[GitHub/mt8127/android_kernel_alcatel_ttab.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;

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

	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
			rtc_alarm_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
			"ab8500-rtc", rtc);
	if (err < 0)
		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 ab8500_rtc_remove(struct platform_device *pdev)
{
	ab8500_sysfs_rtc_unregister(&pdev->dev);

	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 = 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
064407f1 BJ	92	/* Wait for some cycles after enabling the rtc read in ab8500 */
	93	while (time_before(jiffies, timeout)) {
	94	retval = abx500_get_register_interruptible(dev,
	95	AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
	96	if (retval < 0)
	97	return retval;
	98
	99	if (!(value & RTC_READ_REQUEST))
	100	break;
	101
	102	usleep_range(1000, 5000);
0af62f4d VS	103	}
	104
	105	/* Read the Watchtime registers */
	106	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	107	retval = abx500_get_register_interruptible(dev,
47c16975 MW	108	AB8500_RTC, ab8500_rtc_time_regs[i], &value);
0af62f4d VS	109	if (retval < 0)
0af62f4d VS	110	return retval;
47c16975	111	buf[i] = value;
0af62f4d VS	112	}
	113
	114	mins = (buf[0] << 16) \| (buf[1] << 8) \| buf[2];
	115
	116	secs = (buf[3] << 8) \| buf[4];
	117	secs = secs / COUNTS_PER_SEC;
	118	secs = secs + (mins * 60);
	119
	120	/* Add back the initially subtracted number of seconds */
	121	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	122
	123	rtc_time_to_tm(secs, tm);
	124	return rtc_valid_tm(tm);
	125	}
	126
	127	static int ab8500_rtc_set_time(struct device dev, struct rtc_time tm)
	128	{
0af62f4d VS	129	int retval, i;
	130	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	131	unsigned long no_secs, no_mins, secs = 0;
	132
	133	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
	134	dev_dbg(dev, "year should be equal to or greater than %d\n",
	135	AB8500_RTC_EPOCH);
	136	return -EINVAL;
	137	}
	138
	139	/* Get the number of seconds since 1970 */
	140	rtc_tm_to_time(tm, &secs);
	141
	142	/*
	143	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	144	* we only have a small counter in the RTC.
	145	*/
	146	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	147
	148	no_mins = secs / 60;
	149
	150	no_secs = secs % 60;
	151	/* Make the seconds count as per the RTC resolution */
	152	no_secs = no_secs * COUNTS_PER_SEC;
	153
	154	buf[4] = no_secs & 0xFF;
	155	buf[3] = (no_secs >> 8) & 0xFF;
	156
	157	buf[2] = no_mins & 0xFF;
	158	buf[1] = (no_mins >> 8) & 0xFF;
	159	buf[0] = (no_mins >> 16) & 0xFF;
	160
	161	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	162	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	163	ab8500_rtc_time_regs[i], buf[i]);
0af62f4d VS	164	if (retval < 0)
	165	return retval;
	166	}
	167
	168	/* Request a data write */
47c16975 MW	169	return abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	170	AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
0af62f4d VS	171	}
	172
	173	static int ab8500_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	174	{
0af62f4d	175	int retval, i;
47c16975	176	u8 rtc_ctrl, value;
0af62f4d VS	177	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	178	unsigned long secs, mins;
	179
	180	/* Check if the alarm is enabled or not */
47c16975 MW	181	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	182	AB8500_RTC_STAT_REG, &rtc_ctrl);
	183	if (retval < 0)
	184	return retval;
0af62f4d VS	185
	186	if (rtc_ctrl & RTC_ALARM_ENA)
	187	alarm->enabled = 1;
	188	else
	189	alarm->enabled = 0;
	190
	191	alarm->pending = 0;
	192
	193	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	194	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
47c16975 MW	195	ab8500_rtc_alarm_regs[i], &value);
0af62f4d VS	196	if (retval < 0)
0af62f4d VS	197	return retval;
47c16975	198	buf[i] = value;
0af62f4d VS	199	}
	200
	201	mins = (buf[0] << 16) \| (buf[1] << 8) \| (buf[2]);
	202	secs = mins * 60;
	203
	204	/* Add back the initially subtracted number of seconds */
	205	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	206
	207	rtc_time_to_tm(secs, &alarm->time);
	208
	209	return rtc_valid_tm(&alarm->time);
	210	}
	211
	212	static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
	213	{
47c16975 MW	214	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
	215	AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
	216	enabled ? RTC_ALARM_ENA : 0);
0af62f4d VS	217	}
	218
	219	static int ab8500_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	220	{
0af62f4d VS	221	int retval, i;
0af62f4d VS	222	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
dc43d4a2 RC	223	unsigned long mins, secs = 0, cursec = 0;
dc43d4a2 RC	224	struct rtc_time curtm;
0af62f4d VS	225
	226	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
	227	dev_dbg(dev, "year should be equal to or greater than %d\n",
	228	AB8500_RTC_EPOCH);
	229	return -EINVAL;
	230	}
	231
	232	/* Get the number of seconds since 1970 */
	233	rtc_tm_to_time(&alarm->time, &secs);
	234
dc43d4a2 RC	235	/*
	236	* Check whether alarm is set less than 1min.
	237	* Since our RTC doesn't support alarm resolution less than 1min,
	238	* return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
	239	*/
	240	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
	241	rtc_tm_to_time(&curtm, &cursec);
	242	if ((secs - cursec) < 59) {
	243	dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
	244	return -EINVAL;
	245	}
	246
0af62f4d VS	247	/*
	248	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	249	* we only have a small counter in the RTC.
	250	*/
	251	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	252
	253	mins = secs / 60;
	254
	255	buf[2] = mins & 0xFF;
	256	buf[1] = (mins >> 8) & 0xFF;
	257	buf[0] = (mins >> 16) & 0xFF;
	258
	259	/* Set the alarm time */
	260	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	261	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	262	ab8500_rtc_alarm_regs[i], buf[i]);
0af62f4d VS	263	if (retval < 0)
	264	return retval;
	265	}
	266
	267	return ab8500_rtc_irq_enable(dev, alarm->enabled);
	268	}
	269
dda367ac MG	270
	271	static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
	272	{
	273	int retval;
	274	u8 rtccal = 0;
	275
	276	/*
	277	* Check that the calibration value (which is in units of 0.5
	278	* parts-per-million) is in the AB8500's range for RtcCalibration
	279	* register. -128 (0x80) is not permitted because the AB8500 uses
	280	* a sign-bit rather than two's complement, so 0x80 is just another
	281	* representation of zero.
	282	*/
	283	if ((calibration < -127) \|\| (calibration > 127)) {
	284	dev_err(dev, "RtcCalibration value outside permitted range\n");
	285	return -EINVAL;
	286	}
	287
	288	/*
	289	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	290	* so need to convert to this sort of representation before writing
	291	* into RtcCalibration register...
	292	*/
	293	if (calibration >= 0)
	294	rtccal = 0x7F & calibration;
	295	else
	296	rtccal = ~(calibration - 1) \| 0x80;
	297
	298	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
	299	AB8500_RTC_CALIB_REG, rtccal);
	300
	301	return retval;
	302	}
	303
	304	static int ab8500_rtc_get_calibration(struct device dev, int calibration)
	305	{
	306	int retval;
	307	u8 rtccal = 0;
	308
	309	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	310	AB8500_RTC_CALIB_REG, &rtccal);
	311	if (retval >= 0) {
	312	/*
	313	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	314	* so need to convert value from RtcCalibration register into
	315	* a two's complement signed value...
	316	*/
	317	if (rtccal & 0x80)
	318	*calibration = 0 - (rtccal & 0x7F);
	319	else
	320	*calibration = 0x7F & rtccal;
	321	}
	322
	323	return retval;
	324	}
	325
	326	static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
	327	struct device_attribute *attr,
	328	const char *buf, size_t count)
	329	{
	330	int retval;
	331	int calibration = 0;
	332
	333	if (sscanf(buf, " %i ", &calibration) != 1) {
334	dev_err(dev, "Failed to store RTC calibration attribute\n");
335	return -EINVAL;
336	}
337
338	retval = ab8500_rtc_set_calibration(dev, calibration);
339
340	return retval ? retval : count;
341	}
342
343	static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
344	struct device_attribute attr, char buf)
345	{
346	int retval = 0;
347	int calibration = 0;
348
349	retval = ab8500_rtc_get_calibration(dev, &calibration);
350	if (retval < 0) {
351	dev_err(dev, "Failed to read RTC calibration attribute\n");
352	sprintf(buf, "0\n");
353	return retval;
354	}
355
356	return sprintf(buf, "%d\n", calibration);
357	}
358
359	static DEVICE_ATTR(rtc_calibration, S_IRUGO \| S_IWUSR,
360	ab8500_sysfs_show_rtc_calibration,
361	ab8500_sysfs_store_rtc_calibration);
362
363	static int ab8500_sysfs_rtc_register(struct device *dev)
364	{
365	return device_create_file(dev, &dev_attr_rtc_calibration);
366	}
367
368	static void ab8500_sysfs_rtc_unregister(struct device *dev)
369	{
370	device_remove_file(dev, &dev_attr_rtc_calibration);
371	}
372
0af62f4d VS	373	static irqreturn_t rtc_alarm_handler(int irq, void *data)
	374	{
	375	struct rtc_device *rtc = data;
	376	unsigned long events = RTC_IRQF \| RTC_AF;
	377
	378	dev_dbg(&rtc->dev, "%s\n", __func__);
	379	rtc_update_irq(rtc, 1, events);
	380
	381	return IRQ_HANDLED;
	382	}
	383
	384	static const struct rtc_class_ops ab8500_rtc_ops = {
	385	.read_time = ab8500_rtc_read_time,
	386	.set_time = ab8500_rtc_set_time,
	387	.read_alarm = ab8500_rtc_read_alarm,
	388	.set_alarm = ab8500_rtc_set_alarm,
	389	.alarm_irq_enable = ab8500_rtc_irq_enable,
	390	};
	391
5a167f45	392	static int ab8500_rtc_probe(struct platform_device *pdev)
0af62f4d	393	{
0af62f4d VS	394	int err;
0af62f4d VS	395	struct rtc_device *rtc;
47c16975	396	u8 rtc_ctrl;
0af62f4d VS	397	int irq;
	398
	399	irq = platform_get_irq_byname(pdev, "ALARM");
	400	if (irq < 0)
	401	return irq;
	402
	403	/* For RTC supply test */
47c16975 MW	404	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
47c16975 MW	405	AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
0af62f4d VS	406	if (err < 0)
	407	return err;
	408
	409	/* Wait for reset by the PorRtc */
012e52e1	410	usleep_range(1000, 5000);
0af62f4d	411
47c16975 MW	412	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
	413	AB8500_RTC_STAT_REG, &rtc_ctrl);
	414	if (err < 0)
	415	return err;
0af62f4d VS	416
	417	/* Check if the RTC Supply fails */
	418	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
	419	dev_err(&pdev->dev, "RTC supply failure\n");
	420	return -ENODEV;
	421	}
	422
b62581e6 AL	423	device_init_wakeup(&pdev->dev, true);
b62581e6 AL	424
fa11f7e7 JH	425	rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc",
fa11f7e7 JH	426	&ab8500_rtc_ops, THIS_MODULE);
0af62f4d VS	427	if (IS_ERR(rtc)) {
	428	dev_err(&pdev->dev, "Registration failed\n");
	429	err = PTR_ERR(rtc);
	430	return err;
	431	}
	432
fa11f7e7 JH	433	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
	434	rtc_alarm_handler, IRQF_NO_SUSPEND \| IRQF_ONESHOT,
	435	"ab8500-rtc", rtc);
	436	if (err < 0)
0af62f4d	437	return err;
0af62f4d VS	438
	439	platform_set_drvdata(pdev, rtc);
	440
dda367ac MG	441	err = ab8500_sysfs_rtc_register(&pdev->dev);
	442	if (err) {
	443	dev_err(&pdev->dev, "sysfs RTC failed to register\n");
	444	return err;
	445	}
	446
0af62f4d VS	447	return 0;
	448	}
	449
5a167f45	450	static int ab8500_rtc_remove(struct platform_device *pdev)
0af62f4d	451	{
dda367ac MG	452	ab8500_sysfs_rtc_unregister(&pdev->dev);
dda367ac MG	453
0af62f4d VS	454	platform_set_drvdata(pdev, NULL);
	455
	456	return 0;
	457	}
	458
	459	static struct platform_driver ab8500_rtc_driver = {
	460	.driver = {
	461	.name = "ab8500-rtc",
	462	.owner = THIS_MODULE,
	463	},
	464	.probe = ab8500_rtc_probe,
5a167f45	465	.remove = ab8500_rtc_remove,
0af62f4d VS	466	};
0af62f4d VS	467
0c4eae66	468	module_platform_driver(ab8500_rtc_driver);
0af62f4d	469
0af62f4d VS	470	MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
	471	MODULE_DESCRIPTION("AB8500 RTC Driver");
	472	MODULE_LICENSE("GPL v2");