[linux-2.6-block.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
#define AB8540_RTC_ALRM_SEC		0x22
#define AB8540_RTC_ALRM_MIN_LOW_REG	0x23
#define AB8540_RTC_ALRM_MIN_MID_REG	0x24
#define AB8540_RTC_ALRM_MIN_HI_REG	0x25

/* 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
};

static const u8 ab8540_rtc_alarm_regs[] = {
	AB8540_RTC_ALRM_MIN_HI_REG, AB8540_RTC_ALRM_MIN_MID_REG,
	AB8540_RTC_ALRM_MIN_LOW_REG, AB8540_RTC_ALRM_SEC
};

/* 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 ab8540_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	int retval, i;
	unsigned char buf[ARRAY_SIZE(ab8540_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
	 */
	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	mins = secs / 60;

	buf[3] = 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(ab8540_rtc_alarm_regs); i++) {
		retval = abx500_set_register_interruptible(dev, AB8500_RTC,
			ab8540_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 const struct rtc_class_ops ab8540_rtc_ops = {
	.read_time		= ab8500_rtc_read_time,
	.set_time		= ab8500_rtc_set_time,
	.read_alarm		= ab8500_rtc_read_alarm,
	.set_alarm		= ab8540_rtc_set_alarm,
	.alarm_irq_enable	= ab8500_rtc_irq_enable,
};

static struct platform_device_id ab85xx_rtc_ids[] = {
	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
	{ "ab8540-rtc", (kernel_ulong_t)&ab8540_rtc_ops, },
};

static int ab8500_rtc_probe(struct platform_device *pdev)
{
	const struct platform_device_id *platid = platform_get_device_id(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",
				(struct rtc_class_ops *)platid->driver_data,
				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;
	}

	rtc->uie_unsupported = 1;

	return 0;
}

static int ab8500_rtc_remove(struct platform_device *pdev)
{
	ab8500_sysfs_rtc_unregister(&pdev->dev);

	return 0;
}

static struct platform_driver ab8500_rtc_driver = {
	.driver = {
		.name = "ab8500-rtc",
	},
	.probe	= ab8500_rtc_probe,
	.remove = ab8500_rtc_remove,
	.id_table = ab85xx_rtc_ids,
};

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
25d053cf AT	38	#define AB8540_RTC_ALRM_SEC 0x22
	39	#define AB8540_RTC_ALRM_MIN_LOW_REG 0x23
	40	#define AB8540_RTC_ALRM_MIN_MID_REG 0x24
	41	#define AB8540_RTC_ALRM_MIN_HI_REG 0x25
0af62f4d VS	42
	43	/* RtcReadRequest bits */
	44	#define RTC_READ_REQUEST 0x01
	45	#define RTC_WRITE_REQUEST 0x02
	46
	47	/* RtcCtrl bits */
	48	#define RTC_ALARM_ENA 0x04
	49	#define RTC_STATUS_DATA 0x01
	50
	51	#define COUNTS_PER_SEC (0xF000 / 60)
	52	#define AB8500_RTC_EPOCH 2000
	53
47c16975	54	static const u8 ab8500_rtc_time_regs[] = {
0af62f4d VS	55	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
	56	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
	57	AB8500_RTC_WATCH_TSECMID_REG
	58	};
	59
47c16975	60	static const u8 ab8500_rtc_alarm_regs[] = {
0af62f4d VS	61	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
	62	AB8500_RTC_ALRM_MIN_LOW_REG
	63	};
	64
25d053cf AT	65	static const u8 ab8540_rtc_alarm_regs[] = {
	66	AB8540_RTC_ALRM_MIN_HI_REG, AB8540_RTC_ALRM_MIN_MID_REG,
	67	AB8540_RTC_ALRM_MIN_LOW_REG, AB8540_RTC_ALRM_SEC
	68	};
	69
0af62f4d VS	70	/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
	71	static unsigned long get_elapsed_seconds(int year)
	72	{
	73	unsigned long secs;
	74	struct rtc_time tm = {
	75	.tm_year = year - 1900,
	76	.tm_mday = 1,
	77	};
	78
	79	/*
	80	* This function calculates secs from 1970 and not from
	81	* 1900, even if we supply the offset from year 1900.
	82	*/
	83	rtc_tm_to_time(&tm, &secs);
	84	return secs;
	85	}
	86
	87	static int ab8500_rtc_read_time(struct device dev, struct rtc_time tm)
	88	{
0af62f4d VS	89	unsigned long timeout = jiffies + HZ;
	90	int retval, i;
	91	unsigned long mins, secs;
	92	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
47c16975	93	u8 value;
0af62f4d VS	94
0af62f4d VS	95	/* Request a data read */
47c16975 MW	96	retval = abx500_set_register_interruptible(dev,
47c16975 MW	97	AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
0af62f4d VS	98	if (retval < 0)
	99	return retval;
	100
064407f1 BJ	101	/* Wait for some cycles after enabling the rtc read in ab8500 */
	102	while (time_before(jiffies, timeout)) {
	103	retval = abx500_get_register_interruptible(dev,
	104	AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
	105	if (retval < 0)
	106	return retval;
	107
	108	if (!(value & RTC_READ_REQUEST))
	109	break;
	110
	111	usleep_range(1000, 5000);
0af62f4d VS	112	}
	113
	114	/* Read the Watchtime registers */
	115	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	116	retval = abx500_get_register_interruptible(dev,
47c16975 MW	117	AB8500_RTC, ab8500_rtc_time_regs[i], &value);
0af62f4d VS	118	if (retval < 0)
0af62f4d VS	119	return retval;
47c16975	120	buf[i] = value;
0af62f4d VS	121	}
	122
	123	mins = (buf[0] << 16) \| (buf[1] << 8) \| buf[2];
	124
	125	secs = (buf[3] << 8) \| buf[4];
	126	secs = secs / COUNTS_PER_SEC;
	127	secs = secs + (mins * 60);
	128
	129	/* Add back the initially subtracted number of seconds */
	130	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	131
	132	rtc_time_to_tm(secs, tm);
	133	return rtc_valid_tm(tm);
	134	}
	135
	136	static int ab8500_rtc_set_time(struct device dev, struct rtc_time tm)
	137	{
0af62f4d VS	138	int retval, i;
	139	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	140	unsigned long no_secs, no_mins, secs = 0;
	141
	142	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
	143	dev_dbg(dev, "year should be equal to or greater than %d\n",
	144	AB8500_RTC_EPOCH);
	145	return -EINVAL;
	146	}
	147
	148	/* Get the number of seconds since 1970 */
	149	rtc_tm_to_time(tm, &secs);
	150
	151	/*
	152	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	153	* we only have a small counter in the RTC.
	154	*/
	155	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	156
	157	no_mins = secs / 60;
	158
	159	no_secs = secs % 60;
	160	/* Make the seconds count as per the RTC resolution */
	161	no_secs = no_secs * COUNTS_PER_SEC;
	162
	163	buf[4] = no_secs & 0xFF;
	164	buf[3] = (no_secs >> 8) & 0xFF;
	165
	166	buf[2] = no_mins & 0xFF;
	167	buf[1] = (no_mins >> 8) & 0xFF;
	168	buf[0] = (no_mins >> 16) & 0xFF;
	169
	170	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	171	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	172	ab8500_rtc_time_regs[i], buf[i]);
0af62f4d VS	173	if (retval < 0)
	174	return retval;
	175	}
	176
	177	/* Request a data write */
47c16975 MW	178	return abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	179	AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
0af62f4d VS	180	}
	181
	182	static int ab8500_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	183	{
0af62f4d	184	int retval, i;
47c16975	185	u8 rtc_ctrl, value;
0af62f4d VS	186	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	187	unsigned long secs, mins;
	188
	189	/* Check if the alarm is enabled or not */
47c16975 MW	190	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	191	AB8500_RTC_STAT_REG, &rtc_ctrl);
	192	if (retval < 0)
	193	return retval;
0af62f4d VS	194
	195	if (rtc_ctrl & RTC_ALARM_ENA)
	196	alarm->enabled = 1;
	197	else
	198	alarm->enabled = 0;
	199
	200	alarm->pending = 0;
	201
	202	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	203	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
47c16975 MW	204	ab8500_rtc_alarm_regs[i], &value);
0af62f4d VS	205	if (retval < 0)
0af62f4d VS	206	return retval;
47c16975	207	buf[i] = value;
0af62f4d VS	208	}
	209
	210	mins = (buf[0] << 16) \| (buf[1] << 8) \| (buf[2]);
	211	secs = mins * 60;
	212
	213	/* Add back the initially subtracted number of seconds */
	214	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	215
	216	rtc_time_to_tm(secs, &alarm->time);
	217
	218	return rtc_valid_tm(&alarm->time);
	219	}
	220
	221	static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
	222	{
47c16975 MW	223	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
	224	AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
	225	enabled ? RTC_ALARM_ENA : 0);
0af62f4d VS	226	}
	227
	228	static int ab8500_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	229	{
0af62f4d VS	230	int retval, i;
0af62f4d VS	231	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
dc43d4a2 RC	232	unsigned long mins, secs = 0, cursec = 0;
dc43d4a2 RC	233	struct rtc_time curtm;
0af62f4d VS	234
	235	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
	236	dev_dbg(dev, "year should be equal to or greater than %d\n",
	237	AB8500_RTC_EPOCH);
	238	return -EINVAL;
	239	}
	240
	241	/* Get the number of seconds since 1970 */
	242	rtc_tm_to_time(&alarm->time, &secs);
	243
dc43d4a2 RC	244	/*
	245	* Check whether alarm is set less than 1min.
	246	* Since our RTC doesn't support alarm resolution less than 1min,
	247	* return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
	248	*/
	249	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
	250	rtc_tm_to_time(&curtm, &cursec);
	251	if ((secs - cursec) < 59) {
	252	dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
	253	return -EINVAL;
	254	}
	255
0af62f4d VS	256	/*
	257	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	258	* we only have a small counter in the RTC.
	259	*/
	260	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	261
	262	mins = secs / 60;
	263
	264	buf[2] = mins & 0xFF;
	265	buf[1] = (mins >> 8) & 0xFF;
	266	buf[0] = (mins >> 16) & 0xFF;
	267
	268	/* Set the alarm time */
	269	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	270	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	271	ab8500_rtc_alarm_regs[i], buf[i]);
0af62f4d VS	272	if (retval < 0)
	273	return retval;
	274	}
	275
	276	return ab8500_rtc_irq_enable(dev, alarm->enabled);
	277	}
	278
25d053cf AT	279	static int ab8540_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	280	{
	281	int retval, i;
	282	unsigned char buf[ARRAY_SIZE(ab8540_rtc_alarm_regs)];
	283	unsigned long mins, secs = 0;
	284
	285	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
	286	dev_dbg(dev, "year should be equal to or greater than %d\n",
	287	AB8500_RTC_EPOCH);
	288	return -EINVAL;
	289	}
	290
	291	/* Get the number of seconds since 1970 */
	292	rtc_tm_to_time(&alarm->time, &secs);
	293
	294	/*
	295	* Convert it to the number of seconds since 01-01-2000 00:00:00
	296	*/
	297	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	298	mins = secs / 60;
	299
	300	buf[3] = secs % 60;
	301	buf[2] = mins & 0xFF;
	302	buf[1] = (mins >> 8) & 0xFF;
	303	buf[0] = (mins >> 16) & 0xFF;
	304
	305	/* Set the alarm time */
	306	for (i = 0; i < ARRAY_SIZE(ab8540_rtc_alarm_regs); i++) {
	307	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
	308	ab8540_rtc_alarm_regs[i], buf[i]);
	309	if (retval < 0)
	310	return retval;
	311	}
	312
	313	return ab8500_rtc_irq_enable(dev, alarm->enabled);
	314	}
dda367ac MG	315
	316	static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
	317	{
	318	int retval;
	319	u8 rtccal = 0;
	320
	321	/*
	322	* Check that the calibration value (which is in units of 0.5
	323	* parts-per-million) is in the AB8500's range for RtcCalibration
	324	* register. -128 (0x80) is not permitted because the AB8500 uses
	325	* a sign-bit rather than two's complement, so 0x80 is just another
	326	* representation of zero.
	327	*/
	328	if ((calibration < -127) \|\| (calibration > 127)) {
	329	dev_err(dev, "RtcCalibration value outside permitted range\n");
	330	return -EINVAL;
	331	}
	332
	333	/*
	334	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	335	* so need to convert to this sort of representation before writing
	336	* into RtcCalibration register...
	337	*/
	338	if (calibration >= 0)
	339	rtccal = 0x7F & calibration;
	340	else
	341	rtccal = ~(calibration - 1) \| 0x80;
	342
	343	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
	344	AB8500_RTC_CALIB_REG, rtccal);
	345
	346	return retval;
	347	}
	348
	349	static int ab8500_rtc_get_calibration(struct device dev, int calibration)
	350	{
	351	int retval;
	352	u8 rtccal = 0;
	353
	354	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	355	AB8500_RTC_CALIB_REG, &rtccal);
	356	if (retval >= 0) {
	357	/*
	358	* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
	359	* so need to convert value from RtcCalibration register into
	360	* a two's complement signed value...
	361	*/
	362	if (rtccal & 0x80)
	363	*calibration = 0 - (rtccal & 0x7F);
	364	else
	365	*calibration = 0x7F & rtccal;
	366	}
	367
	368	return retval;
	369	}
	370
	371	static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
	372	struct device_attribute *attr,
	373	const char *buf, size_t count)
	374	{
	375	int retval;
	376	int calibration = 0;
	377
	378	if (sscanf(buf, " %i ", &calibration) != 1) {
379	dev_err(dev, "Failed to store RTC calibration attribute\n");
380	return -EINVAL;
381	}
382
383	retval = ab8500_rtc_set_calibration(dev, calibration);
384
385	return retval ? retval : count;
386	}
387
388	static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
389	struct device_attribute attr, char buf)
390	{
391	int retval = 0;
392	int calibration = 0;
393
394	retval = ab8500_rtc_get_calibration(dev, &calibration);
395	if (retval < 0) {
396	dev_err(dev, "Failed to read RTC calibration attribute\n");
397	sprintf(buf, "0\n");
398	return retval;
399	}
400
401	return sprintf(buf, "%d\n", calibration);
402	}
403
404	static DEVICE_ATTR(rtc_calibration, S_IRUGO \| S_IWUSR,
405	ab8500_sysfs_show_rtc_calibration,
406	ab8500_sysfs_store_rtc_calibration);
407
408	static int ab8500_sysfs_rtc_register(struct device *dev)
409	{
410	return device_create_file(dev, &dev_attr_rtc_calibration);
411	}
412
413	static void ab8500_sysfs_rtc_unregister(struct device *dev)
414	{
415	device_remove_file(dev, &dev_attr_rtc_calibration);
416	}
417
0af62f4d VS	418	static irqreturn_t rtc_alarm_handler(int irq, void *data)
	419	{
	420	struct rtc_device *rtc = data;
	421	unsigned long events = RTC_IRQF \| RTC_AF;
	422
	423	dev_dbg(&rtc->dev, "%s\n", __func__);
	424	rtc_update_irq(rtc, 1, events);
	425
	426	return IRQ_HANDLED;
	427	}
	428
	429	static const struct rtc_class_ops ab8500_rtc_ops = {
	430	.read_time = ab8500_rtc_read_time,
	431	.set_time = ab8500_rtc_set_time,
	432	.read_alarm = ab8500_rtc_read_alarm,
	433	.set_alarm = ab8500_rtc_set_alarm,
	434	.alarm_irq_enable = ab8500_rtc_irq_enable,
	435	};
	436
25d053cf AT	437	static const struct rtc_class_ops ab8540_rtc_ops = {
	438	.read_time = ab8500_rtc_read_time,
	439	.set_time = ab8500_rtc_set_time,
	440	.read_alarm = ab8500_rtc_read_alarm,
	441	.set_alarm = ab8540_rtc_set_alarm,
	442	.alarm_irq_enable = ab8500_rtc_irq_enable,
	443	};
	444
	445	static struct platform_device_id ab85xx_rtc_ids[] = {
	446	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
	447	{ "ab8540-rtc", (kernel_ulong_t)&ab8540_rtc_ops, },
	448	};
	449
5a167f45	450	static int ab8500_rtc_probe(struct platform_device *pdev)
0af62f4d	451	{
25d053cf	452	const struct platform_device_id *platid = platform_get_device_id(pdev);
0af62f4d VS	453	int err;
0af62f4d VS	454	struct rtc_device *rtc;
47c16975	455	u8 rtc_ctrl;
0af62f4d VS	456	int irq;
	457
	458	irq = platform_get_irq_byname(pdev, "ALARM");
	459	if (irq < 0)
	460	return irq;
	461
	462	/* For RTC supply test */
47c16975 MW	463	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
47c16975 MW	464	AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
0af62f4d VS	465	if (err < 0)
	466	return err;
	467
	468	/* Wait for reset by the PorRtc */
012e52e1	469	usleep_range(1000, 5000);
0af62f4d	470
47c16975 MW	471	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
	472	AB8500_RTC_STAT_REG, &rtc_ctrl);
	473	if (err < 0)
	474	return err;
0af62f4d VS	475
	476	/* Check if the RTC Supply fails */
	477	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
	478	dev_err(&pdev->dev, "RTC supply failure\n");
	479	return -ENODEV;
	480	}
	481
b62581e6 AL	482	device_init_wakeup(&pdev->dev, true);
b62581e6 AL	483
fa11f7e7	484	rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc",
25d053cf AT	485	(struct rtc_class_ops *)platid->driver_data,
25d053cf AT	486	THIS_MODULE);
0af62f4d VS	487	if (IS_ERR(rtc)) {
	488	dev_err(&pdev->dev, "Registration failed\n");
	489	err = PTR_ERR(rtc);
	490	return err;
	491	}
	492
fa11f7e7 JH	493	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
	494	rtc_alarm_handler, IRQF_NO_SUSPEND \| IRQF_ONESHOT,
	495	"ab8500-rtc", rtc);
	496	if (err < 0)
0af62f4d	497	return err;
0af62f4d VS	498
	499	platform_set_drvdata(pdev, rtc);
	500
dda367ac MG	501	err = ab8500_sysfs_rtc_register(&pdev->dev);
	502	if (err) {
	503	dev_err(&pdev->dev, "sysfs RTC failed to register\n");
	504	return err;
	505	}
	506
c594d678 XP	507	rtc->uie_unsupported = 1;
c594d678 XP	508
0af62f4d VS	509	return 0;
	510	}
	511
5a167f45	512	static int ab8500_rtc_remove(struct platform_device *pdev)
0af62f4d	513	{
dda367ac MG	514	ab8500_sysfs_rtc_unregister(&pdev->dev);
dda367ac MG	515
0af62f4d VS	516	return 0;
	517	}
	518
	519	static struct platform_driver ab8500_rtc_driver = {
	520	.driver = {
	521	.name = "ab8500-rtc",
0af62f4d VS	522	},
0af62f4d VS	523	.probe = ab8500_rtc_probe,
5a167f45	524	.remove = ab8500_rtc_remove,
25d053cf	525	.id_table = ab85xx_rtc_ids,
0af62f4d VS	526	};
0af62f4d VS	527
0c4eae66	528	module_platform_driver(ab8500_rtc_driver);
0af62f4d	529
0af62f4d VS	530	MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
	531	MODULE_DESCRIPTION("AB8500 RTC Driver");
	532	MODULE_LICENSE("GPL v2");