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

/*
 * An rtc driver for the Dallas DS1553
 *
 * Copyright (C) 2006 Atsushi Nemoto <[email protected]>
 *
 * 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 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)
{
	struct resource *res;
	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;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ioaddr = devm_ioremap_resource(&pdev->dev, res);
	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;
	pdata->rtc->nvram_old_abi = true;

	ret = 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;
		}
	}

	if (rtc_nvmem_register(pdata->rtc, &nvmem_cfg))
		dev_err(&pdev->dev, "unable to register nvmem\n");

	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 <[email protected]>");
MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
9bf5b4f5 AN	1	/*
	2	* An rtc driver for the Dallas DS1553
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/bcd.h>
	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
5a0e3ad6	14	#include <linux/gfp.h>
9bf5b4f5 AN	15	#include <linux/delay.h>
	16	#include <linux/jiffies.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/rtc.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/io.h>
2113852b	21	#include <linux/module.h>
9bf5b4f5	22
9bf5b4f5 AN	23	#define RTC_REG_SIZE 0x2000
	24	#define RTC_OFFSET 0x1ff0
	25
	26	#define RTC_FLAGS (RTC_OFFSET + 0)
	27	#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
	28	#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
	29	#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
	30	#define RTC_DATE_ALARM (RTC_OFFSET + 5)
	31	#define RTC_INTERRUPTS (RTC_OFFSET + 6)
	32	#define RTC_WATCHDOG (RTC_OFFSET + 7)
	33	#define RTC_CONTROL (RTC_OFFSET + 8)
	34	#define RTC_CENTURY (RTC_OFFSET + 8)
	35	#define RTC_SECONDS (RTC_OFFSET + 9)
	36	#define RTC_MINUTES (RTC_OFFSET + 10)
	37	#define RTC_HOURS (RTC_OFFSET + 11)
	38	#define RTC_DAY (RTC_OFFSET + 12)
	39	#define RTC_DATE (RTC_OFFSET + 13)
	40	#define RTC_MONTH (RTC_OFFSET + 14)
	41	#define RTC_YEAR (RTC_OFFSET + 15)
	42
	43	#define RTC_CENTURY_MASK 0x3f
	44	#define RTC_SECONDS_MASK 0x7f
	45	#define RTC_DAY_MASK 0x07
	46
	47	/* Bits in the Control/Century register */
	48	#define RTC_WRITE 0x80
	49	#define RTC_READ 0x40
	50
	51	/* Bits in the Seconds register */
	52	#define RTC_STOP 0x80
	53
	54	/* Bits in the Flags register */
	55	#define RTC_FLAGS_AF 0x40
	56	#define RTC_FLAGS_BLF 0x10
	57
	58	/* Bits in the Interrupts register */
	59	#define RTC_INTS_AE 0x80
	60
	61	struct rtc_plat_data {
	62	struct rtc_device *rtc;
	63	void __iomem *ioaddr;
9bf5b4f5 AN	64	unsigned long last_jiffies;
	65	int irq;
	66	unsigned int irqen;
	67	int alrm_sec;
	68	int alrm_min;
	69	int alrm_hour;
	70	int alrm_mday;
618161f7	71	spinlock_t lock;
9bf5b4f5 AN	72	};
	73
	74	static int ds1553_rtc_set_time(struct device dev, struct rtc_time tm)
	75	{
85368bb9	76	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5 AN	77	void __iomem *ioaddr = pdata->ioaddr;
	78	u8 century;
	79
fe20ba70	80	century = bin2bcd((tm->tm_year + 1900) / 100);
9bf5b4f5 AN	81
	82	writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
	83
fe20ba70 AB	84	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	85	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	86	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	87	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	88	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	89	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	90	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
9bf5b4f5 AN	91
	92	/* RTC_CENTURY and RTC_CONTROL share same register */
	93	writeb(RTC_WRITE \| (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
	94	writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	95	return 0;
	96	}
	97
	98	static int ds1553_rtc_read_time(struct device dev, struct rtc_time tm)
	99	{
85368bb9	100	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5 AN	101	void __iomem *ioaddr = pdata->ioaddr;
	102	unsigned int year, month, day, hour, minute, second, week;
	103	unsigned int century;
	104
	105	/* give enough time to update RTC in case of continuous read */
	106	if (pdata->last_jiffies == jiffies)
	107	msleep(1);
	108	pdata->last_jiffies = jiffies;
	109	writeb(RTC_READ, ioaddr + RTC_CONTROL);
	110	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	111	minute = readb(ioaddr + RTC_MINUTES);
	112	hour = readb(ioaddr + RTC_HOURS);
	113	day = readb(ioaddr + RTC_DATE);
	114	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	115	month = readb(ioaddr + RTC_MONTH);
	116	year = readb(ioaddr + RTC_YEAR);
	117	century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	118	writeb(0, ioaddr + RTC_CONTROL);
fe20ba70 AB	119	tm->tm_sec = bcd2bin(second);
	120	tm->tm_min = bcd2bin(minute);
	121	tm->tm_hour = bcd2bin(hour);
	122	tm->tm_mday = bcd2bin(day);
	123	tm->tm_wday = bcd2bin(week);
	124	tm->tm_mon = bcd2bin(month) - 1;
9bf5b4f5	125	/* year is 1900 + tm->tm_year */
fe20ba70	126	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
9bf5b4f5	127
9bf5b4f5 AN	128	return 0;
	129	}
	130
	131	static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
	132	{
	133	void __iomem *ioaddr = pdata->ioaddr;
	134	unsigned long flags;
	135
618161f7	136	spin_lock_irqsave(&pdata->lock, flags);
9bf5b4f5	137	writeb(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	138	0x80 : bin2bcd(pdata->alrm_mday),
9bf5b4f5 AN	139	ioaddr + RTC_DATE_ALARM);
9bf5b4f5 AN	140	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	141	0x80 : bin2bcd(pdata->alrm_hour),
9bf5b4f5 AN	142	ioaddr + RTC_HOURS_ALARM);
9bf5b4f5 AN	143	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	144	0x80 : bin2bcd(pdata->alrm_min),
9bf5b4f5 AN	145	ioaddr + RTC_MINUTES_ALARM);
9bf5b4f5 AN	146	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	147	0x80 : bin2bcd(pdata->alrm_sec),
9bf5b4f5 AN	148	ioaddr + RTC_SECONDS_ALARM);
	149	writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
	150	readb(ioaddr + RTC_FLAGS); /* clear interrupts */
618161f7	151	spin_unlock_irqrestore(&pdata->lock, flags);
9bf5b4f5 AN	152	}
	153
	154	static int ds1553_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	155	{
85368bb9	156	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5	157
2fac6674	158	if (pdata->irq <= 0)
9bf5b4f5 AN	159	return -EINVAL;
	160	pdata->alrm_mday = alrm->time.tm_mday;
	161	pdata->alrm_hour = alrm->time.tm_hour;
	162	pdata->alrm_min = alrm->time.tm_min;
	163	pdata->alrm_sec = alrm->time.tm_sec;
	164	if (alrm->enabled)
	165	pdata->irqen \|= RTC_AF;
	166	ds1553_rtc_update_alarm(pdata);
	167	return 0;
	168	}
	169
	170	static int ds1553_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	171	{
85368bb9	172	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5	173
2fac6674	174	if (pdata->irq <= 0)
9bf5b4f5 AN	175	return -EINVAL;
	176	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	177	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	178	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	179	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	180	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	181	return 0;
	182	}
	183
7d12e780	184	static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
9bf5b4f5 AN	185	{
	186	struct platform_device *pdev = dev_id;
	187	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	188	void __iomem *ioaddr = pdata->ioaddr;
618161f7	189	unsigned long events = 0;
9bf5b4f5	190
618161f7	191	spin_lock(&pdata->lock);
9bf5b4f5	192	/* read and clear interrupt */
618161f7 AN	193	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
	194	events = RTC_IRQF;
	195	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
	196	events \|= RTC_UF;
	197	else
	198	events \|= RTC_AF;
0d71915d	199	rtc_update_irq(pdata->rtc, 1, events);
618161f7 AN	200	}
	201	spin_unlock(&pdata->lock);
	202	return events ? IRQ_HANDLED : IRQ_NONE;
9bf5b4f5 AN	203	}
9bf5b4f5 AN	204
618161f7	205	static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
9bf5b4f5	206	{
85368bb9	207	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
9bf5b4f5	208
2fac6674	209	if (pdata->irq <= 0)
618161f7 AN	210	return -EINVAL;
618161f7 AN	211	if (enabled)
9bf5b4f5	212	pdata->irqen \|= RTC_AF;
618161f7 AN	213	else
	214	pdata->irqen &= ~RTC_AF;
	215	ds1553_rtc_update_alarm(pdata);
	216	return 0;
	217	}
	218
ff8371ac	219	static const struct rtc_class_ops ds1553_rtc_ops = {
618161f7 AN	220	.read_time = ds1553_rtc_read_time,
	221	.set_time = ds1553_rtc_set_time,
	222	.read_alarm = ds1553_rtc_read_alarm,
	223	.set_alarm = ds1553_rtc_set_alarm,
	224	.alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
9bf5b4f5 AN	225	};
9bf5b4f5 AN	226
3a9a06d4 AB	227	static int ds1553_nvram_read(void priv, unsigned int pos, void val,
3a9a06d4 AB	228	size_t bytes)
9bf5b4f5	229	{
3a9a06d4	230	struct platform_device *pdev = priv;
9bf5b4f5 AN	231	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
9bf5b4f5 AN	232	void __iomem *ioaddr = pdata->ioaddr;
3a9a06d4	233	u8 *buf = val;
9bf5b4f5	234
3a9a06d4	235	for (; bytes; bytes--)
9bf5b4f5	236	*buf++ = readb(ioaddr + pos++);
3a9a06d4	237	return 0;
9bf5b4f5 AN	238	}
9bf5b4f5 AN	239
3a9a06d4 AB	240	static int ds1553_nvram_write(void priv, unsigned int pos, void val,
3a9a06d4 AB	241	size_t bytes)
9bf5b4f5	242	{
3a9a06d4	243	struct platform_device *pdev = priv;
9bf5b4f5 AN	244	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
9bf5b4f5 AN	245	void __iomem *ioaddr = pdata->ioaddr;
3a9a06d4	246	u8 *buf = val;
9bf5b4f5	247
3a9a06d4	248	for (; bytes; bytes--)
9bf5b4f5	249	writeb(*buf++, ioaddr + pos++);
3a9a06d4	250	return 0;
9bf5b4f5 AN	251	}
9bf5b4f5 AN	252
5a167f45	253	static int ds1553_rtc_probe(struct platform_device *pdev)
9bf5b4f5	254	{
9bf5b4f5 AN	255	struct resource *res;
9bf5b4f5 AN	256	unsigned int cen, sec;
618161f7 AN	257	struct rtc_plat_data *pdata;
618161f7 AN	258	void __iomem *ioaddr;
9bf5b4f5	259	int ret = 0;
3a9a06d4 AB	260	struct nvmem_config nvmem_cfg = {
	261	.name = "ds1553_nvram",
	262	.word_size = 1,
	263	.stride = 1,
	264	.size = RTC_OFFSET,
	265	.reg_read = ds1553_nvram_read,
	266	.reg_write = ds1553_nvram_write,
	267	.priv = pdev,
	268	};
9bf5b4f5	269
618161f7	270	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
9bf5b4f5 AN	271	if (!pdata)
9bf5b4f5 AN	272	return -ENOMEM;
618161f7	273
7c1d69ee JL	274	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	275	ioaddr = devm_ioremap_resource(&pdev->dev, res);
	276	if (IS_ERR(ioaddr))
	277	return PTR_ERR(ioaddr);
9bf5b4f5 AN	278	pdata->ioaddr = ioaddr;
	279	pdata->irq = platform_get_irq(pdev, 0);
	280
	281	/* turn RTC on if it was not on */
	282	sec = readb(ioaddr + RTC_SECONDS);
	283	if (sec & RTC_STOP) {
	284	sec &= RTC_SECONDS_MASK;
	285	cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
	286	writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
	287	writeb(sec, ioaddr + RTC_SECONDS);
	288	writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
	289	}
	290	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
	291	dev_warn(&pdev->dev, "voltage-low detected.\n");
	292
618161f7 AN	293	spin_lock_init(&pdata->lock);
	294	pdata->last_jiffies = jiffies;
	295	platform_set_drvdata(pdev, pdata);
4071ea25	296
18c88cc9	297	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
4071ea25 AZ	298	if (IS_ERR(pdata->rtc))
	299	return PTR_ERR(pdata->rtc);
	300
18c88cc9	301	pdata->rtc->ops = &ds1553_rtc_ops;
3a9a06d4	302	pdata->rtc->nvram_old_abi = true;
18c88cc9 AB	303
	304	ret = rtc_register_device(pdata->rtc);
	305	if (ret)
	306	return ret;
	307
2fac6674	308	if (pdata->irq > 0) {
9bf5b4f5	309	writeb(0, ioaddr + RTC_INTERRUPTS);
618161f7 AN	310	if (devm_request_irq(&pdev->dev, pdata->irq,
618161f7 AN	311	ds1553_rtc_interrupt,
2f6e5f94	312	0, pdev->name, pdev) < 0) {
9bf5b4f5	313	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	314	pdata->irq = 0;
9bf5b4f5 AN	315	}
	316	}
	317
3a9a06d4 AB	318	if (rtc_nvmem_register(pdata->rtc, &nvmem_cfg))
3a9a06d4 AB	319	dev_err(&pdev->dev, "unable to register nvmem\n");
c1be915e	320
4071ea25	321	return 0;
9bf5b4f5 AN	322	}
9bf5b4f5 AN	323
ad28a07b KS	324	/* work with hotplug and coldplug */
	325	MODULE_ALIAS("platform:rtc-ds1553");
	326
9bf5b4f5 AN	327	static struct platform_driver ds1553_rtc_driver = {
9bf5b4f5 AN	328	.probe = ds1553_rtc_probe,
9bf5b4f5	329	.driver = {
e7634c27	330	.name = "rtc-ds1553",
9bf5b4f5 AN	331	},
	332	};
	333
0c4eae66	334	module_platform_driver(ds1553_rtc_driver);
9bf5b4f5 AN	335
	336	MODULE_AUTHOR("Atsushi Nemoto <[email protected]>");
	337	MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
	338	MODULE_LICENSE("GPL");