[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-ds1511.c

/*
 * An rtc driver for the Dallas DS1511
 *
 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
 *
 * 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.
 *
 * Real time clock driver for the Dallas 1511 chip, which also
 * contains a watchdog timer.  There is a tiny amount of code that
 * platform code could use to mess with the watchdog device a little
 * bit, but not a full watchdog driver.
 */

#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/module.h>

enum ds1511reg {
	DS1511_SEC = 0x0,
	DS1511_MIN = 0x1,
	DS1511_HOUR = 0x2,
	DS1511_DOW = 0x3,
	DS1511_DOM = 0x4,
	DS1511_MONTH = 0x5,
	DS1511_YEAR = 0x6,
	DS1511_CENTURY = 0x7,
	DS1511_AM1_SEC = 0x8,
	DS1511_AM2_MIN = 0x9,
	DS1511_AM3_HOUR = 0xa,
	DS1511_AM4_DATE = 0xb,
	DS1511_WD_MSEC = 0xc,
	DS1511_WD_SEC = 0xd,
	DS1511_CONTROL_A = 0xe,
	DS1511_CONTROL_B = 0xf,
	DS1511_RAMADDR_LSB = 0x10,
	DS1511_RAMDATA = 0x13
};

#define DS1511_BLF1	0x80
#define DS1511_BLF2	0x40
#define DS1511_PRS	0x20
#define DS1511_PAB	0x10
#define DS1511_TDF	0x08
#define DS1511_KSF	0x04
#define DS1511_WDF	0x02
#define DS1511_IRQF	0x01
#define DS1511_TE	0x80
#define DS1511_CS	0x40
#define DS1511_BME	0x20
#define DS1511_TPE	0x10
#define DS1511_TIE	0x08
#define DS1511_KIE	0x04
#define DS1511_WDE	0x02
#define DS1511_WDS	0x01
#define DS1511_RAM_MAX	0x100

#define RTC_CMD		DS1511_CONTROL_B
#define RTC_CMD1	DS1511_CONTROL_A

#define RTC_ALARM_SEC	DS1511_AM1_SEC
#define RTC_ALARM_MIN	DS1511_AM2_MIN
#define RTC_ALARM_HOUR	DS1511_AM3_HOUR
#define RTC_ALARM_DATE	DS1511_AM4_DATE

#define RTC_SEC		DS1511_SEC
#define RTC_MIN		DS1511_MIN
#define RTC_HOUR	DS1511_HOUR
#define RTC_DOW		DS1511_DOW
#define RTC_DOM		DS1511_DOM
#define RTC_MON		DS1511_MONTH
#define RTC_YEAR	DS1511_YEAR
#define RTC_CENTURY	DS1511_CENTURY

#define RTC_TIE	DS1511_TIE
#define RTC_TE	DS1511_TE

struct rtc_plat_data {
	struct rtc_device *rtc;
	void __iomem *ioaddr;		/* virtual base address */
	int irq;
	unsigned int irqen;
	int alrm_sec;
	int alrm_min;
	int alrm_hour;
	int alrm_mday;
	spinlock_t lock;
};

static DEFINE_SPINLOCK(ds1511_lock);

static __iomem char *ds1511_base;
static u32 reg_spacing = 1;

static noinline void
rtc_write(uint8_t val, uint32_t reg)
{
	writeb(val, ds1511_base + (reg * reg_spacing));
}

static inline void
rtc_write_alarm(uint8_t val, enum ds1511reg reg)
{
	rtc_write((val | 0x80), reg);
}

static noinline uint8_t
rtc_read(enum ds1511reg reg)
{
	return readb(ds1511_base + (reg * reg_spacing));
}

static inline void
rtc_disable_update(void)
{
	rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
}

static void
rtc_enable_update(void)
{
	rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD);
}

/*
 * #define DS1511_WDOG_RESET_SUPPORT
 *
 * Uncomment this if you want to use these routines in
 * some platform code.
 */
#ifdef DS1511_WDOG_RESET_SUPPORT
/*
 * just enough code to set the watchdog timer so that it
 * will reboot the system
 */
void
ds1511_wdog_set(unsigned long deciseconds)
{
	/*
	 * the wdog timer can take 99.99 seconds
	 */
	deciseconds %= 10000;
	/*
	 * set the wdog values in the wdog registers
	 */
	rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
	rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
	/*
	 * set wdog enable and wdog 'steering' bit to issue a reset
	 */
	rtc_write(rtc_read(RTC_CMD) | DS1511_WDE | DS1511_WDS, RTC_CMD);
}

void
ds1511_wdog_disable(void)
{
	/*
	 * clear wdog enable and wdog 'steering' bits
	 */
	rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD);
	/*
	 * clear the wdog counter
	 */
	rtc_write(0, DS1511_WD_MSEC);
	rtc_write(0, DS1511_WD_SEC);
}
#endif

/*
 * set the rtc chip's idea of the time.
 * stupidly, some callers call with year unmolested;
 * and some call with  year = year - 1900.  thanks.
 */
static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
{
	u8 mon, day, dow, hrs, min, sec, yrs, cen;
	unsigned long flags;

	/*
	 * won't have to change this for a while
	 */
	if (rtc_tm->tm_year < 1900)
		rtc_tm->tm_year += 1900;

	if (rtc_tm->tm_year < 1970)
		return -EINVAL;

	yrs = rtc_tm->tm_year % 100;
	cen = rtc_tm->tm_year / 100;
	mon = rtc_tm->tm_mon + 1;   /* tm_mon starts at zero */
	day = rtc_tm->tm_mday;
	dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
	hrs = rtc_tm->tm_hour;
	min = rtc_tm->tm_min;
	sec = rtc_tm->tm_sec;

	if ((mon > 12) || (day == 0))
		return -EINVAL;

	if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year))
		return -EINVAL;

	if ((hrs >= 24) || (min >= 60) || (sec >= 60))
		return -EINVAL;

	/*
	 * each register is a different number of valid bits
	 */
	sec = bin2bcd(sec) & 0x7f;
	min = bin2bcd(min) & 0x7f;
	hrs = bin2bcd(hrs) & 0x3f;
	day = bin2bcd(day) & 0x3f;
	mon = bin2bcd(mon) & 0x1f;
	yrs = bin2bcd(yrs) & 0xff;
	cen = bin2bcd(cen) & 0xff;

	spin_lock_irqsave(&ds1511_lock, flags);
	rtc_disable_update();
	rtc_write(cen, RTC_CENTURY);
	rtc_write(yrs, RTC_YEAR);
	rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON);
	rtc_write(day, RTC_DOM);
	rtc_write(hrs, RTC_HOUR);
	rtc_write(min, RTC_MIN);
	rtc_write(sec, RTC_SEC);
	rtc_write(dow, RTC_DOW);
	rtc_enable_update();
	spin_unlock_irqrestore(&ds1511_lock, flags);

	return 0;
}

static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
{
	unsigned int century;
	unsigned long flags;

	spin_lock_irqsave(&ds1511_lock, flags);
	rtc_disable_update();

	rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
	rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
	rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
	rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
	rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
	rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
	rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
	century = rtc_read(RTC_CENTURY);

	rtc_enable_update();
	spin_unlock_irqrestore(&ds1511_lock, flags);

	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
	rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
	century = bcd2bin(century) * 100;

	/*
	 * Account for differences between how the RTC uses the values
	 * and how they are defined in a struct rtc_time;
	 */
	century += rtc_tm->tm_year;
	rtc_tm->tm_year = century - 1900;

	rtc_tm->tm_mon--;

	if (rtc_valid_tm(rtc_tm) < 0) {
		dev_err(dev, "retrieved date/time is not valid.\n");
		rtc_time_to_tm(0, rtc_tm);
	}
	return 0;
}

/*
 * write the alarm register settings
 *
 * we only have the use to interrupt every second, otherwise
 * known as the update interrupt, or the interrupt if the whole
 * date/hours/mins/secs matches.  the ds1511 has many more
 * permutations, but the kernel doesn't.
 */
static void
ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
{
	unsigned long flags;

	spin_lock_irqsave(&pdata->lock, flags);
	rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
	       RTC_ALARM_DATE);
	rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
	       RTC_ALARM_HOUR);
	rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
	       RTC_ALARM_MIN);
	rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
	       RTC_ALARM_SEC);
	rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
	rtc_read(RTC_CMD1);	/* clear interrupts */
	spin_unlock_irqrestore(&pdata->lock, flags);
}

static int
ds1511_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;

	ds1511_rtc_update_alarm(pdata);
	return 0;
}

static int
ds1511_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
ds1511_interrupt(int irq, void *dev_id)
{
	struct platform_device *pdev = dev_id;
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	unsigned long events = 0;

	spin_lock(&pdata->lock);
	/*
	 * read and clear interrupt
	 */
	if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
		events = RTC_IRQF;
		if (rtc_read(RTC_ALARM_SEC) & 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 ds1511_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;
	ds1511_rtc_update_alarm(pdata);
	return 0;
}

static const struct rtc_class_ops ds1511_rtc_ops = {
	.read_time		= ds1511_rtc_read_time,
	.set_time		= ds1511_rtc_set_time,
	.read_alarm		= ds1511_rtc_read_alarm,
	.set_alarm		= ds1511_rtc_set_alarm,
	.alarm_irq_enable	= ds1511_rtc_alarm_irq_enable,
};

static ssize_t
ds1511_nvram_read(struct file *filp, struct kobject *kobj,
		  struct bin_attribute *ba,
		  char *buf, loff_t pos, size_t size)
{
	ssize_t count;

	rtc_write(pos, DS1511_RAMADDR_LSB);
	for (count = 0; count < size; count++)
		*buf++ = rtc_read(DS1511_RAMDATA);

	return count;
}

static ssize_t
ds1511_nvram_write(struct file *filp, struct kobject *kobj,
		   struct bin_attribute *bin_attr,
		   char *buf, loff_t pos, size_t size)
{
	ssize_t count;

	rtc_write(pos, DS1511_RAMADDR_LSB);
	for (count = 0; count < size; count++)
		rtc_write(*buf++, DS1511_RAMDATA);

	return count;
}

static struct bin_attribute ds1511_nvram_attr = {
	.attr = {
		.name = "nvram",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = DS1511_RAM_MAX,
	.read = ds1511_nvram_read,
	.write = ds1511_nvram_write,
};

static int ds1511_rtc_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct rtc_plat_data *pdata;
	int ret = 0;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ds1511_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(ds1511_base))
		return PTR_ERR(ds1511_base);
	pdata->ioaddr = ds1511_base;
	pdata->irq = platform_get_irq(pdev, 0);

	/*
	 * turn on the clock and the crystal, etc.
	 */
	rtc_write(DS1511_BME, RTC_CMD);
	rtc_write(0, RTC_CMD1);
	/*
	 * clear the wdog counter
	 */
	rtc_write(0, DS1511_WD_MSEC);
	rtc_write(0, DS1511_WD_SEC);
	/*
	 * start the clock
	 */
	rtc_enable_update();

	/*
	 * check for a dying bat-tree
	 */
	if (rtc_read(RTC_CMD1) & DS1511_BLF1)
		dev_warn(&pdev->dev, "voltage-low detected.\n");

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

	pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
					      &ds1511_rtc_ops, THIS_MODULE);
	if (IS_ERR(pdata->rtc))
		return PTR_ERR(pdata->rtc);

	/*
	 * if the platform has an interrupt in mind for this device,
	 * then by all means, set it
	 */
	if (pdata->irq > 0) {
		rtc_read(RTC_CMD1);
		if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
			IRQF_SHARED, pdev->name, pdev) < 0) {

			dev_warn(&pdev->dev, "interrupt not available.\n");
			pdata->irq = 0;
		}
	}

	ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
	if (ret)
		dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
			ds1511_nvram_attr.attr.name);

	return 0;
}

static int ds1511_rtc_remove(struct platform_device *pdev)
{
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);

	sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
	if (pdata->irq > 0) {
		/*
		 * disable the alarm interrupt
		 */
		rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
		rtc_read(RTC_CMD1);
	}
	return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:ds1511");

static struct platform_driver ds1511_rtc_driver = {
	.probe		= ds1511_rtc_probe,
	.remove		= ds1511_rtc_remove,
	.driver		= {
		.name	= "ds1511",
	},
};

module_platform_driver(ds1511_rtc_driver);

MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
8f26795a AS	1	/*
	2	* An rtc driver for the Dallas DS1511
	3	*
	4	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5b73a41c	5	* Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
8f26795a AS	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* Real time clock driver for the Dallas 1511 chip, which also
	12	* contains a watchdog timer. There is a tiny amount of code that
	13	* platform code could use to mess with the watchdog device a little
	14	* bit, but not a full watchdog driver.
	15	*/
	16
	17	#include <linux/bcd.h>
	18	#include <linux/init.h>
	19	#include <linux/kernel.h>
5a0e3ad6	20	#include <linux/gfp.h>
8f26795a AS	21	#include <linux/delay.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/rtc.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/io.h>
2113852b	26	#include <linux/module.h>
8f26795a	27
8f26795a AS	28	enum ds1511reg {
	29	DS1511_SEC = 0x0,
	30	DS1511_MIN = 0x1,
	31	DS1511_HOUR = 0x2,
	32	DS1511_DOW = 0x3,
	33	DS1511_DOM = 0x4,
	34	DS1511_MONTH = 0x5,
	35	DS1511_YEAR = 0x6,
	36	DS1511_CENTURY = 0x7,
	37	DS1511_AM1_SEC = 0x8,
	38	DS1511_AM2_MIN = 0x9,
	39	DS1511_AM3_HOUR = 0xa,
	40	DS1511_AM4_DATE = 0xb,
	41	DS1511_WD_MSEC = 0xc,
	42	DS1511_WD_SEC = 0xd,
	43	DS1511_CONTROL_A = 0xe,
	44	DS1511_CONTROL_B = 0xf,
	45	DS1511_RAMADDR_LSB = 0x10,
	46	DS1511_RAMDATA = 0x13
	47	};
	48
	49	#define DS1511_BLF1 0x80
	50	#define DS1511_BLF2 0x40
	51	#define DS1511_PRS 0x20
	52	#define DS1511_PAB 0x10
	53	#define DS1511_TDF 0x08
	54	#define DS1511_KSF 0x04
	55	#define DS1511_WDF 0x02
	56	#define DS1511_IRQF 0x01
	57	#define DS1511_TE 0x80
	58	#define DS1511_CS 0x40
	59	#define DS1511_BME 0x20
	60	#define DS1511_TPE 0x10
	61	#define DS1511_TIE 0x08
	62	#define DS1511_KIE 0x04
	63	#define DS1511_WDE 0x02
	64	#define DS1511_WDS 0x01
8ccba142	65	#define DS1511_RAM_MAX 0x100
8f26795a AS	66
	67	#define RTC_CMD DS1511_CONTROL_B
	68	#define RTC_CMD1 DS1511_CONTROL_A
	69
	70	#define RTC_ALARM_SEC DS1511_AM1_SEC
	71	#define RTC_ALARM_MIN DS1511_AM2_MIN
	72	#define RTC_ALARM_HOUR DS1511_AM3_HOUR
	73	#define RTC_ALARM_DATE DS1511_AM4_DATE
	74
	75	#define RTC_SEC DS1511_SEC
	76	#define RTC_MIN DS1511_MIN
	77	#define RTC_HOUR DS1511_HOUR
	78	#define RTC_DOW DS1511_DOW
	79	#define RTC_DOM DS1511_DOM
	80	#define RTC_MON DS1511_MONTH
	81	#define RTC_YEAR DS1511_YEAR
	82	#define RTC_CENTURY DS1511_CENTURY
	83
	84	#define RTC_TIE DS1511_TIE
	85	#define RTC_TE DS1511_TE
	86
	87	struct rtc_plat_data {
	88	struct rtc_device *rtc;
	89	void __iomem ioaddr; / virtual base address */
8f26795a AS	90	int irq;
	91	unsigned int irqen;
	92	int alrm_sec;
	93	int alrm_min;
	94	int alrm_hour;
	95	int alrm_mday;
ba4f3e47	96	spinlock_t lock;
8f26795a AS	97	};
	98
	99	static DEFINE_SPINLOCK(ds1511_lock);
	100
	101	static __iomem char *ds1511_base;
	102	static u32 reg_spacing = 1;
	103
7b2f0053	104	static noinline void
8f26795a AS	105	rtc_write(uint8_t val, uint32_t reg)
	106	{
	107	writeb(val, ds1511_base + (reg * reg_spacing));
	108	}
	109
7b2f0053	110	static inline void
8f26795a AS	111	rtc_write_alarm(uint8_t val, enum ds1511reg reg)
	112	{
	113	rtc_write((val \| 0x80), reg);
	114	}
	115
7b2f0053	116	static noinline uint8_t
8f26795a AS	117	rtc_read(enum ds1511reg reg)
	118	{
	119	return readb(ds1511_base + (reg * reg_spacing));
	120	}
	121
7b2f0053	122	static inline void
8f26795a AS	123	rtc_disable_update(void)
	124	{
	125	rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
	126	}
	127
7b2f0053	128	static void
8f26795a AS	129	rtc_enable_update(void)
	130	{
	131	rtc_write((rtc_read(RTC_CMD) \| RTC_TE), RTC_CMD);
	132	}
	133
	134	/*
	135	* #define DS1511_WDOG_RESET_SUPPORT
	136	*
	137	* Uncomment this if you want to use these routines in
	138	* some platform code.
	139	*/
	140	#ifdef DS1511_WDOG_RESET_SUPPORT
	141	/*
	142	* just enough code to set the watchdog timer so that it
	143	* will reboot the system
	144	*/
7b2f0053	145	void
8f26795a AS	146	ds1511_wdog_set(unsigned long deciseconds)
	147	{
	148	/*
	149	* the wdog timer can take 99.99 seconds
	150	*/
	151	deciseconds %= 10000;
	152	/*
	153	* set the wdog values in the wdog registers
	154	*/
fe20ba70 AB	155	rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
fe20ba70 AB	156	rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
8f26795a AS	157	/*
	158	* set wdog enable and wdog 'steering' bit to issue a reset
	159	*/
8ccba142	160	rtc_write(rtc_read(RTC_CMD) \| DS1511_WDE \| DS1511_WDS, RTC_CMD);
8f26795a AS	161	}
8f26795a AS	162
7b2f0053	163	void
8f26795a AS	164	ds1511_wdog_disable(void)
	165	{
	166	/*
	167	* clear wdog enable and wdog 'steering' bits
	168	*/
	169	rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE \| DS1511_WDS), RTC_CMD);
	170	/*
	171	* clear the wdog counter
	172	*/
	173	rtc_write(0, DS1511_WD_MSEC);
	174	rtc_write(0, DS1511_WD_SEC);
	175	}
	176	#endif
	177
	178	/*
	179	* set the rtc chip's idea of the time.
	180	* stupidly, some callers call with year unmolested;
	181	* and some call with year = year - 1900. thanks.
	182	*/
a3ed107e	183	static int ds1511_rtc_set_time(struct device dev, struct rtc_time rtc_tm)
8f26795a AS	184	{
8f26795a AS	185	u8 mon, day, dow, hrs, min, sec, yrs, cen;
9a0f4aea	186	unsigned long flags;
8f26795a AS	187
	188	/*
	189	* won't have to change this for a while
	190	*/
7b2f0053	191	if (rtc_tm->tm_year < 1900)
8f26795a	192	rtc_tm->tm_year += 1900;
8f26795a	193
7b2f0053	194	if (rtc_tm->tm_year < 1970)
8f26795a	195	return -EINVAL;
7b2f0053	196
8f26795a AS	197	yrs = rtc_tm->tm_year % 100;
	198	cen = rtc_tm->tm_year / 100;
	199	mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
	200	day = rtc_tm->tm_mday;
	201	dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
	202	hrs = rtc_tm->tm_hour;
	203	min = rtc_tm->tm_min;
	204	sec = rtc_tm->tm_sec;
	205
7b2f0053	206	if ((mon > 12) \|\| (day == 0))
8f26795a	207	return -EINVAL;
8f26795a	208
7b2f0053	209	if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year))
8f26795a	210	return -EINVAL;
8f26795a	211
7b2f0053	212	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
8f26795a	213	return -EINVAL;
8f26795a AS	214
	215	/*
	216	* each register is a different number of valid bits
	217	*/
fe20ba70 AB	218	sec = bin2bcd(sec) & 0x7f;
	219	min = bin2bcd(min) & 0x7f;
	220	hrs = bin2bcd(hrs) & 0x3f;
	221	day = bin2bcd(day) & 0x3f;
	222	mon = bin2bcd(mon) & 0x1f;
	223	yrs = bin2bcd(yrs) & 0xff;
	224	cen = bin2bcd(cen) & 0xff;
8f26795a AS	225
	226	spin_lock_irqsave(&ds1511_lock, flags);
	227	rtc_disable_update();
	228	rtc_write(cen, RTC_CENTURY);
	229	rtc_write(yrs, RTC_YEAR);
	230	rtc_write((rtc_read(RTC_MON) & 0xe0) \| mon, RTC_MON);
	231	rtc_write(day, RTC_DOM);
	232	rtc_write(hrs, RTC_HOUR);
	233	rtc_write(min, RTC_MIN);
	234	rtc_write(sec, RTC_SEC);
	235	rtc_write(dow, RTC_DOW);
	236	rtc_enable_update();
	237	spin_unlock_irqrestore(&ds1511_lock, flags);
	238
	239	return 0;
	240	}
	241
a3ed107e	242	static int ds1511_rtc_read_time(struct device dev, struct rtc_time rtc_tm)
8f26795a AS	243	{
8f26795a AS	244	unsigned int century;
9a0f4aea	245	unsigned long flags;
8f26795a AS	246
	247	spin_lock_irqsave(&ds1511_lock, flags);
	248	rtc_disable_update();
	249
	250	rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
	251	rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
	252	rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
	253	rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
	254	rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
	255	rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
	256	rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
	257	century = rtc_read(RTC_CENTURY);
	258
	259	rtc_enable_update();
	260	spin_unlock_irqrestore(&ds1511_lock, flags);
	261
fe20ba70 AB	262	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
	263	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
	264	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
	265	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
	266	rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
	267	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
	268	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
	269	century = bcd2bin(century) * 100;
8f26795a AS	270
	271	/*
	272	* Account for differences between how the RTC uses the values
	273	* and how they are defined in a struct rtc_time;
	274	*/
	275	century += rtc_tm->tm_year;
	276	rtc_tm->tm_year = century - 1900;
	277
	278	rtc_tm->tm_mon--;
	279
	280	if (rtc_valid_tm(rtc_tm) < 0) {
	281	dev_err(dev, "retrieved date/time is not valid.\n");
	282	rtc_time_to_tm(0, rtc_tm);
	283	}
	284	return 0;
	285	}
	286
	287	/*
	288	* write the alarm register settings
	289	*
	290	* we only have the use to interrupt every second, otherwise
	291	* known as the update interrupt, or the interrupt if the whole
	292	* date/hours/mins/secs matches. the ds1511 has many more
	293	* permutations, but the kernel doesn't.
	294	*/
7b2f0053	295	static void
8f26795a AS	296	ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
	297	{
	298	unsigned long flags;
	299
ba4f3e47	300	spin_lock_irqsave(&pdata->lock, flags);
8f26795a	301	rtc_write(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	302	0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
8f26795a AS	303	RTC_ALARM_DATE);
8f26795a AS	304	rtc_write(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	305	0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
8f26795a AS	306	RTC_ALARM_HOUR);
8f26795a AS	307	rtc_write(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	308	0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
8f26795a AS	309	RTC_ALARM_MIN);
8f26795a AS	310	rtc_write(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	311	0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
8f26795a AS	312	RTC_ALARM_SEC);
	313	rtc_write(rtc_read(RTC_CMD) \| (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
	314	rtc_read(RTC_CMD1); /* clear interrupts */
ba4f3e47	315	spin_unlock_irqrestore(&pdata->lock, flags);
8f26795a AS	316	}
8f26795a AS	317
7b2f0053	318	static int
8f26795a AS	319	ds1511_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	320	{
	321	struct platform_device *pdev = to_platform_device(dev);
	322	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	323
2fac6674	324	if (pdata->irq <= 0)
8f26795a	325	return -EINVAL;
2fac6674	326
8f26795a AS	327	pdata->alrm_mday = alrm->time.tm_mday;
	328	pdata->alrm_hour = alrm->time.tm_hour;
	329	pdata->alrm_min = alrm->time.tm_min;
	330	pdata->alrm_sec = alrm->time.tm_sec;
7b2f0053	331	if (alrm->enabled)
8f26795a	332	pdata->irqen \|= RTC_AF;
7b2f0053	333
8f26795a AS	334	ds1511_rtc_update_alarm(pdata);
	335	return 0;
	336	}
	337
7b2f0053	338	static int
8f26795a AS	339	ds1511_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	340	{
	341	struct platform_device *pdev = to_platform_device(dev);
	342	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	343
2fac6674	344	if (pdata->irq <= 0)
8f26795a	345	return -EINVAL;
2fac6674	346
8f26795a AS	347	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	348	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	349	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	350	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	351	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	352	return 0;
	353	}
	354
7b2f0053	355	static irqreturn_t
8f26795a AS	356	ds1511_interrupt(int irq, void *dev_id)
	357	{
	358	struct platform_device *pdev = dev_id;
	359	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
ba4f3e47	360	unsigned long events = 0;
8f26795a	361
ba4f3e47	362	spin_lock(&pdata->lock);
8f26795a AS	363	/*
	364	* read and clear interrupt
	365	*/
ba4f3e47 AN	366	if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
	367	events = RTC_IRQF;
	368	if (rtc_read(RTC_ALARM_SEC) & 0x80)
	369	events \|= RTC_UF;
	370	else
	371	events \|= RTC_AF;
0d71915d	372	rtc_update_irq(pdata->rtc, 1, events);
ba4f3e47 AN	373	}
	374	spin_unlock(&pdata->lock);
	375	return events ? IRQ_HANDLED : IRQ_NONE;
8f26795a AS	376	}
8f26795a AS	377
ba4f3e47	378	static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
8f26795a AS	379	{
	380	struct platform_device *pdev = to_platform_device(dev);
	381	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	382
ba4f3e47 AN	383	if (pdata->irq <= 0)
	384	return -EINVAL;
	385	if (enabled)
8f26795a	386	pdata->irqen \|= RTC_AF;
ba4f3e47 AN	387	else
	388	pdata->irqen &= ~RTC_AF;
	389	ds1511_rtc_update_alarm(pdata);
	390	return 0;
	391	}
	392
8f26795a	393	static const struct rtc_class_ops ds1511_rtc_ops = {
ba4f3e47 AN	394	.read_time = ds1511_rtc_read_time,
	395	.set_time = ds1511_rtc_set_time,
	396	.read_alarm = ds1511_rtc_read_alarm,
	397	.set_alarm = ds1511_rtc_set_alarm,
	398	.alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
8f26795a AS	399	};
8f26795a AS	400
7b2f0053	401	static ssize_t
2c3c8bea CW	402	ds1511_nvram_read(struct file filp, struct kobject kobj,
	403	struct bin_attribute *ba,
	404	char *buf, loff_t pos, size_t size)
8f26795a AS	405	{
	406	ssize_t count;
	407
8f26795a	408	rtc_write(pos, DS1511_RAMADDR_LSB);
8ccba142	409	for (count = 0; count < size; count++)
8f26795a	410	*buf++ = rtc_read(DS1511_RAMDATA);
7b2f0053	411
8f26795a AS	412	return count;
	413	}
	414
7b2f0053	415	static ssize_t
2c3c8bea CW	416	ds1511_nvram_write(struct file filp, struct kobject kobj,
	417	struct bin_attribute *bin_attr,
	418	char *buf, loff_t pos, size_t size)
8f26795a AS	419	{
	420	ssize_t count;
	421
8f26795a	422	rtc_write(pos, DS1511_RAMADDR_LSB);
8ccba142	423	for (count = 0; count < size; count++)
8f26795a	424	rtc_write(*buf++, DS1511_RAMDATA);
7b2f0053	425
8f26795a AS	426	return count;
	427	}
	428
	429	static struct bin_attribute ds1511_nvram_attr = {
	430	.attr = {
	431	.name = "nvram",
49d50fb1	432	.mode = S_IRUGO \| S_IWUSR,
8f26795a AS	433	},
	434	.size = DS1511_RAM_MAX,
	435	.read = ds1511_nvram_read,
	436	.write = ds1511_nvram_write,
	437	};
	438
5a167f45	439	static int ds1511_rtc_probe(struct platform_device *pdev)
8f26795a	440	{
8f26795a	441	struct resource *res;
ba4f3e47	442	struct rtc_plat_data *pdata;
8f26795a AS	443	int ret = 0;
8f26795a AS	444
ba4f3e47 AN	445	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
ba4f3e47 AN	446	if (!pdata)
8f26795a	447	return -ENOMEM;
7c1d69ee JL	448
	449	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	450	ds1511_base = devm_ioremap_resource(&pdev->dev, res);
	451	if (IS_ERR(ds1511_base))
	452	return PTR_ERR(ds1511_base);
8f26795a AS	453	pdata->ioaddr = ds1511_base;
	454	pdata->irq = platform_get_irq(pdev, 0);
	455
	456	/*
	457	* turn on the clock and the crystal, etc.
	458	*/
8ccba142	459	rtc_write(DS1511_BME, RTC_CMD);
8f26795a AS	460	rtc_write(0, RTC_CMD1);
	461	/*
	462	* clear the wdog counter
	463	*/
	464	rtc_write(0, DS1511_WD_MSEC);
	465	rtc_write(0, DS1511_WD_SEC);
	466	/*
	467	* start the clock
	468	*/
	469	rtc_enable_update();
	470
	471	/*
	472	* check for a dying bat-tree
	473	*/
7b2f0053	474	if (rtc_read(RTC_CMD1) & DS1511_BLF1)
8f26795a	475	dev_warn(&pdev->dev, "voltage-low detected.\n");
8f26795a	476
ba4f3e47 AN	477	spin_lock_init(&pdata->lock);
ba4f3e47 AN	478	platform_set_drvdata(pdev, pdata);
4071ea25 AZ	479
	480	pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
	481	&ds1511_rtc_ops, THIS_MODULE);
	482	if (IS_ERR(pdata->rtc))
	483	return PTR_ERR(pdata->rtc);
	484
8f26795a AS	485	/*
	486	* if the platform has an interrupt in mind for this device,
	487	* then by all means, set it
	488	*/
2fac6674	489	if (pdata->irq > 0) {
8f26795a	490	rtc_read(RTC_CMD1);
ba4f3e47	491	if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
2f6e5f94	492	IRQF_SHARED, pdev->name, pdev) < 0) {
8f26795a AS	493
8f26795a AS	494	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	495	pdata->irq = 0;
8f26795a AS	496	}
	497	}
	498
8f26795a	499	ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
4071ea25 AZ	500	if (ret)
	501	dev_err(&pdev->dev, "Unable to create sysfs entry: %s\n",
	502	ds1511_nvram_attr.attr.name);
f650e657	503
4071ea25	504	return 0;
8f26795a AS	505	}
8f26795a AS	506
5a167f45	507	static int ds1511_rtc_remove(struct platform_device *pdev)
8f26795a AS	508	{
	509	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	510
	511	sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
2fac6674	512	if (pdata->irq > 0) {
8f26795a AS	513	/*
	514	* disable the alarm interrupt
	515	*/
	516	rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
	517	rtc_read(RTC_CMD1);
8f26795a	518	}
8f26795a AS	519	return 0;
	520	}
	521
ad28a07b KS	522	/* work with hotplug and coldplug */
	523	MODULE_ALIAS("platform:ds1511");
	524
8f26795a AS	525	static struct platform_driver ds1511_rtc_driver = {
8f26795a AS	526	.probe = ds1511_rtc_probe,
5a167f45	527	.remove = ds1511_rtc_remove,
8f26795a AS	528	.driver = {
8f26795a AS	529	.name = "ds1511",
8f26795a AS	530	},
	531	};
	532
0c4eae66	533	module_platform_driver(ds1511_rtc_driver);
8f26795a	534
5b73a41c	535	MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
8f26795a AS	536	MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
8f26795a AS	537	MODULE_LICENSE("GPL");