[deliverable/linux.git] / drivers / rtc / rtc-ab8500.c

/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * License terms: GNU General Public License (GPL) version 2
 * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
 *
 * RTC clock driver for the RTC part of the AB8500 Power management chip.
 * Based on RTC clock driver for the AB3100 Analog Baseband Chip by
 * Linus Walleij <linus.walleij@stericsson.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/delay.h>
#include <linux/of.h>

#define AB8500_RTC_SOFF_STAT_REG	0x00
#define AB8500_RTC_CC_CONF_REG		0x01
#define AB8500_RTC_READ_REQ_REG		0x02
#define AB8500_RTC_WATCH_TSECMID_REG	0x03
#define AB8500_RTC_WATCH_TSECHI_REG	0x04
#define AB8500_RTC_WATCH_TMIN_LOW_REG	0x05
#define AB8500_RTC_WATCH_TMIN_MID_REG	0x06
#define AB8500_RTC_WATCH_TMIN_HI_REG	0x07
#define AB8500_RTC_ALRM_MIN_LOW_REG	0x08
#define AB8500_RTC_ALRM_MIN_MID_REG	0x09
#define AB8500_RTC_ALRM_MIN_HI_REG	0x0A
#define AB8500_RTC_STAT_REG		0x0B
#define AB8500_RTC_BKUP_CHG_REG		0x0C
#define AB8500_RTC_FORCE_BKUP_REG	0x0D
#define AB8500_RTC_CALIB_REG		0x0E
#define AB8500_RTC_SWITCH_STAT_REG	0x0F

/* RtcReadRequest bits */
#define RTC_READ_REQUEST		0x01
#define RTC_WRITE_REQUEST		0x02

/* RtcCtrl bits */
#define RTC_ALARM_ENA			0x04
#define RTC_STATUS_DATA			0x01

#define COUNTS_PER_SEC			(0xF000 / 60)
#define AB8500_RTC_EPOCH		2000

static const u8 ab8500_rtc_time_regs[] = {
	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
	AB8500_RTC_WATCH_TSECMID_REG
};

static const u8 ab8500_rtc_alarm_regs[] = {
	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
	AB8500_RTC_ALRM_MIN_LOW_REG
};

/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
static unsigned long get_elapsed_seconds(int year)
{
	unsigned long secs;
	struct rtc_time tm = {
		.tm_year = year - 1900,
		.tm_mday = 1,
	};

	/*
	 * This function calculates secs from 1970 and not from
	 * 1900, even if we supply the offset from year 1900.
	 */
	rtc_tm_to_time(&tm, &secs);
	return secs;
}

static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned long timeout = jiffies + HZ;
	int retval, i;
	unsigned long mins, secs;
	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	u8 value;

	/* Request a data read */
	retval = abx500_set_register_interruptible(dev,
		AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
	if (retval < 0)
		return retval;

	/* Early AB8500 chips will not clear the rtc read request bit */
	if (abx500_get_chip_id(dev) == 0) {
		usleep_range(1000, 1000);
	} else {
		/* Wait for some cycles after enabling the rtc read in ab8500 */
		while (time_before(jiffies, timeout)) {
			retval = abx500_get_register_interruptible(dev,
				AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
			if (retval < 0)
				return retval;

			if (!(value & RTC_READ_REQUEST))
				break;

			usleep_range(1000, 5000);
		}
	}

	/* Read the Watchtime registers */
	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
		retval = abx500_get_register_interruptible(dev,
			AB8500_RTC, ab8500_rtc_time_regs[i], &value);
		if (retval < 0)
			return retval;
		buf[i] = value;
	}

	mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];

	secs =	(buf[3] << 8) | buf[4];
	secs =	secs / COUNTS_PER_SEC;
	secs =	secs + (mins * 60);

	/* Add back the initially subtracted number of seconds */
	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);

	rtc_time_to_tm(secs, tm);
	return rtc_valid_tm(tm);
}

static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	int retval, i;
	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	unsigned long no_secs, no_mins, secs = 0;

	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
		dev_dbg(dev, "year should be equal to or greater than %d\n",
				AB8500_RTC_EPOCH);
		return -EINVAL;
	}

	/* Get the number of seconds since 1970 */
	rtc_tm_to_time(tm, &secs);

	/*
	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
	 * we only have a small counter in the RTC.
	 */
	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);

	no_mins = secs / 60;

	no_secs = secs % 60;
	/* Make the seconds count as per the RTC resolution */
	no_secs = no_secs * COUNTS_PER_SEC;

	buf[4] = no_secs & 0xFF;
	buf[3] = (no_secs >> 8) & 0xFF;

	buf[2] = no_mins & 0xFF;
	buf[1] = (no_mins >> 8) & 0xFF;
	buf[0] = (no_mins >> 16) & 0xFF;

	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
			ab8500_rtc_time_regs[i], buf[i]);
		if (retval < 0)
			return retval;
	}

	/* Request a data write */
	return abx500_set_register_interruptible(dev, AB8500_RTC,
		AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
}

static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	int retval, i;
	u8 rtc_ctrl, value;
	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	unsigned long secs, mins;

	/* Check if the alarm is enabled or not */
	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
		AB8500_RTC_STAT_REG, &rtc_ctrl);
	if (retval < 0)
		return retval;

	if (rtc_ctrl & RTC_ALARM_ENA)
		alarm->enabled = 1;
	else
		alarm->enabled = 0;

	alarm->pending = 0;

	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
		retval = abx500_get_register_interruptible(dev, AB8500_RTC,
			ab8500_rtc_alarm_regs[i], &value);
		if (retval < 0)
			return retval;
		buf[i] = value;
	}

	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
	secs = mins * 60;

	/* Add back the initially subtracted number of seconds */
	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);

	rtc_time_to_tm(secs, &alarm->time);

	return rtc_valid_tm(&alarm->time);
}

static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
{
	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
		AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
		enabled ? RTC_ALARM_ENA : 0);
}

static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	int retval, i;
	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	unsigned long mins, secs = 0, cursec = 0;
	struct rtc_time curtm;

	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
		dev_dbg(dev, "year should be equal to or greater than %d\n",
				AB8500_RTC_EPOCH);
		return -EINVAL;
	}

	/* Get the number of seconds since 1970 */
	rtc_tm_to_time(&alarm->time, &secs);

	/*
	 * Check whether alarm is set less than 1min.
	 * Since our RTC doesn't support alarm resolution less than 1min,
	 * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
	 */
	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
	rtc_tm_to_time(&curtm, &cursec);
	if ((secs - cursec) < 59) {
		dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
		return -EINVAL;
	}

	/*
	 * Convert it to the number of seconds since 01-01-2000 00:00:00, since
	 * we only have a small counter in the RTC.
	 */
	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);

	mins = secs / 60;

	buf[2] = mins & 0xFF;
	buf[1] = (mins >> 8) & 0xFF;
	buf[0] = (mins >> 16) & 0xFF;

	/* Set the alarm time */
	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
			ab8500_rtc_alarm_regs[i], buf[i]);
		if (retval < 0)
			return retval;
	}

	return ab8500_rtc_irq_enable(dev, alarm->enabled);
}


static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
{
	int retval;
	u8  rtccal = 0;

	/*
	 * Check that the calibration value (which is in units of 0.5
	 * parts-per-million) is in the AB8500's range for RtcCalibration
	 * register. -128 (0x80) is not permitted because the AB8500 uses
	 * a sign-bit rather than two's complement, so 0x80 is just another
	 * representation of zero.
	 */
	if ((calibration < -127) || (calibration > 127)) {
		dev_err(dev, "RtcCalibration value outside permitted range\n");
		return -EINVAL;
	}

	/*
	 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	 * so need to convert to this sort of representation before writing
	 * into RtcCalibration register...
	 */
	if (calibration >= 0)
		rtccal = 0x7F & calibration;
	else
		rtccal = ~(calibration - 1) | 0x80;

	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
			AB8500_RTC_CALIB_REG, rtccal);

	return retval;
}

static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
{
	int retval;
	u8  rtccal = 0;

	retval =  abx500_get_register_interruptible(dev, AB8500_RTC,
			AB8500_RTC_CALIB_REG, &rtccal);
	if (retval >= 0) {
		/*
		 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
		 * so need to convert value from RtcCalibration register into
		 * a two's complement signed value...
		 */
		if (rtccal & 0x80)
			*calibration = 0 - (rtccal & 0x7F);
		else
			*calibration = 0x7F & rtccal;
	}

	return retval;
}

static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	int retval;
	int calibration = 0;

	if (sscanf(buf, " %i ", &calibration) != 1) {
		dev_err(dev, "Failed to store RTC calibration attribute\n");
		return -EINVAL;
	}

	retval = ab8500_rtc_set_calibration(dev, calibration);

	return retval ? retval : count;
}

static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	int  retval = 0;
	int  calibration = 0;

	retval = ab8500_rtc_get_calibration(dev, &calibration);
	if (retval < 0) {
		dev_err(dev, "Failed to read RTC calibration attribute\n");
		sprintf(buf, "0\n");
		return retval;
	}

	return sprintf(buf, "%d\n", calibration);
}

static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
		   ab8500_sysfs_show_rtc_calibration,
		   ab8500_sysfs_store_rtc_calibration);

static int ab8500_sysfs_rtc_register(struct device *dev)
{
	return device_create_file(dev, &dev_attr_rtc_calibration);
}

static void ab8500_sysfs_rtc_unregister(struct device *dev)
{
	device_remove_file(dev, &dev_attr_rtc_calibration);
}

static irqreturn_t rtc_alarm_handler(int irq, void *data)
{
	struct rtc_device *rtc = data;
	unsigned long events = RTC_IRQF | RTC_AF;

	dev_dbg(&rtc->dev, "%s\n", __func__);
	rtc_update_irq(rtc, 1, events);

	return IRQ_HANDLED;
}

static const struct rtc_class_ops ab8500_rtc_ops = {
	.read_time		= ab8500_rtc_read_time,
	.set_time		= ab8500_rtc_set_time,
	.read_alarm		= ab8500_rtc_read_alarm,
	.set_alarm		= ab8500_rtc_set_alarm,
	.alarm_irq_enable	= ab8500_rtc_irq_enable,
};

static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
{
	int err;
	struct rtc_device *rtc;
	u8 rtc_ctrl;
	int irq;

	irq = platform_get_irq_byname(pdev, "ALARM");
	if (irq < 0)
		return irq;

	/* For RTC supply test */
	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
		AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
	if (err < 0)
		return err;

	/* Wait for reset by the PorRtc */
	usleep_range(1000, 5000);

	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
		AB8500_RTC_STAT_REG, &rtc_ctrl);
	if (err < 0)
		return err;

	/* Check if the RTC Supply fails */
	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
		dev_err(&pdev->dev, "RTC supply failure\n");
		return -ENODEV;
	}

	device_init_wakeup(&pdev->dev, true);

	rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
			THIS_MODULE);
	if (IS_ERR(rtc)) {
		dev_err(&pdev->dev, "Registration failed\n");
		err = PTR_ERR(rtc);
		return err;
	}

	err = request_threaded_irq(irq, NULL, rtc_alarm_handler,
		IRQF_NO_SUSPEND | IRQF_ONESHOT, "ab8500-rtc", rtc);
	if (err < 0) {
		rtc_device_unregister(rtc);
		return err;
	}

	platform_set_drvdata(pdev, rtc);

	err = ab8500_sysfs_rtc_register(&pdev->dev);
	if (err) {
		dev_err(&pdev->dev, "sysfs RTC failed to register\n");
		return err;
	}

	return 0;
}

static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
{
	struct rtc_device *rtc = platform_get_drvdata(pdev);
	int irq = platform_get_irq_byname(pdev, "ALARM");

	ab8500_sysfs_rtc_unregister(&pdev->dev);

	free_irq(irq, rtc);
	rtc_device_unregister(rtc);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static const struct of_device_id ab8500_rtc_match[] = {
	{ .compatible = "stericsson,ab8500-rtc", },
	{}
};

static struct platform_driver ab8500_rtc_driver = {
	.driver = {
		.name = "ab8500-rtc",
		.owner = THIS_MODULE,
		.of_match_table = ab8500_rtc_match,
	},
	.probe	= ab8500_rtc_probe,
	.remove = __devexit_p(ab8500_rtc_remove),
};

module_platform_driver(ab8500_rtc_driver);

MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
MODULE_DESCRIPTION("AB8500 RTC Driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
0af62f4d VS	1	/*
	2	* Copyright (C) ST-Ericsson SA 2010
	3	*
	4	* License terms: GNU General Public License (GPL) version 2
	5	* Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
	6	*
	7	* RTC clock driver for the RTC part of the AB8500 Power management chip.
	8	* Based on RTC clock driver for the AB3100 Analog Baseband Chip by
	9	* Linus Walleij <linus.walleij@stericsson.com>
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/init.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/rtc.h>
47c16975	17	#include <linux/mfd/abx500.h>
ee66e653	18	#include <linux/mfd/abx500/ab8500.h>
0af62f4d	19	#include <linux/delay.h>
ad49fcbe	20	#include <linux/of.h>
0af62f4d	21
47c16975 MW	22	#define AB8500_RTC_SOFF_STAT_REG 0x00
	23	#define AB8500_RTC_CC_CONF_REG 0x01
	24	#define AB8500_RTC_READ_REQ_REG 0x02
	25	#define AB8500_RTC_WATCH_TSECMID_REG 0x03
	26	#define AB8500_RTC_WATCH_TSECHI_REG 0x04
	27	#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
	28	#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
	29	#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
	30	#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
	31	#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
	32	#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
	33	#define AB8500_RTC_STAT_REG 0x0B
	34	#define AB8500_RTC_BKUP_CHG_REG 0x0C
	35	#define AB8500_RTC_FORCE_BKUP_REG 0x0D
	36	#define AB8500_RTC_CALIB_REG 0x0E
	37	#define AB8500_RTC_SWITCH_STAT_REG 0x0F
0af62f4d VS	38
	39	/* RtcReadRequest bits */
	40	#define RTC_READ_REQUEST 0x01
	41	#define RTC_WRITE_REQUEST 0x02
	42
	43	/* RtcCtrl bits */
	44	#define RTC_ALARM_ENA 0x04
	45	#define RTC_STATUS_DATA 0x01
	46
	47	#define COUNTS_PER_SEC (0xF000 / 60)
	48	#define AB8500_RTC_EPOCH 2000
	49
47c16975	50	static const u8 ab8500_rtc_time_regs[] = {
0af62f4d VS	51	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
	52	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
	53	AB8500_RTC_WATCH_TSECMID_REG
	54	};
	55
47c16975	56	static const u8 ab8500_rtc_alarm_regs[] = {
0af62f4d VS	57	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
	58	AB8500_RTC_ALRM_MIN_LOW_REG
	59	};
	60
	61	/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
	62	static unsigned long get_elapsed_seconds(int year)
	63	{
	64	unsigned long secs;
	65	struct rtc_time tm = {
	66	.tm_year = year - 1900,
	67	.tm_mday = 1,
	68	};
	69
	70	/*
	71	* This function calculates secs from 1970 and not from
	72	* 1900, even if we supply the offset from year 1900.
	73	*/
	74	rtc_tm_to_time(&tm, &secs);
	75	return secs;
	76	}
	77
	78	static int ab8500_rtc_read_time(struct device dev, struct rtc_time tm)
	79	{
0af62f4d VS	80	unsigned long timeout = jiffies + HZ;
	81	int retval, i;
	82	unsigned long mins, secs;
	83	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
47c16975	84	u8 value;
0af62f4d VS	85
0af62f4d VS	86	/* Request a data read */
47c16975 MW	87	retval = abx500_set_register_interruptible(dev,
47c16975 MW	88	AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
0af62f4d VS	89	if (retval < 0)
	90	return retval;
	91
	92	/* Early AB8500 chips will not clear the rtc read request bit */
47c16975	93	if (abx500_get_chip_id(dev) == 0) {
012e52e1	94	usleep_range(1000, 1000);
0af62f4d VS	95	} else {
	96	/* Wait for some cycles after enabling the rtc read in ab8500 */
	97	while (time_before(jiffies, timeout)) {
47c16975 MW	98	retval = abx500_get_register_interruptible(dev,
47c16975 MW	99	AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
0af62f4d VS	100	if (retval < 0)
	101	return retval;
	102
47c16975	103	if (!(value & RTC_READ_REQUEST))
0af62f4d VS	104	break;
0af62f4d VS	105
012e52e1	106	usleep_range(1000, 5000);
0af62f4d VS	107	}
	108	}
	109
	110	/* Read the Watchtime registers */
	111	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	112	retval = abx500_get_register_interruptible(dev,
47c16975 MW	113	AB8500_RTC, ab8500_rtc_time_regs[i], &value);
0af62f4d VS	114	if (retval < 0)
0af62f4d VS	115	return retval;
47c16975	116	buf[i] = value;
0af62f4d VS	117	}
	118
	119	mins = (buf[0] << 16) \| (buf[1] << 8) \| buf[2];
	120
	121	secs = (buf[3] << 8) \| buf[4];
	122	secs = secs / COUNTS_PER_SEC;
	123	secs = secs + (mins * 60);
	124
	125	/* Add back the initially subtracted number of seconds */
	126	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	127
	128	rtc_time_to_tm(secs, tm);
	129	return rtc_valid_tm(tm);
	130	}
	131
	132	static int ab8500_rtc_set_time(struct device dev, struct rtc_time tm)
	133	{
0af62f4d VS	134	int retval, i;
	135	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	136	unsigned long no_secs, no_mins, secs = 0;
	137
	138	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
	139	dev_dbg(dev, "year should be equal to or greater than %d\n",
	140	AB8500_RTC_EPOCH);
	141	return -EINVAL;
	142	}
	143
	144	/* Get the number of seconds since 1970 */
	145	rtc_tm_to_time(tm, &secs);
	146
	147	/*
	148	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	149	* we only have a small counter in the RTC.
	150	*/
	151	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	152
	153	no_mins = secs / 60;
	154
	155	no_secs = secs % 60;
	156	/* Make the seconds count as per the RTC resolution */
	157	no_secs = no_secs * COUNTS_PER_SEC;
	158
	159	buf[4] = no_secs & 0xFF;
	160	buf[3] = (no_secs >> 8) & 0xFF;
	161
	162	buf[2] = no_mins & 0xFF;
	163	buf[1] = (no_mins >> 8) & 0xFF;
	164	buf[0] = (no_mins >> 16) & 0xFF;
	165
	166	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	167	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	168	ab8500_rtc_time_regs[i], buf[i]);
0af62f4d VS	169	if (retval < 0)
	170	return retval;
	171	}
	172
	173	/* Request a data write */
47c16975 MW	174	return abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	175	AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
0af62f4d VS	176	}
	177
	178	static int ab8500_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	179	{
0af62f4d	180	int retval, i;
47c16975	181	u8 rtc_ctrl, value;
0af62f4d VS	182	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	183	unsigned long secs, mins;
	184
	185	/* Check if the alarm is enabled or not */
47c16975 MW	186	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	187	AB8500_RTC_STAT_REG, &rtc_ctrl);
	188	if (retval < 0)
	189	return retval;
0af62f4d VS	190
	191	if (rtc_ctrl & RTC_ALARM_ENA)
	192	alarm->enabled = 1;
	193	else
	194	alarm->enabled = 0;
	195
	196	alarm->pending = 0;
	197
	198	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	199	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
47c16975 MW	200	ab8500_rtc_alarm_regs[i], &value);
0af62f4d VS	201	if (retval < 0)
0af62f4d VS	202	return retval;
47c16975	203	buf[i] = value;
0af62f4d VS	204	}
	205
	206	mins = (buf[0] << 16) \| (buf[1] << 8) \| (buf[2]);
	207	secs = mins * 60;
	208
	209	/* Add back the initially subtracted number of seconds */
	210	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	211
	212	rtc_time_to_tm(secs, &alarm->time);
	213
	214	return rtc_valid_tm(&alarm->time);
	215	}
	216
	217	static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
	218	{
47c16975 MW	219	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
	220	AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
	221	enabled ? RTC_ALARM_ENA : 0);
0af62f4d VS	222	}
	223
	224	static int ab8500_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	225	{
0af62f4d VS	226	int retval, i;
0af62f4d VS	227	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
dc43d4a2 RC	228	unsigned long mins, secs = 0, cursec = 0;
dc43d4a2 RC	229	struct rtc_time curtm;
0af62f4d VS	230
	231	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
	232	dev_dbg(dev, "year should be equal to or greater than %d\n",
	233	AB8500_RTC_EPOCH);
	234	return -EINVAL;
	235	}
	236
	237	/* Get the number of seconds since 1970 */
	238	rtc_tm_to_time(&alarm->time, &secs);
	239
dc43d4a2 RC	240	/*
	241	* Check whether alarm is set less than 1min.
	242	* Since our RTC doesn't support alarm resolution less than 1min,
	243	* return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
	244	*/
	245	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
	246	rtc_tm_to_time(&curtm, &cursec);
	247	if ((secs - cursec) < 59) {
	248	dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
	249	return -EINVAL;
	250	}
	251
0af62f4d VS	252	/*
	253	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	254	* we only have a small counter in the RTC.
	255	*/
	256	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	257
	258	mins = secs / 60;
	259
	260	buf[2] = mins & 0xFF;
	261	buf[1] = (mins >> 8) & 0xFF;
	262	buf[0] = (mins >> 16) & 0xFF;
	263
	264	/* Set the alarm time */
	265	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	266	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	267	ab8500_rtc_alarm_regs[i], buf[i]);
0af62f4d VS	268	if (retval < 0)
	269	return retval;
	270	}
	271
	272	return ab8500_rtc_irq_enable(dev, alarm->enabled);
	273	}
	274
dda367ac MG	275
	276	static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
	277	{
	278	int retval;
	279	u8 rtccal = 0;
	280
	281	/*
	282	* Check that the calibration value (which is in units of 0.5
	283	* parts-per-million) is in the AB8500's range for RtcCalibration
	284	* register. -128 (0x80) is not permitted because the AB8500 uses
	285	* a sign-bit rather than two's complement, so 0x80 is just another
	286	* representation of zero.
	287	*/
	288	if ((calibration < -127) \|\| (calibration > 127)) {
	289	dev_err(dev, "RtcCalibration value outside permitted range\n");
	290	return -EINVAL;
	291	}
	292
	293	/*
	294	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	295	* so need to convert to this sort of representation before writing
	296	* into RtcCalibration register...
	297	*/
	298	if (calibration >= 0)
	299	rtccal = 0x7F & calibration;
	300	else
	301	rtccal = ~(calibration - 1) \| 0x80;
	302
	303	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
	304	AB8500_RTC_CALIB_REG, rtccal);
	305
	306	return retval;
	307	}
	308
	309	static int ab8500_rtc_get_calibration(struct device dev, int calibration)
	310	{
	311	int retval;
	312	u8 rtccal = 0;
	313
	314	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	315	AB8500_RTC_CALIB_REG, &rtccal);
	316	if (retval >= 0) {
	317	/*
	318	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	319	* so need to convert value from RtcCalibration register into
	320	* a two's complement signed value...
	321	*/
	322	if (rtccal & 0x80)
	323	*calibration = 0 - (rtccal & 0x7F);
	324	else
	325	*calibration = 0x7F & rtccal;
	326	}
	327
	328	return retval;
	329	}
	330
	331	static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
	332	struct device_attribute *attr,
	333	const char *buf, size_t count)
	334	{
	335	int retval;
	336	int calibration = 0;
	337
	338	if (sscanf(buf, " %i ", &calibration) != 1) {
339	dev_err(dev, "Failed to store RTC calibration attribute\n");
340	return -EINVAL;
341	}
342
343	retval = ab8500_rtc_set_calibration(dev, calibration);
344
345	return retval ? retval : count;
346	}
347
348	static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
349	struct device_attribute attr, char buf)
350	{
351	int retval = 0;
352	int calibration = 0;
353
354	retval = ab8500_rtc_get_calibration(dev, &calibration);
355	if (retval < 0) {
356	dev_err(dev, "Failed to read RTC calibration attribute\n");
357	sprintf(buf, "0\n");
358	return retval;
359	}
360
361	return sprintf(buf, "%d\n", calibration);
362	}
363
364	static DEVICE_ATTR(rtc_calibration, S_IRUGO \| S_IWUSR,
365	ab8500_sysfs_show_rtc_calibration,
366	ab8500_sysfs_store_rtc_calibration);
367
368	static int ab8500_sysfs_rtc_register(struct device *dev)
369	{
370	return device_create_file(dev, &dev_attr_rtc_calibration);
371	}
372
373	static void ab8500_sysfs_rtc_unregister(struct device *dev)
374	{
375	device_remove_file(dev, &dev_attr_rtc_calibration);
376	}
377
0af62f4d VS	378	static irqreturn_t rtc_alarm_handler(int irq, void *data)
	379	{
	380	struct rtc_device *rtc = data;
	381	unsigned long events = RTC_IRQF \| RTC_AF;
	382
	383	dev_dbg(&rtc->dev, "%s\n", __func__);
	384	rtc_update_irq(rtc, 1, events);
	385
	386	return IRQ_HANDLED;
	387	}
	388
	389	static const struct rtc_class_ops ab8500_rtc_ops = {
	390	.read_time = ab8500_rtc_read_time,
	391	.set_time = ab8500_rtc_set_time,
	392	.read_alarm = ab8500_rtc_read_alarm,
	393	.set_alarm = ab8500_rtc_set_alarm,
	394	.alarm_irq_enable = ab8500_rtc_irq_enable,
	395	};
	396
	397	static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
	398	{
0af62f4d VS	399	int err;
0af62f4d VS	400	struct rtc_device *rtc;
47c16975	401	u8 rtc_ctrl;
0af62f4d VS	402	int irq;
	403
	404	irq = platform_get_irq_byname(pdev, "ALARM");
	405	if (irq < 0)
	406	return irq;
	407
	408	/* For RTC supply test */
47c16975 MW	409	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
47c16975 MW	410	AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
0af62f4d VS	411	if (err < 0)
	412	return err;
	413
	414	/* Wait for reset by the PorRtc */
012e52e1	415	usleep_range(1000, 5000);
0af62f4d	416
47c16975 MW	417	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
	418	AB8500_RTC_STAT_REG, &rtc_ctrl);
	419	if (err < 0)
	420	return err;
0af62f4d VS	421
	422	/* Check if the RTC Supply fails */
	423	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
	424	dev_err(&pdev->dev, "RTC supply failure\n");
	425	return -ENODEV;
	426	}
	427
b62581e6 AL	428	device_init_wakeup(&pdev->dev, true);
b62581e6 AL	429
0af62f4d VS	430	rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
	431	THIS_MODULE);
	432	if (IS_ERR(rtc)) {
	433	dev_err(&pdev->dev, "Registration failed\n");
	434	err = PTR_ERR(rtc);
	435	return err;
	436	}
	437
10d065e6	438	err = request_threaded_irq(irq, NULL, rtc_alarm_handler,
3cfd16a5	439	IRQF_NO_SUSPEND \| IRQF_ONESHOT, "ab8500-rtc", rtc);
0af62f4d VS	440	if (err < 0) {
	441	rtc_device_unregister(rtc);
	442	return err;
	443	}
	444
	445	platform_set_drvdata(pdev, rtc);
	446
dda367ac MG	447	err = ab8500_sysfs_rtc_register(&pdev->dev);
	448	if (err) {
	449	dev_err(&pdev->dev, "sysfs RTC failed to register\n");
	450	return err;
	451	}
	452
0af62f4d VS	453	return 0;
	454	}
	455
	456	static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
	457	{
	458	struct rtc_device *rtc = platform_get_drvdata(pdev);
	459	int irq = platform_get_irq_byname(pdev, "ALARM");
	460
dda367ac MG	461	ab8500_sysfs_rtc_unregister(&pdev->dev);
dda367ac MG	462
0af62f4d VS	463	free_irq(irq, rtc);
	464	rtc_device_unregister(rtc);
	465	platform_set_drvdata(pdev, NULL);
	466
	467	return 0;
	468	}
	469
ad49fcbe LJ	470	static const struct of_device_id ab8500_rtc_match[] = {
	471	{ .compatible = "stericsson,ab8500-rtc", },
	472	{}
	473	};
	474
0af62f4d VS	475	static struct platform_driver ab8500_rtc_driver = {
	476	.driver = {
	477	.name = "ab8500-rtc",
	478	.owner = THIS_MODULE,
ad49fcbe	479	.of_match_table = ab8500_rtc_match,
0af62f4d VS	480	},
	481	.probe = ab8500_rtc_probe,
	482	.remove = __devexit_p(ab8500_rtc_remove),
	483	};
	484
0c4eae66	485	module_platform_driver(ab8500_rtc_driver);
0af62f4d	486
0af62f4d VS	487	MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
	488	MODULE_DESCRIPTION("AB8500 RTC Driver");
	489	MODULE_LICENSE("GPL v2");