[mirror_ubuntu-hirsute-kernel.git] / drivers / rtc / rtc-bd70528.c

// SPDX-License-Identifier: GPL-2.0-or-later
//
// Copyright (C) 2018 ROHM Semiconductors
//
// RTC driver for ROHM BD70528 PMIC

#include <linux/bcd.h>
#include <linux/mfd/rohm-bd70528.h>
#include <linux/mfd/rohm-bd71828.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>

/*
 * We read regs RTC_SEC => RTC_YEAR
 * this struct is ordered according to chip registers.
 * Keep it u8 only (or packed) to avoid padding issues.
 */
struct bd70528_rtc_day {
	u8 sec;
	u8 min;
	u8 hour;
} __packed;

struct bd70528_rtc_data {
	struct bd70528_rtc_day time;
	u8 week;
	u8 day;
	u8 month;
	u8 year;
} __packed;

struct bd70528_rtc_wake {
	struct bd70528_rtc_day time;
	u8 ctrl;
} __packed;

struct bd71828_rtc_alm {
	struct bd70528_rtc_data alm0;
	struct bd70528_rtc_data alm1;
	u8 alm_mask;
	u8 alm1_mask;
} __packed;

struct bd70528_rtc_alm {
	struct bd70528_rtc_data data;
	u8 alm_mask;
	u8 alm_repeat;
} __packed;

struct bd70528_rtc {
	struct rohm_regmap_dev *parent;
	struct device *dev;
	u8 reg_time_start;
	bool has_rtc_timers;
};

static int bd70528_set_wake(struct rohm_regmap_dev *bd70528,
			    int enable, int *old_state)
{
	int ret;
	unsigned int ctrl_reg;

	ret = regmap_read(bd70528->regmap, BD70528_REG_WAKE_EN, &ctrl_reg);
	if (ret)
		return ret;

	if (old_state) {
		if (ctrl_reg & BD70528_MASK_WAKE_EN)
			*old_state |= BD70528_WAKE_STATE_BIT;
		else
			*old_state &= ~BD70528_WAKE_STATE_BIT;

		if (!enable == !(*old_state & BD70528_WAKE_STATE_BIT))
			return 0;
	}

	if (enable)
		ctrl_reg |= BD70528_MASK_WAKE_EN;
	else
		ctrl_reg &= ~BD70528_MASK_WAKE_EN;

	return regmap_write(bd70528->regmap, BD70528_REG_WAKE_EN,
			    ctrl_reg);
}

static int bd70528_set_elapsed_tmr(struct rohm_regmap_dev *bd70528,
				   int enable, int *old_state)
{
	int ret;
	unsigned int ctrl_reg;

	/*
	 * TBD
	 * What is the purpose of elapsed timer ?
	 * Is the timeout registers counting down, or is the disable - re-enable
	 * going to restart the elapsed-time counting? If counting is restarted
	 * the timeout should be decreased by the amount of time that has
	 * elapsed since starting the timer. Maybe we should store the monotonic
	 * clock value when timer is started so that if RTC is set while timer
	 * is armed we could do the compensation. This is a hack if RTC/system
	 * clk are drifting. OTOH, RTC controlled via I2C is in any case
	 * inaccurate...
	 */
	ret = regmap_read(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN,
			  &ctrl_reg);
	if (ret)
		return ret;

	if (old_state) {
		if (ctrl_reg & BD70528_MASK_ELAPSED_TIMER_EN)
			*old_state |= BD70528_ELAPSED_STATE_BIT;
		else
			*old_state &= ~BD70528_ELAPSED_STATE_BIT;

		if ((!enable) == (!(*old_state & BD70528_ELAPSED_STATE_BIT)))
			return 0;
	}

	if (enable)
		ctrl_reg |= BD70528_MASK_ELAPSED_TIMER_EN;
	else
		ctrl_reg &= ~BD70528_MASK_ELAPSED_TIMER_EN;

	return regmap_write(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN,
			    ctrl_reg);
}

static int bd70528_set_rtc_based_timers(struct bd70528_rtc *r, int new_state,
					int *old_state)
{
	int ret;

	ret = bd70528_wdt_set(r->parent, new_state & BD70528_WDT_STATE_BIT,
			      old_state);
	if (ret) {
		dev_err(r->dev,
			"Failed to disable WDG for RTC setting (%d)\n", ret);
		return ret;
	}
	ret = bd70528_set_elapsed_tmr(r->parent,
				      new_state & BD70528_ELAPSED_STATE_BIT,
				      old_state);
	if (ret) {
		dev_err(r->dev,
			"Failed to disable 'elapsed timer' for RTC setting\n");
		return ret;
	}
	ret = bd70528_set_wake(r->parent, new_state & BD70528_WAKE_STATE_BIT,
			       old_state);
	if (ret) {
		dev_err(r->dev,
			"Failed to disable 'wake timer' for RTC setting\n");
		return ret;
	}

	return ret;
}

static int bd70528_re_enable_rtc_based_timers(struct bd70528_rtc *r,
					      int old_state)
{
	if (!r->has_rtc_timers)
		return 0;

	return bd70528_set_rtc_based_timers(r, old_state, NULL);
}

static int bd70528_disable_rtc_based_timers(struct bd70528_rtc *r,
					    int *old_state)
{
	if (!r->has_rtc_timers)
		return 0;

	return bd70528_set_rtc_based_timers(r, 0, old_state);
}

static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d)
{
	d->sec &= ~BD70528_MASK_RTC_SEC;
	d->min &= ~BD70528_MASK_RTC_MINUTE;
	d->hour &= ~BD70528_MASK_RTC_HOUR;
	d->sec |= bin2bcd(t->tm_sec);
	d->min |= bin2bcd(t->tm_min);
	d->hour |= bin2bcd(t->tm_hour);
}

static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r)
{
	r->day &= ~BD70528_MASK_RTC_DAY;
	r->week &= ~BD70528_MASK_RTC_WEEK;
	r->month &= ~BD70528_MASK_RTC_MONTH;
	/*
	 * PM and 24H bits are not used by Wake - thus we clear them
	 * here and not in tmday2rtc() which is also used by wake.
	 */
	r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H);

	tmday2rtc(t, &r->time);
	/*
	 * We do always set time in 24H mode.
	 */
	r->time.hour |= BD70528_MASK_RTC_HOUR_24H;
	r->day |= bin2bcd(t->tm_mday);
	r->week |= bin2bcd(t->tm_wday);
	r->month |= bin2bcd(t->tm_mon + 1);
	r->year = bin2bcd(t->tm_year - 100);
}

static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t)
{
	t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
	t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
	t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
	/*
	 * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
	 * is not BCD value but tells whether it is AM or PM
	 */
	if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
		t->tm_hour %= 12;
		if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
			t->tm_hour += 12;
	}
	t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
	t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
	t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
	t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
}

static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	int ret;
	struct bd71828_rtc_alm alm;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD71828_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	tm2rtc(&a->time, &alm.alm0);

	if (!a->enabled)
		alm.alm_mask &= ~BD70528_MASK_ALM_EN;
	else
		alm.alm_mask |= BD70528_MASK_ALM_EN;

	ret = regmap_bulk_write(parent->regmap, BD71828_REG_RTC_ALM_START,
				&alm, sizeof(alm));
	if (ret)
		dev_err(dev, "Failed to set alarm time\n");

	return ret;

}

static int bd70528_set_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	struct bd70528_rtc_wake wake;
	struct bd70528_rtc_alm alm;
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_WAKE_START,
			       &wake, sizeof(wake));
	if (ret) {
		dev_err(dev, "Failed to read wake regs\n");
		return ret;
	}

	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	tm2rtc(&a->time, &alm.data);
	tmday2rtc(&a->time, &wake.time);

	if (a->enabled) {
		alm.alm_mask &= ~BD70528_MASK_ALM_EN;
		wake.ctrl |= BD70528_MASK_WAKE_EN;
	} else {
		alm.alm_mask |= BD70528_MASK_ALM_EN;
		wake.ctrl &= ~BD70528_MASK_WAKE_EN;
	}

	ret = regmap_bulk_write(parent->regmap,
				BD70528_REG_RTC_WAKE_START, &wake,
				sizeof(wake));
	if (ret) {
		dev_err(dev, "Failed to set wake time\n");
		return ret;
	}
	ret = regmap_bulk_write(parent->regmap, BD70528_REG_RTC_ALM_START,
				&alm, sizeof(alm));
	if (ret)
		dev_err(dev, "Failed to set alarm time\n");

	return ret;
}

static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	int ret;
	struct bd71828_rtc_alm alm;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD71828_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	rtc2tm(&alm.alm0, &a->time);
	a->time.tm_mday = -1;
	a->time.tm_mon = -1;
	a->time.tm_year = -1;
	a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
	a->pending = 0;

	return 0;
}

static int bd70528_read_alarm(struct device *dev, struct rtc_wkalrm *a)
{
	struct bd70528_rtc_alm alm;
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_ALM_START,
			       &alm, sizeof(alm));
	if (ret) {
		dev_err(dev, "Failed to read alarm regs\n");
		return ret;
	}

	rtc2tm(&alm.data, &a->time);
	a->time.tm_mday = -1;
	a->time.tm_mon = -1;
	a->time.tm_year = -1;
	a->enabled = !(alm.alm_mask & BD70528_MASK_ALM_EN);
	a->pending = 0;

	return 0;
}

static int bd70528_set_time_locked(struct device *dev, struct rtc_time *t)
{
	int ret, tmpret, old_states;
	struct bd70528_rtc_data rtc_data;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;

	ret = bd70528_disable_rtc_based_timers(r, &old_states);
	if (ret)
		return ret;

	tmpret = regmap_bulk_read(parent->regmap,
				  r->reg_time_start, &rtc_data,
				  sizeof(rtc_data));
	if (tmpret) {
		dev_err(dev, "Failed to read RTC time registers\n");
		goto renable_out;
	}
	tm2rtc(t, &rtc_data);

	tmpret = regmap_bulk_write(parent->regmap,
				   r->reg_time_start, &rtc_data,
				   sizeof(rtc_data));
	if (tmpret) {
		dev_err(dev, "Failed to set RTC time\n");
		goto renable_out;
	}

renable_out:
	ret = bd70528_re_enable_rtc_based_timers(r, old_states);
	if (tmpret)
		ret = tmpret;

	return ret;
}

static int bd71828_set_time(struct device *dev, struct rtc_time *t)
{
	return bd70528_set_time_locked(dev, t);
}

static int bd70528_set_time(struct device *dev, struct rtc_time *t)
{
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);

	bd70528_wdt_lock(r->parent);
	ret = bd70528_set_time_locked(dev, t);
	bd70528_wdt_unlock(r->parent);
	return ret;
}

static int bd70528_get_time(struct device *dev, struct rtc_time *t)
{
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	struct rohm_regmap_dev *parent = r->parent;
	struct bd70528_rtc_data rtc_data;
	int ret;

	/* read the RTC date and time registers all at once */
	ret = regmap_bulk_read(parent->regmap,
			       r->reg_time_start, &rtc_data,
			       sizeof(rtc_data));
	if (ret) {
		dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
		return ret;
	}

	rtc2tm(&rtc_data, t);

	return 0;
}

static int bd70528_alm_enable(struct device *dev, unsigned int enabled)
{
	int ret;
	unsigned int enableval = BD70528_MASK_ALM_EN;
	struct bd70528_rtc *r = dev_get_drvdata(dev);

	if (enabled)
		enableval = 0;

	bd70528_wdt_lock(r->parent);
	ret = bd70528_set_wake(r->parent, enabled, NULL);
	if (ret) {
		dev_err(dev, "Failed to change wake state\n");
		goto out_unlock;
	}
	ret = regmap_update_bits(r->parent->regmap, BD70528_REG_RTC_ALM_MASK,
				 BD70528_MASK_ALM_EN, enableval);
	if (ret)
		dev_err(dev, "Failed to change alarm state\n");

out_unlock:
	bd70528_wdt_unlock(r->parent);
	return ret;
}

static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
{
	int ret;
	struct bd70528_rtc *r = dev_get_drvdata(dev);
	unsigned int enableval = BD70528_MASK_ALM_EN;

	if (!enabled)
		enableval = 0;

	ret = regmap_update_bits(r->parent->regmap, BD71828_REG_RTC_ALM0_MASK,
				 BD70528_MASK_ALM_EN, enableval);
	if (ret)
		dev_err(dev, "Failed to change alarm state\n");

	return ret;
}

static const struct rtc_class_ops bd70528_rtc_ops = {
	.read_time		= bd70528_get_time,
	.set_time		= bd70528_set_time,
	.read_alarm		= bd70528_read_alarm,
	.set_alarm		= bd70528_set_alarm,
	.alarm_irq_enable	= bd70528_alm_enable,
};

static const struct rtc_class_ops bd71828_rtc_ops = {
	.read_time		= bd70528_get_time,
	.set_time		= bd71828_set_time,
	.read_alarm		= bd71828_read_alarm,
	.set_alarm		= bd71828_set_alarm,
	.alarm_irq_enable	= bd71828_alm_enable,
};

static irqreturn_t alm_hndlr(int irq, void *data)
{
	struct rtc_device *rtc = data;

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

static int bd70528_probe(struct platform_device *pdev)
{
	struct bd70528_rtc *bd_rtc;
	const struct rtc_class_ops *rtc_ops;
	struct rohm_regmap_dev *parent;
	const char *irq_name;
	int ret;
	struct rtc_device *rtc;
	int irq;
	unsigned int hr;
	bool enable_main_irq = false;
	u8 hour_reg;
	enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;

	parent = dev_get_drvdata(pdev->dev.parent);
	if (!parent) {
		dev_err(&pdev->dev, "No MFD driver data\n");
		return -EINVAL;
	}
	bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
	if (!bd_rtc)
		return -ENOMEM;

	bd_rtc->parent = parent;
	bd_rtc->dev = &pdev->dev;

	switch (chip) {
	case ROHM_CHIP_TYPE_BD70528:
		irq_name = "bd70528-rtc-alm";
		bd_rtc->has_rtc_timers = true;
		bd_rtc->reg_time_start = BD70528_REG_RTC_START;
		hour_reg = BD70528_REG_RTC_HOUR;
		enable_main_irq = true;
		rtc_ops = &bd70528_rtc_ops;
		break;
	case ROHM_CHIP_TYPE_BD71828:
		irq_name = "bd71828-rtc-alm-0";
		bd_rtc->reg_time_start = BD71828_REG_RTC_START;
		hour_reg = BD71828_REG_RTC_HOUR;
		rtc_ops = &bd71828_rtc_ops;
		break;
	default:
		dev_err(&pdev->dev, "Unknown chip\n");
		return -ENOENT;
	}

	irq = platform_get_irq_byname(pdev, irq_name);

	if (irq < 0)
		return irq;

	platform_set_drvdata(pdev, bd_rtc);

	ret = regmap_read(parent->regmap, hour_reg, &hr);

	if (ret) {
		dev_err(&pdev->dev, "Failed to reag RTC clock\n");
		return ret;
	}

	if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
		struct rtc_time t;

		ret = rtc_ops->read_time(&pdev->dev, &t);

		if (!ret)
			ret = rtc_ops->set_time(&pdev->dev, &t);

		if (ret) {
			dev_err(&pdev->dev,
				"Setting 24H clock for RTC failed\n");
			return ret;
		}
	}

	device_set_wakeup_capable(&pdev->dev, true);
	device_wakeup_enable(&pdev->dev);

	rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(rtc)) {
		dev_err(&pdev->dev, "RTC device creation failed\n");
		return PTR_ERR(rtc);
	}

	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	rtc->range_max = RTC_TIMESTAMP_END_2099;
	rtc->ops = rtc_ops;

	/* Request alarm IRQ prior to registerig the RTC */
	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
					IRQF_ONESHOT, "bd70528-rtc", rtc);
	if (ret)
		return ret;

	/*
	 *  BD70528 irq controller is not touching the main mask register.
	 *  So enable the RTC block interrupts at main level. We can just
	 *  leave them enabled as irq-controller should disable irqs
	 *  from sub-registers when IRQ is disabled or freed.
	 */
	if (enable_main_irq) {
		ret = regmap_update_bits(parent->regmap,
				 BD70528_REG_INT_MAIN_MASK,
				 BD70528_INT_RTC_MASK, 0);
		if (ret) {
			dev_err(&pdev->dev, "Failed to enable RTC interrupts\n");
			return ret;
		}
	}

	return rtc_register_device(rtc);
}

static const struct platform_device_id bd718x7_rtc_id[] = {
	{ "bd70528-rtc", ROHM_CHIP_TYPE_BD70528 },
	{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
	{ },
};
MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);

static struct platform_driver bd70528_rtc = {
	.driver = {
		.name = "bd70528-rtc"
	},
	.probe = bd70528_probe,
	.id_table = bd718x7_rtc_id,
};

module_platform_driver(bd70528_rtc);

MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
MODULE_DESCRIPTION("ROHM BD70528 and BD71828 PMIC RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:bd70528-rtc");
Commit	Line	Data
32a4a4eb MV	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	//
	3	// Copyright (C) 2018 ROHM Semiconductors
	4	//
	5	// RTC driver for ROHM BD70528 PMIC
	6
	7	#include <linux/bcd.h>
	8	#include <linux/mfd/rohm-bd70528.h>
fe5a591b	9	#include <linux/mfd/rohm-bd71828.h>
32a4a4eb MV	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	/*
	17	* We read regs RTC_SEC => RTC_YEAR
	18	* this struct is ordered according to chip registers.
fe5a591b	19	* Keep it u8 only (or packed) to avoid padding issues.
32a4a4eb MV	20	*/
	21	struct bd70528_rtc_day {
	22	u8 sec;
	23	u8 min;
	24	u8 hour;
	25	} __packed;
	26
	27	struct bd70528_rtc_data {
	28	struct bd70528_rtc_day time;
	29	u8 week;
	30	u8 day;
	31	u8 month;
	32	u8 year;
	33	} __packed;
	34
	35	struct bd70528_rtc_wake {
	36	struct bd70528_rtc_day time;
	37	u8 ctrl;
	38	} __packed;
	39
fe5a591b MV	40	struct bd71828_rtc_alm {
	41	struct bd70528_rtc_data alm0;
	42	struct bd70528_rtc_data alm1;
	43	u8 alm_mask;
	44	u8 alm1_mask;
	45	} __packed;
	46
32a4a4eb MV	47	struct bd70528_rtc_alm {
	48	struct bd70528_rtc_data data;
	49	u8 alm_mask;
	50	u8 alm_repeat;
	51	} __packed;
	52
	53	struct bd70528_rtc {
fe5a591b	54	struct rohm_regmap_dev *parent;
32a4a4eb	55	struct device *dev;
fe5a591b MV	56	u8 reg_time_start;
fe5a591b MV	57	bool has_rtc_timers;
32a4a4eb MV	58	};
	59
	60	static int bd70528_set_wake(struct rohm_regmap_dev *bd70528,
	61	int enable, int *old_state)
	62	{
	63	int ret;
	64	unsigned int ctrl_reg;
	65
	66	ret = regmap_read(bd70528->regmap, BD70528_REG_WAKE_EN, &ctrl_reg);
	67	if (ret)
	68	return ret;
	69
	70	if (old_state) {
	71	if (ctrl_reg & BD70528_MASK_WAKE_EN)
	72	*old_state \|= BD70528_WAKE_STATE_BIT;
	73	else
	74	*old_state &= ~BD70528_WAKE_STATE_BIT;
	75
	76	if (!enable == !(*old_state & BD70528_WAKE_STATE_BIT))
	77	return 0;
	78	}
	79
	80	if (enable)
	81	ctrl_reg \|= BD70528_MASK_WAKE_EN;
	82	else
	83	ctrl_reg &= ~BD70528_MASK_WAKE_EN;
	84
	85	return regmap_write(bd70528->regmap, BD70528_REG_WAKE_EN,
	86	ctrl_reg);
	87	}
	88
	89	static int bd70528_set_elapsed_tmr(struct rohm_regmap_dev *bd70528,
	90	int enable, int *old_state)
	91	{
	92	int ret;
	93	unsigned int ctrl_reg;
	94
	95	/*
	96	* TBD
	97	* What is the purpose of elapsed timer ?
	98	* Is the timeout registers counting down, or is the disable - re-enable
	99	* going to restart the elapsed-time counting? If counting is restarted
	100	* the timeout should be decreased by the amount of time that has
	101	* elapsed since starting the timer. Maybe we should store the monotonic
	102	* clock value when timer is started so that if RTC is set while timer
	103	* is armed we could do the compensation. This is a hack if RTC/system
	104	* clk are drifting. OTOH, RTC controlled via I2C is in any case
	105	* inaccurate...
	106	*/
	107	ret = regmap_read(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN,
	108	&ctrl_reg);
	109	if (ret)
	110	return ret;
	111
	112	if (old_state) {
	113	if (ctrl_reg & BD70528_MASK_ELAPSED_TIMER_EN)
	114	*old_state \|= BD70528_ELAPSED_STATE_BIT;
	115	else
	116	*old_state &= ~BD70528_ELAPSED_STATE_BIT;
	117
	118	if ((!enable) == (!(*old_state & BD70528_ELAPSED_STATE_BIT)))
	119	return 0;
	120	}
	121
122	if (enable)
123	ctrl_reg \|= BD70528_MASK_ELAPSED_TIMER_EN;
124	else
125	ctrl_reg &= ~BD70528_MASK_ELAPSED_TIMER_EN;
126
127	return regmap_write(bd70528->regmap, BD70528_REG_ELAPSED_TIMER_EN,
128	ctrl_reg);
129	}
130
131	static int bd70528_set_rtc_based_timers(struct bd70528_rtc *r, int new_state,
132	int *old_state)
133	{
134	int ret;
135
fe5a591b	136	ret = bd70528_wdt_set(r->parent, new_state & BD70528_WDT_STATE_BIT,
32a4a4eb MV	137	old_state);
	138	if (ret) {
	139	dev_err(r->dev,
	140	"Failed to disable WDG for RTC setting (%d)\n", ret);
	141	return ret;
	142	}
fe5a591b	143	ret = bd70528_set_elapsed_tmr(r->parent,
32a4a4eb MV	144	new_state & BD70528_ELAPSED_STATE_BIT,
	145	old_state);
	146	if (ret) {
	147	dev_err(r->dev,
	148	"Failed to disable 'elapsed timer' for RTC setting\n");
	149	return ret;
	150	}
fe5a591b	151	ret = bd70528_set_wake(r->parent, new_state & BD70528_WAKE_STATE_BIT,
32a4a4eb MV	152	old_state);
	153	if (ret) {
	154	dev_err(r->dev,
	155	"Failed to disable 'wake timer' for RTC setting\n");
	156	return ret;
	157	}
	158
	159	return ret;
	160	}
	161
	162	static int bd70528_re_enable_rtc_based_timers(struct bd70528_rtc *r,
	163	int old_state)
	164	{
fe5a591b MV	165	if (!r->has_rtc_timers)
	166	return 0;
	167
32a4a4eb MV	168	return bd70528_set_rtc_based_timers(r, old_state, NULL);
	169	}
	170
	171	static int bd70528_disable_rtc_based_timers(struct bd70528_rtc *r,
	172	int *old_state)
	173	{
fe5a591b MV	174	if (!r->has_rtc_timers)
	175	return 0;
	176
32a4a4eb MV	177	return bd70528_set_rtc_based_timers(r, 0, old_state);
	178	}
	179
	180	static inline void tmday2rtc(struct rtc_time t, struct bd70528_rtc_day d)
	181	{
	182	d->sec &= ~BD70528_MASK_RTC_SEC;
	183	d->min &= ~BD70528_MASK_RTC_MINUTE;
	184	d->hour &= ~BD70528_MASK_RTC_HOUR;
	185	d->sec \|= bin2bcd(t->tm_sec);
	186	d->min \|= bin2bcd(t->tm_min);
	187	d->hour \|= bin2bcd(t->tm_hour);
	188	}
	189
	190	static inline void tm2rtc(struct rtc_time t, struct bd70528_rtc_data r)
	191	{
	192	r->day &= ~BD70528_MASK_RTC_DAY;
	193	r->week &= ~BD70528_MASK_RTC_WEEK;
	194	r->month &= ~BD70528_MASK_RTC_MONTH;
	195	/*
	196	* PM and 24H bits are not used by Wake - thus we clear them
	197	* here and not in tmday2rtc() which is also used by wake.
	198	*/
	199	r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM \| BD70528_MASK_RTC_HOUR_24H);
	200
	201	tmday2rtc(t, &r->time);
	202	/*
	203	* We do always set time in 24H mode.
	204	*/
	205	r->time.hour \|= BD70528_MASK_RTC_HOUR_24H;
	206	r->day \|= bin2bcd(t->tm_mday);
	207	r->week \|= bin2bcd(t->tm_wday);
	208	r->month \|= bin2bcd(t->tm_mon + 1);
	209	r->year = bin2bcd(t->tm_year - 100);
	210	}
	211
	212	static inline void rtc2tm(struct bd70528_rtc_data r, struct rtc_time t)
	213	{
	214	t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
	215	t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
	216	t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
	217	/*
	218	* If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
	219	* is not BCD value but tells whether it is AM or PM
	220	*/
	221	if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
	222	t->tm_hour %= 12;
	223	if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
	224	t->tm_hour += 12;
	225	}
	226	t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
	227	t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
	228	t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
	229	t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
	230	}
	231
fe5a591b MV	232	static int bd71828_set_alarm(struct device dev, struct rtc_wkalrm a)
	233	{
	234	int ret;
	235	struct bd71828_rtc_alm alm;
	236	struct bd70528_rtc *r = dev_get_drvdata(dev);
	237	struct rohm_regmap_dev *parent = r->parent;
	238
	239	ret = regmap_bulk_read(parent->regmap, BD71828_REG_RTC_ALM_START,
	240	&alm, sizeof(alm));
	241	if (ret) {
	242	dev_err(dev, "Failed to read alarm regs\n");
	243	return ret;
	244	}
	245
	246	tm2rtc(&a->time, &alm.alm0);
	247
	248	if (!a->enabled)
	249	alm.alm_mask &= ~BD70528_MASK_ALM_EN;
	250	else
	251	alm.alm_mask \|= BD70528_MASK_ALM_EN;
	252
	253	ret = regmap_bulk_write(parent->regmap, BD71828_REG_RTC_ALM_START,
	254	&alm, sizeof(alm));
	255	if (ret)
	256	dev_err(dev, "Failed to set alarm time\n");
	257
	258	return ret;
	259
	260	}
	261
32a4a4eb MV	262	static int bd70528_set_alarm(struct device dev, struct rtc_wkalrm a)
	263	{
	264	struct bd70528_rtc_wake wake;
	265	struct bd70528_rtc_alm alm;
	266	int ret;
	267	struct bd70528_rtc *r = dev_get_drvdata(dev);
fe5a591b	268	struct rohm_regmap_dev *parent = r->parent;
32a4a4eb	269
fe5a591b	270	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_WAKE_START,
32a4a4eb MV	271	&wake, sizeof(wake));
	272	if (ret) {
	273	dev_err(dev, "Failed to read wake regs\n");
	274	return ret;
	275	}
	276
fe5a591b	277	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_ALM_START,
32a4a4eb MV	278	&alm, sizeof(alm));
	279	if (ret) {
	280	dev_err(dev, "Failed to read alarm regs\n");
	281	return ret;
	282	}
	283
	284	tm2rtc(&a->time, &alm.data);
	285	tmday2rtc(&a->time, &wake.time);
	286
	287	if (a->enabled) {
	288	alm.alm_mask &= ~BD70528_MASK_ALM_EN;
	289	wake.ctrl \|= BD70528_MASK_WAKE_EN;
	290	} else {
	291	alm.alm_mask \|= BD70528_MASK_ALM_EN;
	292	wake.ctrl &= ~BD70528_MASK_WAKE_EN;
	293	}
	294
fe5a591b	295	ret = regmap_bulk_write(parent->regmap,
32a4a4eb MV	296	BD70528_REG_RTC_WAKE_START, &wake,
	297	sizeof(wake));
	298	if (ret) {
	299	dev_err(dev, "Failed to set wake time\n");
	300	return ret;
	301	}
fe5a591b	302	ret = regmap_bulk_write(parent->regmap, BD70528_REG_RTC_ALM_START,
32a4a4eb MV	303	&alm, sizeof(alm));
	304	if (ret)
	305	dev_err(dev, "Failed to set alarm time\n");
	306
	307	return ret;
	308	}
	309
fe5a591b MV	310	static int bd71828_read_alarm(struct device dev, struct rtc_wkalrm a)
	311	{
	312	int ret;
	313	struct bd71828_rtc_alm alm;
	314	struct bd70528_rtc *r = dev_get_drvdata(dev);
	315	struct rohm_regmap_dev *parent = r->parent;
	316
	317	ret = regmap_bulk_read(parent->regmap, BD71828_REG_RTC_ALM_START,
	318	&alm, sizeof(alm));
	319	if (ret) {
	320	dev_err(dev, "Failed to read alarm regs\n");
	321	return ret;
	322	}
	323
	324	rtc2tm(&alm.alm0, &a->time);
	325	a->time.tm_mday = -1;
	326	a->time.tm_mon = -1;
	327	a->time.tm_year = -1;
	328	a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
	329	a->pending = 0;
	330
	331	return 0;
	332	}
	333
32a4a4eb MV	334	static int bd70528_read_alarm(struct device dev, struct rtc_wkalrm a)
	335	{
	336	struct bd70528_rtc_alm alm;
	337	int ret;
	338	struct bd70528_rtc *r = dev_get_drvdata(dev);
fe5a591b	339	struct rohm_regmap_dev *parent = r->parent;
32a4a4eb	340
fe5a591b	341	ret = regmap_bulk_read(parent->regmap, BD70528_REG_RTC_ALM_START,
32a4a4eb MV	342	&alm, sizeof(alm));
	343	if (ret) {
	344	dev_err(dev, "Failed to read alarm regs\n");
	345	return ret;
	346	}
	347
	348	rtc2tm(&alm.data, &a->time);
	349	a->time.tm_mday = -1;
	350	a->time.tm_mon = -1;
	351	a->time.tm_year = -1;
	352	a->enabled = !(alm.alm_mask & BD70528_MASK_ALM_EN);
	353	a->pending = 0;
	354
	355	return 0;
	356	}
	357
	358	static int bd70528_set_time_locked(struct device dev, struct rtc_time t)
	359	{
	360	int ret, tmpret, old_states;
	361	struct bd70528_rtc_data rtc_data;
	362	struct bd70528_rtc *r = dev_get_drvdata(dev);
fe5a591b	363	struct rohm_regmap_dev *parent = r->parent;
32a4a4eb MV	364
	365	ret = bd70528_disable_rtc_based_timers(r, &old_states);
	366	if (ret)
	367	return ret;
	368
fe5a591b MV	369	tmpret = regmap_bulk_read(parent->regmap,
fe5a591b MV	370	r->reg_time_start, &rtc_data,
32a4a4eb MV	371	sizeof(rtc_data));
	372	if (tmpret) {
	373	dev_err(dev, "Failed to read RTC time registers\n");
	374	goto renable_out;
	375	}
	376	tm2rtc(t, &rtc_data);
	377
fe5a591b MV	378	tmpret = regmap_bulk_write(parent->regmap,
fe5a591b MV	379	r->reg_time_start, &rtc_data,
32a4a4eb MV	380	sizeof(rtc_data));
	381	if (tmpret) {
	382	dev_err(dev, "Failed to set RTC time\n");
	383	goto renable_out;
	384	}
	385
	386	renable_out:
	387	ret = bd70528_re_enable_rtc_based_timers(r, old_states);
	388	if (tmpret)
	389	ret = tmpret;
	390
	391	return ret;
	392	}
	393
fe5a591b MV	394	static int bd71828_set_time(struct device dev, struct rtc_time t)
	395	{
	396	return bd70528_set_time_locked(dev, t);
	397	}
	398
32a4a4eb MV	399	static int bd70528_set_time(struct device dev, struct rtc_time t)
	400	{
	401	int ret;
	402	struct bd70528_rtc *r = dev_get_drvdata(dev);
	403
fe5a591b	404	bd70528_wdt_lock(r->parent);
32a4a4eb	405	ret = bd70528_set_time_locked(dev, t);
fe5a591b	406	bd70528_wdt_unlock(r->parent);
32a4a4eb MV	407	return ret;
	408	}
	409
	410	static int bd70528_get_time(struct device dev, struct rtc_time t)
	411	{
	412	struct bd70528_rtc *r = dev_get_drvdata(dev);
fe5a591b	413	struct rohm_regmap_dev *parent = r->parent;
32a4a4eb MV	414	struct bd70528_rtc_data rtc_data;
	415	int ret;
	416
	417	/* read the RTC date and time registers all at once */
fe5a591b MV	418	ret = regmap_bulk_read(parent->regmap,
fe5a591b MV	419	r->reg_time_start, &rtc_data,
32a4a4eb MV	420	sizeof(rtc_data));
	421	if (ret) {
	422	dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
	423	return ret;
	424	}
	425
	426	rtc2tm(&rtc_data, t);
	427
	428	return 0;
	429	}
	430
	431	static int bd70528_alm_enable(struct device *dev, unsigned int enabled)
	432	{
	433	int ret;
	434	unsigned int enableval = BD70528_MASK_ALM_EN;
	435	struct bd70528_rtc *r = dev_get_drvdata(dev);
	436
	437	if (enabled)
	438	enableval = 0;
	439
fe5a591b MV	440	bd70528_wdt_lock(r->parent);
fe5a591b MV	441	ret = bd70528_set_wake(r->parent, enabled, NULL);
32a4a4eb MV	442	if (ret) {
	443	dev_err(dev, "Failed to change wake state\n");
	444	goto out_unlock;
	445	}
fe5a591b	446	ret = regmap_update_bits(r->parent->regmap, BD70528_REG_RTC_ALM_MASK,
32a4a4eb MV	447	BD70528_MASK_ALM_EN, enableval);
	448	if (ret)
	449	dev_err(dev, "Failed to change alarm state\n");
	450
	451	out_unlock:
fe5a591b MV	452	bd70528_wdt_unlock(r->parent);
	453	return ret;
	454	}
	455
	456	static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
	457	{
	458	int ret;
	459	struct bd70528_rtc *r = dev_get_drvdata(dev);
	460	unsigned int enableval = BD70528_MASK_ALM_EN;
	461
	462	if (!enabled)
	463	enableval = 0;
	464
	465	ret = regmap_update_bits(r->parent->regmap, BD71828_REG_RTC_ALM0_MASK,
	466	BD70528_MASK_ALM_EN, enableval);
	467	if (ret)
	468	dev_err(dev, "Failed to change alarm state\n");
	469
32a4a4eb MV	470	return ret;
	471	}
	472
	473	static const struct rtc_class_ops bd70528_rtc_ops = {
	474	.read_time = bd70528_get_time,
	475	.set_time = bd70528_set_time,
	476	.read_alarm = bd70528_read_alarm,
	477	.set_alarm = bd70528_set_alarm,
	478	.alarm_irq_enable = bd70528_alm_enable,
	479	};
	480
fe5a591b MV	481	static const struct rtc_class_ops bd71828_rtc_ops = {
	482	.read_time = bd70528_get_time,
	483	.set_time = bd71828_set_time,
	484	.read_alarm = bd71828_read_alarm,
	485	.set_alarm = bd71828_set_alarm,
	486	.alarm_irq_enable = bd71828_alm_enable,
	487	};
	488
32a4a4eb MV	489	static irqreturn_t alm_hndlr(int irq, void *data)
	490	{
	491	struct rtc_device *rtc = data;
	492
	493	rtc_update_irq(rtc, 1, RTC_IRQF \| RTC_AF \| RTC_PF);
	494	return IRQ_HANDLED;
	495	}
	496
	497	static int bd70528_probe(struct platform_device *pdev)
	498	{
	499	struct bd70528_rtc *bd_rtc;
fe5a591b MV	500	const struct rtc_class_ops *rtc_ops;
	501	struct rohm_regmap_dev *parent;
	502	const char *irq_name;
32a4a4eb MV	503	int ret;
	504	struct rtc_device *rtc;
	505	int irq;
	506	unsigned int hr;
fe5a591b MV	507	bool enable_main_irq = false;
	508	u8 hour_reg;
	509	enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
32a4a4eb	510
fe5a591b MV	511	parent = dev_get_drvdata(pdev->dev.parent);
fe5a591b MV	512	if (!parent) {
32a4a4eb MV	513	dev_err(&pdev->dev, "No MFD driver data\n");
	514	return -EINVAL;
	515	}
	516	bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
	517	if (!bd_rtc)
	518	return -ENOMEM;
	519
fe5a591b	520	bd_rtc->parent = parent;
32a4a4eb MV	521	bd_rtc->dev = &pdev->dev;
32a4a4eb MV	522
fe5a591b MV	523	switch (chip) {
	524	case ROHM_CHIP_TYPE_BD70528:
	525	irq_name = "bd70528-rtc-alm";
	526	bd_rtc->has_rtc_timers = true;
	527	bd_rtc->reg_time_start = BD70528_REG_RTC_START;
	528	hour_reg = BD70528_REG_RTC_HOUR;
	529	enable_main_irq = true;
	530	rtc_ops = &bd70528_rtc_ops;
	531	break;
	532	case ROHM_CHIP_TYPE_BD71828:
	533	irq_name = "bd71828-rtc-alm-0";
	534	bd_rtc->reg_time_start = BD71828_REG_RTC_START;
	535	hour_reg = BD71828_REG_RTC_HOUR;
	536	rtc_ops = &bd71828_rtc_ops;
	537	break;
	538	default:
	539	dev_err(&pdev->dev, "Unknown chip\n");
	540	return -ENOENT;
	541	}
	542
	543	irq = platform_get_irq_byname(pdev, irq_name);
	544
6e7af451	545	if (irq < 0)
32a4a4eb	546	return irq;
32a4a4eb MV	547
	548	platform_set_drvdata(pdev, bd_rtc);
	549
fe5a591b	550	ret = regmap_read(parent->regmap, hour_reg, &hr);
32a4a4eb MV	551
	552	if (ret) {
	553	dev_err(&pdev->dev, "Failed to reag RTC clock\n");
	554	return ret;
	555	}
	556
	557	if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
	558	struct rtc_time t;
	559
fe5a591b	560	ret = rtc_ops->read_time(&pdev->dev, &t);
32a4a4eb MV	561
32a4a4eb MV	562	if (!ret)
fe5a591b	563	ret = rtc_ops->set_time(&pdev->dev, &t);
32a4a4eb MV	564
	565	if (ret) {
	566	dev_err(&pdev->dev,
	567	"Setting 24H clock for RTC failed\n");
	568	return ret;
	569	}
	570	}
	571
	572	device_set_wakeup_capable(&pdev->dev, true);
	573	device_wakeup_enable(&pdev->dev);
	574
	575	rtc = devm_rtc_allocate_device(&pdev->dev);
	576	if (IS_ERR(rtc)) {
	577	dev_err(&pdev->dev, "RTC device creation failed\n");
	578	return PTR_ERR(rtc);
	579	}
	580
	581	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	582	rtc->range_max = RTC_TIMESTAMP_END_2099;
fe5a591b	583	rtc->ops = rtc_ops;
32a4a4eb MV	584
	585	/* Request alarm IRQ prior to registerig the RTC */
	586	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
	587	IRQF_ONESHOT, "bd70528-rtc", rtc);
	588	if (ret)
	589	return ret;
	590
	591	/*
	592	* BD70528 irq controller is not touching the main mask register.
	593	* So enable the RTC block interrupts at main level. We can just
	594	* leave them enabled as irq-controller should disable irqs
	595	* from sub-registers when IRQ is disabled or freed.
	596	*/
fe5a591b MV	597	if (enable_main_irq) {
fe5a591b MV	598	ret = regmap_update_bits(parent->regmap,
32a4a4eb MV	599	BD70528_REG_INT_MAIN_MASK,
32a4a4eb MV	600	BD70528_INT_RTC_MASK, 0);
fe5a591b MV	601	if (ret) {
	602	dev_err(&pdev->dev, "Failed to enable RTC interrupts\n");
	603	return ret;
	604	}
32a4a4eb MV	605	}
32a4a4eb MV	606
44c638ce	607	return rtc_register_device(rtc);
32a4a4eb MV	608	}
32a4a4eb MV	609
fe5a591b MV	610	static const struct platform_device_id bd718x7_rtc_id[] = {
	611	{ "bd70528-rtc", ROHM_CHIP_TYPE_BD70528 },
	612	{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
	613	{ },
	614	};
	615	MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
	616
32a4a4eb MV	617	static struct platform_driver bd70528_rtc = {
	618	.driver = {
	619	.name = "bd70528-rtc"
	620	},
	621	.probe = bd70528_probe,
fe5a591b	622	.id_table = bd718x7_rtc_id,
32a4a4eb MV	623	};
	624
	625	module_platform_driver(bd70528_rtc);
	626
	627	MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
fe5a591b	628	MODULE_DESCRIPTION("ROHM BD70528 and BD71828 PMIC RTC driver");
32a4a4eb	629	MODULE_LICENSE("GPL");
afe19a7a	630	MODULE_ALIAS("platform:bd70528-rtc");