[linux-block.git] / drivers / rtc / rtc-ds1553.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * An rtc driver for the Dallas DS1553
 *
 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 */

#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 RTC_REG_SIZE		0x2000
#define RTC_OFFSET		0x1ff0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	return 0;
}

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

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

static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);

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

static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);

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

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

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

static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);

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

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

static int ds1553_nvram_read(void *priv, unsigned int pos, void *val,
			     size_t bytes)
{
	struct platform_device *pdev = priv;
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	u8 *buf = val;

	for (; bytes; bytes--)
		*buf++ = readb(ioaddr + pos++);
	return 0;
}

static int ds1553_nvram_write(void *priv, unsigned int pos, void *val,
			      size_t bytes)
{
	struct platform_device *pdev = priv;
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	u8 *buf = val;

	for (; bytes; bytes--)
		writeb(*buf++, ioaddr + pos++);
	return 0;
}

static int ds1553_rtc_probe(struct platform_device *pdev)
{
	unsigned int cen, sec;
	struct rtc_plat_data *pdata;
	void __iomem *ioaddr;
	int ret = 0;
	struct nvmem_config nvmem_cfg = {
		.name = "ds1553_nvram",
		.word_size = 1,
		.stride = 1,
		.size = RTC_OFFSET,
		.reg_read = ds1553_nvram_read,
		.reg_write = ds1553_nvram_write,
		.priv = pdev,
	};

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	ioaddr = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(ioaddr))
		return PTR_ERR(ioaddr);
	pdata->ioaddr = ioaddr;
	pdata->irq = platform_get_irq(pdev, 0);

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

	spin_lock_init(&pdata->lock);
	pdata->last_jiffies = jiffies;
	platform_set_drvdata(pdev, pdata);

	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(pdata->rtc))
		return PTR_ERR(pdata->rtc);

	pdata->rtc->ops = &ds1553_rtc_ops;

	ret = devm_rtc_register_device(pdata->rtc);
	if (ret)
		return ret;

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

	devm_rtc_nvmem_register(pdata->rtc, &nvmem_cfg);

	return 0;
}

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

static struct platform_driver ds1553_rtc_driver = {
	.probe		= ds1553_rtc_probe,
	.driver		= {
		.name	= "rtc-ds1553",
	},
};

module_platform_driver(ds1553_rtc_driver);

MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
9bf5b4f5 AN	2	/*
	3	* An rtc driver for the Dallas DS1553
	4	*
	5	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
9bf5b4f5 AN	6	*/
	7
	8	#include <linux/bcd.h>
	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
5a0e3ad6	11	#include <linux/gfp.h>
9bf5b4f5 AN	12	#include <linux/delay.h>
	13	#include <linux/jiffies.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/rtc.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/io.h>
2113852b	18	#include <linux/module.h>
9bf5b4f5	19
9bf5b4f5 AN	20	#define RTC_REG_SIZE 0x2000
	21	#define RTC_OFFSET 0x1ff0
	22
	23	#define RTC_FLAGS (RTC_OFFSET + 0)
	24	#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
	25	#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
	26	#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
	27	#define RTC_DATE_ALARM (RTC_OFFSET + 5)
	28	#define RTC_INTERRUPTS (RTC_OFFSET + 6)
	29	#define RTC_WATCHDOG (RTC_OFFSET + 7)
	30	#define RTC_CONTROL (RTC_OFFSET + 8)
	31	#define RTC_CENTURY (RTC_OFFSET + 8)
	32	#define RTC_SECONDS (RTC_OFFSET + 9)
	33	#define RTC_MINUTES (RTC_OFFSET + 10)
	34	#define RTC_HOURS (RTC_OFFSET + 11)
	35	#define RTC_DAY (RTC_OFFSET + 12)
	36	#define RTC_DATE (RTC_OFFSET + 13)
	37	#define RTC_MONTH (RTC_OFFSET + 14)
	38	#define RTC_YEAR (RTC_OFFSET + 15)
	39
	40	#define RTC_CENTURY_MASK 0x3f
	41	#define RTC_SECONDS_MASK 0x7f
	42	#define RTC_DAY_MASK 0x07
	43
	44	/* Bits in the Control/Century register */
	45	#define RTC_WRITE 0x80
	46	#define RTC_READ 0x40
	47
	48	/* Bits in the Seconds register */
	49	#define RTC_STOP 0x80
	50
	51	/* Bits in the Flags register */
	52	#define RTC_FLAGS_AF 0x40
	53	#define RTC_FLAGS_BLF 0x10
	54
	55	/* Bits in the Interrupts register */
	56	#define RTC_INTS_AE 0x80
	57
	58	struct rtc_plat_data {
	59	struct rtc_device *rtc;
	60	void __iomem *ioaddr;
9bf5b4f5 AN	61	unsigned long last_jiffies;
	62	int irq;
	63	unsigned int irqen;
	64	int alrm_sec;
	65	int alrm_min;
	66	int alrm_hour;
	67	int alrm_mday;
618161f7	68	spinlock_t lock;
9bf5b4f5 AN	69	};
	70
	71	static int ds1553_rtc_set_time(struct device dev, struct rtc_time tm)
	72	{
85368bb9	73	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5 AN	74	void __iomem *ioaddr = pdata->ioaddr;
	75	u8 century;
	76
fe20ba70	77	century = bin2bcd((tm->tm_year + 1900) / 100);
9bf5b4f5 AN	78
	79	writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
	80
fe20ba70 AB	81	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	82	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	83	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	84	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	85	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	86	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	87	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
9bf5b4f5 AN	88
	89	/* RTC_CENTURY and RTC_CONTROL share same register */
	90	writeb(RTC_WRITE \| (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	91	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	92	return 0;
	93	}
	94
	95	static int ds1553_rtc_read_time(struct device dev, struct rtc_time tm)
	96	{
85368bb9	97	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5 AN	98	void __iomem *ioaddr = pdata->ioaddr;
	99	unsigned int year, month, day, hour, minute, second, week;
	100	unsigned int century;
	101
	102	/* give enough time to update RTC in case of continuous read */
	103	if (pdata->last_jiffies == jiffies)
	104	msleep(1);
	105	pdata->last_jiffies = jiffies;
	106	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	107	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	108	minute = readb(ioaddr + RTC_MINUTES);
	109	hour = readb(ioaddr + RTC_HOURS);
	110	day = readb(ioaddr + RTC_DATE);
	111	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	112	month = readb(ioaddr + RTC_MONTH);
	113	year = readb(ioaddr + RTC_YEAR);
	114	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	115	writeb(0, ioaddr + RTC_CONTROL);
fe20ba70 AB	116	tm->tm_sec = bcd2bin(second);
	117	tm->tm_min = bcd2bin(minute);
	118	tm->tm_hour = bcd2bin(hour);
	119	tm->tm_mday = bcd2bin(day);
	120	tm->tm_wday = bcd2bin(week);
	121	tm->tm_mon = bcd2bin(month) - 1;
9bf5b4f5	122	/* year is 1900 + tm->tm_year */
fe20ba70	123	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
9bf5b4f5	124
9bf5b4f5 AN	125	return 0;
	126	}
	127
	128	static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
	129	{
	130	void __iomem *ioaddr = pdata->ioaddr;
	131	unsigned long flags;
	132
618161f7	133	spin_lock_irqsave(&pdata->lock, flags);
9bf5b4f5	134	writeb(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	135	0x80 : bin2bcd(pdata->alrm_mday),
9bf5b4f5 AN	136	ioaddr + RTC_DATE_ALARM);
9bf5b4f5 AN	137	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	138	0x80 : bin2bcd(pdata->alrm_hour),
9bf5b4f5 AN	139	ioaddr + RTC_HOURS_ALARM);
9bf5b4f5 AN	140	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	141	0x80 : bin2bcd(pdata->alrm_min),
9bf5b4f5 AN	142	ioaddr + RTC_MINUTES_ALARM);
9bf5b4f5 AN	143	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	144	0x80 : bin2bcd(pdata->alrm_sec),
9bf5b4f5 AN	145	ioaddr + RTC_SECONDS_ALARM);
	146	writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
	147	readb(ioaddr + RTC_FLAGS); /* clear interrupts */
618161f7	148	spin_unlock_irqrestore(&pdata->lock, flags);
9bf5b4f5 AN	149	}
	150
	151	static int ds1553_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	152	{
85368bb9	153	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5	154
2fac6674	155	if (pdata->irq <= 0)
9bf5b4f5 AN	156	return -EINVAL;
	157	pdata->alrm_mday = alrm->time.tm_mday;
	158	pdata->alrm_hour = alrm->time.tm_hour;
	159	pdata->alrm_min = alrm->time.tm_min;
	160	pdata->alrm_sec = alrm->time.tm_sec;
	161	if (alrm->enabled)
	162	pdata->irqen \|= RTC_AF;
	163	ds1553_rtc_update_alarm(pdata);
	164	return 0;
	165	}
	166
	167	static int ds1553_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	168	{
85368bb9	169	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5	170
2fac6674	171	if (pdata->irq <= 0)
9bf5b4f5 AN	172	return -EINVAL;
	173	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	174	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	175	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	176	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	177	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	178	return 0;
	179	}
	180
7d12e780	181	static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
9bf5b4f5 AN	182	{
	183	struct platform_device *pdev = dev_id;
	184	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	185	void __iomem *ioaddr = pdata->ioaddr;
618161f7	186	unsigned long events = 0;
9bf5b4f5	187
618161f7	188	spin_lock(&pdata->lock);
9bf5b4f5	189	/* read and clear interrupt */
618161f7 AN	190	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
	191	events = RTC_IRQF;
	192	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
	193	events \|= RTC_UF;
	194	else
	195	events \|= RTC_AF;
0d71915d	196	rtc_update_irq(pdata->rtc, 1, events);
618161f7 AN	197	}
	198	spin_unlock(&pdata->lock);
	199	return events ? IRQ_HANDLED : IRQ_NONE;
9bf5b4f5 AN	200	}
9bf5b4f5 AN	201
618161f7	202	static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
9bf5b4f5	203	{
85368bb9	204	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5	205
2fac6674	206	if (pdata->irq <= 0)
618161f7 AN	207	return -EINVAL;
618161f7 AN	208	if (enabled)
9bf5b4f5	209	pdata->irqen \|= RTC_AF;
618161f7 AN	210	else
	211	pdata->irqen &= ~RTC_AF;
	212	ds1553_rtc_update_alarm(pdata);
	213	return 0;
	214	}
	215
ff8371ac	216	static const struct rtc_class_ops ds1553_rtc_ops = {
618161f7 AN	217	.read_time = ds1553_rtc_read_time,
	218	.set_time = ds1553_rtc_set_time,
	219	.read_alarm = ds1553_rtc_read_alarm,
	220	.set_alarm = ds1553_rtc_set_alarm,
	221	.alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
9bf5b4f5 AN	222	};
9bf5b4f5 AN	223
3a9a06d4 AB	224	static int ds1553_nvram_read(void priv, unsigned int pos, void val,
3a9a06d4 AB	225	size_t bytes)
9bf5b4f5	226	{
3a9a06d4	227	struct platform_device *pdev = priv;
9bf5b4f5 AN	228	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
9bf5b4f5 AN	229	void __iomem *ioaddr = pdata->ioaddr;
3a9a06d4	230	u8 *buf = val;
9bf5b4f5	231
3a9a06d4	232	for (; bytes; bytes--)
9bf5b4f5	233	*buf++ = readb(ioaddr + pos++);
3a9a06d4	234	return 0;
9bf5b4f5 AN	235	}
9bf5b4f5 AN	236
3a9a06d4 AB	237	static int ds1553_nvram_write(void priv, unsigned int pos, void val,
3a9a06d4 AB	238	size_t bytes)
9bf5b4f5	239	{
3a9a06d4	240	struct platform_device *pdev = priv;
9bf5b4f5 AN	241	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
9bf5b4f5 AN	242	void __iomem *ioaddr = pdata->ioaddr;
3a9a06d4	243	u8 *buf = val;
9bf5b4f5	244
3a9a06d4	245	for (; bytes; bytes--)
9bf5b4f5	246	writeb(*buf++, ioaddr + pos++);
3a9a06d4	247	return 0;
9bf5b4f5 AN	248	}
9bf5b4f5 AN	249
5a167f45	250	static int ds1553_rtc_probe(struct platform_device *pdev)
9bf5b4f5	251	{
9bf5b4f5	252	unsigned int cen, sec;
618161f7 AN	253	struct rtc_plat_data *pdata;
618161f7 AN	254	void __iomem *ioaddr;
9bf5b4f5	255	int ret = 0;
3a9a06d4 AB	256	struct nvmem_config nvmem_cfg = {
	257	.name = "ds1553_nvram",
	258	.word_size = 1,
	259	.stride = 1,
	260	.size = RTC_OFFSET,
	261	.reg_read = ds1553_nvram_read,
	262	.reg_write = ds1553_nvram_write,
	263	.priv = pdev,
	264	};
9bf5b4f5	265
618161f7	266	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
9bf5b4f5 AN	267	if (!pdata)
9bf5b4f5 AN	268	return -ENOMEM;
618161f7	269
09ef18bc	270	ioaddr = devm_platform_ioremap_resource(pdev, 0);
7c1d69ee JL	271	if (IS_ERR(ioaddr))
7c1d69ee JL	272	return PTR_ERR(ioaddr);
9bf5b4f5 AN	273	pdata->ioaddr = ioaddr;
	274	pdata->irq = platform_get_irq(pdev, 0);
	275
	276	/* turn RTC on if it was not on */
	277	sec = readb(ioaddr + RTC_SECONDS);
	278	if (sec & RTC_STOP) {
	279	sec &= RTC_SECONDS_MASK;
	280	cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	281	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	282	writeb(sec, ioaddr + RTC_SECONDS);
	283	writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	284	}
	285	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
	286	dev_warn(&pdev->dev, "voltage-low detected.\n");
	287
618161f7 AN	288	spin_lock_init(&pdata->lock);
	289	pdata->last_jiffies = jiffies;
	290	platform_set_drvdata(pdev, pdata);
4071ea25	291
18c88cc9	292	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
4071ea25 AZ	293	if (IS_ERR(pdata->rtc))
	294	return PTR_ERR(pdata->rtc);
	295
18c88cc9 AB	296	pdata->rtc->ops = &ds1553_rtc_ops;
18c88cc9 AB	297
fdcfd854	298	ret = devm_rtc_register_device(pdata->rtc);
18c88cc9 AB	299	if (ret)
	300	return ret;
	301
2fac6674	302	if (pdata->irq > 0) {
9bf5b4f5	303	writeb(0, ioaddr + RTC_INTERRUPTS);
618161f7 AN	304	if (devm_request_irq(&pdev->dev, pdata->irq,
618161f7 AN	305	ds1553_rtc_interrupt,
2f6e5f94	306	0, pdev->name, pdev) < 0) {
9bf5b4f5	307	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	308	pdata->irq = 0;
9bf5b4f5 AN	309	}
	310	}
	311
6746bc09	312	devm_rtc_nvmem_register(pdata->rtc, &nvmem_cfg);
c1be915e	313
4071ea25	314	return 0;
9bf5b4f5 AN	315	}
9bf5b4f5 AN	316
ad28a07b KS	317	/* work with hotplug and coldplug */
	318	MODULE_ALIAS("platform:rtc-ds1553");
	319
9bf5b4f5 AN	320	static struct platform_driver ds1553_rtc_driver = {
9bf5b4f5 AN	321	.probe = ds1553_rtc_probe,
9bf5b4f5	322	.driver = {
e7634c27	323	.name = "rtc-ds1553",
9bf5b4f5 AN	324	},
	325	};
	326
0c4eae66	327	module_platform_driver(ds1553_rtc_driver);
9bf5b4f5 AN	328
	329	MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
	330	MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
	331	MODULE_LICENSE("GPL");