[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / rtc / rtc-stk17ta8.c

/*
 * A RTC driver for the Simtek STK17TA8
 *
 * By Thomas Hommel <thomas.hommel@ge.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/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>
#include <linux/module.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 file *filp, struct kobject *kobj,
				 struct bin_attribute *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 stk17ta8_nvram_write(struct file *filp, struct kobject *kobj,
				  struct bin_attribute *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 stk17ta8_nvram_attr = {
	.attr = {
		.name = "nvram",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = RTC_OFFSET,
	.read = stk17ta8_nvram_read,
	.write = stk17ta8_nvram_write,
};

static int 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_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 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		= stk17ta8_rtc_remove,
	.driver		= {
		.name	= "stk17ta8",
		.owner	= THIS_MODULE,
	},
};

module_platform_driver(stk17ta8_rtc_driver);

MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.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	*
ab4364d3	4	* By Thomas Hommel <thomas.hommel@ge.com>
02964115 TH	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>
5a0e3ad6	17	#include <linux/gfp.h>
02964115 TH	18	#include <linux/delay.h>
	19	#include <linux/jiffies.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/rtc.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/io.h>
2113852b	24	#include <linux/module.h>
02964115 TH	25
	26	#define DRV_VERSION "0.1"
	27
	28	#define RTC_REG_SIZE 0x20000
	29	#define RTC_OFFSET 0x1fff0
	30
	31	#define RTC_FLAGS (RTC_OFFSET + 0)
	32	#define RTC_CENTURY (RTC_OFFSET + 1)
	33	#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
	34	#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
	35	#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
	36	#define RTC_DATE_ALARM (RTC_OFFSET + 5)
	37	#define RTC_INTERRUPTS (RTC_OFFSET + 6)
	38	#define RTC_WATCHDOG (RTC_OFFSET + 7)
	39	#define RTC_CALIBRATION (RTC_OFFSET + 8)
	40	#define RTC_SECONDS (RTC_OFFSET + 9)
	41	#define RTC_MINUTES (RTC_OFFSET + 10)
	42	#define RTC_HOURS (RTC_OFFSET + 11)
	43	#define RTC_DAY (RTC_OFFSET + 12)
	44	#define RTC_DATE (RTC_OFFSET + 13)
	45	#define RTC_MONTH (RTC_OFFSET + 14)
	46	#define RTC_YEAR (RTC_OFFSET + 15)
	47
	48	#define RTC_SECONDS_MASK 0x7f
	49	#define RTC_DAY_MASK 0x07
	50	#define RTC_CAL_MASK 0x3f
	51
	52	/* Bits in the Calibration register */
	53	#define RTC_STOP 0x80
	54
	55	/* Bits in the Flags register */
	56	#define RTC_FLAGS_AF 0x40
	57	#define RTC_FLAGS_PF 0x20
	58	#define RTC_WRITE 0x02
	59	#define RTC_READ 0x01
	60
	61	/* Bits in the Interrupts register */
	62	#define RTC_INTS_AIE 0x40
	63
	64	struct rtc_plat_data {
	65	struct rtc_device *rtc;
	66	void __iomem *ioaddr;
02964115 TH	67	unsigned long last_jiffies;
	68	int irq;
	69	unsigned int irqen;
	70	int alrm_sec;
	71	int alrm_min;
	72	int alrm_hour;
	73	int alrm_mday;
3151520d	74	spinlock_t lock;
02964115 TH	75	};
	76
	77	static int stk17ta8_rtc_set_time(struct device dev, struct rtc_time tm)
	78	{
	79	struct platform_device *pdev = to_platform_device(dev);
	80	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	81	void __iomem *ioaddr = pdata->ioaddr;
	82	u8 flags;
	83
	84	flags = readb(pdata->ioaddr + RTC_FLAGS);
	85	writeb(flags \| RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	86
fe20ba70 AB	87	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	88	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	89	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	90	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	91	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	92	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	93	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
	94	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
02964115 TH	95
	96	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	97	return 0;
	98	}
	99
	100	static int stk17ta8_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	u8 flags;
	108
	109	/* give enough time to update RTC in case of continuous read */
	110	if (pdata->last_jiffies == jiffies)
	111	msleep(1);
	112	pdata->last_jiffies = jiffies;
	113
	114	flags = readb(pdata->ioaddr + RTC_FLAGS);
	115	writeb(flags \| RTC_READ, ioaddr + RTC_FLAGS);
	116	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	117	minute = readb(ioaddr + RTC_MINUTES);
	118	hour = readb(ioaddr + RTC_HOURS);
	119	day = readb(ioaddr + RTC_DATE);
	120	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	121	month = readb(ioaddr + RTC_MONTH);
	122	year = readb(ioaddr + RTC_YEAR);
	123	century = readb(ioaddr + RTC_CENTURY);
	124	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
fe20ba70 AB	125	tm->tm_sec = bcd2bin(second);
	126	tm->tm_min = bcd2bin(minute);
	127	tm->tm_hour = bcd2bin(hour);
	128	tm->tm_mday = bcd2bin(day);
	129	tm->tm_wday = bcd2bin(week);
	130	tm->tm_mon = bcd2bin(month) - 1;
02964115	131	/* year is 1900 + tm->tm_year */
fe20ba70	132	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
02964115 TH	133
	134	if (rtc_valid_tm(tm) < 0) {
	135	dev_err(dev, "retrieved date/time is not valid.\n");
	136	rtc_time_to_tm(0, tm);
	137	}
	138	return 0;
	139	}
	140
	141	static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
	142	{
	143	void __iomem *ioaddr = pdata->ioaddr;
	144	unsigned long irqflags;
	145	u8 flags;
	146
3151520d	147	spin_lock_irqsave(&pdata->lock, irqflags);
02964115 TH	148
	149	flags = readb(ioaddr + RTC_FLAGS);
	150	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
	151
	152	writeb(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	153	0x80 : bin2bcd(pdata->alrm_mday),
02964115 TH	154	ioaddr + RTC_DATE_ALARM);
02964115 TH	155	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	156	0x80 : bin2bcd(pdata->alrm_hour),
02964115 TH	157	ioaddr + RTC_HOURS_ALARM);
02964115 TH	158	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	159	0x80 : bin2bcd(pdata->alrm_min),
02964115 TH	160	ioaddr + RTC_MINUTES_ALARM);
02964115 TH	161	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	162	0x80 : bin2bcd(pdata->alrm_sec),
02964115 TH	163	ioaddr + RTC_SECONDS_ALARM);
	164	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
	165	readb(ioaddr + RTC_FLAGS); /* clear interrupts */
	166	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
3151520d	167	spin_unlock_irqrestore(&pdata->lock, irqflags);
02964115 TH	168	}
	169
	170	static int stk17ta8_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	171	{
	172	struct platform_device *pdev = to_platform_device(dev);
	173	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	174
2fac6674	175	if (pdata->irq <= 0)
02964115 TH	176	return -EINVAL;
	177	pdata->alrm_mday = alrm->time.tm_mday;
	178	pdata->alrm_hour = alrm->time.tm_hour;
	179	pdata->alrm_min = alrm->time.tm_min;
	180	pdata->alrm_sec = alrm->time.tm_sec;
	181	if (alrm->enabled)
	182	pdata->irqen \|= RTC_AF;
	183	stk17ta8_rtc_update_alarm(pdata);
	184	return 0;
	185	}
	186
	187	static int stk17ta8_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	188	{
	189	struct platform_device *pdev = to_platform_device(dev);
	190	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	191
2fac6674	192	if (pdata->irq <= 0)
02964115 TH	193	return -EINVAL;
	194	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	195	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	196	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	197	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	198	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	199	return 0;
	200	}
	201
	202	static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
	203	{
	204	struct platform_device *pdev = dev_id;
	205	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	206	void __iomem *ioaddr = pdata->ioaddr;
3151520d	207	unsigned long events = 0;
02964115	208
3151520d	209	spin_lock(&pdata->lock);
02964115	210	/* read and clear interrupt */
3151520d AN	211	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
	212	events = RTC_IRQF;
	213	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
	214	events \|= RTC_UF;
	215	else
	216	events \|= RTC_AF;
	217	if (likely(pdata->rtc))
	218	rtc_update_irq(pdata->rtc, 1, events);
	219	}
	220	spin_unlock(&pdata->lock);
	221	return events ? IRQ_HANDLED : IRQ_NONE;
02964115 TH	222	}
02964115 TH	223
3151520d AN	224	static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
3151520d AN	225	unsigned int enabled)
02964115 TH	226	{
	227	struct platform_device *pdev = to_platform_device(dev);
	228	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	229
2fac6674	230	if (pdata->irq <= 0)
3151520d AN	231	return -EINVAL;
3151520d AN	232	if (enabled)
02964115	233	pdata->irqen \|= RTC_AF;
3151520d AN	234	else
	235	pdata->irqen &= ~RTC_AF;
	236	stk17ta8_rtc_update_alarm(pdata);
02964115 TH	237	return 0;
	238	}
	239
	240	static const struct rtc_class_ops stk17ta8_rtc_ops = {
3151520d AN	241	.read_time = stk17ta8_rtc_read_time,
	242	.set_time = stk17ta8_rtc_set_time,
	243	.read_alarm = stk17ta8_rtc_read_alarm,
	244	.set_alarm = stk17ta8_rtc_set_alarm,
	245	.alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable,
02964115 TH	246	};
02964115 TH	247
2c3c8bea	248	static ssize_t stk17ta8_nvram_read(struct file filp, struct kobject kobj,
c98dbe59	249	struct bin_attribute attr, char buf,
02964115 TH	250	loff_t pos, size_t size)
02964115 TH	251	{
50e49bee AN	252	struct device *dev = container_of(kobj, struct device, kobj);
50e49bee AN	253	struct platform_device *pdev = to_platform_device(dev);
02964115 TH	254	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	255	void __iomem *ioaddr = pdata->ioaddr;
	256	ssize_t count;
	257
	258	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
	259	*buf++ = readb(ioaddr + pos++);
	260	return count;
	261	}
	262
2c3c8bea	263	static ssize_t stk17ta8_nvram_write(struct file filp, struct kobject kobj,
c98dbe59	264	struct bin_attribute attr, char buf,
02964115 TH	265	loff_t pos, size_t size)
02964115 TH	266	{
50e49bee AN	267	struct device *dev = container_of(kobj, struct device, kobj);
50e49bee AN	268	struct platform_device *pdev = to_platform_device(dev);
02964115 TH	269	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	270	void __iomem *ioaddr = pdata->ioaddr;
	271	ssize_t count;
	272
	273	for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
	274	writeb(*buf++, ioaddr + pos++);
	275	return count;
	276	}
	277
	278	static struct bin_attribute stk17ta8_nvram_attr = {
	279	.attr = {
	280	.name = "nvram",
a4b1d50e	281	.mode = S_IRUGO \| S_IWUSR,
02964115 TH	282	},
	283	.size = RTC_OFFSET,
	284	.read = stk17ta8_nvram_read,
	285	.write = stk17ta8_nvram_write,
	286	};
	287
5a167f45	288	static int stk17ta8_rtc_probe(struct platform_device *pdev)
02964115	289	{
02964115 TH	290	struct resource *res;
	291	unsigned int cal;
	292	unsigned int flags;
	293	struct rtc_plat_data *pdata;
3151520d	294	void __iomem *ioaddr;
02964115 TH	295	int ret = 0;
	296
	297	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	298	if (!res)
	299	return -ENODEV;
	300
3151520d	301	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
02964115 TH	302	if (!pdata)
02964115 TH	303	return -ENOMEM;
3151520d AN	304	if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
	305	pdev->name))
	306	return -EBUSY;
	307	ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
	308	if (!ioaddr)
	309	return -ENOMEM;
02964115 TH	310	pdata->ioaddr = ioaddr;
	311	pdata->irq = platform_get_irq(pdev, 0);
	312
	313	/* turn RTC on if it was not on */
	314	cal = readb(ioaddr + RTC_CALIBRATION);
	315	if (cal & RTC_STOP) {
	316	cal &= RTC_CAL_MASK;
	317	flags = readb(ioaddr + RTC_FLAGS);
	318	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
	319	writeb(cal, ioaddr + RTC_CALIBRATION);
	320	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	321	}
	322	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
	323	dev_warn(&pdev->dev, "voltage-low detected.\n");
	324
3151520d AN	325	spin_lock_init(&pdata->lock);
	326	pdata->last_jiffies = jiffies;
	327	platform_set_drvdata(pdev, pdata);
2fac6674	328	if (pdata->irq > 0) {
02964115	329	writeb(0, ioaddr + RTC_INTERRUPTS);
3151520d AN	330	if (devm_request_irq(&pdev->dev, pdata->irq,
3151520d AN	331	stk17ta8_rtc_interrupt,
2f6e5f94	332	IRQF_SHARED,
02964115 TH	333	pdev->name, pdev) < 0) {
02964115 TH	334	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	335	pdata->irq = 0;
02964115 TH	336	}
	337	}
	338
b74d2caa	339	pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
02964115	340	&stk17ta8_rtc_ops, THIS_MODULE);
3151520d AN	341	if (IS_ERR(pdata->rtc))
3151520d AN	342	return PTR_ERR(pdata->rtc);
b74d2caa	343
02964115	344	ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
3151520d	345	if (ret)
b74d2caa	346	rtc_device_unregister(pdata->rtc);
02964115 TH	347	return ret;
	348	}
	349
5a167f45	350	static int stk17ta8_rtc_remove(struct platform_device *pdev)
02964115 TH	351	{
	352	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	353
	354	sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
	355	rtc_device_unregister(pdata->rtc);
3151520d	356	if (pdata->irq > 0)
02964115	357	writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
02964115 TH	358	return 0;
	359	}
	360
ad28a07b KS	361	/* work with hotplug and coldplug */
	362	MODULE_ALIAS("platform:stk17ta8");
	363
02964115 TH	364	static struct platform_driver stk17ta8_rtc_driver = {
02964115 TH	365	.probe = stk17ta8_rtc_probe,
5a167f45	366	.remove = stk17ta8_rtc_remove,
02964115 TH	367	.driver = {
	368	.name = "stk17ta8",
	369	.owner = THIS_MODULE,
	370	},
	371	};
	372
0c4eae66	373	module_platform_driver(stk17ta8_rtc_driver);
02964115	374
ab4364d3	375	MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
02964115 TH	376	MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
	377	MODULE_LICENSE("GPL");
	378	MODULE_VERSION(DRV_VERSION);