[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 <[email protected]>
 *
 * 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 <[email protected]>
 */

#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>
#include <linux/pm_wakeirq.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 0;
}

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 const struct platform_device_id ab85xx_rtc_ids[] = {
	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);

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_ONESHOT,
			"ab8500-rtc", rtc);
	if (err < 0)
		return err;

	dev_pm_set_wake_irq(&pdev->dev, irq);
	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)
{
	dev_pm_clear_wake_irq(&pdev->dev);
	device_init_wakeup(&pdev->dev, false);
	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 <[email protected]>");
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 <[email protected]>
	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 <[email protected]>
	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>
93a6f916	21	#include <linux/pm_wakeirq.h>
0af62f4d	22
47c16975 MW	23	#define AB8500_RTC_SOFF_STAT_REG 0x00
	24	#define AB8500_RTC_CC_CONF_REG 0x01
	25	#define AB8500_RTC_READ_REQ_REG 0x02
	26	#define AB8500_RTC_WATCH_TSECMID_REG 0x03
	27	#define AB8500_RTC_WATCH_TSECHI_REG 0x04
	28	#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
	29	#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
	30	#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
	31	#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
	32	#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
	33	#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
	34	#define AB8500_RTC_STAT_REG 0x0B
	35	#define AB8500_RTC_BKUP_CHG_REG 0x0C
	36	#define AB8500_RTC_FORCE_BKUP_REG 0x0D
	37	#define AB8500_RTC_CALIB_REG 0x0E
	38	#define AB8500_RTC_SWITCH_STAT_REG 0x0F
0af62f4d VS	39
	40	/* RtcReadRequest bits */
	41	#define RTC_READ_REQUEST 0x01
	42	#define RTC_WRITE_REQUEST 0x02
	43
	44	/* RtcCtrl bits */
	45	#define RTC_ALARM_ENA 0x04
	46	#define RTC_STATUS_DATA 0x01
	47
	48	#define COUNTS_PER_SEC (0xF000 / 60)
	49	#define AB8500_RTC_EPOCH 2000
	50
47c16975	51	static const u8 ab8500_rtc_time_regs[] = {
0af62f4d VS	52	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
	53	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
	54	AB8500_RTC_WATCH_TSECMID_REG
	55	};
	56
47c16975	57	static const u8 ab8500_rtc_alarm_regs[] = {
0af62f4d VS	58	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
	59	AB8500_RTC_ALRM_MIN_LOW_REG
	60	};
	61
	62	/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
	63	static unsigned long get_elapsed_seconds(int year)
	64	{
	65	unsigned long secs;
	66	struct rtc_time tm = {
	67	.tm_year = year - 1900,
	68	.tm_mday = 1,
	69	};
	70
	71	/*
	72	* This function calculates secs from 1970 and not from
	73	* 1900, even if we supply the offset from year 1900.
	74	*/
	75	rtc_tm_to_time(&tm, &secs);
	76	return secs;
	77	}
	78
	79	static int ab8500_rtc_read_time(struct device dev, struct rtc_time tm)
	80	{
0af62f4d VS	81	unsigned long timeout = jiffies + HZ;
	82	int retval, i;
	83	unsigned long mins, secs;
	84	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
47c16975	85	u8 value;
0af62f4d VS	86
0af62f4d VS	87	/* Request a data read */
47c16975 MW	88	retval = abx500_set_register_interruptible(dev,
47c16975 MW	89	AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
0af62f4d VS	90	if (retval < 0)
	91	return retval;
	92
064407f1 BJ	93	/* Wait for some cycles after enabling the rtc read in ab8500 */
	94	while (time_before(jiffies, timeout)) {
	95	retval = abx500_get_register_interruptible(dev,
	96	AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
	97	if (retval < 0)
	98	return retval;
	99
	100	if (!(value & RTC_READ_REQUEST))
	101	break;
	102
	103	usleep_range(1000, 5000);
0af62f4d VS	104	}
	105
	106	/* Read the Watchtime registers */
	107	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	108	retval = abx500_get_register_interruptible(dev,
47c16975 MW	109	AB8500_RTC, ab8500_rtc_time_regs[i], &value);
0af62f4d VS	110	if (retval < 0)
0af62f4d VS	111	return retval;
47c16975	112	buf[i] = value;
0af62f4d VS	113	}
	114
	115	mins = (buf[0] << 16) \| (buf[1] << 8) \| buf[2];
	116
	117	secs = (buf[3] << 8) \| buf[4];
	118	secs = secs / COUNTS_PER_SEC;
	119	secs = secs + (mins * 60);
	120
	121	/* Add back the initially subtracted number of seconds */
	122	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	123
	124	rtc_time_to_tm(secs, tm);
ab62670e	125	return 0;
0af62f4d VS	126	}
	127
	128	static int ab8500_rtc_set_time(struct device dev, struct rtc_time tm)
	129	{
0af62f4d VS	130	int retval, i;
	131	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
	132	unsigned long no_secs, no_mins, secs = 0;
	133
	134	if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
	135	dev_dbg(dev, "year should be equal to or greater than %d\n",
	136	AB8500_RTC_EPOCH);
	137	return -EINVAL;
	138	}
	139
	140	/* Get the number of seconds since 1970 */
	141	rtc_tm_to_time(tm, &secs);
	142
	143	/*
	144	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	145	* we only have a small counter in the RTC.
	146	*/
	147	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	148
	149	no_mins = secs / 60;
	150
	151	no_secs = secs % 60;
	152	/* Make the seconds count as per the RTC resolution */
	153	no_secs = no_secs * COUNTS_PER_SEC;
	154
	155	buf[4] = no_secs & 0xFF;
	156	buf[3] = (no_secs >> 8) & 0xFF;
	157
	158	buf[2] = no_mins & 0xFF;
	159	buf[1] = (no_mins >> 8) & 0xFF;
	160	buf[0] = (no_mins >> 16) & 0xFF;
	161
	162	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
47c16975 MW	163	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	164	ab8500_rtc_time_regs[i], buf[i]);
0af62f4d VS	165	if (retval < 0)
	166	return retval;
	167	}
	168
	169	/* Request a data write */
47c16975 MW	170	return abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	171	AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
0af62f4d VS	172	}
	173
	174	static int ab8500_rtc_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	175	{
0af62f4d	176	int retval, i;
47c16975	177	u8 rtc_ctrl, value;
0af62f4d VS	178	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
	179	unsigned long secs, mins;
	180
	181	/* Check if the alarm is enabled or not */
47c16975 MW	182	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
	183	AB8500_RTC_STAT_REG, &rtc_ctrl);
	184	if (retval < 0)
	185	return retval;
0af62f4d VS	186
	187	if (rtc_ctrl & RTC_ALARM_ENA)
	188	alarm->enabled = 1;
	189	else
	190	alarm->enabled = 0;
	191
	192	alarm->pending = 0;
	193
	194	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	195	retval = abx500_get_register_interruptible(dev, AB8500_RTC,
47c16975 MW	196	ab8500_rtc_alarm_regs[i], &value);
0af62f4d VS	197	if (retval < 0)
0af62f4d VS	198	return retval;
47c16975	199	buf[i] = value;
0af62f4d VS	200	}
	201
	202	mins = (buf[0] << 16) \| (buf[1] << 8) \| (buf[2]);
	203	secs = mins * 60;
	204
	205	/* Add back the initially subtracted number of seconds */
	206	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
	207
	208	rtc_time_to_tm(secs, &alarm->time);
	209
	210	return rtc_valid_tm(&alarm->time);
	211	}
	212
	213	static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
	214	{
47c16975 MW	215	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
	216	AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
	217	enabled ? RTC_ALARM_ENA : 0);
0af62f4d VS	218	}
	219
	220	static int ab8500_rtc_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	221	{
0af62f4d VS	222	int retval, i;
0af62f4d VS	223	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
dc43d4a2 RC	224	unsigned long mins, secs = 0, cursec = 0;
dc43d4a2 RC	225	struct rtc_time curtm;
0af62f4d VS	226
	227	if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
	228	dev_dbg(dev, "year should be equal to or greater than %d\n",
	229	AB8500_RTC_EPOCH);
	230	return -EINVAL;
	231	}
	232
	233	/* Get the number of seconds since 1970 */
	234	rtc_tm_to_time(&alarm->time, &secs);
	235
dc43d4a2 RC	236	/*
	237	* Check whether alarm is set less than 1min.
	238	* Since our RTC doesn't support alarm resolution less than 1min,
	239	* return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
	240	*/
	241	ab8500_rtc_read_time(dev, &curtm); /* Read current time */
	242	rtc_tm_to_time(&curtm, &cursec);
	243	if ((secs - cursec) < 59) {
	244	dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
	245	return -EINVAL;
	246	}
	247
0af62f4d VS	248	/*
	249	* Convert it to the number of seconds since 01-01-2000 00:00:00, since
	250	* we only have a small counter in the RTC.
	251	*/
	252	secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
	253
	254	mins = secs / 60;
	255
	256	buf[2] = mins & 0xFF;
	257	buf[1] = (mins >> 8) & 0xFF;
	258	buf[0] = (mins >> 16) & 0xFF;
	259
	260	/* Set the alarm time */
	261	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
47c16975 MW	262	retval = abx500_set_register_interruptible(dev, AB8500_RTC,
47c16975 MW	263	ab8500_rtc_alarm_regs[i], buf[i]);
0af62f4d VS	264	if (retval < 0)
	265	return retval;
	266	}
	267
	268	return ab8500_rtc_irq_enable(dev, alarm->enabled);
	269	}
	270
dda367ac MG	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
9a72f410	392	static const struct platform_device_id ab85xx_rtc_ids[] = {
25d053cf	393	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
8a67e931	394	{ /* sentinel */ }
25d053cf	395	};
63074cc3	396	MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);
25d053cf	397
5a167f45	398	static int ab8500_rtc_probe(struct platform_device *pdev)
0af62f4d	399	{
25d053cf	400	const struct platform_device_id *platid = platform_get_device_id(pdev);
0af62f4d VS	401	int err;
0af62f4d VS	402	struct rtc_device *rtc;
47c16975	403	u8 rtc_ctrl;
0af62f4d VS	404	int irq;
	405
	406	irq = platform_get_irq_byname(pdev, "ALARM");
	407	if (irq < 0)
	408	return irq;
	409
	410	/* For RTC supply test */
47c16975 MW	411	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
47c16975 MW	412	AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
0af62f4d VS	413	if (err < 0)
	414	return err;
	415
	416	/* Wait for reset by the PorRtc */
012e52e1	417	usleep_range(1000, 5000);
0af62f4d	418
47c16975 MW	419	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
	420	AB8500_RTC_STAT_REG, &rtc_ctrl);
	421	if (err < 0)
	422	return err;
0af62f4d VS	423
	424	/* Check if the RTC Supply fails */
	425	if (!(rtc_ctrl & RTC_STATUS_DATA)) {
	426	dev_err(&pdev->dev, "RTC supply failure\n");
	427	return -ENODEV;
	428	}
	429
b62581e6 AL	430	device_init_wakeup(&pdev->dev, true);
b62581e6 AL	431
fa11f7e7	432	rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc",
25d053cf AT	433	(struct rtc_class_ops *)platid->driver_data,
25d053cf AT	434	THIS_MODULE);
0af62f4d VS	435	if (IS_ERR(rtc)) {
	436	dev_err(&pdev->dev, "Registration failed\n");
	437	err = PTR_ERR(rtc);
	438	return err;
	439	}
	440
fa11f7e7	441	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
93a6f916	442	rtc_alarm_handler, IRQF_ONESHOT,
fa11f7e7 JH	443	"ab8500-rtc", rtc);
fa11f7e7 JH	444	if (err < 0)
0af62f4d	445	return err;
0af62f4d	446
93a6f916	447	dev_pm_set_wake_irq(&pdev->dev, irq);
0af62f4d VS	448	platform_set_drvdata(pdev, rtc);
0af62f4d VS	449
dda367ac MG	450	err = ab8500_sysfs_rtc_register(&pdev->dev);
	451	if (err) {
	452	dev_err(&pdev->dev, "sysfs RTC failed to register\n");
	453	return err;
	454	}
	455
c594d678 XP	456	rtc->uie_unsupported = 1;
c594d678 XP	457
0af62f4d VS	458	return 0;
	459	}
	460
5a167f45	461	static int ab8500_rtc_remove(struct platform_device *pdev)
0af62f4d	462	{
93a6f916 SH	463	dev_pm_clear_wake_irq(&pdev->dev);
93a6f916 SH	464	device_init_wakeup(&pdev->dev, false);
dda367ac MG	465	ab8500_sysfs_rtc_unregister(&pdev->dev);
dda367ac MG	466
0af62f4d VS	467	return 0;
	468	}
	469
	470	static struct platform_driver ab8500_rtc_driver = {
	471	.driver = {
	472	.name = "ab8500-rtc",
0af62f4d VS	473	},
0af62f4d VS	474	.probe = ab8500_rtc_probe,
5a167f45	475	.remove = ab8500_rtc_remove,
25d053cf	476	.id_table = ab85xx_rtc_ids,
0af62f4d VS	477	};
0af62f4d VS	478
0c4eae66	479	module_platform_driver(ab8500_rtc_driver);
0af62f4d	480
0af62f4d VS	481	MODULE_AUTHOR("Virupax Sadashivpetimath <[email protected]>");
	482	MODULE_DESCRIPTION("AB8500 RTC Driver");
	483	MODULE_LICENSE("GPL v2");