[linux-block.git] / drivers / rtc / rtc-ds1511.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 *
 * 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--;

	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 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;

	ds1511_rtc_update_alarm(pdata);
	return 0;
}

static int
ds1511_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
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 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;
	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 int ds1511_nvram_read(void *priv, unsigned int pos, void *buf,
			     size_t size)
{
	int i;

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

	return 0;
}

static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
			      size_t size)
{
	int i;

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

	return 0;
}

static int ds1511_rtc_probe(struct platform_device *pdev)
{
	struct rtc_plat_data *pdata;
	int ret = 0;
	struct nvmem_config ds1511_nvmem_cfg = {
		.name = "ds1511_nvram",
		.word_size = 1,
		.stride = 1,
		.size = DS1511_RAM_MAX,
		.reg_read = ds1511_nvram_read,
		.reg_write = ds1511_nvram_write,
		.priv = &pdev->dev,
	};

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

	ds1511_base = devm_platform_ioremap_resource(pdev, 0);
	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_allocate_device(&pdev->dev);
	if (IS_ERR(pdata->rtc))
		return PTR_ERR(pdata->rtc);

	pdata->rtc->ops = &ds1511_rtc_ops;

	pdata->rtc->nvram_old_abi = true;

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

	rtc_nvmem_register(pdata->rtc, &ds1511_nvmem_cfg);

	/*
	 * 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;
		}
	}

	return 0;
}

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

static struct platform_driver ds1511_rtc_driver = {
	.probe		= ds1511_rtc_probe,
	.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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
8f26795a AS	2	/*
	3	* An rtc driver for the Dallas DS1511
	4	*
	5	* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5b73a41c	6	* Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
8f26795a	7	*
8f26795a AS	8	* Real time clock driver for the Dallas 1511 chip, which also
	9	* contains a watchdog timer. There is a tiny amount of code that
	10	* platform code could use to mess with the watchdog device a little
	11	* bit, but not a full watchdog driver.
	12	*/
	13
	14	#include <linux/bcd.h>
	15	#include <linux/init.h>
	16	#include <linux/kernel.h>
5a0e3ad6	17	#include <linux/gfp.h>
8f26795a AS	18	#include <linux/delay.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/rtc.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/io.h>
2113852b	23	#include <linux/module.h>
8f26795a	24
8f26795a AS	25	enum ds1511reg {
	26	DS1511_SEC = 0x0,
	27	DS1511_MIN = 0x1,
	28	DS1511_HOUR = 0x2,
	29	DS1511_DOW = 0x3,
	30	DS1511_DOM = 0x4,
	31	DS1511_MONTH = 0x5,
	32	DS1511_YEAR = 0x6,
	33	DS1511_CENTURY = 0x7,
	34	DS1511_AM1_SEC = 0x8,
	35	DS1511_AM2_MIN = 0x9,
	36	DS1511_AM3_HOUR = 0xa,
	37	DS1511_AM4_DATE = 0xb,
	38	DS1511_WD_MSEC = 0xc,
	39	DS1511_WD_SEC = 0xd,
	40	DS1511_CONTROL_A = 0xe,
	41	DS1511_CONTROL_B = 0xf,
	42	DS1511_RAMADDR_LSB = 0x10,
	43	DS1511_RAMDATA = 0x13
	44	};
	45
	46	#define DS1511_BLF1 0x80
	47	#define DS1511_BLF2 0x40
	48	#define DS1511_PRS 0x20
	49	#define DS1511_PAB 0x10
	50	#define DS1511_TDF 0x08
	51	#define DS1511_KSF 0x04
	52	#define DS1511_WDF 0x02
	53	#define DS1511_IRQF 0x01
	54	#define DS1511_TE 0x80
	55	#define DS1511_CS 0x40
	56	#define DS1511_BME 0x20
	57	#define DS1511_TPE 0x10
	58	#define DS1511_TIE 0x08
	59	#define DS1511_KIE 0x04
	60	#define DS1511_WDE 0x02
	61	#define DS1511_WDS 0x01
8ccba142	62	#define DS1511_RAM_MAX 0x100
8f26795a AS	63
	64	#define RTC_CMD DS1511_CONTROL_B
	65	#define RTC_CMD1 DS1511_CONTROL_A
	66
	67	#define RTC_ALARM_SEC DS1511_AM1_SEC
	68	#define RTC_ALARM_MIN DS1511_AM2_MIN
	69	#define RTC_ALARM_HOUR DS1511_AM3_HOUR
	70	#define RTC_ALARM_DATE DS1511_AM4_DATE
	71
	72	#define RTC_SEC DS1511_SEC
	73	#define RTC_MIN DS1511_MIN
	74	#define RTC_HOUR DS1511_HOUR
	75	#define RTC_DOW DS1511_DOW
	76	#define RTC_DOM DS1511_DOM
	77	#define RTC_MON DS1511_MONTH
	78	#define RTC_YEAR DS1511_YEAR
	79	#define RTC_CENTURY DS1511_CENTURY
	80
	81	#define RTC_TIE DS1511_TIE
	82	#define RTC_TE DS1511_TE
	83
	84	struct rtc_plat_data {
	85	struct rtc_device *rtc;
	86	void __iomem ioaddr; / virtual base address */
8f26795a AS	87	int irq;
	88	unsigned int irqen;
	89	int alrm_sec;
	90	int alrm_min;
	91	int alrm_hour;
	92	int alrm_mday;
ba4f3e47	93	spinlock_t lock;
8f26795a AS	94	};
	95
	96	static DEFINE_SPINLOCK(ds1511_lock);
	97
	98	static __iomem char *ds1511_base;
	99	static u32 reg_spacing = 1;
	100
7b2f0053	101	static noinline void
8f26795a AS	102	rtc_write(uint8_t val, uint32_t reg)
	103	{
	104	writeb(val, ds1511_base + (reg * reg_spacing));
	105	}
	106
7b2f0053	107	static inline void
8f26795a AS	108	rtc_write_alarm(uint8_t val, enum ds1511reg reg)
	109	{
	110	rtc_write((val \| 0x80), reg);
	111	}
	112
7b2f0053	113	static noinline uint8_t
8f26795a AS	114	rtc_read(enum ds1511reg reg)
	115	{
	116	return readb(ds1511_base + (reg * reg_spacing));
	117	}
	118
7b2f0053	119	static inline void
8f26795a AS	120	rtc_disable_update(void)
	121	{
	122	rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
	123	}
	124
7b2f0053	125	static void
8f26795a AS	126	rtc_enable_update(void)
	127	{
	128	rtc_write((rtc_read(RTC_CMD) \| RTC_TE), RTC_CMD);
	129	}
	130
	131	/*
	132	* #define DS1511_WDOG_RESET_SUPPORT
	133	*
	134	* Uncomment this if you want to use these routines in
	135	* some platform code.
	136	*/
	137	#ifdef DS1511_WDOG_RESET_SUPPORT
	138	/*
	139	* just enough code to set the watchdog timer so that it
	140	* will reboot the system
	141	*/
7b2f0053	142	void
8f26795a AS	143	ds1511_wdog_set(unsigned long deciseconds)
	144	{
	145	/*
	146	* the wdog timer can take 99.99 seconds
	147	*/
	148	deciseconds %= 10000;
	149	/*
	150	* set the wdog values in the wdog registers
	151	*/
fe20ba70 AB	152	rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
fe20ba70 AB	153	rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
8f26795a AS	154	/*
	155	* set wdog enable and wdog 'steering' bit to issue a reset
	156	*/
8ccba142	157	rtc_write(rtc_read(RTC_CMD) \| DS1511_WDE \| DS1511_WDS, RTC_CMD);
8f26795a AS	158	}
8f26795a AS	159
7b2f0053	160	void
8f26795a AS	161	ds1511_wdog_disable(void)
	162	{
	163	/*
	164	* clear wdog enable and wdog 'steering' bits
	165	*/
	166	rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE \| DS1511_WDS), RTC_CMD);
	167	/*
	168	* clear the wdog counter
	169	*/
	170	rtc_write(0, DS1511_WD_MSEC);
	171	rtc_write(0, DS1511_WD_SEC);
	172	}
	173	#endif
	174
	175	/*
	176	* set the rtc chip's idea of the time.
	177	* stupidly, some callers call with year unmolested;
	178	* and some call with year = year - 1900. thanks.
	179	*/
a3ed107e	180	static int ds1511_rtc_set_time(struct device dev, struct rtc_time rtc_tm)
8f26795a AS	181	{
8f26795a AS	182	u8 mon, day, dow, hrs, min, sec, yrs, cen;
9a0f4aea	183	unsigned long flags;
8f26795a AS	184
	185	/*
	186	* won't have to change this for a while
	187	*/
7b2f0053	188	if (rtc_tm->tm_year < 1900)
8f26795a	189	rtc_tm->tm_year += 1900;
8f26795a	190
7b2f0053	191	if (rtc_tm->tm_year < 1970)
8f26795a	192	return -EINVAL;
7b2f0053	193
8f26795a AS	194	yrs = rtc_tm->tm_year % 100;
	195	cen = rtc_tm->tm_year / 100;
	196	mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
	197	day = rtc_tm->tm_mday;
	198	dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
	199	hrs = rtc_tm->tm_hour;
	200	min = rtc_tm->tm_min;
	201	sec = rtc_tm->tm_sec;
	202
7b2f0053	203	if ((mon > 12) \|\| (day == 0))
8f26795a	204	return -EINVAL;
8f26795a	205
7b2f0053	206	if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year))
8f26795a	207	return -EINVAL;
8f26795a	208
7b2f0053	209	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
8f26795a	210	return -EINVAL;
8f26795a AS	211
	212	/*
	213	* each register is a different number of valid bits
	214	*/
fe20ba70 AB	215	sec = bin2bcd(sec) & 0x7f;
	216	min = bin2bcd(min) & 0x7f;
	217	hrs = bin2bcd(hrs) & 0x3f;
	218	day = bin2bcd(day) & 0x3f;
	219	mon = bin2bcd(mon) & 0x1f;
	220	yrs = bin2bcd(yrs) & 0xff;
	221	cen = bin2bcd(cen) & 0xff;
8f26795a AS	222
	223	spin_lock_irqsave(&ds1511_lock, flags);
	224	rtc_disable_update();
	225	rtc_write(cen, RTC_CENTURY);
	226	rtc_write(yrs, RTC_YEAR);
	227	rtc_write((rtc_read(RTC_MON) & 0xe0) \| mon, RTC_MON);
	228	rtc_write(day, RTC_DOM);
	229	rtc_write(hrs, RTC_HOUR);
	230	rtc_write(min, RTC_MIN);
	231	rtc_write(sec, RTC_SEC);
	232	rtc_write(dow, RTC_DOW);
	233	rtc_enable_update();
	234	spin_unlock_irqrestore(&ds1511_lock, flags);
	235
	236	return 0;
	237	}
	238
a3ed107e	239	static int ds1511_rtc_read_time(struct device dev, struct rtc_time rtc_tm)
8f26795a AS	240	{
8f26795a AS	241	unsigned int century;
9a0f4aea	242	unsigned long flags;
8f26795a AS	243
	244	spin_lock_irqsave(&ds1511_lock, flags);
	245	rtc_disable_update();
	246
	247	rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
	248	rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
	249	rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
	250	rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
	251	rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
	252	rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
	253	rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
	254	century = rtc_read(RTC_CENTURY);
	255
	256	rtc_enable_update();
	257	spin_unlock_irqrestore(&ds1511_lock, flags);
	258
fe20ba70 AB	259	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
	260	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
	261	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
	262	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
	263	rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
	264	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
	265	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
	266	century = bcd2bin(century) * 100;
8f26795a AS	267
	268	/*
	269	* Account for differences between how the RTC uses the values
	270	* and how they are defined in a struct rtc_time;
	271	*/
	272	century += rtc_tm->tm_year;
	273	rtc_tm->tm_year = century - 1900;
	274
	275	rtc_tm->tm_mon--;
	276
8f26795a AS	277	return 0;
	278	}
	279
	280	/*
	281	* write the alarm register settings
	282	*
	283	* we only have the use to interrupt every second, otherwise
	284	* known as the update interrupt, or the interrupt if the whole
	285	* date/hours/mins/secs matches. the ds1511 has many more
	286	* permutations, but the kernel doesn't.
	287	*/
7b2f0053	288	static void
8f26795a AS	289	ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
	290	{
	291	unsigned long flags;
	292
ba4f3e47	293	spin_lock_irqsave(&pdata->lock, flags);
8f26795a	294	rtc_write(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	295	0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
8f26795a AS	296	RTC_ALARM_DATE);
8f26795a AS	297	rtc_write(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	298	0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
8f26795a AS	299	RTC_ALARM_HOUR);
8f26795a AS	300	rtc_write(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	301	0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
8f26795a AS	302	RTC_ALARM_MIN);
8f26795a AS	303	rtc_write(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	304	0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
8f26795a AS	305	RTC_ALARM_SEC);
	306	rtc_write(rtc_read(RTC_CMD) \| (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
	307	rtc_read(RTC_CMD1); /* clear interrupts */
ba4f3e47	308	spin_unlock_irqrestore(&pdata->lock, flags);
8f26795a AS	309	}
8f26795a AS	310
7b2f0053	311	static int
8f26795a AS	312	ds1511_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
8f26795a AS	313	{
85368bb9	314	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
8f26795a	315
2fac6674	316	if (pdata->irq <= 0)
8f26795a	317	return -EINVAL;
2fac6674	318
8f26795a AS	319	pdata->alrm_mday = alrm->time.tm_mday;
	320	pdata->alrm_hour = alrm->time.tm_hour;
	321	pdata->alrm_min = alrm->time.tm_min;
	322	pdata->alrm_sec = alrm->time.tm_sec;
7b2f0053	323	if (alrm->enabled)
8f26795a	324	pdata->irqen \|= RTC_AF;
7b2f0053	325
8f26795a AS	326	ds1511_rtc_update_alarm(pdata);
	327	return 0;
	328	}
	329
7b2f0053	330	static int
8f26795a AS	331	ds1511_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
8f26795a AS	332	{
85368bb9	333	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
8f26795a	334
2fac6674	335	if (pdata->irq <= 0)
8f26795a	336	return -EINVAL;
2fac6674	337
8f26795a AS	338	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	339	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	340	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	341	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	342	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	343	return 0;
	344	}
	345
7b2f0053	346	static irqreturn_t
8f26795a AS	347	ds1511_interrupt(int irq, void *dev_id)
	348	{
	349	struct platform_device *pdev = dev_id;
	350	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
ba4f3e47	351	unsigned long events = 0;
8f26795a	352
ba4f3e47	353	spin_lock(&pdata->lock);
8f26795a AS	354	/*
	355	* read and clear interrupt
	356	*/
ba4f3e47 AN	357	if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
	358	events = RTC_IRQF;
	359	if (rtc_read(RTC_ALARM_SEC) & 0x80)
	360	events \|= RTC_UF;
	361	else
	362	events \|= RTC_AF;
0d71915d	363	rtc_update_irq(pdata->rtc, 1, events);
ba4f3e47 AN	364	}
	365	spin_unlock(&pdata->lock);
	366	return events ? IRQ_HANDLED : IRQ_NONE;
8f26795a AS	367	}
8f26795a AS	368
ba4f3e47	369	static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
8f26795a	370	{
85368bb9	371	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
8f26795a	372
ba4f3e47 AN	373	if (pdata->irq <= 0)
	374	return -EINVAL;
	375	if (enabled)
8f26795a	376	pdata->irqen \|= RTC_AF;
ba4f3e47 AN	377	else
	378	pdata->irqen &= ~RTC_AF;
	379	ds1511_rtc_update_alarm(pdata);
	380	return 0;
	381	}
	382
8f26795a	383	static const struct rtc_class_ops ds1511_rtc_ops = {
ba4f3e47 AN	384	.read_time = ds1511_rtc_read_time,
	385	.set_time = ds1511_rtc_set_time,
	386	.read_alarm = ds1511_rtc_read_alarm,
	387	.set_alarm = ds1511_rtc_set_alarm,
	388	.alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
8f26795a AS	389	};
8f26795a AS	390
9d7ed21f AB	391	static int ds1511_nvram_read(void priv, unsigned int pos, void buf,
9d7ed21f AB	392	size_t size)
8f26795a	393	{
9d7ed21f	394	int i;
8f26795a	395
8f26795a	396	rtc_write(pos, DS1511_RAMADDR_LSB);
9d7ed21f AB	397	for (i = 0; i < size; i++)
9d7ed21f AB	398	(char )buf++ = rtc_read(DS1511_RAMDATA);
7b2f0053	399
9d7ed21f	400	return 0;
8f26795a AS	401	}
8f26795a AS	402
9d7ed21f AB	403	static int ds1511_nvram_write(void priv, unsigned int pos, void buf,
9d7ed21f AB	404	size_t size)
8f26795a	405	{
9d7ed21f	406	int i;
8f26795a	407
8f26795a	408	rtc_write(pos, DS1511_RAMADDR_LSB);
9d7ed21f AB	409	for (i = 0; i < size; i++)
9d7ed21f AB	410	rtc_write((char )buf++, DS1511_RAMDATA);
7b2f0053	411
9d7ed21f	412	return 0;
8f26795a AS	413	}
8f26795a AS	414
5a167f45	415	static int ds1511_rtc_probe(struct platform_device *pdev)
8f26795a	416	{
ba4f3e47	417	struct rtc_plat_data *pdata;
8f26795a	418	int ret = 0;
71e19c5e AB	419	struct nvmem_config ds1511_nvmem_cfg = {
	420	.name = "ds1511_nvram",
	421	.word_size = 1,
	422	.stride = 1,
	423	.size = DS1511_RAM_MAX,
	424	.reg_read = ds1511_nvram_read,
	425	.reg_write = ds1511_nvram_write,
	426	.priv = &pdev->dev,
	427	};
8f26795a	428
ba4f3e47 AN	429	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
ba4f3e47 AN	430	if (!pdata)
8f26795a	431	return -ENOMEM;
7c1d69ee	432
09ef18bc	433	ds1511_base = devm_platform_ioremap_resource(pdev, 0);
7c1d69ee JL	434	if (IS_ERR(ds1511_base))
7c1d69ee JL	435	return PTR_ERR(ds1511_base);
8f26795a AS	436	pdata->ioaddr = ds1511_base;
	437	pdata->irq = platform_get_irq(pdev, 0);
	438
	439	/*
	440	* turn on the clock and the crystal, etc.
	441	*/
8ccba142	442	rtc_write(DS1511_BME, RTC_CMD);
8f26795a AS	443	rtc_write(0, RTC_CMD1);
	444	/*
	445	* clear the wdog counter
	446	*/
	447	rtc_write(0, DS1511_WD_MSEC);
	448	rtc_write(0, DS1511_WD_SEC);
	449	/*
	450	* start the clock
	451	*/
	452	rtc_enable_update();
	453
	454	/*
	455	* check for a dying bat-tree
	456	*/
7b2f0053	457	if (rtc_read(RTC_CMD1) & DS1511_BLF1)
8f26795a	458	dev_warn(&pdev->dev, "voltage-low detected.\n");
8f26795a	459
ba4f3e47 AN	460	spin_lock_init(&pdata->lock);
ba4f3e47 AN	461	platform_set_drvdata(pdev, pdata);
4071ea25	462
3032269b	463	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
4071ea25 AZ	464	if (IS_ERR(pdata->rtc))
	465	return PTR_ERR(pdata->rtc);
	466
3032269b AB	467	pdata->rtc->ops = &ds1511_rtc_ops;
3032269b AB	468
9d7ed21f AB	469	pdata->rtc->nvram_old_abi = true;
9d7ed21f AB	470
3032269b AB	471	ret = rtc_register_device(pdata->rtc);
	472	if (ret)
	473	return ret;
	474
16fef391 AB	475	rtc_nvmem_register(pdata->rtc, &ds1511_nvmem_cfg);
16fef391 AB	476
8f26795a AS	477	/*
	478	* if the platform has an interrupt in mind for this device,
	479	* then by all means, set it
	480	*/
2fac6674	481	if (pdata->irq > 0) {
8f26795a	482	rtc_read(RTC_CMD1);
ba4f3e47	483	if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
2f6e5f94	484	IRQF_SHARED, pdev->name, pdev) < 0) {
8f26795a AS	485
8f26795a AS	486	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	487	pdata->irq = 0;
8f26795a AS	488	}
	489	}
	490
8f26795a AS	491	return 0;
	492	}
	493
ad28a07b KS	494	/* work with hotplug and coldplug */
	495	MODULE_ALIAS("platform:ds1511");
	496
8f26795a AS	497	static struct platform_driver ds1511_rtc_driver = {
8f26795a AS	498	.probe = ds1511_rtc_probe,
8f26795a AS	499	.driver = {
8f26795a AS	500	.name = "ds1511",
8f26795a AS	501	},
	502	};
	503
0c4eae66	504	module_platform_driver(ds1511_rtc_driver);
8f26795a	505
5b73a41c	506	MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
8f26795a AS	507	MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
8f26795a AS	508	MODULE_LICENSE("GPL");