[deliverable/linux.git] / drivers / rtc / rtc-vt8500.c

/*
 * drivers/rtc/rtc-vt8500.c
 *
 *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
 *
 * Based on rtc-pxa.c
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/*
 * Register definitions
 */
#define VT8500_RTC_TS		0x00	/* Time set */
#define VT8500_RTC_DS		0x04	/* Date set */
#define VT8500_RTC_AS		0x08	/* Alarm set */
#define VT8500_RTC_CR		0x0c	/* Control */
#define VT8500_RTC_TR		0x10	/* Time read */
#define VT8500_RTC_DR		0x14	/* Date read */
#define VT8500_RTC_WS		0x18	/* Write status */
#define VT8500_RTC_CL		0x20	/* Calibration */
#define VT8500_RTC_IS		0x24	/* Interrupt status */
#define VT8500_RTC_ST		0x28	/* Status */

#define INVALID_TIME_BIT	(1 << 31)

#define DATE_CENTURY_S		19
#define DATE_YEAR_S		11
#define DATE_YEAR_MASK		(0xff << DATE_YEAR_S)
#define DATE_MONTH_S		6
#define DATE_MONTH_MASK		(0x1f << DATE_MONTH_S)
#define DATE_DAY_MASK		0x3f

#define TIME_DOW_S		20
#define TIME_DOW_MASK		(0x07 << TIME_DOW_S)
#define TIME_HOUR_S		14
#define TIME_HOUR_MASK		(0x3f << TIME_HOUR_S)
#define TIME_MIN_S		7
#define TIME_MIN_MASK		(0x7f << TIME_MIN_S)
#define TIME_SEC_MASK		0x7f

#define ALARM_DAY_S		20
#define ALARM_DAY_MASK		(0x3f << ALARM_DAY_S)

#define ALARM_DAY_BIT		(1 << 29)
#define ALARM_HOUR_BIT		(1 << 28)
#define ALARM_MIN_BIT		(1 << 27)
#define ALARM_SEC_BIT		(1 << 26)

#define ALARM_ENABLE_MASK	(ALARM_DAY_BIT \
				| ALARM_HOUR_BIT \
				| ALARM_MIN_BIT \
				| ALARM_SEC_BIT)

#define VT8500_RTC_CR_ENABLE	(1 << 0)	/* Enable RTC */
#define VT8500_RTC_CR_24H	(1 << 1)	/* 24h time format */
#define VT8500_RTC_CR_SM_ENABLE	(1 << 2)	/* Enable periodic irqs */
#define VT8500_RTC_CR_SM_SEC	(1 << 3)	/* 0: 1Hz/60, 1: 1Hz */
#define VT8500_RTC_CR_CALIB	(1 << 4)	/* Enable calibration */

struct vt8500_rtc {
	void __iomem		*regbase;
	struct resource		*res;
	int			irq_alarm;
	struct rtc_device	*rtc;
	spinlock_t		lock;		/* Protects this structure */
};

static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
{
	struct vt8500_rtc *vt8500_rtc = dev_id;
	u32 isr;
	unsigned long events = 0;

	spin_lock(&vt8500_rtc->lock);

	/* clear interrupt sources */
	isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
	writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);

	spin_unlock(&vt8500_rtc->lock);

	if (isr & 1)
		events |= RTC_AF | RTC_IRQF;

	rtc_update_irq(vt8500_rtc->rtc, 1, events);

	return IRQ_HANDLED;
}

static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
	u32 date, time;

	date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
	time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);

	tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
	tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
	tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
	tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
	tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
	tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
			+ ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
	tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;

	return 0;
}

static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);

	if (tm->tm_year < 100) {
		dev_warn(dev, "Only years 2000-2199 are supported by the "
			      "hardware!\n");
		return -EINVAL;
	}

	writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
		| (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
		| (bin2bcd(tm->tm_mday)),
		vt8500_rtc->regbase + VT8500_RTC_DS);
	writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
		| (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
		| (bin2bcd(tm->tm_min) << TIME_MIN_S)
		| (bin2bcd(tm->tm_sec)),
		vt8500_rtc->regbase + VT8500_RTC_TS);

	return 0;
}

static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
	u32 isr, alarm;

	alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
	isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);

	alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
	alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
	alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
	alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));

	alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;

	alrm->pending = (isr & 1) ? 1 : 0;
	return rtc_valid_tm(&alrm->time);
}

static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);

	writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
		| (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
		| (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
		| (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
		| (bin2bcd(alrm->time.tm_sec)),
		vt8500_rtc->regbase + VT8500_RTC_AS);

	return 0;
}

static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
	unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);

	if (enabled)
		tmp |= ALARM_ENABLE_MASK;
	else
		tmp &= ~ALARM_ENABLE_MASK;

	writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
	return 0;
}

static const struct rtc_class_ops vt8500_rtc_ops = {
	.read_time = vt8500_rtc_read_time,
	.set_time = vt8500_rtc_set_time,
	.read_alarm = vt8500_rtc_read_alarm,
	.set_alarm = vt8500_rtc_set_alarm,
	.alarm_irq_enable = vt8500_alarm_irq_enable,
};

static int __devinit vt8500_rtc_probe(struct platform_device *pdev)
{
	struct vt8500_rtc *vt8500_rtc;
	int ret;

	vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL);
	if (!vt8500_rtc)
		return -ENOMEM;

	spin_lock_init(&vt8500_rtc->lock);
	platform_set_drvdata(pdev, vt8500_rtc);

	vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!vt8500_rtc->res) {
		dev_err(&pdev->dev, "No I/O memory resource defined\n");
		ret = -ENXIO;
		goto err_free;
	}

	vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
	if (vt8500_rtc->irq_alarm < 0) {
		dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
		ret = -ENXIO;
		goto err_free;
	}

	vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start,
					     resource_size(vt8500_rtc->res),
					     "vt8500-rtc");
	if (vt8500_rtc->res == NULL) {
		dev_err(&pdev->dev, "failed to request I/O memory\n");
		ret = -EBUSY;
		goto err_free;
	}

	vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start,
				      resource_size(vt8500_rtc->res));
	if (!vt8500_rtc->regbase) {
		dev_err(&pdev->dev, "Unable to map RTC I/O memory\n");
		ret = -EBUSY;
		goto err_release;
	}

	/* Enable RTC and set it to 24-hour mode */
	writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H,
	       vt8500_rtc->regbase + VT8500_RTC_CR);

	vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev,
					      &vt8500_rtc_ops, THIS_MODULE);
	if (IS_ERR(vt8500_rtc->rtc)) {
		ret = PTR_ERR(vt8500_rtc->rtc);
		dev_err(&pdev->dev,
			"Failed to register RTC device -> %d\n", ret);
		goto err_unmap;
	}

	ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0,
			  "rtc alarm", vt8500_rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "can't get irq %i, err %d\n",
			vt8500_rtc->irq_alarm, ret);
		goto err_unreg;
	}

	return 0;

err_unreg:
	rtc_device_unregister(vt8500_rtc->rtc);
err_unmap:
	iounmap(vt8500_rtc->regbase);
err_release:
	release_mem_region(vt8500_rtc->res->start,
			   resource_size(vt8500_rtc->res));
err_free:
	kfree(vt8500_rtc);
	return ret;
}

static int __devexit vt8500_rtc_remove(struct platform_device *pdev)
{
	struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);

	free_irq(vt8500_rtc->irq_alarm, vt8500_rtc);

	rtc_device_unregister(vt8500_rtc->rtc);

	/* Disable alarm matching */
	writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
	iounmap(vt8500_rtc->regbase);
	release_mem_region(vt8500_rtc->res->start,
			   resource_size(vt8500_rtc->res));

	kfree(vt8500_rtc);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver vt8500_rtc_driver = {
	.probe		= vt8500_rtc_probe,
	.remove		= __devexit_p(vt8500_rtc_remove),
	.driver		= {
		.name	= "vt8500-rtc",
		.owner	= THIS_MODULE,
	},
};

static int __init vt8500_rtc_init(void)
{
	return platform_driver_register(&vt8500_rtc_driver);
}
module_init(vt8500_rtc_init);

static void __exit vt8500_rtc_exit(void)
{
	platform_driver_unregister(&vt8500_rtc_driver);
}
module_exit(vt8500_rtc_exit);

MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:vt8500-rtc");
Commit	Line	Data
f77fbdf9 AC	1	/*
	2	* drivers/rtc/rtc-vt8500.c
	3	*
	4	* Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
	5	*
	6	* Based on rtc-pxa.c
	7	*
	8	* This software is licensed under the terms of the GNU General Public
	9	* License version 2, as published by the Free Software Foundation, and
	10	* may be copied, distributed, and modified under those terms.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*/
	17
	18	#include <linux/module.h>
	19	#include <linux/rtc.h>
	20	#include <linux/init.h>
	21	#include <linux/interrupt.h>
	22	#include <linux/io.h>
	23	#include <linux/bcd.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/slab.h>
	26
	27	/*
	28	* Register definitions
	29	*/
	30	#define VT8500_RTC_TS 0x00 /* Time set */
	31	#define VT8500_RTC_DS 0x04 /* Date set */
	32	#define VT8500_RTC_AS 0x08 /* Alarm set */
	33	#define VT8500_RTC_CR 0x0c /* Control */
	34	#define VT8500_RTC_TR 0x10 /* Time read */
	35	#define VT8500_RTC_DR 0x14 /* Date read */
	36	#define VT8500_RTC_WS 0x18 /* Write status */
	37	#define VT8500_RTC_CL 0x20 /* Calibration */
	38	#define VT8500_RTC_IS 0x24 /* Interrupt status */
	39	#define VT8500_RTC_ST 0x28 /* Status */
	40
	41	#define INVALID_TIME_BIT (1 << 31)
	42
	43	#define DATE_CENTURY_S 19
	44	#define DATE_YEAR_S 11
	45	#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)
	46	#define DATE_MONTH_S 6
	47	#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)
	48	#define DATE_DAY_MASK 0x3f
	49
	50	#define TIME_DOW_S 20
	51	#define TIME_DOW_MASK (0x07 << TIME_DOW_S)
	52	#define TIME_HOUR_S 14
	53	#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)
	54	#define TIME_MIN_S 7
	55	#define TIME_MIN_MASK (0x7f << TIME_MIN_S)
	56	#define TIME_SEC_MASK 0x7f
	57
	58	#define ALARM_DAY_S 20
	59	#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)
	60
	61	#define ALARM_DAY_BIT (1 << 29)
	62	#define ALARM_HOUR_BIT (1 << 28)
	63	#define ALARM_MIN_BIT (1 << 27)
	64	#define ALARM_SEC_BIT (1 << 26)
65
66	#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \
67	\| ALARM_HOUR_BIT \
68	\| ALARM_MIN_BIT \
69	\| ALARM_SEC_BIT)
70
71	#define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */
72	#define VT8500_RTC_CR_24H (1 << 1) /* 24h time format */
73	#define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */
74	#define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */
75	#define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */
76
77	struct vt8500_rtc {
78	void __iomem *regbase;
79	struct resource *res;
80	int irq_alarm;
f77fbdf9 AC	81	struct rtc_device *rtc;
	82	spinlock_t lock; /* Protects this structure */
	83	};
	84
	85	static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
	86	{
	87	struct vt8500_rtc *vt8500_rtc = dev_id;
	88	u32 isr;
	89	unsigned long events = 0;
	90
	91	spin_lock(&vt8500_rtc->lock);
	92
	93	/* clear interrupt sources */
	94	isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
	95	writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
	96
	97	spin_unlock(&vt8500_rtc->lock);
	98
	99	if (isr & 1)
	100	events \|= RTC_AF \| RTC_IRQF;
	101
f77fbdf9 AC	102	rtc_update_irq(vt8500_rtc->rtc, 1, events);
	103
	104	return IRQ_HANDLED;
	105	}
	106
	107	static int vt8500_rtc_read_time(struct device dev, struct rtc_time tm)
	108	{
	109	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
	110	u32 date, time;
	111
	112	date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
	113	time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
	114
	115	tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
	116	tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
	117	tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
	118	tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
	119	tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
	120	tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
	121	+ ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
	122	tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
	123
	124	return 0;
	125	}
	126
	127	static int vt8500_rtc_set_time(struct device dev, struct rtc_time tm)
	128	{
	129	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
	130
	131	if (tm->tm_year < 100) {
	132	dev_warn(dev, "Only years 2000-2199 are supported by the "
	133	"hardware!\n");
	134	return -EINVAL;
	135	}
	136
	137	writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
	138	\| (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
	139	\| (bin2bcd(tm->tm_mday)),
	140	vt8500_rtc->regbase + VT8500_RTC_DS);
	141	writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
	142	\| (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
	143	\| (bin2bcd(tm->tm_min) << TIME_MIN_S)
	144	\| (bin2bcd(tm->tm_sec)),
	145	vt8500_rtc->regbase + VT8500_RTC_TS);
	146
	147	return 0;
	148	}
	149
	150	static int vt8500_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	151	{
	152	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
	153	u32 isr, alarm;
	154
	155	alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
	156	isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
	157
	158	alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
	159	alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
	160	alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
	161	alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
	162
	163	alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
	164
	165	alrm->pending = (isr & 1) ? 1 : 0;
166	return rtc_valid_tm(&alrm->time);
167	}
168
169	static int vt8500_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
170	{
171	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
172
173	writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
174	\| (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
175	\| (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
176	\| (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
177	\| (bin2bcd(alrm->time.tm_sec)),
178	vt8500_rtc->regbase + VT8500_RTC_AS);
179
180	return 0;
181	}
182
183	static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
184	{
185	struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
186	unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
187
188	if (enabled)
189	tmp \|= ALARM_ENABLE_MASK;
190	else
191	tmp &= ~ALARM_ENABLE_MASK;
192
193	writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
194	return 0;
195	}
196
f77fbdf9 AC	197	static const struct rtc_class_ops vt8500_rtc_ops = {
	198	.read_time = vt8500_rtc_read_time,
	199	.set_time = vt8500_rtc_set_time,
	200	.read_alarm = vt8500_rtc_read_alarm,
	201	.set_alarm = vt8500_rtc_set_alarm,
	202	.alarm_irq_enable = vt8500_alarm_irq_enable,
f77fbdf9 AC	203	};
	204
	205	static int __devinit vt8500_rtc_probe(struct platform_device *pdev)
	206	{
	207	struct vt8500_rtc *vt8500_rtc;
	208	int ret;
	209
	210	vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL);
	211	if (!vt8500_rtc)
	212	return -ENOMEM;
	213
	214	spin_lock_init(&vt8500_rtc->lock);
	215	platform_set_drvdata(pdev, vt8500_rtc);
	216
	217	vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	218	if (!vt8500_rtc->res) {
	219	dev_err(&pdev->dev, "No I/O memory resource defined\n");
	220	ret = -ENXIO;
	221	goto err_free;
	222	}
	223
	224	vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
	225	if (vt8500_rtc->irq_alarm < 0) {
	226	dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
	227	ret = -ENXIO;
	228	goto err_free;
	229	}
	230
f77fbdf9 AC	231	vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start,
	232	resource_size(vt8500_rtc->res),
	233	"vt8500-rtc");
	234	if (vt8500_rtc->res == NULL) {
	235	dev_err(&pdev->dev, "failed to request I/O memory\n");
	236	ret = -EBUSY;
	237	goto err_free;
	238	}
	239
	240	vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start,
	241	resource_size(vt8500_rtc->res));
	242	if (!vt8500_rtc->regbase) {
	243	dev_err(&pdev->dev, "Unable to map RTC I/O memory\n");
	244	ret = -EBUSY;
	245	goto err_release;
	246	}
	247
03ad2d50 AC	248	/* Enable RTC and set it to 24-hour mode */
03ad2d50 AC	249	writel(VT8500_RTC_CR_ENABLE \| VT8500_RTC_CR_24H,
f77fbdf9 AC	250	vt8500_rtc->regbase + VT8500_RTC_CR);
	251
	252	vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev,
	253	&vt8500_rtc_ops, THIS_MODULE);
	254	if (IS_ERR(vt8500_rtc->rtc)) {
	255	ret = PTR_ERR(vt8500_rtc->rtc);
	256	dev_err(&pdev->dev,
	257	"Failed to register RTC device -> %d\n", ret);
	258	goto err_unmap;
	259	}
	260
f77fbdf9 AC	261	ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0,
	262	"rtc alarm", vt8500_rtc);
	263	if (ret < 0) {
	264	dev_err(&pdev->dev, "can't get irq %i, err %d\n",
	265	vt8500_rtc->irq_alarm, ret);
03ad2d50	266	goto err_unreg;
f77fbdf9 AC	267	}
	268
	269	return 0;
	270
f77fbdf9 AC	271	err_unreg:
	272	rtc_device_unregister(vt8500_rtc->rtc);
	273	err_unmap:
	274	iounmap(vt8500_rtc->regbase);
	275	err_release:
	276	release_mem_region(vt8500_rtc->res->start,
	277	resource_size(vt8500_rtc->res));
	278	err_free:
	279	kfree(vt8500_rtc);
	280	return ret;
	281	}
	282
	283	static int __devexit vt8500_rtc_remove(struct platform_device *pdev)
	284	{
	285	struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
	286
	287	free_irq(vt8500_rtc->irq_alarm, vt8500_rtc);
f77fbdf9 AC	288
	289	rtc_device_unregister(vt8500_rtc->rtc);
	290
	291	/* Disable alarm matching */
	292	writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
	293	iounmap(vt8500_rtc->regbase);
	294	release_mem_region(vt8500_rtc->res->start,
	295	resource_size(vt8500_rtc->res));
	296
	297	kfree(vt8500_rtc);
	298	platform_set_drvdata(pdev, NULL);
	299
	300	return 0;
	301	}
	302
	303	static struct platform_driver vt8500_rtc_driver = {
	304	.probe = vt8500_rtc_probe,
	305	.remove = __devexit_p(vt8500_rtc_remove),
	306	.driver = {
	307	.name = "vt8500-rtc",
	308	.owner = THIS_MODULE,
	309	},
	310	};
	311
	312	static int __init vt8500_rtc_init(void)
	313	{
	314	return platform_driver_register(&vt8500_rtc_driver);
	315	}
	316	module_init(vt8500_rtc_init);
	317
	318	static void __exit vt8500_rtc_exit(void)
	319	{
	320	platform_driver_unregister(&vt8500_rtc_driver);
	321	}
	322	module_exit(vt8500_rtc_exit);
	323
	324	MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
	325	MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
	326	MODULE_LICENSE("GPL");
	327	MODULE_ALIAS("platform:vt8500-rtc");