[linux-2.6-block.git] / drivers / rtc / rtc-sc27xx.c

/*
 * Copyright (C) 2017 Spreadtrum Communications Inc.
 *
 * SPDX-License-Identifier: GPL-2.0
 */

#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>

#define SPRD_RTC_SEC_CNT_VALUE		0x0
#define SPRD_RTC_MIN_CNT_VALUE		0x4
#define SPRD_RTC_HOUR_CNT_VALUE		0x8
#define SPRD_RTC_DAY_CNT_VALUE		0xc
#define SPRD_RTC_SEC_CNT_UPD		0x10
#define SPRD_RTC_MIN_CNT_UPD		0x14
#define SPRD_RTC_HOUR_CNT_UPD		0x18
#define SPRD_RTC_DAY_CNT_UPD		0x1c
#define SPRD_RTC_SEC_ALM_UPD		0x20
#define SPRD_RTC_MIN_ALM_UPD		0x24
#define SPRD_RTC_HOUR_ALM_UPD		0x28
#define SPRD_RTC_DAY_ALM_UPD		0x2c
#define SPRD_RTC_INT_EN			0x30
#define SPRD_RTC_INT_RAW_STS		0x34
#define SPRD_RTC_INT_CLR		0x38
#define SPRD_RTC_INT_MASK_STS		0x3C
#define SPRD_RTC_SEC_ALM_VALUE		0x40
#define SPRD_RTC_MIN_ALM_VALUE		0x44
#define SPRD_RTC_HOUR_ALM_VALUE		0x48
#define SPRD_RTC_DAY_ALM_VALUE		0x4c
#define SPRD_RTC_SPG_VALUE		0x50
#define SPRD_RTC_SPG_UPD		0x54
#define SPRD_RTC_PWR_CTRL		0x58
#define SPRD_RTC_PWR_STS		0x5c
#define SPRD_RTC_SEC_AUXALM_UPD		0x60
#define SPRD_RTC_MIN_AUXALM_UPD		0x64
#define SPRD_RTC_HOUR_AUXALM_UPD	0x68
#define SPRD_RTC_DAY_AUXALM_UPD		0x6c

/* BIT & MASK definition for SPRD_RTC_INT_* registers */
#define SPRD_RTC_SEC_EN			BIT(0)
#define SPRD_RTC_MIN_EN			BIT(1)
#define SPRD_RTC_HOUR_EN		BIT(2)
#define SPRD_RTC_DAY_EN			BIT(3)
#define SPRD_RTC_ALARM_EN		BIT(4)
#define SPRD_RTC_HRS_FORMAT_EN		BIT(5)
#define SPRD_RTC_AUXALM_EN		BIT(6)
#define SPRD_RTC_SPG_UPD_EN		BIT(7)
#define SPRD_RTC_SEC_UPD_EN		BIT(8)
#define SPRD_RTC_MIN_UPD_EN		BIT(9)
#define SPRD_RTC_HOUR_UPD_EN		BIT(10)
#define SPRD_RTC_DAY_UPD_EN		BIT(11)
#define SPRD_RTC_ALMSEC_UPD_EN		BIT(12)
#define SPRD_RTC_ALMMIN_UPD_EN		BIT(13)
#define SPRD_RTC_ALMHOUR_UPD_EN		BIT(14)
#define SPRD_RTC_ALMDAY_UPD_EN		BIT(15)
#define SPRD_RTC_INT_MASK		GENMASK(15, 0)

#define SPRD_RTC_TIME_INT_MASK				\
	(SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN |	\
	 SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN)

#define SPRD_RTC_ALMTIME_INT_MASK				\
	(SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN |	\
	 SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN)

#define SPRD_RTC_ALM_INT_MASK			\
	(SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN |	\
	 SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN |	\
	 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN)

/* second/minute/hour/day values mask definition */
#define SPRD_RTC_SEC_MASK		GENMASK(5, 0)
#define SPRD_RTC_MIN_MASK		GENMASK(5, 0)
#define SPRD_RTC_HOUR_MASK		GENMASK(4, 0)
#define SPRD_RTC_DAY_MASK		GENMASK(15, 0)

/* alarm lock definition for SPRD_RTC_SPG_UPD register */
#define SPRD_RTC_ALMLOCK_MASK		GENMASK(7, 0)
#define SPRD_RTC_ALM_UNLOCK		0xa5
#define SPRD_RTC_ALM_LOCK		(~SPRD_RTC_ALM_UNLOCK &	\
					 SPRD_RTC_ALMLOCK_MASK)

/* SPG values definition for SPRD_RTC_SPG_UPD register */
#define SPRD_RTC_POWEROFF_ALM_FLAG	BIT(8)

/* power control/status definition */
#define SPRD_RTC_POWER_RESET_VALUE	0x96
#define SPRD_RTC_POWER_STS_CLEAR	GENMASK(7, 0)
#define SPRD_RTC_POWER_STS_SHIFT	8
#define SPRD_RTC_POWER_STS_VALID	\
	(~SPRD_RTC_POWER_RESET_VALUE << SPRD_RTC_POWER_STS_SHIFT)

/* timeout of synchronizing time and alarm registers (us) */
#define SPRD_RTC_POLL_TIMEOUT		200000
#define SPRD_RTC_POLL_DELAY_US		20000

struct sprd_rtc {
	struct rtc_device	*rtc;
	struct regmap		*regmap;
	struct device		*dev;
	u32			base;
	int			irq;
	bool			valid;
};

/*
 * The Spreadtrum RTC controller has 3 groups registers, including time, normal
 * alarm and auxiliary alarm. The time group registers are used to set RTC time,
 * the normal alarm registers are used to set normal alarm, and the auxiliary
 * alarm registers are used to set auxiliary alarm. Both alarm event and
 * auxiliary alarm event can wake up system from deep sleep, but only alarm
 * event can power up system from power down status.
 */
enum sprd_rtc_reg_types {
	SPRD_RTC_TIME,
	SPRD_RTC_ALARM,
	SPRD_RTC_AUX_ALARM,
};

static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
{
	return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
			    SPRD_RTC_ALM_INT_MASK);
}

static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
{
	int ret;
	u32 val;

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
	if (ret)
		return ret;

	val &= ~(SPRD_RTC_ALMLOCK_MASK | SPRD_RTC_POWEROFF_ALM_FLAG);
	if (lock)
		val |= SPRD_RTC_ALM_LOCK;
	else
		val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG;

	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
	if (ret)
		return ret;

	/* wait until the SPG value is updated successfully */
	ret = regmap_read_poll_timeout(rtc->regmap,
				       rtc->base + SPRD_RTC_INT_RAW_STS, val,
				       (val & SPRD_RTC_SPG_UPD_EN),
				       SPRD_RTC_POLL_DELAY_US,
				       SPRD_RTC_POLL_TIMEOUT);
	if (ret) {
		dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
		return ret;
	}

	return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
			    SPRD_RTC_SPG_UPD_EN);
}

static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
			     time64_t *secs)
{
	u32 sec_reg, min_reg, hour_reg, day_reg;
	u32 val, sec, min, hour, day;
	int ret;

	switch (type) {
	case SPRD_RTC_TIME:
		sec_reg = SPRD_RTC_SEC_CNT_VALUE;
		min_reg = SPRD_RTC_MIN_CNT_VALUE;
		hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
		day_reg = SPRD_RTC_DAY_CNT_VALUE;
		break;
	case SPRD_RTC_ALARM:
		sec_reg = SPRD_RTC_SEC_ALM_VALUE;
		min_reg = SPRD_RTC_MIN_ALM_VALUE;
		hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
		day_reg = SPRD_RTC_DAY_ALM_VALUE;
		break;
	case SPRD_RTC_AUX_ALARM:
		sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
		min_reg = SPRD_RTC_MIN_AUXALM_UPD;
		hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
		day_reg = SPRD_RTC_DAY_AUXALM_UPD;
		break;
	default:
		return -EINVAL;
	}

	ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
	if (ret)
		return ret;

	sec = val & SPRD_RTC_SEC_MASK;

	ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
	if (ret)
		return ret;

	min = val & SPRD_RTC_MIN_MASK;

	ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
	if (ret)
		return ret;

	hour = val & SPRD_RTC_HOUR_MASK;

	ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
	if (ret)
		return ret;

	day = val & SPRD_RTC_DAY_MASK;
	*secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec;
	return 0;
}

static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
			     time64_t secs)
{
	u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
	u32 sec, min, hour, day, val;
	int ret, rem;

	/* convert seconds to RTC time format */
	day = div_s64_rem(secs, 86400, &rem);
	hour = rem / 3600;
	rem -= hour * 3600;
	min = rem / 60;
	sec = rem - min * 60;

	switch (type) {
	case SPRD_RTC_TIME:
		sec_reg = SPRD_RTC_SEC_CNT_UPD;
		min_reg = SPRD_RTC_MIN_CNT_UPD;
		hour_reg = SPRD_RTC_HOUR_CNT_UPD;
		day_reg = SPRD_RTC_DAY_CNT_UPD;
		sts_mask = SPRD_RTC_TIME_INT_MASK;
		break;
	case SPRD_RTC_ALARM:
		sec_reg = SPRD_RTC_SEC_ALM_UPD;
		min_reg = SPRD_RTC_MIN_ALM_UPD;
		hour_reg = SPRD_RTC_HOUR_ALM_UPD;
		day_reg = SPRD_RTC_DAY_ALM_UPD;
		sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
		break;
	case SPRD_RTC_AUX_ALARM:
		sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
		min_reg = SPRD_RTC_MIN_AUXALM_UPD;
		hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
		day_reg = SPRD_RTC_DAY_AUXALM_UPD;
		sts_mask = 0;
		break;
	default:
		return -EINVAL;
	}

	ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
	if (ret)
		return ret;

	ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
	if (ret)
		return ret;

	ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
	if (ret)
		return ret;

	ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
	if (ret)
		return ret;

	if (type == SPRD_RTC_AUX_ALARM)
		return 0;

	/*
	 * Since the time and normal alarm registers are put in always-power-on
	 * region supplied by VDDRTC, then these registers changing time will
	 * be very long, about 125ms. Thus here we should wait until all
	 * values are updated successfully.
	 */
	ret = regmap_read_poll_timeout(rtc->regmap,
				       rtc->base + SPRD_RTC_INT_RAW_STS, val,
				       ((val & sts_mask) == sts_mask),
				       SPRD_RTC_POLL_DELAY_US,
				       SPRD_RTC_POLL_TIMEOUT);
	if (ret < 0) {
		dev_err(rtc->dev, "set time/alarm values timeout\n");
		return ret;
	}

	return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
			    sts_mask);
}

static int sprd_rtc_read_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	time64_t secs;
	u32 val;
	int ret;

	ret = sprd_rtc_get_secs(rtc, SPRD_RTC_AUX_ALARM, &secs);
	if (ret)
		return ret;

	rtc_time64_to_tm(secs, &alrm->time);

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
	if (ret)
		return ret;

	alrm->enabled = !!(val & SPRD_RTC_AUXALM_EN);

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
	if (ret)
		return ret;

	alrm->pending = !!(val & SPRD_RTC_AUXALM_EN);
	return 0;
}

static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	time64_t secs = rtc_tm_to_time64(&alrm->time);
	int ret;

	/* clear the auxiliary alarm interrupt status */
	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
			   SPRD_RTC_AUXALM_EN);
	if (ret)
		return ret;

	ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
	if (ret)
		return ret;

	if (alrm->enabled) {
		ret = regmap_update_bits(rtc->regmap,
					 rtc->base + SPRD_RTC_INT_EN,
					 SPRD_RTC_AUXALM_EN,
					 SPRD_RTC_AUXALM_EN);
	} else {
		ret = regmap_update_bits(rtc->regmap,
					 rtc->base + SPRD_RTC_INT_EN,
					 SPRD_RTC_AUXALM_EN, 0);
	}

	return ret;
}

static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	time64_t secs;
	int ret;

	if (!rtc->valid) {
		dev_warn(dev, "RTC values are invalid\n");
		return -EINVAL;
	}

	ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
	if (ret)
		return ret;

	rtc_time64_to_tm(secs, tm);
	return 0;
}

static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	time64_t secs = rtc_tm_to_time64(tm);
	int ret;

	ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
	if (ret)
		return ret;

	if (!rtc->valid) {
		/* Clear RTC power status firstly */
		ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
				   SPRD_RTC_POWER_STS_CLEAR);
		if (ret)
			return ret;

		/*
		 * Set RTC power status to indicate now RTC has valid time
		 * values.
		 */
		ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
				   SPRD_RTC_POWER_STS_VALID);
		if (ret)
			return ret;

		rtc->valid = true;
	}

	return 0;
}

static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	time64_t secs;
	int ret;
	u32 val;

	/*
	 * Before RTC device is registered, it will check to see if there is an
	 * alarm already set in RTC hardware, and we always read the normal
	 * alarm at this time.
	 *
	 * Or if aie_timer is enabled, we should get the normal alarm time.
	 * Otherwise we should get auxiliary alarm time.
	 */
	if (rtc->rtc && rtc->rtc->registered && rtc->rtc->aie_timer.enabled == 0)
		return sprd_rtc_read_aux_alarm(dev, alrm);

	ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
	if (ret)
		return ret;

	rtc_time64_to_tm(secs, &alrm->time);

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
	if (ret)
		return ret;

	alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
	if (ret)
		return ret;

	alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
	return 0;
}

static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	time64_t secs = rtc_tm_to_time64(&alrm->time);
	struct rtc_time aie_time =
		rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
	int ret;

	/*
	 * We have 2 groups alarms: normal alarm and auxiliary alarm. Since
	 * both normal alarm event and auxiliary alarm event can wake up system
	 * from deep sleep, but only alarm event can power up system from power
	 * down status. Moreover we do not need to poll about 125ms when
	 * updating auxiliary alarm registers. Thus we usually set auxiliary
	 * alarm when wake up system from deep sleep, and for other scenarios,
	 * we should set normal alarm with polling status.
	 *
	 * So here we check if the alarm time is set by aie_timer, if yes, we
	 * should set normal alarm, if not, we should set auxiliary alarm which
	 * means it is just a wake event.
	 */
	if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
		return sprd_rtc_set_aux_alarm(dev, alrm);

	/* clear the alarm interrupt status firstly */
	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
			   SPRD_RTC_ALARM_EN);
	if (ret)
		return ret;

	ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
	if (ret)
		return ret;

	if (alrm->enabled) {
		ret = regmap_update_bits(rtc->regmap,
					 rtc->base + SPRD_RTC_INT_EN,
					 SPRD_RTC_ALARM_EN,
					 SPRD_RTC_ALARM_EN);
		if (ret)
			return ret;

		/* unlock the alarm to enable the alarm function. */
		ret = sprd_rtc_lock_alarm(rtc, false);
	} else {
		regmap_update_bits(rtc->regmap,
				   rtc->base + SPRD_RTC_INT_EN,
				   SPRD_RTC_ALARM_EN, 0);

		/*
		 * Lock the alarm function in case fake alarm event will power
		 * up systems.
		 */
		ret = sprd_rtc_lock_alarm(rtc, true);
	}

	return ret;
}

static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	int ret;

	if (enabled) {
		ret = regmap_update_bits(rtc->regmap,
					 rtc->base + SPRD_RTC_INT_EN,
					 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
					 SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
		if (ret)
			return ret;

		ret = sprd_rtc_lock_alarm(rtc, false);
	} else {
		regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
				   SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);

		ret = sprd_rtc_lock_alarm(rtc, true);
	}

	return ret;
}

static const struct rtc_class_ops sprd_rtc_ops = {
	.read_time = sprd_rtc_read_time,
	.set_time = sprd_rtc_set_time,
	.read_alarm = sprd_rtc_read_alarm,
	.set_alarm = sprd_rtc_set_alarm,
	.alarm_irq_enable = sprd_rtc_alarm_irq_enable,
};

static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
{
	struct sprd_rtc *rtc = dev_id;
	int ret;

	ret = sprd_rtc_clear_alarm_ints(rtc);
	if (ret)
		return IRQ_RETVAL(ret);

	rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
	return IRQ_HANDLED;
}

static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
{
	u32 val;
	int ret;

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val);
	if (ret)
		return ret;

	/*
	 * If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which
	 * means the RTC has been powered down, so the RTC time values are
	 * invalid.
	 */
	rtc->valid = val == SPRD_RTC_POWER_RESET_VALUE ? false : true;
	return 0;
}

static int sprd_rtc_check_alarm_int(struct sprd_rtc *rtc)
{
	u32 val;
	int ret;

	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
	if (ret)
		return ret;

	/*
	 * The SPRD_RTC_INT_EN register is not put in always-power-on region
	 * supplied by VDDRTC, so we should check if we need enable the alarm
	 * interrupt when system booting.
	 *
	 * If we have set SPRD_RTC_POWEROFF_ALM_FLAG which is saved in
	 * always-power-on region, that means we have set one alarm last time,
	 * so we should enable the alarm interrupt to help RTC core to see if
	 * there is an alarm already set in RTC hardware.
	 */
	if (!(val & SPRD_RTC_POWEROFF_ALM_FLAG))
		return 0;

	return regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
				  SPRD_RTC_ALARM_EN, SPRD_RTC_ALARM_EN);
}

static int sprd_rtc_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	struct sprd_rtc *rtc;
	int ret;

	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
	if (!rtc)
		return -ENOMEM;

	rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!rtc->regmap)
		return -ENODEV;

	ret = of_property_read_u32(node, "reg", &rtc->base);
	if (ret) {
		dev_err(&pdev->dev, "failed to get RTC base address\n");
		return ret;
	}

	rtc->irq = platform_get_irq(pdev, 0);
	if (rtc->irq < 0) {
		dev_err(&pdev->dev, "failed to get RTC irq number\n");
		return rtc->irq;
	}

	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(rtc->rtc))
		return PTR_ERR(rtc->rtc);

	rtc->dev = &pdev->dev;
	platform_set_drvdata(pdev, rtc);

	/* check if we need set the alarm interrupt */
	ret = sprd_rtc_check_alarm_int(rtc);
	if (ret) {
		dev_err(&pdev->dev, "failed to check RTC alarm interrupt\n");
		return ret;
	}

	/* check if RTC time values are valid */
	ret = sprd_rtc_check_power_down(rtc);
	if (ret) {
		dev_err(&pdev->dev, "failed to check RTC time values\n");
		return ret;
	}

	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
					sprd_rtc_handler,
					IRQF_ONESHOT | IRQF_EARLY_RESUME,
					pdev->name, rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to request RTC irq\n");
		return ret;
	}

	device_init_wakeup(&pdev->dev, 1);

	rtc->rtc->ops = &sprd_rtc_ops;
	rtc->rtc->range_min = 0;
	rtc->rtc->range_max = 5662310399LL;
	ret = rtc_register_device(rtc->rtc);
	if (ret) {
		dev_err(&pdev->dev, "failed to register rtc device\n");
		device_init_wakeup(&pdev->dev, 0);
		return ret;
	}

	return 0;
}

static int sprd_rtc_remove(struct platform_device *pdev)
{
	device_init_wakeup(&pdev->dev, 0);
	return 0;
}

static const struct of_device_id sprd_rtc_of_match[] = {
	{ .compatible = "sprd,sc2731-rtc", },
	{ },
};
MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);

static struct platform_driver sprd_rtc_driver = {
	.driver = {
		.name = "sprd-rtc",
		.of_match_table = sprd_rtc_of_match,
	},
	.probe	= sprd_rtc_probe,
	.remove = sprd_rtc_remove,
};
module_platform_driver(sprd_rtc_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
Commit	Line	Data
495bbde5 BW	1	/*
	2	* Copyright (C) 2017 Spreadtrum Communications Inc.
	3	*
	4	* SPDX-License-Identifier: GPL-2.0
	5	*/
	6
	7	#include <linux/bitops.h>
	8	#include <linux/delay.h>
	9	#include <linux/err.h>
	10	#include <linux/module.h>
	11	#include <linux/of.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/regmap.h>
	14	#include <linux/rtc.h>
	15
	16	#define SPRD_RTC_SEC_CNT_VALUE 0x0
	17	#define SPRD_RTC_MIN_CNT_VALUE 0x4
	18	#define SPRD_RTC_HOUR_CNT_VALUE 0x8
	19	#define SPRD_RTC_DAY_CNT_VALUE 0xc
	20	#define SPRD_RTC_SEC_CNT_UPD 0x10
	21	#define SPRD_RTC_MIN_CNT_UPD 0x14
	22	#define SPRD_RTC_HOUR_CNT_UPD 0x18
	23	#define SPRD_RTC_DAY_CNT_UPD 0x1c
	24	#define SPRD_RTC_SEC_ALM_UPD 0x20
	25	#define SPRD_RTC_MIN_ALM_UPD 0x24
	26	#define SPRD_RTC_HOUR_ALM_UPD 0x28
	27	#define SPRD_RTC_DAY_ALM_UPD 0x2c
	28	#define SPRD_RTC_INT_EN 0x30
	29	#define SPRD_RTC_INT_RAW_STS 0x34
	30	#define SPRD_RTC_INT_CLR 0x38
	31	#define SPRD_RTC_INT_MASK_STS 0x3C
	32	#define SPRD_RTC_SEC_ALM_VALUE 0x40
	33	#define SPRD_RTC_MIN_ALM_VALUE 0x44
	34	#define SPRD_RTC_HOUR_ALM_VALUE 0x48
	35	#define SPRD_RTC_DAY_ALM_VALUE 0x4c
	36	#define SPRD_RTC_SPG_VALUE 0x50
	37	#define SPRD_RTC_SPG_UPD 0x54
a0defd7c BW	38	#define SPRD_RTC_PWR_CTRL 0x58
a0defd7c BW	39	#define SPRD_RTC_PWR_STS 0x5c
495bbde5 BW	40	#define SPRD_RTC_SEC_AUXALM_UPD 0x60
	41	#define SPRD_RTC_MIN_AUXALM_UPD 0x64
	42	#define SPRD_RTC_HOUR_AUXALM_UPD 0x68
	43	#define SPRD_RTC_DAY_AUXALM_UPD 0x6c
	44
	45	/* BIT & MASK definition for SPRD_RTC_INT_* registers */
	46	#define SPRD_RTC_SEC_EN BIT(0)
	47	#define SPRD_RTC_MIN_EN BIT(1)
	48	#define SPRD_RTC_HOUR_EN BIT(2)
	49	#define SPRD_RTC_DAY_EN BIT(3)
	50	#define SPRD_RTC_ALARM_EN BIT(4)
	51	#define SPRD_RTC_HRS_FORMAT_EN BIT(5)
	52	#define SPRD_RTC_AUXALM_EN BIT(6)
	53	#define SPRD_RTC_SPG_UPD_EN BIT(7)
	54	#define SPRD_RTC_SEC_UPD_EN BIT(8)
	55	#define SPRD_RTC_MIN_UPD_EN BIT(9)
	56	#define SPRD_RTC_HOUR_UPD_EN BIT(10)
	57	#define SPRD_RTC_DAY_UPD_EN BIT(11)
	58	#define SPRD_RTC_ALMSEC_UPD_EN BIT(12)
	59	#define SPRD_RTC_ALMMIN_UPD_EN BIT(13)
	60	#define SPRD_RTC_ALMHOUR_UPD_EN BIT(14)
	61	#define SPRD_RTC_ALMDAY_UPD_EN BIT(15)
	62	#define SPRD_RTC_INT_MASK GENMASK(15, 0)
	63
	64	#define SPRD_RTC_TIME_INT_MASK \
	65	(SPRD_RTC_SEC_UPD_EN \| SPRD_RTC_MIN_UPD_EN \| \
	66	SPRD_RTC_HOUR_UPD_EN \| SPRD_RTC_DAY_UPD_EN)
	67
	68	#define SPRD_RTC_ALMTIME_INT_MASK \
	69	(SPRD_RTC_ALMSEC_UPD_EN \| SPRD_RTC_ALMMIN_UPD_EN \| \
	70	SPRD_RTC_ALMHOUR_UPD_EN \| SPRD_RTC_ALMDAY_UPD_EN)
	71
	72	#define SPRD_RTC_ALM_INT_MASK \
	73	(SPRD_RTC_SEC_EN \| SPRD_RTC_MIN_EN \| \
	74	SPRD_RTC_HOUR_EN \| SPRD_RTC_DAY_EN \| \
	75	SPRD_RTC_ALARM_EN \| SPRD_RTC_AUXALM_EN)
	76
	77	/* second/minute/hour/day values mask definition */
	78	#define SPRD_RTC_SEC_MASK GENMASK(5, 0)
	79	#define SPRD_RTC_MIN_MASK GENMASK(5, 0)
	80	#define SPRD_RTC_HOUR_MASK GENMASK(4, 0)
	81	#define SPRD_RTC_DAY_MASK GENMASK(15, 0)
	82
	83	/* alarm lock definition for SPRD_RTC_SPG_UPD register */
	84	#define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0)
	85	#define SPRD_RTC_ALM_UNLOCK 0xa5
	86	#define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \
	87	SPRD_RTC_ALMLOCK_MASK)
	88
	89	/* SPG values definition for SPRD_RTC_SPG_UPD register */
	90	#define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8)
a0defd7c BW	91
	92	/* power control/status definition */
	93	#define SPRD_RTC_POWER_RESET_VALUE 0x96
	94	#define SPRD_RTC_POWER_STS_CLEAR GENMASK(7, 0)
	95	#define SPRD_RTC_POWER_STS_SHIFT 8
	96	#define SPRD_RTC_POWER_STS_VALID \
	97	(~SPRD_RTC_POWER_RESET_VALUE << SPRD_RTC_POWER_STS_SHIFT)
495bbde5 BW	98
	99	/* timeout of synchronizing time and alarm registers (us) */
	100	#define SPRD_RTC_POLL_TIMEOUT 200000
	101	#define SPRD_RTC_POLL_DELAY_US 20000
	102
	103	struct sprd_rtc {
	104	struct rtc_device *rtc;
	105	struct regmap *regmap;
	106	struct device *dev;
	107	u32 base;
	108	int irq;
	109	bool valid;
	110	};
	111
	112	/*
	113	* The Spreadtrum RTC controller has 3 groups registers, including time, normal
	114	* alarm and auxiliary alarm. The time group registers are used to set RTC time,
	115	* the normal alarm registers are used to set normal alarm, and the auxiliary
	116	* alarm registers are used to set auxiliary alarm. Both alarm event and
	117	* auxiliary alarm event can wake up system from deep sleep, but only alarm
	118	* event can power up system from power down status.
	119	*/
	120	enum sprd_rtc_reg_types {
	121	SPRD_RTC_TIME,
	122	SPRD_RTC_ALARM,
	123	SPRD_RTC_AUX_ALARM,
	124	};
	125
	126	static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
	127	{
	128	return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
	129	SPRD_RTC_ALM_INT_MASK);
	130	}
	131
495bbde5 BW	132	static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
	133	{
	134	int ret;
	135	u32 val;
	136
	137	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
	138	if (ret)
	139	return ret;
	140
	141	val &= ~(SPRD_RTC_ALMLOCK_MASK \| SPRD_RTC_POWEROFF_ALM_FLAG);
	142	if (lock)
	143	val \|= SPRD_RTC_ALM_LOCK;
	144	else
	145	val \|= SPRD_RTC_ALM_UNLOCK \| SPRD_RTC_POWEROFF_ALM_FLAG;
	146
	147	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
	148	if (ret)
	149	return ret;
	150
	151	/* wait until the SPG value is updated successfully */
	152	ret = regmap_read_poll_timeout(rtc->regmap,
	153	rtc->base + SPRD_RTC_INT_RAW_STS, val,
	154	(val & SPRD_RTC_SPG_UPD_EN),
	155	SPRD_RTC_POLL_DELAY_US,
	156	SPRD_RTC_POLL_TIMEOUT);
	157	if (ret) {
	158	dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
	159	return ret;
	160	}
	161
7db5adfa BW	162	return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
7db5adfa BW	163	SPRD_RTC_SPG_UPD_EN);
495bbde5 BW	164	}
	165
	166	static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
	167	time64_t *secs)
	168	{
	169	u32 sec_reg, min_reg, hour_reg, day_reg;
	170	u32 val, sec, min, hour, day;
	171	int ret;
	172
	173	switch (type) {
	174	case SPRD_RTC_TIME:
	175	sec_reg = SPRD_RTC_SEC_CNT_VALUE;
	176	min_reg = SPRD_RTC_MIN_CNT_VALUE;
	177	hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
	178	day_reg = SPRD_RTC_DAY_CNT_VALUE;
	179	break;
	180	case SPRD_RTC_ALARM:
	181	sec_reg = SPRD_RTC_SEC_ALM_VALUE;
	182	min_reg = SPRD_RTC_MIN_ALM_VALUE;
	183	hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
	184	day_reg = SPRD_RTC_DAY_ALM_VALUE;
	185	break;
	186	case SPRD_RTC_AUX_ALARM:
	187	sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
	188	min_reg = SPRD_RTC_MIN_AUXALM_UPD;
	189	hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
	190	day_reg = SPRD_RTC_DAY_AUXALM_UPD;
	191	break;
	192	default:
	193	return -EINVAL;
	194	}
	195
	196	ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
	197	if (ret)
	198	return ret;
	199
	200	sec = val & SPRD_RTC_SEC_MASK;
	201
	202	ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
	203	if (ret)
	204	return ret;
	205
	206	min = val & SPRD_RTC_MIN_MASK;
	207
	208	ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
	209	if (ret)
	210	return ret;
	211
	212	hour = val & SPRD_RTC_HOUR_MASK;
	213
	214	ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
	215	if (ret)
	216	return ret;
	217
	218	day = val & SPRD_RTC_DAY_MASK;
	219	secs = (((time64_t)(day 24) + hour) * 60 + min) * 60 + sec;
	220	return 0;
	221	}
	222
	223	static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
	224	time64_t secs)
	225	{
	226	u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
	227	u32 sec, min, hour, day, val;
228	int ret, rem;
229
230	/* convert seconds to RTC time format */
231	day = div_s64_rem(secs, 86400, &rem);
232	hour = rem / 3600;
233	rem -= hour * 3600;
234	min = rem / 60;
235	sec = rem - min * 60;
236
237	switch (type) {
238	case SPRD_RTC_TIME:
239	sec_reg = SPRD_RTC_SEC_CNT_UPD;
240	min_reg = SPRD_RTC_MIN_CNT_UPD;
241	hour_reg = SPRD_RTC_HOUR_CNT_UPD;
242	day_reg = SPRD_RTC_DAY_CNT_UPD;
243	sts_mask = SPRD_RTC_TIME_INT_MASK;
244	break;
245	case SPRD_RTC_ALARM:
246	sec_reg = SPRD_RTC_SEC_ALM_UPD;
247	min_reg = SPRD_RTC_MIN_ALM_UPD;
248	hour_reg = SPRD_RTC_HOUR_ALM_UPD;
249	day_reg = SPRD_RTC_DAY_ALM_UPD;
250	sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
251	break;
252	case SPRD_RTC_AUX_ALARM:
253	sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
254	min_reg = SPRD_RTC_MIN_AUXALM_UPD;
255	hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
256	day_reg = SPRD_RTC_DAY_AUXALM_UPD;
257	sts_mask = 0;
258	break;
259	default:
260	return -EINVAL;
261	}
262
263	ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
264	if (ret)
265	return ret;
266
267	ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
268	if (ret)
269	return ret;
270
271	ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
272	if (ret)
273	return ret;
274
275	ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
276	if (ret)
277	return ret;
278
279	if (type == SPRD_RTC_AUX_ALARM)
280	return 0;
281
282	/*
283	* Since the time and normal alarm registers are put in always-power-on
284	* region supplied by VDDRTC, then these registers changing time will
285	* be very long, about 125ms. Thus here we should wait until all
286	* values are updated successfully.
287	*/
288	ret = regmap_read_poll_timeout(rtc->regmap,
289	rtc->base + SPRD_RTC_INT_RAW_STS, val,
290	((val & sts_mask) == sts_mask),
291	SPRD_RTC_POLL_DELAY_US,
292	SPRD_RTC_POLL_TIMEOUT);
293	if (ret < 0) {
294	dev_err(rtc->dev, "set time/alarm values timeout\n");
295	return ret;
296	}
297
298	return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
299	sts_mask);
300	}
301
302	static int sprd_rtc_read_aux_alarm(struct device dev, struct rtc_wkalrm alrm)
303	{
304	struct sprd_rtc *rtc = dev_get_drvdata(dev);
305	time64_t secs;
306	u32 val;
307	int ret;
308
309	ret = sprd_rtc_get_secs(rtc, SPRD_RTC_AUX_ALARM, &secs);
310	if (ret)
311	return ret;
312
313	rtc_time64_to_tm(secs, &alrm->time);
314
315	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
316	if (ret)
317	return ret;
318
319	alrm->enabled = !!(val & SPRD_RTC_AUXALM_EN);
320
321	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
322	if (ret)
323	return ret;
324
325	alrm->pending = !!(val & SPRD_RTC_AUXALM_EN);
326	return 0;
327	}
328
329	static int sprd_rtc_set_aux_alarm(struct device dev, struct rtc_wkalrm alrm)
330	{
331	struct sprd_rtc *rtc = dev_get_drvdata(dev);
332	time64_t secs = rtc_tm_to_time64(&alrm->time);
333	int ret;
334
335	/* clear the auxiliary alarm interrupt status */
336	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
337	SPRD_RTC_AUXALM_EN);
338	if (ret)
339	return ret;
340
341	ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
342	if (ret)
343	return ret;
344
345	if (alrm->enabled) {
346	ret = regmap_update_bits(rtc->regmap,
347	rtc->base + SPRD_RTC_INT_EN,
348	SPRD_RTC_AUXALM_EN,
349	SPRD_RTC_AUXALM_EN);
350	} else {
351	ret = regmap_update_bits(rtc->regmap,
352	rtc->base + SPRD_RTC_INT_EN,
353	SPRD_RTC_AUXALM_EN, 0);
354	}
355
356	return ret;
357	}
358
359	static int sprd_rtc_read_time(struct device dev, struct rtc_time tm)
360	{
361	struct sprd_rtc *rtc = dev_get_drvdata(dev);
362	time64_t secs;
363	int ret;
364
365	if (!rtc->valid) {
366	dev_warn(dev, "RTC values are invalid\n");
367	return -EINVAL;
368	}
369
370	ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
371	if (ret)
372	return ret;
373
374	rtc_time64_to_tm(secs, tm);
66b32fc5	375	return 0;
495bbde5 BW	376	}
	377
	378	static int sprd_rtc_set_time(struct device dev, struct rtc_time tm)
	379	{
	380	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	381	time64_t secs = rtc_tm_to_time64(tm);
495bbde5 BW	382	int ret;
	383
	384	ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
	385	if (ret)
	386	return ret;
	387
	388	if (!rtc->valid) {
a0defd7c BW	389	/* Clear RTC power status firstly */
	390	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
	391	SPRD_RTC_POWER_STS_CLEAR);
495bbde5 BW	392	if (ret)
	393	return ret;
	394
a0defd7c BW	395	/*
	396	* Set RTC power status to indicate now RTC has valid time
	397	* values.
	398	*/
	399	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
	400	SPRD_RTC_POWER_STS_VALID);
	401	if (ret)
495bbde5	402	return ret;
495bbde5 BW	403
	404	rtc->valid = true;
	405	}
	406
	407	return 0;
	408	}
	409
	410	static int sprd_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	411	{
	412	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	413	time64_t secs;
	414	int ret;
	415	u32 val;
	416
	417	/*
3822d1bb BW	418	* Before RTC device is registered, it will check to see if there is an
	419	* alarm already set in RTC hardware, and we always read the normal
	420	* alarm at this time.
	421	*
	422	* Or if aie_timer is enabled, we should get the normal alarm time.
495bbde5 BW	423	* Otherwise we should get auxiliary alarm time.
495bbde5 BW	424	*/
3822d1bb	425	if (rtc->rtc && rtc->rtc->registered && rtc->rtc->aie_timer.enabled == 0)
495bbde5 BW	426	return sprd_rtc_read_aux_alarm(dev, alrm);
	427
	428	ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
	429	if (ret)
	430	return ret;
	431
	432	rtc_time64_to_tm(secs, &alrm->time);
	433
	434	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
	435	if (ret)
	436	return ret;
	437
	438	alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
	439
	440	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
	441	if (ret)
	442	return ret;
	443
	444	alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
	445	return 0;
	446	}
	447
	448	static int sprd_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	449	{
	450	struct sprd_rtc *rtc = dev_get_drvdata(dev);
	451	time64_t secs = rtc_tm_to_time64(&alrm->time);
	452	struct rtc_time aie_time =
	453	rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
	454	int ret;
	455
	456	/*
	457	* We have 2 groups alarms: normal alarm and auxiliary alarm. Since
	458	* both normal alarm event and auxiliary alarm event can wake up system
	459	* from deep sleep, but only alarm event can power up system from power
	460	* down status. Moreover we do not need to poll about 125ms when
	461	* updating auxiliary alarm registers. Thus we usually set auxiliary
	462	* alarm when wake up system from deep sleep, and for other scenarios,
	463	* we should set normal alarm with polling status.
	464	*
	465	* So here we check if the alarm time is set by aie_timer, if yes, we
	466	* should set normal alarm, if not, we should set auxiliary alarm which
	467	* means it is just a wake event.
	468	*/
	469	if (!rtc->rtc->aie_timer.enabled \|\| rtc_tm_sub(&aie_time, &alrm->time))
	470	return sprd_rtc_set_aux_alarm(dev, alrm);
	471
	472	/* clear the alarm interrupt status firstly */
	473	ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
	474	SPRD_RTC_ALARM_EN);
	475	if (ret)
	476	return ret;
	477
	478	ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
	479	if (ret)
	480	return ret;
	481
	482	if (alrm->enabled) {
	483	ret = regmap_update_bits(rtc->regmap,
	484	rtc->base + SPRD_RTC_INT_EN,
	485	SPRD_RTC_ALARM_EN,
	486	SPRD_RTC_ALARM_EN);
	487	if (ret)
	488	return ret;
	489
490	/* unlock the alarm to enable the alarm function. */
491	ret = sprd_rtc_lock_alarm(rtc, false);
492	} else {
493	regmap_update_bits(rtc->regmap,
494	rtc->base + SPRD_RTC_INT_EN,
495	SPRD_RTC_ALARM_EN, 0);
496
497	/*
498	* Lock the alarm function in case fake alarm event will power
499	* up systems.
500	*/
501	ret = sprd_rtc_lock_alarm(rtc, true);
502	}
503
504	return ret;
505	}
506
507	static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
508	{
509	struct sprd_rtc *rtc = dev_get_drvdata(dev);
510	int ret;
511
512	if (enabled) {
513	ret = regmap_update_bits(rtc->regmap,
514	rtc->base + SPRD_RTC_INT_EN,
515	SPRD_RTC_ALARM_EN \| SPRD_RTC_AUXALM_EN,
516	SPRD_RTC_ALARM_EN \| SPRD_RTC_AUXALM_EN);
517	if (ret)
518	return ret;
519
520	ret = sprd_rtc_lock_alarm(rtc, false);
521	} else {
522	regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
523	SPRD_RTC_ALARM_EN \| SPRD_RTC_AUXALM_EN, 0);
524
525	ret = sprd_rtc_lock_alarm(rtc, true);
526	}
527
528	return ret;
529	}
530
531	static const struct rtc_class_ops sprd_rtc_ops = {
532	.read_time = sprd_rtc_read_time,
533	.set_time = sprd_rtc_set_time,
534	.read_alarm = sprd_rtc_read_alarm,
535	.set_alarm = sprd_rtc_set_alarm,
536	.alarm_irq_enable = sprd_rtc_alarm_irq_enable,
537	};
538
539	static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
540	{
541	struct sprd_rtc *rtc = dev_id;
542	int ret;
543
544	ret = sprd_rtc_clear_alarm_ints(rtc);
545	if (ret)
546	return IRQ_RETVAL(ret);
547
548	rtc_update_irq(rtc->rtc, 1, RTC_AF \| RTC_IRQF);
549	return IRQ_HANDLED;
550	}
551
552	static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
553	{
554	u32 val;
555	int ret;
556
a0defd7c	557	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val);
495bbde5 BW	558	if (ret)
	559	return ret;
	560
	561	/*
a0defd7c BW	562	* If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which
	563	* means the RTC has been powered down, so the RTC time values are
	564	* invalid.
495bbde5	565	*/
a0defd7c	566	rtc->valid = val == SPRD_RTC_POWER_RESET_VALUE ? false : true;
495bbde5 BW	567	return 0;
	568	}
	569
bf2c532b BW	570	static int sprd_rtc_check_alarm_int(struct sprd_rtc *rtc)
	571	{
	572	u32 val;
	573	int ret;
	574
	575	ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
	576	if (ret)
	577	return ret;
	578
	579	/*
	580	* The SPRD_RTC_INT_EN register is not put in always-power-on region
	581	* supplied by VDDRTC, so we should check if we need enable the alarm
	582	* interrupt when system booting.
	583	*
	584	* If we have set SPRD_RTC_POWEROFF_ALM_FLAG which is saved in
	585	* always-power-on region, that means we have set one alarm last time,
	586	* so we should enable the alarm interrupt to help RTC core to see if
	587	* there is an alarm already set in RTC hardware.
	588	*/
	589	if (!(val & SPRD_RTC_POWEROFF_ALM_FLAG))
	590	return 0;
	591
	592	return regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
	593	SPRD_RTC_ALARM_EN, SPRD_RTC_ALARM_EN);
	594	}
	595
495bbde5 BW	596	static int sprd_rtc_probe(struct platform_device *pdev)
	597	{
	598	struct device_node *node = pdev->dev.of_node;
	599	struct sprd_rtc *rtc;
	600	int ret;
	601
	602	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
	603	if (!rtc)
	604	return -ENOMEM;
	605
	606	rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
	607	if (!rtc->regmap)
	608	return -ENODEV;
	609
	610	ret = of_property_read_u32(node, "reg", &rtc->base);
	611	if (ret) {
	612	dev_err(&pdev->dev, "failed to get RTC base address\n");
	613	return ret;
	614	}
	615
	616	rtc->irq = platform_get_irq(pdev, 0);
	617	if (rtc->irq < 0) {
	618	dev_err(&pdev->dev, "failed to get RTC irq number\n");
	619	return rtc->irq;
	620	}
	621
369a30a5 BW	622	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
	623	if (IS_ERR(rtc->rtc))
	624	return PTR_ERR(rtc->rtc);
	625
495bbde5 BW	626	rtc->dev = &pdev->dev;
	627	platform_set_drvdata(pdev, rtc);
	628
bf2c532b BW	629	/* check if we need set the alarm interrupt */
	630	ret = sprd_rtc_check_alarm_int(rtc);
	631	if (ret) {
	632	dev_err(&pdev->dev, "failed to check RTC alarm interrupt\n");
	633	return ret;
	634	}
	635
495bbde5 BW	636	/* check if RTC time values are valid */
	637	ret = sprd_rtc_check_power_down(rtc);
	638	if (ret) {
	639	dev_err(&pdev->dev, "failed to check RTC time values\n");
	640	return ret;
	641	}
	642
	643	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
	644	sprd_rtc_handler,
	645	IRQF_ONESHOT \| IRQF_EARLY_RESUME,
	646	pdev->name, rtc);
	647	if (ret < 0) {
	648	dev_err(&pdev->dev, "failed to request RTC irq\n");
	649	return ret;
	650	}
	651
a86d6b23 BW	652	device_init_wakeup(&pdev->dev, 1);
a86d6b23 BW	653
369a30a5	654	rtc->rtc->ops = &sprd_rtc_ops;
149aa91c BW	655	rtc->rtc->range_min = 0;
149aa91c BW	656	rtc->rtc->range_max = 5662310399LL;
369a30a5 BW	657	ret = rtc_register_device(rtc->rtc);
	658	if (ret) {
	659	dev_err(&pdev->dev, "failed to register rtc device\n");
a86d6b23	660	device_init_wakeup(&pdev->dev, 0);
369a30a5 BW	661	return ret;
369a30a5 BW	662	}
495bbde5	663
495bbde5 BW	664	return 0;
	665	}
	666
	667	static int sprd_rtc_remove(struct platform_device *pdev)
	668	{
	669	device_init_wakeup(&pdev->dev, 0);
	670	return 0;
	671	}
	672
	673	static const struct of_device_id sprd_rtc_of_match[] = {
	674	{ .compatible = "sprd,sc2731-rtc", },
	675	{ },
	676	};
	677	MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
	678
	679	static struct platform_driver sprd_rtc_driver = {
	680	.driver = {
	681	.name = "sprd-rtc",
	682	.of_match_table = sprd_rtc_of_match,
	683	},
	684	.probe = sprd_rtc_probe,
	685	.remove = sprd_rtc_remove,
	686	};
	687	module_platform_driver(sprd_rtc_driver);
	688
	689	MODULE_LICENSE("GPL v2");
	690	MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
	691	MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");