[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/ab8500.h>
#include <linux/delay.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;

	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);

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

static int __init ab8500_rtc_init(void)
{
	return platform_driver_register(&ab8500_rtc_driver);
}

static void __exit ab8500_rtc_exit(void)
{
	platform_driver_unregister(&ab8500_rtc_driver);
}

module_init(ab8500_rtc_init);
module_exit(ab8500_rtc_exit);
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>
0af62f4d VS	18	#include <linux/mfd/ab8500.h>
	19	#include <linux/delay.h>
	20
47c16975 MW	21	#define AB8500_RTC_SOFF_STAT_REG 0x00
	22	#define AB8500_RTC_CC_CONF_REG 0x01
	23	#define AB8500_RTC_READ_REQ_REG 0x02
	24	#define AB8500_RTC_WATCH_TSECMID_REG 0x03
	25	#define AB8500_RTC_WATCH_TSECHI_REG 0x04
	26	#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
	27	#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
	28	#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
	29	#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
	30	#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
	31	#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
	32	#define AB8500_RTC_STAT_REG 0x0B
	33	#define AB8500_RTC_BKUP_CHG_REG 0x0C
	34	#define AB8500_RTC_FORCE_BKUP_REG 0x0D
	35	#define AB8500_RTC_CALIB_REG 0x0E
	36	#define AB8500_RTC_SWITCH_STAT_REG 0x0F
0af62f4d VS	37
	38	/* RtcReadRequest bits */
	39	#define RTC_READ_REQUEST 0x01
	40	#define RTC_WRITE_REQUEST 0x02
	41
	42	/* RtcCtrl bits */
	43	#define RTC_ALARM_ENA 0x04
	44	#define RTC_STATUS_DATA 0x01
	45
	46	#define COUNTS_PER_SEC (0xF000 / 60)
	47	#define AB8500_RTC_EPOCH 2000
	48
47c16975	49	static const u8 ab8500_rtc_time_regs[] = {
0af62f4d VS	50	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
	51	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
	52	AB8500_RTC_WATCH_TSECMID_REG
	53	};
	54
47c16975	55	static const u8 ab8500_rtc_alarm_regs[] = {
0af62f4d VS	56	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
	57	AB8500_RTC_ALRM_MIN_LOW_REG
	58	};
	59
	60	/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
	61	static unsigned long get_elapsed_seconds(int year)
	62	{
	63	unsigned long secs;
	64	struct rtc_time tm = {
	65	.tm_year = year - 1900,
	66	.tm_mday = 1,
	67	};
	68
	69	/*
	70	* This function calculates secs from 1970 and not from
	71	* 1900, even if we supply the offset from year 1900.
	72	*/
	73	rtc_tm_to_time(&tm, &secs);
	74	return secs;
	75	}
	76
	77	static int ab8500_rtc_read_time(struct device dev, struct rtc_time tm)
	78	{
0af62f4d VS	79	unsigned long timeout = jiffies + HZ;
	80	int retval, i;
	81	unsigned long mins, secs;
	82	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
47c16975	83	u8 value;
0af62f4d VS	84
0af62f4d VS	85	/* Request a data read */
47c16975 MW	86	retval = abx500_set_register_interruptible(dev,
47c16975 MW	87	AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
0af62f4d VS	88	if (retval < 0)
	89	return retval;
	90
	91	/* Early AB8500 chips will not clear the rtc read request bit */
47c16975	92	if (abx500_get_chip_id(dev) == 0) {
012e52e1	93	usleep_range(1000, 1000);
0af62f4d VS	94	} else {
	95	/* Wait for some cycles after enabling the rtc read in ab8500 */
	96	while (time_before(jiffies, timeout)) {
47c16975 MW	97	retval = abx500_get_register_interruptible(dev,
47c16975 MW	98	AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
0af62f4d VS	99	if (retval < 0)
	100	return retval;
	101
47c16975	102	if (!(value & RTC_READ_REQUEST))
0af62f4d VS	103	break;
0af62f4d VS	104
012e52e1	105	usleep_range(1000, 5000);
0af62f4d VS	106	}
	107	}
	108
	109	/* Read the Watchtime registers */
	110	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	111	retval = abx500_get_register_interruptible(dev,
47c16975 MW	112	AB8500_RTC, ab8500_rtc_time_regs[i], &value);
0af62f4d VS	113	if (retval < 0)
0af62f4d VS	114	return retval;
47c16975	115	buf[i] = value;
0af62f4d VS	116	}
	117
	118	mins = (buf[0] << 16) \| (buf[1] << 8) \| buf[2];
	119
	120	secs = (buf[3] << 8) \| buf[4];
	121	secs = secs / COUNTS_PER_SEC;
	122	secs = secs + (mins * 60);
	123
	124	/* Add back the initially subtracted number of seconds */
	125	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	126
	127	rtc_time_to_tm(secs, tm);
	128	return rtc_valid_tm(tm);
	129	}
	130
	131	static int ab8500_rtc_set_time(struct device dev, struct rtc_time tm)
	132	{
0af62f4d VS	133	int retval, i;
	134	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	135	unsigned long no_secs, no_mins, secs = 0;
	136
	137	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
	138	dev_dbg(dev, "year should be equal to or greater than %d\n",
	139	AB8500_RTC_EPOCH);
	140	return -EINVAL;
	141	}
	142
	143	/* Get the number of seconds since 1970 */
	144	rtc_tm_to_time(tm, &secs);
	145
	146	/*
	147	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	148	* we only have a small counter in the RTC.
	149	*/
	150	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	151
	152	no_mins = secs / 60;
	153
	154	no_secs = secs % 60;
	155	/* Make the seconds count as per the RTC resolution */
	156	no_secs = no_secs * COUNTS_PER_SEC;
	157
	158	buf[4] = no_secs & 0xFF;
	159	buf[3] = (no_secs >> 8) & 0xFF;
	160
	161	buf[2] = no_mins & 0xFF;
	162	buf[1] = (no_mins >> 8) & 0xFF;
	163	buf[0] = (no_mins >> 16) & 0xFF;
	164
	165	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	166	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	167	ab8500_rtc_time_regs[i], buf[i]);
0af62f4d VS	168	if (retval < 0)
	169	return retval;
	170	}
	171
	172	/* Request a data write */
47c16975 MW	173	return abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	174	AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
0af62f4d VS	175	}
	176
	177	static int ab8500_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	178	{
0af62f4d	179	int retval, i;
47c16975	180	u8 rtc_ctrl, value;
0af62f4d VS	181	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	182	unsigned long secs, mins;
	183
	184	/* Check if the alarm is enabled or not */
47c16975 MW	185	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	186	AB8500_RTC_STAT_REG, &rtc_ctrl);
	187	if (retval < 0)
	188	return retval;
0af62f4d VS	189
	190	if (rtc_ctrl & RTC_ALARM_ENA)
	191	alarm->enabled = 1;
	192	else
	193	alarm->enabled = 0;
	194
	195	alarm->pending = 0;
	196
	197	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	198	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
47c16975 MW	199	ab8500_rtc_alarm_regs[i], &value);
0af62f4d VS	200	if (retval < 0)
0af62f4d VS	201	return retval;
47c16975	202	buf[i] = value;
0af62f4d VS	203	}
	204
	205	mins = (buf[0] << 16) \| (buf[1] << 8) \| (buf[2]);
	206	secs = mins * 60;
	207
	208	/* Add back the initially subtracted number of seconds */
	209	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	210
	211	rtc_time_to_tm(secs, &alarm->time);
	212
	213	return rtc_valid_tm(&alarm->time);
	214	}
	215
	216	static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
	217	{
47c16975 MW	218	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
	219	AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
	220	enabled ? RTC_ALARM_ENA : 0);
0af62f4d VS	221	}
	222
	223	static int ab8500_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	224	{
0af62f4d VS	225	int retval, i;
	226	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	227	unsigned long mins, secs = 0;
	228
	229	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
	230	dev_dbg(dev, "year should be equal to or greater than %d\n",
	231	AB8500_RTC_EPOCH);
	232	return -EINVAL;
	233	}
	234
	235	/* Get the number of seconds since 1970 */
	236	rtc_tm_to_time(&alarm->time, &secs);
	237
	238	/*
	239	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	240	* we only have a small counter in the RTC.
	241	*/
	242	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	243
	244	mins = secs / 60;
	245
	246	buf[2] = mins & 0xFF;
	247	buf[1] = (mins >> 8) & 0xFF;
	248	buf[0] = (mins >> 16) & 0xFF;
	249
	250	/* Set the alarm time */
	251	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	252	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	253	ab8500_rtc_alarm_regs[i], buf[i]);
0af62f4d VS	254	if (retval < 0)
	255	return retval;
	256	}
	257
	258	return ab8500_rtc_irq_enable(dev, alarm->enabled);
	259	}
	260
dda367ac MG	261
	262	static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
	263	{
	264	int retval;
	265	u8 rtccal = 0;
	266
	267	/*
	268	* Check that the calibration value (which is in units of 0.5
	269	* parts-per-million) is in the AB8500's range for RtcCalibration
	270	* register. -128 (0x80) is not permitted because the AB8500 uses
	271	* a sign-bit rather than two's complement, so 0x80 is just another
	272	* representation of zero.
	273	*/
	274	if ((calibration < -127) \|\| (calibration > 127)) {
	275	dev_err(dev, "RtcCalibration value outside permitted range\n");
	276	return -EINVAL;
	277	}
	278
	279	/*
	280	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	281	* so need to convert to this sort of representation before writing
	282	* into RtcCalibration register...
	283	*/
	284	if (calibration >= 0)
	285	rtccal = 0x7F & calibration;
	286	else
	287	rtccal = ~(calibration - 1) \| 0x80;
	288
	289	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
	290	AB8500_RTC_CALIB_REG, rtccal);
	291
	292	return retval;
	293	}
	294
	295	static int ab8500_rtc_get_calibration(struct device dev, int calibration)
	296	{
	297	int retval;
	298	u8 rtccal = 0;
	299
	300	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	301	AB8500_RTC_CALIB_REG, &rtccal);
	302	if (retval >= 0) {
	303	/*
	304	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	305	* so need to convert value from RtcCalibration register into
	306	* a two's complement signed value...
	307	*/
	308	if (rtccal & 0x80)
	309	*calibration = 0 - (rtccal & 0x7F);
	310	else
	311	*calibration = 0x7F & rtccal;
	312	}
	313
	314	return retval;
	315	}
	316
	317	static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
	318	struct device_attribute *attr,
	319	const char *buf, size_t count)
	320	{
	321	int retval;
	322	int calibration = 0;
	323
	324	if (sscanf(buf, " %i ", &calibration) != 1) {
325	dev_err(dev, "Failed to store RTC calibration attribute\n");
326	return -EINVAL;
327	}
328
329	retval = ab8500_rtc_set_calibration(dev, calibration);
330
331	return retval ? retval : count;
332	}
333
334	static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
335	struct device_attribute attr, char buf)
336	{
337	int retval = 0;
338	int calibration = 0;
339
340	retval = ab8500_rtc_get_calibration(dev, &calibration);
341	if (retval < 0) {
342	dev_err(dev, "Failed to read RTC calibration attribute\n");
343	sprintf(buf, "0\n");
344	return retval;
345	}
346
347	return sprintf(buf, "%d\n", calibration);
348	}
349
350	static DEVICE_ATTR(rtc_calibration, S_IRUGO \| S_IWUSR,
351	ab8500_sysfs_show_rtc_calibration,
352	ab8500_sysfs_store_rtc_calibration);
353
354	static int ab8500_sysfs_rtc_register(struct device *dev)
355	{
356	return device_create_file(dev, &dev_attr_rtc_calibration);
357	}
358
359	static void ab8500_sysfs_rtc_unregister(struct device *dev)
360	{
361	device_remove_file(dev, &dev_attr_rtc_calibration);
362	}
363
0af62f4d VS	364	static irqreturn_t rtc_alarm_handler(int irq, void *data)
	365	{
	366	struct rtc_device *rtc = data;
	367	unsigned long events = RTC_IRQF \| RTC_AF;
	368
	369	dev_dbg(&rtc->dev, "%s\n", __func__);
	370	rtc_update_irq(rtc, 1, events);
	371
	372	return IRQ_HANDLED;
	373	}
	374
	375	static const struct rtc_class_ops ab8500_rtc_ops = {
	376	.read_time = ab8500_rtc_read_time,
	377	.set_time = ab8500_rtc_set_time,
	378	.read_alarm = ab8500_rtc_read_alarm,
	379	.set_alarm = ab8500_rtc_set_alarm,
	380	.alarm_irq_enable = ab8500_rtc_irq_enable,
	381	};
	382
	383	static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
	384	{
0af62f4d VS	385	int err;
0af62f4d VS	386	struct rtc_device *rtc;
47c16975	387	u8 rtc_ctrl;
0af62f4d VS	388	int irq;
	389
	390	irq = platform_get_irq_byname(pdev, "ALARM");
	391	if (irq < 0)
	392	return irq;
	393
	394	/* For RTC supply test */
47c16975 MW	395	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
47c16975 MW	396	AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
0af62f4d VS	397	if (err < 0)
	398	return err;
	399
	400	/* Wait for reset by the PorRtc */
012e52e1	401	usleep_range(1000, 5000);
0af62f4d	402
47c16975 MW	403	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
	404	AB8500_RTC_STAT_REG, &rtc_ctrl);
	405	if (err < 0)
	406	return err;
0af62f4d VS	407
	408	/* Check if the RTC Supply fails */
	409	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
	410	dev_err(&pdev->dev, "RTC supply failure\n");
	411	return -ENODEV;
	412	}
	413
b62581e6 AL	414	device_init_wakeup(&pdev->dev, true);
b62581e6 AL	415
0af62f4d VS	416	rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
	417	THIS_MODULE);
	418	if (IS_ERR(rtc)) {
	419	dev_err(&pdev->dev, "Registration failed\n");
	420	err = PTR_ERR(rtc);
	421	return err;
	422	}
	423
10d065e6 RM	424	err = request_threaded_irq(irq, NULL, rtc_alarm_handler,
10d065e6 RM	425	IRQF_NO_SUSPEND, "ab8500-rtc", rtc);
0af62f4d VS	426	if (err < 0) {
	427	rtc_device_unregister(rtc);
	428	return err;
	429	}
	430
	431	platform_set_drvdata(pdev, rtc);
	432
dda367ac MG	433
	434	err = ab8500_sysfs_rtc_register(&pdev->dev);
	435	if (err) {
	436	dev_err(&pdev->dev, "sysfs RTC failed to register\n");
	437	return err;
	438	}
	439
0af62f4d VS	440	return 0;
	441	}
	442
	443	static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
	444	{
	445	struct rtc_device *rtc = platform_get_drvdata(pdev);
	446	int irq = platform_get_irq_byname(pdev, "ALARM");
	447
dda367ac MG	448	ab8500_sysfs_rtc_unregister(&pdev->dev);
dda367ac MG	449
0af62f4d VS	450	free_irq(irq, rtc);
	451	rtc_device_unregister(rtc);
	452	platform_set_drvdata(pdev, NULL);
	453
	454	return 0;
	455	}
	456
	457	static struct platform_driver ab8500_rtc_driver = {
	458	.driver = {
	459	.name = "ab8500-rtc",
	460	.owner = THIS_MODULE,
	461	},
	462	.probe = ab8500_rtc_probe,
	463	.remove = __devexit_p(ab8500_rtc_remove),
	464	};
	465
	466	static int __init ab8500_rtc_init(void)
	467	{
	468	return platform_driver_register(&ab8500_rtc_driver);
	469	}
	470
	471	static void __exit ab8500_rtc_exit(void)
	472	{
	473	platform_driver_unregister(&ab8500_rtc_driver);
	474	}
	475
	476	module_init(ab8500_rtc_init);
	477	module_exit(ab8500_rtc_exit);
	478	MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
	479	MODULE_DESCRIPTION("AB8500 RTC Driver");
	480	MODULE_LICENSE("GPL v2");