[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-ds3232.c

/*
 * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
 *
 * Copyright (C) 2009-2011 Freescale Semiconductor.
 * Author: Jack Lan <jack.lan@freescale.com>
 * Copyright (C) 2008 MIMOMax Wireless Ltd.
 *
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/regmap.h>

#define DS3232_REG_SECONDS	0x00
#define DS3232_REG_MINUTES	0x01
#define DS3232_REG_HOURS	0x02
#define DS3232_REG_AMPM		0x02
#define DS3232_REG_DAY		0x03
#define DS3232_REG_DATE		0x04
#define DS3232_REG_MONTH	0x05
#define DS3232_REG_CENTURY	0x05
#define DS3232_REG_YEAR		0x06
#define DS3232_REG_ALARM1         0x07	/* Alarm 1 BASE */
#define DS3232_REG_ALARM2         0x0B	/* Alarm 2 BASE */
#define DS3232_REG_CR		0x0E	/* Control register */
#	define DS3232_REG_CR_nEOSC        0x80
#       define DS3232_REG_CR_INTCN        0x04
#       define DS3232_REG_CR_A2IE        0x02
#       define DS3232_REG_CR_A1IE        0x01

#define DS3232_REG_SR	0x0F	/* control/status register */
#	define DS3232_REG_SR_OSF   0x80
#       define DS3232_REG_SR_BSY   0x04
#       define DS3232_REG_SR_A2F   0x02
#       define DS3232_REG_SR_A1F   0x01

struct ds3232 {
	struct device *dev;
	struct regmap *regmap;
	int irq;
	struct rtc_device *rtc;
	struct work_struct work;

	/* The mutex protects alarm operations, and prevents a race
	 * between the enable_irq() in the workqueue and the free_irq()
	 * in the remove function.
	 */
	struct mutex mutex;
	bool suspended;
	int exiting;
};

static int ds3232_check_rtc_status(struct device *dev)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);
	int ret = 0;
	int control, stat;

	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
	if (ret)
		return ret;

	if (stat & DS3232_REG_SR_OSF)
		dev_warn(dev,
				"oscillator discontinuity flagged, "
				"time unreliable\n");

	stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);

	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
	if (ret)
		return ret;

	/* If the alarm is pending, clear it before requesting
	 * the interrupt, so an interrupt event isn't reported
	 * before everything is initialized.
	 */

	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
	if (ret)
		return ret;

	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
	control |= DS3232_REG_CR_INTCN;

	return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
}

static int ds3232_read_time(struct device *dev, struct rtc_time *time)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);
	int ret;
	u8 buf[7];
	unsigned int year, month, day, hour, minute, second;
	unsigned int week, twelve_hr, am_pm;
	unsigned int century, add_century = 0;

	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
	if (ret)
		return ret;

	second = buf[0];
	minute = buf[1];
	hour = buf[2];
	week = buf[3];
	day = buf[4];
	month = buf[5];
	year = buf[6];

	/* Extract additional information for AM/PM and century */

	twelve_hr = hour & 0x40;
	am_pm = hour & 0x20;
	century = month & 0x80;

	/* Write to rtc_time structure */

	time->tm_sec = bcd2bin(second);
	time->tm_min = bcd2bin(minute);
	if (twelve_hr) {
		/* Convert to 24 hr */
		if (am_pm)
			time->tm_hour = bcd2bin(hour & 0x1F) + 12;
		else
			time->tm_hour = bcd2bin(hour & 0x1F);
	} else {
		time->tm_hour = bcd2bin(hour);
	}

	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
	time->tm_wday = bcd2bin(week) - 1;
	time->tm_mday = bcd2bin(day);
	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
	time->tm_mon = bcd2bin(month & 0x7F) - 1;
	if (century)
		add_century = 100;

	time->tm_year = bcd2bin(year) + add_century;

	return rtc_valid_tm(time);
}

static int ds3232_set_time(struct device *dev, struct rtc_time *time)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);
	u8 buf[7];

	/* Extract time from rtc_time and load into ds3232*/

	buf[0] = bin2bcd(time->tm_sec);
	buf[1] = bin2bcd(time->tm_min);
	buf[2] = bin2bcd(time->tm_hour);
	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
	buf[3] = bin2bcd(time->tm_wday + 1);
	buf[4] = bin2bcd(time->tm_mday); /* Date */
	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
	buf[5] = bin2bcd(time->tm_mon + 1);
	if (time->tm_year >= 100) {
		buf[5] |= 0x80;
		buf[6] = bin2bcd(time->tm_year - 100);
	} else {
		buf[6] = bin2bcd(time->tm_year);
	}

	return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
}

/*
 * DS3232 has two alarm, we only use alarm1
 * According to linux specification, only support one-shot alarm
 * no periodic alarm mode
 */
static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);
	int control, stat;
	int ret;
	u8 buf[4];

	mutex_lock(&ds3232->mutex);

	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
	if (ret)
		goto out;
	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
	if (ret)
		goto out;
	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
	if (ret)
		goto out;

	alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
	alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
	alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
	alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);

	alarm->time.tm_mon = -1;
	alarm->time.tm_year = -1;
	alarm->time.tm_wday = -1;
	alarm->time.tm_yday = -1;
	alarm->time.tm_isdst = -1;

	alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
	alarm->pending = !!(stat & DS3232_REG_SR_A1F);

	ret = 0;
out:
	mutex_unlock(&ds3232->mutex);
	return ret;
}

/*
 * linux rtc-module does not support wday alarm
 * and only 24h time mode supported indeed
 */
static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);
	int control, stat;
	int ret;
	u8 buf[4];

	if (ds3232->irq <= 0)
		return -EINVAL;

	mutex_lock(&ds3232->mutex);

	buf[0] = bin2bcd(alarm->time.tm_sec);
	buf[1] = bin2bcd(alarm->time.tm_min);
	buf[2] = bin2bcd(alarm->time.tm_hour);
	buf[3] = bin2bcd(alarm->time.tm_mday);

	/* clear alarm interrupt enable bit */
	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
	if (ret)
		goto out;
	control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE);
	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
	if (ret)
		goto out;

	/* clear any pending alarm flag */
	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
	if (ret)
		goto out;
	stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F);
	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
	if (ret)
		goto out;

	ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
	if (ret)
		goto out;

	if (alarm->enabled) {
		control |= DS3232_REG_CR_A1IE;
		ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
	}
out:
	mutex_unlock(&ds3232->mutex);
	return ret;
}

static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);
	int control;
	int ret;

	mutex_lock(&ds3232->mutex);

	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
	if (ret)
		goto unlock;

	if (enabled)
		/* enable alarm1 interrupt */
		control |= DS3232_REG_CR_A1IE;
	else
		/* disable alarm1 interrupt */
		control &= ~(DS3232_REG_CR_A1IE);
	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);

unlock:
	mutex_unlock(&ds3232->mutex);

	return ret;
}

static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	if (ds3232->irq <= 0)
		return -EINVAL;

	return ds3232_update_alarm(dev, enabled);
}

static irqreturn_t ds3232_irq(int irq, void *dev_id)
{
	struct device *dev = dev_id;
	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	disable_irq_nosync(irq);

	/*
	 * If rtc as a wakeup source, can't schedule the work
	 * at system resume flow, because at this time the i2c bus
	 * has not been resumed.
	 */
	if (!ds3232->suspended)
		schedule_work(&ds3232->work);

	return IRQ_HANDLED;
}

static void ds3232_work(struct work_struct *work)
{
	struct ds3232 *ds3232 = container_of(work, struct ds3232, work);
	int ret;
	int stat, control;

	mutex_lock(&ds3232->mutex);

	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
	if (ret)
		goto unlock;

	if (stat & DS3232_REG_SR_A1F) {
		ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
		if (ret) {
			pr_warn("Read Control Register error - Disable IRQ%d\n",
				ds3232->irq);
		} else {
			/* disable alarm1 interrupt */
			control &= ~(DS3232_REG_CR_A1IE);
			ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
					   control);
			if (ret) {
				dev_warn(ds3232->dev,
					 "Write Control Register error %d\n",
					 ret);
				goto unlock;
			}

			/* clear the alarm pend flag */
			stat &= ~DS3232_REG_SR_A1F;
			ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
			if (ret) {
				dev_warn(ds3232->dev,
					 "Write Status Register error %d\n",
					 ret);
				goto unlock;
			}

			rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF);

			if (!ds3232->exiting)
				enable_irq(ds3232->irq);
		}
	}

unlock:
	mutex_unlock(&ds3232->mutex);
}

static const struct rtc_class_ops ds3232_rtc_ops = {
	.read_time = ds3232_read_time,
	.set_time = ds3232_set_time,
	.read_alarm = ds3232_read_alarm,
	.set_alarm = ds3232_set_alarm,
	.alarm_irq_enable = ds3232_alarm_irq_enable,
};

static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq,
			const char *name)
{
	struct ds3232 *ds3232;
	int ret;

	ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
	if (!ds3232)
		return -ENOMEM;

	ds3232->regmap = regmap;
	ds3232->irq = irq;
	ds3232->dev = dev;
	dev_set_drvdata(dev, ds3232);

	INIT_WORK(&ds3232->work, ds3232_work);
	mutex_init(&ds3232->mutex);

	ret = ds3232_check_rtc_status(dev);
	if (ret)
		return ret;

	if (ds3232->irq > 0) {
		ret = devm_request_irq(dev, ds3232->irq, ds3232_irq,
				       IRQF_SHARED, name, dev);
		if (ret) {
			ds3232->irq = 0;
			dev_err(dev, "unable to request IRQ\n");
		} else
			device_init_wakeup(dev, 1);
	}
	ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
						THIS_MODULE);

	return PTR_ERR_OR_ZERO(ds3232->rtc);
}

static int ds3232_remove(struct device *dev)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	if (ds3232->irq > 0) {
		mutex_lock(&ds3232->mutex);
		ds3232->exiting = 1;
		mutex_unlock(&ds3232->mutex);

		devm_free_irq(dev, ds3232->irq, dev);
		cancel_work_sync(&ds3232->work);
	}

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int ds3232_suspend(struct device *dev)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	if (device_can_wakeup(dev)) {
		ds3232->suspended = true;
		if (irq_set_irq_wake(ds3232->irq, 1)) {
			dev_warn_once(dev, "Cannot set wakeup source\n");
			ds3232->suspended = false;
		}
	}

	return 0;
}

static int ds3232_resume(struct device *dev)
{
	struct ds3232 *ds3232 = dev_get_drvdata(dev);

	if (ds3232->suspended) {
		ds3232->suspended = false;

		/* Clear the hardware alarm pend flag */
		schedule_work(&ds3232->work);

		irq_set_irq_wake(ds3232->irq, 0);
	}

	return 0;
}
#endif

static const struct dev_pm_ops ds3232_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
};

#if IS_ENABLED(CONFIG_I2C)

static int ds3232_i2c_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
	struct regmap *regmap;
	static const struct regmap_config config = {
		.reg_bits = 8,
		.val_bits = 8,
	};

	regmap = devm_regmap_init_i2c(client, &config);
	if (IS_ERR(regmap)) {
		dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
			__func__, PTR_ERR(regmap));
		return PTR_ERR(regmap);
	}

	return ds3232_probe(&client->dev, regmap, client->irq, client->name);
}

static int ds3232_i2c_remove(struct i2c_client *client)
{
	return ds3232_remove(&client->dev);
}

static const struct i2c_device_id ds3232_id[] = {
	{ "ds3232", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ds3232_id);

static struct i2c_driver ds3232_driver = {
	.driver = {
		.name = "rtc-ds3232",
		.pm	= &ds3232_pm_ops,
	},
	.probe = ds3232_i2c_probe,
	.remove = ds3232_i2c_remove,
	.id_table = ds3232_id,
};

static int ds3232_register_driver(void)
{
	return i2c_add_driver(&ds3232_driver);
}

static void ds3232_unregister_driver(void)
{
	i2c_del_driver(&ds3232_driver);
}

#else

static int ds3232_register_driver(void)
{
	return 0;
}

static void ds3232_unregister_driver(void)
{
}

#endif

#if IS_ENABLED(CONFIG_SPI_MASTER)

static int ds3234_probe(struct spi_device *spi)
{
	int res;
	unsigned int tmp;
	static const struct regmap_config config = {
		.reg_bits = 8,
		.val_bits = 8,
		.write_flag_mask = 0x80,
	};
	struct regmap *regmap;

	regmap = devm_regmap_init_spi(spi, &config);
	if (IS_ERR(regmap)) {
		dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
			__func__, PTR_ERR(regmap));
		return PTR_ERR(regmap);
	}

	spi->mode = SPI_MODE_3;
	spi->bits_per_word = 8;
	spi_setup(spi);

	res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
	if (res)
		return res;

	/* Control settings
	 *
	 * CONTROL_REG
	 * BIT 7	6	5	4	3	2	1	0
	 *     EOSC	BBSQW	CONV	RS2	RS1	INTCN	A2IE	A1IE
	 *
	 *     0	0	0	1	1	1	0	0
	 *
	 * CONTROL_STAT_REG
	 * BIT 7	6	5	4	3	2	1	0
	 *     OSF	BB32kHz	CRATE1	CRATE0	EN32kHz	BSY	A2F	A1F
	 *
	 *     1	0	0	0	1	0	0	0
	 */
	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
	if (res)
		return res;
	res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
	if (res)
		return res;

	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
	if (res)
		return res;
	res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
	if (res)
		return res;

	/* Print our settings */
	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
	if (res)
		return res;
	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);

	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
	if (res)
		return res;
	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);

	return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
}

static int ds3234_remove(struct spi_device *spi)
{
	return ds3232_remove(&spi->dev);
}

static struct spi_driver ds3234_driver = {
	.driver = {
		.name	 = "ds3234",
	},
	.probe	 = ds3234_probe,
	.remove = ds3234_remove,
};

static int ds3234_register_driver(void)
{
	return spi_register_driver(&ds3234_driver);
}

static void ds3234_unregister_driver(void)
{
	spi_unregister_driver(&ds3234_driver);
}

#else

static int ds3234_register_driver(void)
{
	return 0;
}

static void ds3234_unregister_driver(void)
{
}

#endif

static int __init ds323x_init(void)
{
	int ret;

	ret = ds3232_register_driver();
	if (ret) {
		pr_err("Failed to register ds3232 driver: %d\n", ret);
		return ret;
	}

	ret = ds3234_register_driver();
	if (ret) {
		pr_err("Failed to register ds3234 driver: %d\n", ret);
		ds3232_unregister_driver();
	}

	return ret;
}
module_init(ds323x_init)

static void __exit ds323x_exit(void)
{
	ds3234_unregister_driver();
	ds3232_unregister_driver();
}
module_exit(ds323x_exit)

MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:ds3234");
Commit	Line	Data
c03675f0	1	/*
080481f5	2	* RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
c03675f0	3	*
a2d6d2fa	4	* Copyright (C) 2009-2011 Freescale Semiconductor.
f46418c5	5	* Author: Jack Lan <jack.lan@freescale.com>
080481f5	6	* Copyright (C) 2008 MIMOMax Wireless Ltd.
c03675f0 RZ	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	*/
c03675f0	13
a737e835 JP	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a737e835 JP	15
c03675f0 RZ	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/interrupt.h>
	19	#include <linux/i2c.h>
080481f5	20	#include <linux/spi/spi.h>
c03675f0 RZ	21	#include <linux/rtc.h>
	22	#include <linux/bcd.h>
	23	#include <linux/workqueue.h>
	24	#include <linux/slab.h>
370927c4	25	#include <linux/regmap.h>
c03675f0 RZ	26
	27	#define DS3232_REG_SECONDS 0x00
	28	#define DS3232_REG_MINUTES 0x01
	29	#define DS3232_REG_HOURS 0x02
	30	#define DS3232_REG_AMPM 0x02
	31	#define DS3232_REG_DAY 0x03
	32	#define DS3232_REG_DATE 0x04
	33	#define DS3232_REG_MONTH 0x05
	34	#define DS3232_REG_CENTURY 0x05
	35	#define DS3232_REG_YEAR 0x06
	36	#define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */
	37	#define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */
	38	#define DS3232_REG_CR 0x0E /* Control register */
	39	# define DS3232_REG_CR_nEOSC 0x80
	40	# define DS3232_REG_CR_INTCN 0x04
	41	# define DS3232_REG_CR_A2IE 0x02
	42	# define DS3232_REG_CR_A1IE 0x01
	43
	44	#define DS3232_REG_SR 0x0F /* control/status register */
	45	# define DS3232_REG_SR_OSF 0x80
	46	# define DS3232_REG_SR_BSY 0x04
	47	# define DS3232_REG_SR_A2F 0x02
	48	# define DS3232_REG_SR_A1F 0x01
	49
	50	struct ds3232 {
370927c4 AM	51	struct device *dev;
	52	struct regmap *regmap;
	53	int irq;
c03675f0 RZ	54	struct rtc_device *rtc;
	55	struct work_struct work;
	56
	57	/* The mutex protects alarm operations, and prevents a race
	58	* between the enable_irq() in the workqueue and the free_irq()
	59	* in the remove function.
	60	*/
	61	struct mutex mutex;
c93a3ae2	62	bool suspended;
c03675f0 RZ	63	int exiting;
	64	};
	65
370927c4	66	static int ds3232_check_rtc_status(struct device *dev)
c03675f0	67	{
370927c4	68	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c03675f0 RZ	69	int ret = 0;
	70	int control, stat;
	71
370927c4 AM	72	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
	73	if (ret)
	74	return ret;
c03675f0 RZ	75
c03675f0 RZ	76	if (stat & DS3232_REG_SR_OSF)
370927c4	77	dev_warn(dev,
c03675f0 RZ	78	"oscillator discontinuity flagged, "
	79	"time unreliable\n");
	80
	81	stat &= ~(DS3232_REG_SR_OSF \| DS3232_REG_SR_A1F \| DS3232_REG_SR_A2F);
	82
370927c4 AM	83	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
370927c4 AM	84	if (ret)
c03675f0 RZ	85	return ret;
	86
	87	/* If the alarm is pending, clear it before requesting
	88	* the interrupt, so an interrupt event isn't reported
	89	* before everything is initialized.
	90	*/
	91
370927c4 AM	92	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
	93	if (ret)
	94	return ret;
c03675f0 RZ	95
	96	control &= ~(DS3232_REG_CR_A1IE \| DS3232_REG_CR_A2IE);
	97	control \|= DS3232_REG_CR_INTCN;
	98
370927c4	99	return regmap_write(ds3232->regmap, DS3232_REG_CR, control);
c03675f0 RZ	100	}
	101
	102	static int ds3232_read_time(struct device dev, struct rtc_time time)
	103	{
370927c4	104	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c03675f0 RZ	105	int ret;
	106	u8 buf[7];
	107	unsigned int year, month, day, hour, minute, second;
	108	unsigned int week, twelve_hr, am_pm;
	109	unsigned int century, add_century = 0;
	110
370927c4 AM	111	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
370927c4 AM	112	if (ret)
c03675f0	113	return ret;
c03675f0 RZ	114
	115	second = buf[0];
	116	minute = buf[1];
	117	hour = buf[2];
	118	week = buf[3];
	119	day = buf[4];
	120	month = buf[5];
	121	year = buf[6];
	122
	123	/* Extract additional information for AM/PM and century */
	124
	125	twelve_hr = hour & 0x40;
	126	am_pm = hour & 0x20;
	127	century = month & 0x80;
	128
	129	/* Write to rtc_time structure */
	130
	131	time->tm_sec = bcd2bin(second);
	132	time->tm_min = bcd2bin(minute);
	133	if (twelve_hr) {
	134	/* Convert to 24 hr */
	135	if (am_pm)
	136	time->tm_hour = bcd2bin(hour & 0x1F) + 12;
	137	else
	138	time->tm_hour = bcd2bin(hour & 0x1F);
	139	} else {
	140	time->tm_hour = bcd2bin(hour);
	141	}
	142
a2d6d2fa LX	143	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
a2d6d2fa LX	144	time->tm_wday = bcd2bin(week) - 1;
c03675f0	145	time->tm_mday = bcd2bin(day);
a2d6d2fa LX	146	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
a2d6d2fa LX	147	time->tm_mon = bcd2bin(month & 0x7F) - 1;
c03675f0 RZ	148	if (century)
	149	add_century = 100;
	150
	151	time->tm_year = bcd2bin(year) + add_century;
	152
	153	return rtc_valid_tm(time);
	154	}
	155
	156	static int ds3232_set_time(struct device dev, struct rtc_time time)
	157	{
370927c4	158	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c03675f0 RZ	159	u8 buf[7];
	160
	161	/* Extract time from rtc_time and load into ds3232*/
	162
	163	buf[0] = bin2bcd(time->tm_sec);
	164	buf[1] = bin2bcd(time->tm_min);
	165	buf[2] = bin2bcd(time->tm_hour);
a2d6d2fa LX	166	/* Day of the week in linux range is 0~6 while 1~7 in RTC chip */
a2d6d2fa LX	167	buf[3] = bin2bcd(time->tm_wday + 1);
c03675f0	168	buf[4] = bin2bcd(time->tm_mday); /* Date */
a2d6d2fa LX	169	/* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */
a2d6d2fa LX	170	buf[5] = bin2bcd(time->tm_mon + 1);
c03675f0 RZ	171	if (time->tm_year >= 100) {
	172	buf[5] \|= 0x80;
	173	buf[6] = bin2bcd(time->tm_year - 100);
	174	} else {
	175	buf[6] = bin2bcd(time->tm_year);
	176	}
	177
370927c4	178	return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7);
c03675f0 RZ	179	}
c03675f0 RZ	180
f46418c5 LCB	181	/*
	182	* DS3232 has two alarm, we only use alarm1
	183	* According to linux specification, only support one-shot alarm
	184	* no periodic alarm mode
	185	*/
	186	static int ds3232_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	187	{
370927c4	188	struct ds3232 *ds3232 = dev_get_drvdata(dev);
f46418c5 LCB	189	int control, stat;
	190	int ret;
	191	u8 buf[4];
	192
	193	mutex_lock(&ds3232->mutex);
	194
370927c4 AM	195	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
370927c4 AM	196	if (ret)
f46418c5	197	goto out;
370927c4 AM	198	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
370927c4 AM	199	if (ret)
f46418c5	200	goto out;
370927c4 AM	201	ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
370927c4 AM	202	if (ret)
f46418c5 LCB	203	goto out;
	204
	205	alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
	206	alarm->time.tm_min = bcd2bin(buf[1] & 0x7F);
	207	alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F);
	208	alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F);
	209
	210	alarm->time.tm_mon = -1;
	211	alarm->time.tm_year = -1;
	212	alarm->time.tm_wday = -1;
	213	alarm->time.tm_yday = -1;
	214	alarm->time.tm_isdst = -1;
	215
	216	alarm->enabled = !!(control & DS3232_REG_CR_A1IE);
	217	alarm->pending = !!(stat & DS3232_REG_SR_A1F);
	218
	219	ret = 0;
	220	out:
	221	mutex_unlock(&ds3232->mutex);
	222	return ret;
	223	}
	224
	225	/*
	226	* linux rtc-module does not support wday alarm
	227	* and only 24h time mode supported indeed
	228	*/
	229	static int ds3232_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	230	{
370927c4	231	struct ds3232 *ds3232 = dev_get_drvdata(dev);
f46418c5 LCB	232	int control, stat;
	233	int ret;
	234	u8 buf[4];
	235
370927c4	236	if (ds3232->irq <= 0)
f46418c5 LCB	237	return -EINVAL;
	238
	239	mutex_lock(&ds3232->mutex);
	240
	241	buf[0] = bin2bcd(alarm->time.tm_sec);
	242	buf[1] = bin2bcd(alarm->time.tm_min);
	243	buf[2] = bin2bcd(alarm->time.tm_hour);
	244	buf[3] = bin2bcd(alarm->time.tm_mday);
	245
	246	/* clear alarm interrupt enable bit */
370927c4 AM	247	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
370927c4 AM	248	if (ret)
f46418c5	249	goto out;
f46418c5	250	control &= ~(DS3232_REG_CR_A1IE \| DS3232_REG_CR_A2IE);
370927c4 AM	251	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
370927c4 AM	252	if (ret)
f46418c5 LCB	253	goto out;
	254
	255	/* clear any pending alarm flag */
370927c4 AM	256	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
370927c4 AM	257	if (ret)
f46418c5	258	goto out;
f46418c5	259	stat &= ~(DS3232_REG_SR_A1F \| DS3232_REG_SR_A2F);
370927c4 AM	260	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
370927c4 AM	261	if (ret)
f46418c5 LCB	262	goto out;
f46418c5 LCB	263
370927c4	264	ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4);
7b4393a6 AM	265	if (ret)
7b4393a6 AM	266	goto out;
f46418c5 LCB	267
	268	if (alarm->enabled) {
	269	control \|= DS3232_REG_CR_A1IE;
370927c4	270	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
f46418c5 LCB	271	}
	272	out:
	273	mutex_unlock(&ds3232->mutex);
	274	return ret;
	275	}
	276
7b4393a6	277	static int ds3232_update_alarm(struct device *dev, unsigned int enabled)
f46418c5	278	{
370927c4	279	struct ds3232 *ds3232 = dev_get_drvdata(dev);
f46418c5 LCB	280	int control;
f46418c5 LCB	281	int ret;
f46418c5 LCB	282
	283	mutex_lock(&ds3232->mutex);
	284
370927c4 AM	285	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
370927c4 AM	286	if (ret)
f46418c5 LCB	287	goto unlock;
f46418c5 LCB	288
7522297e	289	if (enabled)
f46418c5 LCB	290	/* enable alarm1 interrupt */
	291	control \|= DS3232_REG_CR_A1IE;
	292	else
	293	/* disable alarm1 interrupt */
	294	control &= ~(DS3232_REG_CR_A1IE);
7b4393a6	295	ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control);
f46418c5 LCB	296
	297	unlock:
	298	mutex_unlock(&ds3232->mutex);
7b4393a6 AM	299
7b4393a6 AM	300	return ret;
f46418c5 LCB	301	}
	302
	303	static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled)
	304	{
370927c4	305	struct ds3232 *ds3232 = dev_get_drvdata(dev);
f46418c5	306
370927c4	307	if (ds3232->irq <= 0)
f46418c5 LCB	308	return -EINVAL;
f46418c5 LCB	309
7b4393a6	310	return ds3232_update_alarm(dev, enabled);
f46418c5 LCB	311	}
f46418c5 LCB	312
c03675f0 RZ	313	static irqreturn_t ds3232_irq(int irq, void *dev_id)
c03675f0 RZ	314	{
370927c4 AM	315	struct device *dev = dev_id;
370927c4 AM	316	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c03675f0 RZ	317
c03675f0 RZ	318	disable_irq_nosync(irq);
c93a3ae2 WD	319
	320	/*
	321	* If rtc as a wakeup source, can't schedule the work
	322	* at system resume flow, because at this time the i2c bus
	323	* has not been resumed.
	324	*/
	325	if (!ds3232->suspended)
	326	schedule_work(&ds3232->work);
	327
c03675f0 RZ	328	return IRQ_HANDLED;
	329	}
	330
	331	static void ds3232_work(struct work_struct *work)
	332	{
	333	struct ds3232 *ds3232 = container_of(work, struct ds3232, work);
370927c4	334	int ret;
c03675f0 RZ	335	int stat, control;
	336
	337	mutex_lock(&ds3232->mutex);
	338
370927c4 AM	339	ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat);
370927c4 AM	340	if (ret)
c03675f0 RZ	341	goto unlock;
	342
	343	if (stat & DS3232_REG_SR_A1F) {
370927c4 AM	344	ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control);
370927c4 AM	345	if (ret) {
a737e835	346	pr_warn("Read Control Register error - Disable IRQ%d\n",
370927c4	347	ds3232->irq);
c93a3ae2 WD	348	} else {
	349	/* disable alarm1 interrupt */
	350	control &= ~(DS3232_REG_CR_A1IE);
7b4393a6 AM	351	ret = regmap_write(ds3232->regmap, DS3232_REG_CR,
	352	control);
	353	if (ret) {
	354	dev_warn(ds3232->dev,
	355	"Write Control Register error %d\n",
	356	ret);
	357	goto unlock;
	358	}
c93a3ae2 WD	359
	360	/* clear the alarm pend flag */
	361	stat &= ~DS3232_REG_SR_A1F;
7b4393a6 AM	362	ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat);
	363	if (ret) {
	364	dev_warn(ds3232->dev,
	365	"Write Status Register error %d\n",
	366	ret);
	367	goto unlock;
	368	}
c93a3ae2 WD	369
	370	rtc_update_irq(ds3232->rtc, 1, RTC_AF \| RTC_IRQF);
	371
	372	if (!ds3232->exiting)
370927c4	373	enable_irq(ds3232->irq);
c93a3ae2	374	}
c03675f0 RZ	375	}
c03675f0 RZ	376
c03675f0 RZ	377	unlock:
	378	mutex_unlock(&ds3232->mutex);
	379	}
	380
	381	static const struct rtc_class_ops ds3232_rtc_ops = {
	382	.read_time = ds3232_read_time,
	383	.set_time = ds3232_set_time,
f46418c5 LCB	384	.read_alarm = ds3232_read_alarm,
	385	.set_alarm = ds3232_set_alarm,
	386	.alarm_irq_enable = ds3232_alarm_irq_enable,
c03675f0 RZ	387	};
c03675f0 RZ	388
370927c4 AM	389	static int ds3232_probe(struct device dev, struct regmap regmap, int irq,
370927c4 AM	390	const char *name)
c03675f0 RZ	391	{
	392	struct ds3232 *ds3232;
	393	int ret;
	394
370927c4	395	ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL);
c03675f0 RZ	396	if (!ds3232)
	397	return -ENOMEM;
	398
370927c4 AM	399	ds3232->regmap = regmap;
	400	ds3232->irq = irq;
	401	ds3232->dev = dev;
	402	dev_set_drvdata(dev, ds3232);
c03675f0 RZ	403
	404	INIT_WORK(&ds3232->work, ds3232_work);
	405	mutex_init(&ds3232->mutex);
	406
370927c4	407	ret = ds3232_check_rtc_status(dev);
c03675f0	408	if (ret)
66714612	409	return ret;
c03675f0	410
370927c4 AM	411	if (ds3232->irq > 0) {
	412	ret = devm_request_irq(dev, ds3232->irq, ds3232_irq,
	413	IRQF_SHARED, name, dev);
c03675f0	414	if (ret) {
370927c4 AM	415	ds3232->irq = 0;
	416	dev_err(dev, "unable to request IRQ\n");
	417	} else
	418	device_init_wakeup(dev, 1);
c03675f0	419	}
370927c4 AM	420	ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
	421	THIS_MODULE);
	422
c93a3ae2	423	return PTR_ERR_OR_ZERO(ds3232->rtc);
c03675f0 RZ	424	}
c03675f0 RZ	425
370927c4	426	static int ds3232_remove(struct device *dev)
c03675f0	427	{
370927c4	428	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c03675f0	429
370927c4	430	if (ds3232->irq > 0) {
c03675f0 RZ	431	mutex_lock(&ds3232->mutex);
	432	ds3232->exiting = 1;
	433	mutex_unlock(&ds3232->mutex);
	434
370927c4	435	devm_free_irq(dev, ds3232->irq, dev);
9db8995b	436	cancel_work_sync(&ds3232->work);
c03675f0 RZ	437	}
c03675f0 RZ	438
c03675f0 RZ	439	return 0;
	440	}
	441
c93a3ae2 WD	442	#ifdef CONFIG_PM_SLEEP
	443	static int ds3232_suspend(struct device *dev)
	444	{
	445	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c93a3ae2 WD	446
	447	if (device_can_wakeup(dev)) {
	448	ds3232->suspended = true;
370927c4	449	if (irq_set_irq_wake(ds3232->irq, 1)) {
dc2280eb WD	450	dev_warn_once(dev, "Cannot set wakeup source\n");
	451	ds3232->suspended = false;
	452	}
c93a3ae2 WD	453	}
	454
	455	return 0;
	456	}
	457
	458	static int ds3232_resume(struct device *dev)
	459	{
	460	struct ds3232 *ds3232 = dev_get_drvdata(dev);
c93a3ae2 WD	461
	462	if (ds3232->suspended) {
	463	ds3232->suspended = false;
	464
	465	/* Clear the hardware alarm pend flag */
	466	schedule_work(&ds3232->work);
	467
370927c4	468	irq_set_irq_wake(ds3232->irq, 0);
c93a3ae2 WD	469	}
	470
	471	return 0;
	472	}
	473	#endif
	474
	475	static const struct dev_pm_ops ds3232_pm_ops = {
	476	SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
	477	};
	478
080481f5 AM	479	#if IS_ENABLED(CONFIG_I2C)
080481f5 AM	480
370927c4 AM	481	static int ds3232_i2c_probe(struct i2c_client *client,
	482	const struct i2c_device_id *id)
	483	{
	484	struct regmap *regmap;
	485	static const struct regmap_config config = {
	486	.reg_bits = 8,
	487	.val_bits = 8,
	488	};
	489
	490	regmap = devm_regmap_init_i2c(client, &config);
	491	if (IS_ERR(regmap)) {
	492	dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
	493	__func__, PTR_ERR(regmap));
	494	return PTR_ERR(regmap);
	495	}
	496
	497	return ds3232_probe(&client->dev, regmap, client->irq, client->name);
	498	}
	499
	500	static int ds3232_i2c_remove(struct i2c_client *client)
	501	{
	502	return ds3232_remove(&client->dev);
	503	}
	504
c03675f0 RZ	505	static const struct i2c_device_id ds3232_id[] = {
	506	{ "ds3232", 0 },
	507	{ }
	508	};
	509	MODULE_DEVICE_TABLE(i2c, ds3232_id);
	510
	511	static struct i2c_driver ds3232_driver = {
	512	.driver = {
	513	.name = "rtc-ds3232",
c93a3ae2	514	.pm = &ds3232_pm_ops,
c03675f0	515	},
370927c4 AM	516	.probe = ds3232_i2c_probe,
370927c4 AM	517	.remove = ds3232_i2c_remove,
c03675f0 RZ	518	.id_table = ds3232_id,
c03675f0 RZ	519	};
080481f5 AM	520
	521	static int ds3232_register_driver(void)
	522	{
	523	return i2c_add_driver(&ds3232_driver);
	524	}
	525
	526	static void ds3232_unregister_driver(void)
	527	{
	528	i2c_del_driver(&ds3232_driver);
	529	}
	530
	531	#else
	532
	533	static int ds3232_register_driver(void)
	534	{
	535	return 0;
	536	}
	537
	538	static void ds3232_unregister_driver(void)
	539	{
	540	}
	541
	542	#endif
	543
	544	#if IS_ENABLED(CONFIG_SPI_MASTER)
	545
	546	static int ds3234_probe(struct spi_device *spi)
	547	{
	548	int res;
	549	unsigned int tmp;
	550	static const struct regmap_config config = {
	551	.reg_bits = 8,
	552	.val_bits = 8,
	553	.write_flag_mask = 0x80,
	554	};
	555	struct regmap *regmap;
	556
	557	regmap = devm_regmap_init_spi(spi, &config);
	558	if (IS_ERR(regmap)) {
	559	dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
	560	__func__, PTR_ERR(regmap));
	561	return PTR_ERR(regmap);
	562	}
	563
	564	spi->mode = SPI_MODE_3;
	565	spi->bits_per_word = 8;
	566	spi_setup(spi);
	567
	568	res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
	569	if (res)
	570	return res;
	571
	572	/* Control settings
	573	*
	574	* CONTROL_REG
	575	* BIT 7 6 5 4 3 2 1 0
	576	* EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE
	577	*
	578	* 0 0 0 1 1 1 0 0
	579	*
	580	* CONTROL_STAT_REG
	581	* BIT 7 6 5 4 3 2 1 0
	582	* OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F
	583	*
584	* 1 0 0 0 1 0 0 0
585	*/
586	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
587	if (res)
588	return res;
589	res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
590	if (res)
591	return res;
592
593	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
594	if (res)
595	return res;
596	res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
597	if (res)
598	return res;
599
600	/* Print our settings */
601	res = regmap_read(regmap, DS3232_REG_CR, &tmp);
602	if (res)
603	return res;
604	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
605
606	res = regmap_read(regmap, DS3232_REG_SR, &tmp);
607	if (res)
608	return res;
609	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
610
611	return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
612	}
613
614	static int ds3234_remove(struct spi_device *spi)
615	{
616	return ds3232_remove(&spi->dev);
617	}
618
619	static struct spi_driver ds3234_driver = {
620	.driver = {
621	.name = "ds3234",
622	},
623	.probe = ds3234_probe,
624	.remove = ds3234_remove,
625	};
626
627	static int ds3234_register_driver(void)
628	{
629	return spi_register_driver(&ds3234_driver);
630	}
631
632	static void ds3234_unregister_driver(void)
633	{
634	spi_unregister_driver(&ds3234_driver);
635	}
636
637	#else
638
639	static int ds3234_register_driver(void)
640	{
641	return 0;
642	}
643
644	static void ds3234_unregister_driver(void)
645	{
646	}
647
648	#endif
649
650	static int __init ds323x_init(void)
651	{
652	int ret;
653
654	ret = ds3232_register_driver();
655	if (ret) {
656	pr_err("Failed to register ds3232 driver: %d\n", ret);
657	return ret;
658	}
659
660	ret = ds3234_register_driver();
661	if (ret) {
662	pr_err("Failed to register ds3234 driver: %d\n", ret);
663	ds3232_unregister_driver();
664	}
665
666	return ret;
667	}
668	module_init(ds323x_init)
669
670	static void __exit ds323x_exit(void)
671	{
672	ds3234_unregister_driver();
673	ds3232_unregister_driver();
674	}
675	module_exit(ds323x_exit)
c03675f0 RZ	676
c03675f0 RZ	677	MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
080481f5 AM	678	MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
080481f5 AM	679	MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
c03675f0	680	MODULE_LICENSE("GPL");
080481f5	681	MODULE_ALIAS("spi:ds3234");