[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / rtc / rtc-max77686.c

/*
 * RTC driver for Maxim MAX77686
 *
 * Copyright (C) 2012 Samsung Electronics Co.Ltd
 *
 *  based on rtc-max8997.c
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/max77686-private.h>
#include <linux/irqdomain.h>
#include <linux/regmap.h>

/* RTC Control Register */
#define BCD_EN_SHIFT			0
#define BCD_EN_MASK			(1 << BCD_EN_SHIFT)
#define MODEL24_SHIFT			1
#define MODEL24_MASK			(1 << MODEL24_SHIFT)
/* RTC Update Register1 */
#define RTC_UDR_SHIFT			0
#define RTC_UDR_MASK			(1 << RTC_UDR_SHIFT)
#define RTC_RBUDR_SHIFT			4
#define RTC_RBUDR_MASK			(1 << RTC_RBUDR_SHIFT)
/* WTSR and SMPL Register */
#define WTSRT_SHIFT			0
#define SMPLT_SHIFT			2
#define WTSR_EN_SHIFT			6
#define SMPL_EN_SHIFT			7
#define WTSRT_MASK			(3 << WTSRT_SHIFT)
#define SMPLT_MASK			(3 << SMPLT_SHIFT)
#define WTSR_EN_MASK			(1 << WTSR_EN_SHIFT)
#define SMPL_EN_MASK			(1 << SMPL_EN_SHIFT)
/* RTC Hour register */
#define HOUR_PM_SHIFT			6
#define HOUR_PM_MASK			(1 << HOUR_PM_SHIFT)
/* RTC Alarm Enable */
#define ALARM_ENABLE_SHIFT		7
#define ALARM_ENABLE_MASK		(1 << ALARM_ENABLE_SHIFT)

#define MAX77686_RTC_UPDATE_DELAY	16
#undef MAX77686_RTC_WTSR_SMPL

enum {
	RTC_SEC = 0,
	RTC_MIN,
	RTC_HOUR,
	RTC_WEEKDAY,
	RTC_MONTH,
	RTC_YEAR,
	RTC_DATE,
	RTC_NR_TIME
};

struct max77686_rtc_info {
	struct device		*dev;
	struct max77686_dev	*max77686;
	struct i2c_client	*rtc;
	struct rtc_device	*rtc_dev;
	struct mutex		lock;

	struct regmap		*regmap;

	int virq;
	int rtc_24hr_mode;
};

enum MAX77686_RTC_OP {
	MAX77686_RTC_WRITE,
	MAX77686_RTC_READ,
};

static inline int max77686_rtc_calculate_wday(u8 shifted)
{
	int counter = -1;
	while (shifted) {
		shifted >>= 1;
		counter++;
	}
	return counter;
}

static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
				   int rtc_24hr_mode)
{
	tm->tm_sec = data[RTC_SEC] & 0x7f;
	tm->tm_min = data[RTC_MIN] & 0x7f;
	if (rtc_24hr_mode)
		tm->tm_hour = data[RTC_HOUR] & 0x1f;
	else {
		tm->tm_hour = data[RTC_HOUR] & 0x0f;
		if (data[RTC_HOUR] & HOUR_PM_MASK)
			tm->tm_hour += 12;
	}

	tm->tm_wday = max77686_rtc_calculate_wday(data[RTC_WEEKDAY] & 0x7f);
	tm->tm_mday = data[RTC_DATE] & 0x1f;
	tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
	tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
	tm->tm_yday = 0;
	tm->tm_isdst = 0;
}

static int max77686_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
{
	data[RTC_SEC] = tm->tm_sec;
	data[RTC_MIN] = tm->tm_min;
	data[RTC_HOUR] = tm->tm_hour;
	data[RTC_WEEKDAY] = 1 << tm->tm_wday;
	data[RTC_DATE] = tm->tm_mday;
	data[RTC_MONTH] = tm->tm_mon + 1;
	data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0 ;

	if (tm->tm_year < 100) {
		pr_warn("%s: MAX77686 RTC cannot handle the year %d."
			"Assume it's 2000.\n", __func__, 1900 + tm->tm_year);
		return -EINVAL;
	}
	return 0;
}

static int max77686_rtc_update(struct max77686_rtc_info *info,
	enum MAX77686_RTC_OP op)
{
	int ret;
	unsigned int data;

	if (op == MAX77686_RTC_WRITE)
		data = 1 << RTC_UDR_SHIFT;
	else
		data = 1 << RTC_RBUDR_SHIFT;

	ret = regmap_update_bits(info->max77686->rtc_regmap,
				 MAX77686_RTC_UPDATE0, data, data);
	if (ret < 0)
		dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
				__func__, ret, data);
	else {
		/* Minimum 16ms delay required before RTC update. */
		msleep(MAX77686_RTC_UPDATE_DELAY);
	}

	return ret;
}

static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct max77686_rtc_info *info = dev_get_drvdata(dev);
	u8 data[RTC_NR_TIME];
	int ret;

	mutex_lock(&info->lock);

	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
	if (ret < 0)
		goto out;

	ret = regmap_bulk_read(info->max77686->rtc_regmap,
				MAX77686_RTC_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__,	ret);
		goto out;
	}

	max77686_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);

	ret = rtc_valid_tm(tm);

out:
	mutex_unlock(&info->lock);
	return ret;
}

static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct max77686_rtc_info *info = dev_get_drvdata(dev);
	u8 data[RTC_NR_TIME];
	int ret;

	ret = max77686_rtc_tm_to_data(tm, data);
	if (ret < 0)
		return ret;

	mutex_lock(&info->lock);

	ret = regmap_bulk_write(info->max77686->rtc_regmap,
				 MAX77686_RTC_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
				ret);
		goto out;
	}

	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);

out:
	mutex_unlock(&info->lock);
	return ret;
}

static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct max77686_rtc_info *info = dev_get_drvdata(dev);
	u8 data[RTC_NR_TIME];
	unsigned int val;
	int i, ret;

	mutex_lock(&info->lock);

	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
	if (ret < 0)
		goto out;

	ret = regmap_bulk_read(info->max77686->rtc_regmap,
				 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
				__func__, __LINE__, ret);
		goto out;
	}

	max77686_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);

	alrm->enabled = 0;
	for (i = 0; i < RTC_NR_TIME; i++) {
		if (data[i] & ALARM_ENABLE_MASK) {
			alrm->enabled = 1;
			break;
		}
	}

	alrm->pending = 0;
	ret = regmap_read(info->max77686->regmap, MAX77686_REG_STATUS2, &val);
	if (ret < 0) {
		dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n",
				__func__, __LINE__, ret);
		goto out;
	}

	if (val & (1 << 4)) /* RTCA1 */
		alrm->pending = 1;

out:
	mutex_unlock(&info->lock);
	return 0;
}

static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
{
	u8 data[RTC_NR_TIME];
	int ret, i;
	struct rtc_time tm;

	if (!mutex_is_locked(&info->lock))
		dev_warn(info->dev, "%s: should have mutex locked\n", __func__);

	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
	if (ret < 0)
		goto out;

	ret = regmap_bulk_read(info->max77686->rtc_regmap,
				 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
				__func__, ret);
		goto out;
	}

	max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);

	for (i = 0; i < RTC_NR_TIME; i++)
		data[i] &= ~ALARM_ENABLE_MASK;

	ret = regmap_bulk_write(info->max77686->rtc_regmap,
				 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
				__func__, ret);
		goto out;
	}

	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
	return ret;
}

static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
{
	u8 data[RTC_NR_TIME];
	int ret;
	struct rtc_time tm;

	if (!mutex_is_locked(&info->lock))
		dev_warn(info->dev, "%s: should have mutex locked\n", __func__);

	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
	if (ret < 0)
		goto out;

	ret = regmap_bulk_read(info->max77686->rtc_regmap,
				 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
				__func__, ret);
		goto out;
	}

	max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);

	data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
	data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
	data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
	data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
	if (data[RTC_MONTH] & 0xf)
		data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
	if (data[RTC_YEAR] & 0x7f)
		data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
	if (data[RTC_DATE] & 0x1f)
		data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);

	ret = regmap_bulk_write(info->max77686->rtc_regmap,
				 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
				__func__, ret);
		goto out;
	}

	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
	return ret;
}

static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct max77686_rtc_info *info = dev_get_drvdata(dev);
	u8 data[RTC_NR_TIME];
	int ret;

	ret = max77686_rtc_tm_to_data(&alrm->time, data);
	if (ret < 0)
		return ret;

	mutex_lock(&info->lock);

	ret = max77686_rtc_stop_alarm(info);
	if (ret < 0)
		goto out;

	ret = regmap_bulk_write(info->max77686->rtc_regmap,
				 MAX77686_ALARM1_SEC, data, RTC_NR_TIME);

	if (ret < 0) {
		dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
				__func__, ret);
		goto out;
	}

	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
	if (ret < 0)
		goto out;

	if (alrm->enabled)
		ret = max77686_rtc_start_alarm(info);
out:
	mutex_unlock(&info->lock);
	return ret;
}

static int max77686_rtc_alarm_irq_enable(struct device *dev,
					unsigned int enabled)
{
	struct max77686_rtc_info *info = dev_get_drvdata(dev);
	int ret;

	mutex_lock(&info->lock);
	if (enabled)
		ret = max77686_rtc_start_alarm(info);
	else
		ret = max77686_rtc_stop_alarm(info);
	mutex_unlock(&info->lock);

	return ret;
}

static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
{
	struct max77686_rtc_info *info = data;

	dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);

	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);

	return IRQ_HANDLED;
}

static const struct rtc_class_ops max77686_rtc_ops = {
	.read_time = max77686_rtc_read_time,
	.set_time = max77686_rtc_set_time,
	.read_alarm = max77686_rtc_read_alarm,
	.set_alarm = max77686_rtc_set_alarm,
	.alarm_irq_enable = max77686_rtc_alarm_irq_enable,
};

#ifdef MAX77686_RTC_WTSR_SMPL
static void max77686_rtc_enable_wtsr(struct max77686_rtc_info *info, bool enable)
{
	int ret;
	unsigned int val, mask;

	if (enable)
		val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT);
	else
		val = 0;

	mask = WTSR_EN_MASK | WTSRT_MASK;

	dev_info(info->dev, "%s: %s WTSR\n", __func__,
			enable ? "enable" : "disable");

	ret = regmap_update_bits(info->max77686->rtc_regmap,
				 MAX77686_WTSR_SMPL_CNTL, mask, val);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
				__func__, ret);
		return;
	}

	max77686_rtc_update(info, MAX77686_RTC_WRITE);
}

static void max77686_rtc_enable_smpl(struct max77686_rtc_info *info, bool enable)
{
	int ret;
	unsigned int val, mask;

	if (enable)
		val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT);
	else
		val = 0;

	mask = SMPL_EN_MASK | SMPLT_MASK;

	dev_info(info->dev, "%s: %s SMPL\n", __func__,
			enable ? "enable" : "disable");

	ret = regmap_update_bits(info->max77686->rtc_regmap,
				 MAX77686_WTSR_SMPL_CNTL, mask, val);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
				__func__, ret);
		return;
	}

	max77686_rtc_update(info, MAX77686_RTC_WRITE);

	val = 0;
	regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
	dev_info(info->dev, "%s: WTSR_SMPL(0x%02x)\n", __func__, val);
}
#endif /* MAX77686_RTC_WTSR_SMPL */

static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
{
	u8 data[2];
	int ret;

	/* Set RTC control register : Binary mode, 24hour mdoe */
	data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
	data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);

	info->rtc_24hr_mode = 1;

	ret = regmap_bulk_write(info->max77686->rtc_regmap, MAX77686_RTC_CONTROLM, data, 2);
	if (ret < 0) {
		dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
				__func__, ret);
		return ret;
	}

	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
	return ret;
}

static struct regmap_config max77686_rtc_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
};

static int max77686_rtc_probe(struct platform_device *pdev)
{
	struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
	struct max77686_rtc_info *info;
	int ret, virq;

	dev_info(&pdev->dev, "%s\n", __func__);

	info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
				GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	mutex_init(&info->lock);
	info->dev = &pdev->dev;
	info->max77686 = max77686;
	info->rtc = max77686->rtc;
	info->max77686->rtc_regmap = devm_regmap_init_i2c(info->max77686->rtc,
					 &max77686_rtc_regmap_config);
	if (IS_ERR(info->max77686->rtc_regmap)) {
		ret = PTR_ERR(info->max77686->rtc_regmap);
		dev_err(info->max77686->dev, "Failed to allocate register map: %d\n",
				ret);
		return ret;
	}
	platform_set_drvdata(pdev, info);

	ret = max77686_rtc_init_reg(info);

	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
		goto err_rtc;
	}

#ifdef MAX77686_RTC_WTSR_SMPL
	max77686_rtc_enable_wtsr(info, true);
	max77686_rtc_enable_smpl(info, true);
#endif

	device_init_wakeup(&pdev->dev, 1);

	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max77686-rtc",
					&max77686_rtc_ops, THIS_MODULE);

	if (IS_ERR(info->rtc_dev)) {
		dev_info(&pdev->dev, "%s: fail\n", __func__);

		ret = PTR_ERR(info->rtc_dev);
		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
		if (ret == 0)
			ret = -EINVAL;
		goto err_rtc;
	}
	virq = irq_create_mapping(max77686->irq_domain, MAX77686_RTCIRQ_RTCA1);
	if (!virq) {
		ret = -ENXIO;
		goto err_rtc;
	}
	info->virq = virq;

	ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
				max77686_rtc_alarm_irq, 0, "rtc-alarm0", info);
	if (ret < 0)
		dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
			info->virq, ret);

err_rtc:
	return ret;
}

static int max77686_rtc_remove(struct platform_device *pdev)
{
	return 0;
}

static void max77686_rtc_shutdown(struct platform_device *pdev)
{
#ifdef MAX77686_RTC_WTSR_SMPL
	struct max77686_rtc_info *info = platform_get_drvdata(pdev);
	int i;
	u8 val = 0;

	for (i = 0; i < 3; i++) {
		max77686_rtc_enable_wtsr(info, false);
		regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
		dev_info(info->dev, "%s: WTSR_SMPL reg(0x%02x)\n", __func__,
				val);
		if (val & WTSR_EN_MASK) {
			dev_emerg(info->dev, "%s: fail to disable WTSR\n",
					__func__);
		} else {
			dev_info(info->dev, "%s: success to disable WTSR\n",
					__func__);
			break;
		}
	}

	/* Disable SMPL when power off */
	max77686_rtc_enable_smpl(info, false);
#endif /* MAX77686_RTC_WTSR_SMPL */
}

static const struct platform_device_id rtc_id[] = {
	{ "max77686-rtc", 0 },
	{},
};

static struct platform_driver max77686_rtc_driver = {
	.driver		= {
		.name	= "max77686-rtc",
		.owner	= THIS_MODULE,
	},
	.probe		= max77686_rtc_probe,
	.remove		= max77686_rtc_remove,
	.shutdown	= max77686_rtc_shutdown,
	.id_table	= rtc_id,
};

module_platform_driver(max77686_rtc_driver);

MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
fca1dd03 JL	1	/*
	2	* RTC driver for Maxim MAX77686
	3	*
	4	* Copyright (C) 2012 Samsung Electronics Co.Ltd
	5	*
	6	* based on rtc-max8997.c
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*
	13	*/
	14
	15	#include <linux/slab.h>
	16	#include <linux/rtc.h>
	17	#include <linux/delay.h>
	18	#include <linux/mutex.h>
	19	#include <linux/module.h>
	20	#include <linux/platform_device.h>
	21	#include <linux/mfd/max77686-private.h>
	22	#include <linux/irqdomain.h>
	23	#include <linux/regmap.h>
	24
	25	/* RTC Control Register */
	26	#define BCD_EN_SHIFT 0
ac60bf31	27	#define BCD_EN_MASK (1 << BCD_EN_SHIFT)
fca1dd03 JL	28	#define MODEL24_SHIFT 1
	29	#define MODEL24_MASK (1 << MODEL24_SHIFT)
	30	/* RTC Update Register1 */
	31	#define RTC_UDR_SHIFT 0
	32	#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT)
	33	#define RTC_RBUDR_SHIFT 4
	34	#define RTC_RBUDR_MASK (1 << RTC_RBUDR_SHIFT)
	35	/* WTSR and SMPL Register */
ac60bf31 JH	36	#define WTSRT_SHIFT 0
ac60bf31 JH	37	#define SMPLT_SHIFT 2
fca1dd03 JL	38	#define WTSR_EN_SHIFT 6
fca1dd03 JL	39	#define SMPL_EN_SHIFT 7
ac60bf31 JH	40	#define WTSRT_MASK (3 << WTSRT_SHIFT)
ac60bf31 JH	41	#define SMPLT_MASK (3 << SMPLT_SHIFT)
fca1dd03 JL	42	#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT)
	43	#define SMPL_EN_MASK (1 << SMPL_EN_SHIFT)
	44	/* RTC Hour register */
	45	#define HOUR_PM_SHIFT 6
	46	#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT)
	47	/* RTC Alarm Enable */
	48	#define ALARM_ENABLE_SHIFT 7
	49	#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
	50
	51	#define MAX77686_RTC_UPDATE_DELAY 16
	52	#undef MAX77686_RTC_WTSR_SMPL
	53
	54	enum {
	55	RTC_SEC = 0,
	56	RTC_MIN,
	57	RTC_HOUR,
	58	RTC_WEEKDAY,
	59	RTC_MONTH,
	60	RTC_YEAR,
	61	RTC_DATE,
	62	RTC_NR_TIME
	63	};
	64
	65	struct max77686_rtc_info {
	66	struct device *dev;
	67	struct max77686_dev *max77686;
	68	struct i2c_client *rtc;
	69	struct rtc_device *rtc_dev;
	70	struct mutex lock;
	71
	72	struct regmap *regmap;
	73
	74	int virq;
	75	int rtc_24hr_mode;
	76	};
	77
	78	enum MAX77686_RTC_OP {
	79	MAX77686_RTC_WRITE,
	80	MAX77686_RTC_READ,
	81	};
	82
	83	static inline int max77686_rtc_calculate_wday(u8 shifted)
	84	{
	85	int counter = -1;
	86	while (shifted) {
	87	shifted >>= 1;
	88	counter++;
	89	}
	90	return counter;
	91	}
	92
	93	static void max77686_rtc_data_to_tm(u8 data, struct rtc_time tm,
	94	int rtc_24hr_mode)
	95	{
	96	tm->tm_sec = data[RTC_SEC] & 0x7f;
	97	tm->tm_min = data[RTC_MIN] & 0x7f;
	98	if (rtc_24hr_mode)
	99	tm->tm_hour = data[RTC_HOUR] & 0x1f;
	100	else {
	101	tm->tm_hour = data[RTC_HOUR] & 0x0f;
	102	if (data[RTC_HOUR] & HOUR_PM_MASK)
	103	tm->tm_hour += 12;
	104	}
	105
106	tm->tm_wday = max77686_rtc_calculate_wday(data[RTC_WEEKDAY] & 0x7f);
107	tm->tm_mday = data[RTC_DATE] & 0x1f;
108	tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
109	tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
110	tm->tm_yday = 0;
111	tm->tm_isdst = 0;
112	}
113
114	static int max77686_rtc_tm_to_data(struct rtc_time tm, u8 data)
115	{
116	data[RTC_SEC] = tm->tm_sec;
117	data[RTC_MIN] = tm->tm_min;
118	data[RTC_HOUR] = tm->tm_hour;
119	data[RTC_WEEKDAY] = 1 << tm->tm_wday;
120	data[RTC_DATE] = tm->tm_mday;
121	data[RTC_MONTH] = tm->tm_mon + 1;
122	data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0 ;
123
124	if (tm->tm_year < 100) {
125	pr_warn("%s: MAX77686 RTC cannot handle the year %d."
126	"Assume it's 2000.\n", __func__, 1900 + tm->tm_year);
127	return -EINVAL;
128	}
129	return 0;
130	}
131
132	static int max77686_rtc_update(struct max77686_rtc_info *info,
133	enum MAX77686_RTC_OP op)
134	{
135	int ret;
136	unsigned int data;
137
138	if (op == MAX77686_RTC_WRITE)
139	data = 1 << RTC_UDR_SHIFT;
140	else
141	data = 1 << RTC_RBUDR_SHIFT;
142
143	ret = regmap_update_bits(info->max77686->rtc_regmap,
144	MAX77686_RTC_UPDATE0, data, data);
145	if (ret < 0)
146	dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
147	__func__, ret, data);
148	else {
149	/* Minimum 16ms delay required before RTC update. */
150	msleep(MAX77686_RTC_UPDATE_DELAY);
151	}
152
153	return ret;
154	}
155
156	static int max77686_rtc_read_time(struct device dev, struct rtc_time tm)
157	{
158	struct max77686_rtc_info *info = dev_get_drvdata(dev);
159	u8 data[RTC_NR_TIME];
160	int ret;
161
162	mutex_lock(&info->lock);
163
164	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
165	if (ret < 0)
166	goto out;
167
168	ret = regmap_bulk_read(info->max77686->rtc_regmap,
169	MAX77686_RTC_SEC, data, RTC_NR_TIME);
170	if (ret < 0) {
171	dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, ret);
172	goto out;
173	}
174
175	max77686_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
176
177	ret = rtc_valid_tm(tm);
178
179	out:
180	mutex_unlock(&info->lock);
181	return ret;
182	}
183
184	static int max77686_rtc_set_time(struct device dev, struct rtc_time tm)
185	{
186	struct max77686_rtc_info *info = dev_get_drvdata(dev);
187	u8 data[RTC_NR_TIME];
188	int ret;
189
190	ret = max77686_rtc_tm_to_data(tm, data);
191	if (ret < 0)
192	return ret;
193
194	mutex_lock(&info->lock);
195
196	ret = regmap_bulk_write(info->max77686->rtc_regmap,
197	MAX77686_RTC_SEC, data, RTC_NR_TIME);
198	if (ret < 0) {
199	dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
200	ret);
201	goto out;
202	}
203
204	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
205
206	out:
207	mutex_unlock(&info->lock);
208	return ret;
209	}
210
211	static int max77686_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
212	{
213	struct max77686_rtc_info *info = dev_get_drvdata(dev);
214	u8 data[RTC_NR_TIME];
215	unsigned int val;
216	int i, ret;
217
218	mutex_lock(&info->lock);
219
220	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
221	if (ret < 0)
222	goto out;
223
224	ret = regmap_bulk_read(info->max77686->rtc_regmap,
225	MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
226	if (ret < 0) {
227	dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
228	__func__, __LINE__, ret);
229	goto out;
230	}
231
232	max77686_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
233
234	alrm->enabled = 0;
235	for (i = 0; i < RTC_NR_TIME; i++) {
236	if (data[i] & ALARM_ENABLE_MASK) {
237	alrm->enabled = 1;
238	break;
239	}
240	}
241
242	alrm->pending = 0;
70aa7b8f	243	ret = regmap_read(info->max77686->regmap, MAX77686_REG_STATUS2, &val);
fca1dd03	244	if (ret < 0) {
70aa7b8f	245	dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n",
fca1dd03 JL	246	__func__, __LINE__, ret);
	247	goto out;
	248	}
	249
	250	if (val & (1 << 4)) /* RTCA1 */
	251	alrm->pending = 1;
	252
	253	out:
	254	mutex_unlock(&info->lock);
	255	return 0;
	256	}
	257
	258	static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
	259	{
	260	u8 data[RTC_NR_TIME];
	261	int ret, i;
	262	struct rtc_time tm;
	263
	264	if (!mutex_is_locked(&info->lock))
	265	dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
	266
	267	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
	268	if (ret < 0)
	269	goto out;
	270
	271	ret = regmap_bulk_read(info->max77686->rtc_regmap,
	272	MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	273	if (ret < 0) {
	274	dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
	275	__func__, ret);
	276	goto out;
	277	}
	278
	279	max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
	280
	281	for (i = 0; i < RTC_NR_TIME; i++)
	282	data[i] &= ~ALARM_ENABLE_MASK;
	283
	284	ret = regmap_bulk_write(info->max77686->rtc_regmap,
	285	MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
	286	if (ret < 0) {
	287	dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
	288	__func__, ret);
	289	goto out;
	290	}
	291
	292	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
	293	out:
	294	return ret;
	295	}
	296
	297	static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
	298	{
	299	u8 data[RTC_NR_TIME];
	300	int ret;
	301	struct rtc_time tm;
	302
	303	if (!mutex_is_locked(&info->lock))
	304	dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
	305
	306	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
	307	if (ret < 0)
	308	goto out;
	309
310	ret = regmap_bulk_read(info->max77686->rtc_regmap,
311	MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
312	if (ret < 0) {
313	dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
314	__func__, ret);
315	goto out;
316	}
317
318	max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
319
320	data[RTC_SEC] \|= (1 << ALARM_ENABLE_SHIFT);
321	data[RTC_MIN] \|= (1 << ALARM_ENABLE_SHIFT);
322	data[RTC_HOUR] \|= (1 << ALARM_ENABLE_SHIFT);
323	data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
324	if (data[RTC_MONTH] & 0xf)
325	data[RTC_MONTH] \|= (1 << ALARM_ENABLE_SHIFT);
326	if (data[RTC_YEAR] & 0x7f)
327	data[RTC_YEAR] \|= (1 << ALARM_ENABLE_SHIFT);
328	if (data[RTC_DATE] & 0x1f)
329	data[RTC_DATE] \|= (1 << ALARM_ENABLE_SHIFT);
330
331	ret = regmap_bulk_write(info->max77686->rtc_regmap,
332	MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
333	if (ret < 0) {
334	dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
335	__func__, ret);
336	goto out;
337	}
338
339	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
340	out:
341	return ret;
342	}
343
344	static int max77686_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
345	{
346	struct max77686_rtc_info *info = dev_get_drvdata(dev);
347	u8 data[RTC_NR_TIME];
348	int ret;
349
350	ret = max77686_rtc_tm_to_data(&alrm->time, data);
351	if (ret < 0)
352	return ret;
353
354	mutex_lock(&info->lock);
355
356	ret = max77686_rtc_stop_alarm(info);
357	if (ret < 0)
358	goto out;
359
360	ret = regmap_bulk_write(info->max77686->rtc_regmap,
361	MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
362
363	if (ret < 0) {
364	dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
365	__func__, ret);
366	goto out;
367	}
368
369	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
370	if (ret < 0)
371	goto out;
372
373	if (alrm->enabled)
374	ret = max77686_rtc_start_alarm(info);
375	out:
376	mutex_unlock(&info->lock);
377	return ret;
378	}
379
380	static int max77686_rtc_alarm_irq_enable(struct device *dev,
381	unsigned int enabled)
382	{
383	struct max77686_rtc_info *info = dev_get_drvdata(dev);
384	int ret;
385
386	mutex_lock(&info->lock);
387	if (enabled)
388	ret = max77686_rtc_start_alarm(info);
389	else
390	ret = max77686_rtc_stop_alarm(info);
391	mutex_unlock(&info->lock);
392
393	return ret;
394	}
395
396	static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
397	{
398	struct max77686_rtc_info *info = data;
399
400	dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);
401
402	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF \| RTC_AF);
403
404	return IRQ_HANDLED;
405	}
406
407	static const struct rtc_class_ops max77686_rtc_ops = {
408	.read_time = max77686_rtc_read_time,
409	.set_time = max77686_rtc_set_time,
410	.read_alarm = max77686_rtc_read_alarm,
411	.set_alarm = max77686_rtc_set_alarm,
412	.alarm_irq_enable = max77686_rtc_alarm_irq_enable,
413	};
414
415	#ifdef MAX77686_RTC_WTSR_SMPL
416	static void max77686_rtc_enable_wtsr(struct max77686_rtc_info *info, bool enable)
417	{
418	int ret;
419	unsigned int val, mask;
420
421	if (enable)
422	val = (1 << WTSR_EN_SHIFT) \| (3 << WTSRT_SHIFT);
423	else
424	val = 0;
425
426	mask = WTSR_EN_MASK \| WTSRT_MASK;
427
428	dev_info(info->dev, "%s: %s WTSR\n", __func__,
429	enable ? "enable" : "disable");
430
431	ret = regmap_update_bits(info->max77686->rtc_regmap,
432	MAX77686_WTSR_SMPL_CNTL, mask, val);
433	if (ret < 0) {
434	dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
435	__func__, ret);
436	return;
437	}
438
439	max77686_rtc_update(info, MAX77686_RTC_WRITE);
440	}
441
442	static void max77686_rtc_enable_smpl(struct max77686_rtc_info *info, bool enable)
443	{
444	int ret;
445	unsigned int val, mask;
446
447	if (enable)
448	val = (1 << SMPL_EN_SHIFT) \| (0 << SMPLT_SHIFT);
449	else
450	val = 0;
451
452	mask = SMPL_EN_MASK \| SMPLT_MASK;
453
454	dev_info(info->dev, "%s: %s SMPL\n", __func__,
455	enable ? "enable" : "disable");
456
457	ret = regmap_update_bits(info->max77686->rtc_regmap,
458	MAX77686_WTSR_SMPL_CNTL, mask, val);
459	if (ret < 0) {
460	dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
461	__func__, ret);
462	return;
463	}
464
465	max77686_rtc_update(info, MAX77686_RTC_WRITE);
466
467	val = 0;
468	regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
e2bf1151	469	dev_info(info->dev, "%s: WTSR_SMPL(0x%02x)\n", __func__, val);
fca1dd03 JL	470	}
	471	#endif /* MAX77686_RTC_WTSR_SMPL */
	472
	473	static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
	474	{
	475	u8 data[2];
	476	int ret;
	477
	478	/* Set RTC control register : Binary mode, 24hour mdoe */
	479	data[0] = (1 << BCD_EN_SHIFT) \| (1 << MODEL24_SHIFT);
	480	data[1] = (0 << BCD_EN_SHIFT) \| (1 << MODEL24_SHIFT);
	481
	482	info->rtc_24hr_mode = 1;
	483
	484	ret = regmap_bulk_write(info->max77686->rtc_regmap, MAX77686_RTC_CONTROLM, data, 2);
	485	if (ret < 0) {
	486	dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
	487	__func__, ret);
	488	return ret;
	489	}
	490
	491	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
	492	return ret;
	493	}
	494
	495	static struct regmap_config max77686_rtc_regmap_config = {
	496	.reg_bits = 8,
	497	.val_bits = 8,
	498	};
	499
	500	static int max77686_rtc_probe(struct platform_device *pdev)
	501	{
	502	struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
	503	struct max77686_rtc_info *info;
	504	int ret, virq;
	505
3cebeb53	506	dev_info(&pdev->dev, "%s\n", __func__);
fca1dd03	507
0f64f853 JH	508	info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
0f64f853 JH	509	GFP_KERNEL);
fca1dd03 JL	510	if (!info)
	511	return -ENOMEM;
	512
	513	mutex_init(&info->lock);
	514	info->dev = &pdev->dev;
	515	info->max77686 = max77686;
	516	info->rtc = max77686->rtc;
7f391f54	517	info->max77686->rtc_regmap = devm_regmap_init_i2c(info->max77686->rtc,
fca1dd03 JL	518	&max77686_rtc_regmap_config);
	519	if (IS_ERR(info->max77686->rtc_regmap)) {
	520	ret = PTR_ERR(info->max77686->rtc_regmap);
	521	dev_err(info->max77686->dev, "Failed to allocate register map: %d\n",
	522	ret);
fca1dd03 JL	523	return ret;
	524	}
	525	platform_set_drvdata(pdev, info);
	526
	527	ret = max77686_rtc_init_reg(info);
	528
	529	if (ret < 0) {
	530	dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
	531	goto err_rtc;
	532	}
	533
	534	#ifdef MAX77686_RTC_WTSR_SMPL
	535	max77686_rtc_enable_wtsr(info, true);
	536	max77686_rtc_enable_smpl(info, true);
	537	#endif
	538
	539	device_init_wakeup(&pdev->dev, 1);
	540
f56950ec JH	541	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max77686-rtc",
f56950ec JH	542	&max77686_rtc_ops, THIS_MODULE);
fca1dd03 JL	543
fca1dd03 JL	544	if (IS_ERR(info->rtc_dev)) {
3cebeb53	545	dev_info(&pdev->dev, "%s: fail\n", __func__);
fca1dd03 JL	546
	547	ret = PTR_ERR(info->rtc_dev);
	548	dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
	549	if (ret == 0)
	550	ret = -EINVAL;
	551	goto err_rtc;
	552	}
	553	virq = irq_create_mapping(max77686->irq_domain, MAX77686_RTCIRQ_RTCA1);
ad819039 SK	554	if (!virq) {
ad819039 SK	555	ret = -ENXIO;
fca1dd03	556	goto err_rtc;
ad819039	557	}
fca1dd03 JL	558	info->virq = virq;
fca1dd03 JL	559
f56950ec JH	560	ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
f56950ec JH	561	max77686_rtc_alarm_irq, 0, "rtc-alarm0", info);
ad819039	562	if (ret < 0)
fca1dd03 JL	563	dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
fca1dd03 JL	564	info->virq, ret);
fca1dd03	565
fca1dd03	566	err_rtc:
fca1dd03 JL	567	return ret;
	568	}
	569
	570	static int max77686_rtc_remove(struct platform_device *pdev)
	571	{
fca1dd03 JL	572	return 0;
	573	}
	574
	575	static void max77686_rtc_shutdown(struct platform_device *pdev)
	576	{
	577	#ifdef MAX77686_RTC_WTSR_SMPL
	578	struct max77686_rtc_info *info = platform_get_drvdata(pdev);
	579	int i;
	580	u8 val = 0;
	581
	582	for (i = 0; i < 3; i++) {
	583	max77686_rtc_enable_wtsr(info, false);
	584	regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
e2bf1151 JH	585	dev_info(info->dev, "%s: WTSR_SMPL reg(0x%02x)\n", __func__,
	586	val);
	587	if (val & WTSR_EN_MASK) {
	588	dev_emerg(info->dev, "%s: fail to disable WTSR\n",
	589	__func__);
	590	} else {
	591	dev_info(info->dev, "%s: success to disable WTSR\n",
	592	__func__);
fca1dd03 JL	593	break;
	594	}
	595	}
	596
	597	/* Disable SMPL when power off */
	598	max77686_rtc_enable_smpl(info, false);
	599	#endif /* MAX77686_RTC_WTSR_SMPL */
	600	}
	601
	602	static const struct platform_device_id rtc_id[] = {
	603	{ "max77686-rtc", 0 },
	604	{},
	605	};
	606
	607	static struct platform_driver max77686_rtc_driver = {
	608	.driver = {
	609	.name = "max77686-rtc",
	610	.owner = THIS_MODULE,
	611	},
	612	.probe = max77686_rtc_probe,
	613	.remove = max77686_rtc_remove,
	614	.shutdown = max77686_rtc_shutdown,
	615	.id_table = rtc_id,
	616	};
	617
0c58ff58	618	module_platform_driver(max77686_rtc_driver);
fca1dd03 JL	619
fca1dd03 JL	620	MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
f5b1d3c5	621	MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
fca1dd03	622	MODULE_LICENSE("GPL");