247	return -ENOIOCTLCMD;
248	}
249	return 0;
250	}
251
252	static const struct rtc_class_ops stk17ta8_rtc_ops = {
253	.read_time = stk17ta8_rtc_read_time,
254	.set_time = stk17ta8_rtc_set_time,
255	.read_alarm = stk17ta8_rtc_read_alarm,
256	.set_alarm = stk17ta8_rtc_set_alarm,
257	.release = stk17ta8_rtc_release,
258	.ioctl = stk17ta8_rtc_ioctl,
259	};
260
261	static ssize_t stk17ta8_nvram_read(struct kobject kobj, char buf,
262	loff_t pos, size_t size)
263	{
264	struct platform_device *pdev =
265	to_platform_device(container_of(kobj, struct device, kobj));
266	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
267	void __iomem *ioaddr = pdata->ioaddr;
268	ssize_t count;
269
270	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
271	*buf++ = readb(ioaddr + pos++);
272	return count;
273	}
274
275	static ssize_t stk17ta8_nvram_write(struct kobject kobj, char buf,
276	loff_t pos, size_t size)
277	{
278	struct platform_device *pdev =
279	to_platform_device(container_of(kobj, struct device, kobj));
280	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
281	void __iomem *ioaddr = pdata->ioaddr;
282	ssize_t count;
283
284	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
285	writeb(*buf++, ioaddr + pos++);
286	return count;
287	}
288
289	static struct bin_attribute stk17ta8_nvram_attr = {
290	.attr = {
291	.name = "nvram",
292	.mode = S_IRUGO \| S_IWUGO,
293	.owner = THIS_MODULE,
294	},
295	.size = RTC_OFFSET,
296	.read = stk17ta8_nvram_read,
297	.write = stk17ta8_nvram_write,
298	};
299
300	static int __init stk17ta8_rtc_probe(struct platform_device *pdev)
301	{
302	struct rtc_device *rtc;
303	struct resource *res;
304	unsigned int cal;
305	unsigned int flags;
306	struct rtc_plat_data *pdata;
307	void __iomem *ioaddr = NULL;
308	int ret = 0;
309
310	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
311	if (!res)
312	return -ENODEV;
313
314	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
315	if (!pdata)
316	return -ENOMEM;
317	pdata->irq = -1;
318	if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
319	ret = -EBUSY;
320	goto out;
321	}
322	pdata->baseaddr = res->start;
323	ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
324	if (!ioaddr) {
325	ret = -ENOMEM;
326	goto out;
327	}
328	pdata->ioaddr = ioaddr;
329	pdata->irq = platform_get_irq(pdev, 0);
330
331	/* turn RTC on if it was not on */
332	cal = readb(ioaddr + RTC_CALIBRATION);
333	if (cal & RTC_STOP) {
334	cal &= RTC_CAL_MASK;
335	flags = readb(ioaddr + RTC_FLAGS);
336	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
337	writeb(cal, ioaddr + RTC_CALIBRATION);
338	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
339	}
340	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
341	dev_warn(&pdev->dev, "voltage-low detected.\n");
342
343	if (pdata->irq >= 0) {
344	writeb(0, ioaddr + RTC_INTERRUPTS);
345	if (request_irq(pdata->irq, stk17ta8_rtc_interrupt,
346	IRQF_DISABLED \| IRQF_SHARED,
347	pdev->name, pdev) < 0) {
348	dev_warn(&pdev->dev, "interrupt not available.\n");
349	pdata->irq = -1;
350	}
351	}
352
353	rtc = rtc_device_register(pdev->name, &pdev->dev,
354	&stk17ta8_rtc_ops, THIS_MODULE);
355	if (IS_ERR(rtc)) {
356	ret = PTR_ERR(rtc);
357	goto out;
358	}
359	pdata->rtc = rtc;
360	pdata->last_jiffies = jiffies;
361	platform_set_drvdata(pdev, pdata);
362	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
363	if (ret)
364	goto out;
365	return 0;
366	out:
367	if (pdata->rtc)
368	rtc_device_unregister(pdata->rtc);
369	if (pdata->irq >= 0)
370	free_irq(pdata->irq, pdev);
371	if (ioaddr)
372	iounmap(ioaddr);
373	if (pdata->baseaddr)
374	release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
375	kfree(pdata);
376	return ret;
377	}
378
379	static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
380	{
381	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
382
383	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
384	rtc_device_unregister(pdata->rtc);
385	if (pdata->irq >= 0) {
386	writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
387	free_irq(pdata->irq, pdev);
388	}
389	iounmap(pdata->ioaddr);
390	release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
391	kfree(pdata);
392	return 0;
393	}
394
395	static struct platform_driver stk17ta8_rtc_driver = {
396	.probe = stk17ta8_rtc_probe,
397	.remove = __devexit_p(stk17ta8_rtc_remove),
398	.driver = {
399	.name = "stk17ta8",
400	.owner = THIS_MODULE,
401	},
402	};
403
404	static __init int stk17ta8_init(void)
405	{
406	return platform_driver_register(&stk17ta8_rtc_driver);
407	}
408
409	static __exit void stk17ta8_exit(void)
410	{
411	return platform_driver_unregister(&stk17ta8_rtc_driver);
412	}
413
414	module_init(stk17ta8_init);
415	module_exit(stk17ta8_exit);
416
417	MODULE_AUTHOR("Thomas Hommel <thomas.hommel@gefanuc.com>");
418	MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
419	MODULE_LICENSE("GPL");
420	MODULE_VERSION(DRV_VERSION);