[linux.git] / drivers / rtc / rtc-ds1374.c

/*
 * RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C
 *
 * Based on code by Randy Vinson <[email protected]>,
 * which was based on the m41t00.c by Mark Greer <[email protected]>.
 *
 * Copyright (C) 2014 Rose Technology
 * Copyright (C) 2006-2007 Freescale Semiconductor
 *
 * 2005 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */
/*
 * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
 * recommened in .../Documentation/i2c/writing-clients section
 * "Sending and receiving", using SMBus level communication is preferred.
 */

#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/rtc.h>
#include <linux/bcd.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/pm.h>
#ifdef CONFIG_RTC_DRV_DS1374_WDT
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/miscdevice.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
#endif

#define DS1374_REG_TOD0		0x00 /* Time of Day */
#define DS1374_REG_TOD1		0x01
#define DS1374_REG_TOD2		0x02
#define DS1374_REG_TOD3		0x03
#define DS1374_REG_WDALM0	0x04 /* Watchdog/Alarm */
#define DS1374_REG_WDALM1	0x05
#define DS1374_REG_WDALM2	0x06
#define DS1374_REG_CR		0x07 /* Control */
#define DS1374_REG_CR_AIE	0x01 /* Alarm Int. Enable */
#define DS1374_REG_CR_WDALM	0x20 /* 1=Watchdog, 0=Alarm */
#define DS1374_REG_CR_WACE	0x40 /* WD/Alarm counter enable */
#define DS1374_REG_SR		0x08 /* Status */
#define DS1374_REG_SR_OSF	0x80 /* Oscillator Stop Flag */
#define DS1374_REG_SR_AF	0x01 /* Alarm Flag */
#define DS1374_REG_TCR		0x09 /* Trickle Charge */

static const struct i2c_device_id ds1374_id[] = {
	{ "ds1374", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ds1374_id);

#ifdef CONFIG_OF
static const struct of_device_id ds1374_of_match[] = {
	{ .compatible = "dallas,ds1374" },
	{ }
};
MODULE_DEVICE_TABLE(of, ds1374_of_match);
#endif

struct ds1374 {
	struct i2c_client *client;
	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;
	int exiting;
};

static struct i2c_driver ds1374_driver;

static int ds1374_read_rtc(struct i2c_client *client, u32 *time,
			   int reg, int nbytes)
{
	u8 buf[4];
	int ret;
	int i;

	if (WARN_ON(nbytes > 4))
		return -EINVAL;

	ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf);

	if (ret < 0)
		return ret;
	if (ret < nbytes)
		return -EIO;

	for (i = nbytes - 1, *time = 0; i >= 0; i--)
		*time = (*time << 8) | buf[i];

	return 0;
}

static int ds1374_write_rtc(struct i2c_client *client, u32 time,
			    int reg, int nbytes)
{
	u8 buf[4];
	int i;

	if (nbytes > 4) {
		WARN_ON(1);
		return -EINVAL;
	}

	for (i = 0; i < nbytes; i++) {
		buf[i] = time & 0xff;
		time >>= 8;
	}

	return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf);
}

static int ds1374_check_rtc_status(struct i2c_client *client)
{
	int ret = 0;
	int control, stat;

	stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
	if (stat < 0)
		return stat;

	if (stat & DS1374_REG_SR_OSF)
		dev_warn(&client->dev,
			 "oscillator discontinuity flagged, time unreliable\n");

	stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF);

	ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
	if (ret < 0)
		return ret;

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

	control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	if (control < 0)
		return control;

	control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
	return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
}

static int ds1374_read_time(struct device *dev, struct rtc_time *time)
{
	struct i2c_client *client = to_i2c_client(dev);
	u32 itime;
	int ret;

	ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
	if (!ret)
		rtc_time_to_tm(itime, time);

	return ret;
}

static int ds1374_set_time(struct device *dev, struct rtc_time *time)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned long itime;

	rtc_tm_to_time(time, &itime);
	return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
}

#ifndef CONFIG_RTC_DRV_DS1374_WDT
/* The ds1374 has a decrementer for an alarm, rather than a comparator.
 * If the time of day is changed, then the alarm will need to be
 * reset.
 */
static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1374 *ds1374 = i2c_get_clientdata(client);
	u32 now, cur_alarm;
	int cr, sr;
	int ret = 0;

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

	mutex_lock(&ds1374->mutex);

	cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	if (ret < 0)
		goto out;

	sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
	if (ret < 0)
		goto out;

	ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4);
	if (ret)
		goto out;

	ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3);
	if (ret)
		goto out;

	rtc_time_to_tm(now + cur_alarm, &alarm->time);
	alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
	alarm->pending = !!(sr & DS1374_REG_SR_AF);

out:
	mutex_unlock(&ds1374->mutex);
	return ret;
}

static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1374 *ds1374 = i2c_get_clientdata(client);
	struct rtc_time now;
	unsigned long new_alarm, itime;
	int cr;
	int ret = 0;

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

	ret = ds1374_read_time(dev, &now);
	if (ret < 0)
		return ret;

	rtc_tm_to_time(&alarm->time, &new_alarm);
	rtc_tm_to_time(&now, &itime);

	/* This can happen due to races, in addition to dates that are
	 * truly in the past.  To avoid requiring the caller to check for
	 * races, dates in the past are assumed to be in the recent past
	 * (i.e. not something that we'd rather the caller know about via
	 * an error), and the alarm is set to go off as soon as possible.
	 */
	if (time_before_eq(new_alarm, itime))
		new_alarm = 1;
	else
		new_alarm -= itime;

	mutex_lock(&ds1374->mutex);

	ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	if (ret < 0)
		goto out;

	/* Disable any existing alarm before setting the new one
	 * (or lack thereof). */
	cr &= ~DS1374_REG_CR_WACE;

	ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
	if (ret < 0)
		goto out;

	ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3);
	if (ret)
		goto out;

	if (alarm->enabled) {
		cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
		cr &= ~DS1374_REG_CR_WDALM;

		ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
	}

out:
	mutex_unlock(&ds1374->mutex);
	return ret;
}
#endif

static irqreturn_t ds1374_irq(int irq, void *dev_id)
{
	struct i2c_client *client = dev_id;
	struct ds1374 *ds1374 = i2c_get_clientdata(client);

	disable_irq_nosync(irq);
	schedule_work(&ds1374->work);
	return IRQ_HANDLED;
}

static void ds1374_work(struct work_struct *work)
{
	struct ds1374 *ds1374 = container_of(work, struct ds1374, work);
	struct i2c_client *client = ds1374->client;
	int stat, control;

	mutex_lock(&ds1374->mutex);

	stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
	if (stat < 0)
		goto unlock;

	if (stat & DS1374_REG_SR_AF) {
		stat &= ~DS1374_REG_SR_AF;
		i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);

		control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
		if (control < 0)
			goto out;

		control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
		i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);

		rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF);
	}

out:
	if (!ds1374->exiting)
		enable_irq(client->irq);
unlock:
	mutex_unlock(&ds1374->mutex);
}

#ifndef CONFIG_RTC_DRV_DS1374_WDT
static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds1374 *ds1374 = i2c_get_clientdata(client);
	int ret;

	mutex_lock(&ds1374->mutex);

	ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	if (ret < 0)
		goto out;

	if (enabled) {
		ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
		ret &= ~DS1374_REG_CR_WDALM;
	} else {
		ret &= ~DS1374_REG_CR_WACE;
	}
	ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret);

out:
	mutex_unlock(&ds1374->mutex);
	return ret;
}
#endif

static const struct rtc_class_ops ds1374_rtc_ops = {
	.read_time = ds1374_read_time,
	.set_time = ds1374_set_time,
#ifndef CONFIG_RTC_DRV_DS1374_WDT
	.read_alarm = ds1374_read_alarm,
	.set_alarm = ds1374_set_alarm,
	.alarm_irq_enable = ds1374_alarm_irq_enable,
#endif
};

#ifdef CONFIG_RTC_DRV_DS1374_WDT
/*
 *****************************************************************************
 *
 * Watchdog Driver
 *
 *****************************************************************************
 */
static struct i2c_client *save_client;
/* Default margin */
#define WD_TIMO 131762

#define DRV_NAME "DS1374 Watchdog"

static int wdt_margin = WD_TIMO;
static unsigned long wdt_is_open;
module_param(wdt_margin, int, 0);
MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");

static const struct watchdog_info ds1374_wdt_info = {
	.identity       = "DS1374 WTD",
	.options        = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
						WDIOF_MAGICCLOSE,
};

static int ds1374_wdt_settimeout(unsigned int timeout)
{
	int ret = -ENOIOCTLCMD;
	int cr;

	ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
	if (ret < 0)
		goto out;

	/* Disable any existing watchdog/alarm before setting the new one */
	cr &= ~DS1374_REG_CR_WACE;

	ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
	if (ret < 0)
		goto out;

	/* Set new watchdog time */
	ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
	if (ret) {
		pr_info("couldn't set new watchdog time\n");
		goto out;
	}

	/* Enable watchdog timer */
	cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM;
	cr &= ~DS1374_REG_CR_AIE;

	ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
	if (ret < 0)
		goto out;

	return 0;
out:
	return ret;
}


/*
 * Reload the watchdog timer.  (ie, pat the watchdog)
 */
static void ds1374_wdt_ping(void)
{
	u32 val;
	int ret = 0;

	ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3);
	if (ret)
		pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret);
}

static void ds1374_wdt_disable(void)
{
	int ret = -ENOIOCTLCMD;
	int cr;

	cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
	/* Disable watchdog timer */
	cr &= ~DS1374_REG_CR_WACE;

	ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
}

/*
 * Watchdog device is opened, and watchdog starts running.
 */
static int ds1374_wdt_open(struct inode *inode, struct file *file)
{
	struct ds1374 *ds1374 = i2c_get_clientdata(save_client);

	if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
		mutex_lock(&ds1374->mutex);
		if (test_and_set_bit(0, &wdt_is_open)) {
			mutex_unlock(&ds1374->mutex);
			return -EBUSY;
		}
		/*
		 *      Activate
		 */
		wdt_is_open = 1;
		mutex_unlock(&ds1374->mutex);
		return nonseekable_open(inode, file);
	}
	return -ENODEV;
}

/*
 * Close the watchdog device.
 */
static int ds1374_wdt_release(struct inode *inode, struct file *file)
{
	if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
		clear_bit(0, &wdt_is_open);

	return 0;
}

/*
 * Pat the watchdog whenever device is written to.
 */
static ssize_t ds1374_wdt_write(struct file *file, const char __user *data,
				size_t len, loff_t *ppos)
{
	if (len) {
		ds1374_wdt_ping();
		return 1;
	}
	return 0;
}

static ssize_t ds1374_wdt_read(struct file *file, char __user *data,
				size_t len, loff_t *ppos)
{
	return 0;
}

/*
 * Handle commands from user-space.
 */
static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	int new_margin, options;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user((struct watchdog_info __user *)arg,
		&ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, (int __user *)arg);
	case WDIOC_KEEPALIVE:
		ds1374_wdt_ping();
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_margin, (int __user *)arg))
			return -EFAULT;

		/* the hardware's tick rate is 4096 Hz, so
		 * the counter value needs to be scaled accordingly
		 */
		new_margin <<= 12;
		if (new_margin < 1 || new_margin > 16777216)
			return -EINVAL;

		wdt_margin = new_margin;
		ds1374_wdt_settimeout(new_margin);
		ds1374_wdt_ping();
		/* fallthrough */
	case WDIOC_GETTIMEOUT:
		/* when returning ... inverse is true */
		return put_user((wdt_margin >> 12), (int __user *)arg);
	case WDIOC_SETOPTIONS:
		if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			pr_info("disable watchdog\n");
			ds1374_wdt_disable();
			return 0;
		}

		if (options & WDIOS_ENABLECARD) {
			pr_info("enable watchdog\n");
			ds1374_wdt_settimeout(wdt_margin);
			ds1374_wdt_ping();
			return 0;
		}
		return -EINVAL;
	}
	return -ENOTTY;
}

static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
			unsigned long arg)
{
	int ret;
	struct ds1374 *ds1374 = i2c_get_clientdata(save_client);

	mutex_lock(&ds1374->mutex);
	ret = ds1374_wdt_ioctl(file, cmd, arg);
	mutex_unlock(&ds1374->mutex);

	return ret;
}

static int ds1374_wdt_notify_sys(struct notifier_block *this,
			unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		/* Disable Watchdog */
		ds1374_wdt_disable();
	return NOTIFY_DONE;
}

static const struct file_operations ds1374_wdt_fops = {
	.owner			= THIS_MODULE,
	.read			= ds1374_wdt_read,
	.unlocked_ioctl		= ds1374_wdt_unlocked_ioctl,
	.write			= ds1374_wdt_write,
	.open                   = ds1374_wdt_open,
	.release                = ds1374_wdt_release,
	.llseek			= no_llseek,
};

static struct miscdevice ds1374_miscdev = {
	.minor          = WATCHDOG_MINOR,
	.name           = "watchdog",
	.fops           = &ds1374_wdt_fops,
};

static struct notifier_block ds1374_wdt_notifier = {
	.notifier_call = ds1374_wdt_notify_sys,
};

#endif /*CONFIG_RTC_DRV_DS1374_WDT*/
/*
 *****************************************************************************
 *
 *	Driver Interface
 *
 *****************************************************************************
 */
static int ds1374_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct ds1374 *ds1374;
	int ret;

	ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL);
	if (!ds1374)
		return -ENOMEM;

	ds1374->client = client;
	i2c_set_clientdata(client, ds1374);

	INIT_WORK(&ds1374->work, ds1374_work);
	mutex_init(&ds1374->mutex);

	ret = ds1374_check_rtc_status(client);
	if (ret)
		return ret;

	if (client->irq > 0) {
		ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0,
					"ds1374", client);
		if (ret) {
			dev_err(&client->dev, "unable to request IRQ\n");
			return ret;
		}

		device_set_wakeup_capable(&client->dev, 1);
	}

	ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
						&ds1374_rtc_ops, THIS_MODULE);
	if (IS_ERR(ds1374->rtc)) {
		dev_err(&client->dev, "unable to register the class device\n");
		return PTR_ERR(ds1374->rtc);
	}

#ifdef CONFIG_RTC_DRV_DS1374_WDT
	save_client = client;
	ret = misc_register(&ds1374_miscdev);
	if (ret)
		return ret;
	ret = register_reboot_notifier(&ds1374_wdt_notifier);
	if (ret) {
		misc_deregister(&ds1374_miscdev);
		return ret;
	}
	ds1374_wdt_settimeout(131072);
#endif

	return 0;
}

static int ds1374_remove(struct i2c_client *client)
{
	struct ds1374 *ds1374 = i2c_get_clientdata(client);
#ifdef CONFIG_RTC_DRV_DS1374_WDT
	misc_deregister(&ds1374_miscdev);
	ds1374_miscdev.parent = NULL;
	unregister_reboot_notifier(&ds1374_wdt_notifier);
#endif

	if (client->irq > 0) {
		mutex_lock(&ds1374->mutex);
		ds1374->exiting = 1;
		mutex_unlock(&ds1374->mutex);

		devm_free_irq(&client->dev, client->irq, client);
		cancel_work_sync(&ds1374->work);
	}

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int ds1374_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	if (client->irq > 0 && device_may_wakeup(&client->dev))
		enable_irq_wake(client->irq);
	return 0;
}

static int ds1374_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	if (client->irq > 0 && device_may_wakeup(&client->dev))
		disable_irq_wake(client->irq);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);

static struct i2c_driver ds1374_driver = {
	.driver = {
		.name = "rtc-ds1374",
		.of_match_table = of_match_ptr(ds1374_of_match),
		.pm = &ds1374_pm,
	},
	.probe = ds1374_probe,
	.remove = ds1374_remove,
	.id_table = ds1374_id,
};

module_i2c_driver(ds1374_driver);

MODULE_AUTHOR("Scott Wood <[email protected]>");
MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
bf4994d7 SW	1	/*
	2	* RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C
	3	*
	4	* Based on code by Randy Vinson <[email protected]>,
	5	* which was based on the m41t00.c by Mark Greer <[email protected]>.
	6	*
920f91e5	7	* Copyright (C) 2014 Rose Technology
bf4994d7 SW	8	* Copyright (C) 2006-2007 Freescale Semiconductor
	9	*
	10	* 2005 (c) MontaVista Software, Inc. This file is licensed under
	11	* the terms of the GNU General Public License version 2. This program
	12	* is licensed "as is" without any warranty of any kind, whether express
	13	* or implied.
	14	*/
	15	/*
	16	* It would be more efficient to use i2c msgs/i2c_transfer directly but, as
	17	* recommened in .../Documentation/i2c/writing-clients section
	18	* "Sending and receiving", using SMBus level communication is preferred.
	19	*/
	20
a737e835 JP	21	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a737e835 JP	22
bf4994d7 SW	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/interrupt.h>
	26	#include <linux/i2c.h>
	27	#include <linux/rtc.h>
	28	#include <linux/bcd.h>
	29	#include <linux/workqueue.h>
5a0e3ad6	30	#include <linux/slab.h>
bc96ba74	31	#include <linux/pm.h>
920f91e5 SA	32	#ifdef CONFIG_RTC_DRV_DS1374_WDT
	33	#include <linux/fs.h>
	34	#include <linux/ioctl.h>
	35	#include <linux/miscdevice.h>
	36	#include <linux/reboot.h>
	37	#include <linux/watchdog.h>
	38	#endif
bf4994d7 SW	39
	40	#define DS1374_REG_TOD0 0x00 /* Time of Day */
	41	#define DS1374_REG_TOD1 0x01
	42	#define DS1374_REG_TOD2 0x02
	43	#define DS1374_REG_TOD3 0x03
	44	#define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */
	45	#define DS1374_REG_WDALM1 0x05
	46	#define DS1374_REG_WDALM2 0x06
	47	#define DS1374_REG_CR 0x07 /* Control */
	48	#define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */
	49	#define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */
	50	#define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */
	51	#define DS1374_REG_SR 0x08 /* Status */
	52	#define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */
	53	#define DS1374_REG_SR_AF 0x01 /* Alarm Flag */
	54	#define DS1374_REG_TCR 0x09 /* Trickle Charge */
	55
3760f736	56	static const struct i2c_device_id ds1374_id[] = {
f2eb4327	57	{ "ds1374", 0 },
3760f736 JD	58	{ }
	59	};
	60	MODULE_DEVICE_TABLE(i2c, ds1374_id);
	61
920f91e5 SA	62	#ifdef CONFIG_OF
	63	static const struct of_device_id ds1374_of_match[] = {
	64	{ .compatible = "dallas,ds1374" },
	65	{ }
	66	};
	67	MODULE_DEVICE_TABLE(of, ds1374_of_match);
	68	#endif
	69
bf4994d7 SW	70	struct ds1374 {
	71	struct i2c_client *client;
	72	struct rtc_device *rtc;
	73	struct work_struct work;
	74
	75	/* The mutex protects alarm operations, and prevents a race
	76	* between the enable_irq() in the workqueue and the free_irq()
	77	* in the remove function.
	78	*/
	79	struct mutex mutex;
	80	int exiting;
	81	};
	82
	83	static struct i2c_driver ds1374_driver;
	84
	85	static int ds1374_read_rtc(struct i2c_client client, u32 time,
adc7b9b6	86	int reg, int nbytes)
bf4994d7 SW	87	{
	88	u8 buf[4];
	89	int ret;
	90	int i;
	91
01835fad	92	if (WARN_ON(nbytes > 4))
bf4994d7	93	return -EINVAL;
bf4994d7 SW	94
	95	ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf);
	96
	97	if (ret < 0)
	98	return ret;
	99	if (ret < nbytes)
	100	return -EIO;
	101
	102	for (i = nbytes - 1, *time = 0; i >= 0; i--)
	103	time = (time << 8) \| buf[i];
	104
	105	return 0;
	106	}
	107
	108	static int ds1374_write_rtc(struct i2c_client *client, u32 time,
adc7b9b6	109	int reg, int nbytes)
bf4994d7 SW	110	{
	111	u8 buf[4];
	112	int i;
	113
	114	if (nbytes > 4) {
	115	WARN_ON(1);
	116	return -EINVAL;
	117	}
	118
	119	for (i = 0; i < nbytes; i++) {
	120	buf[i] = time & 0xff;
	121	time >>= 8;
	122	}
	123
	124	return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf);
	125	}
	126
	127	static int ds1374_check_rtc_status(struct i2c_client *client)
	128	{
	129	int ret = 0;
	130	int control, stat;
	131
	132	stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
	133	if (stat < 0)
	134	return stat;
	135
	136	if (stat & DS1374_REG_SR_OSF)
	137	dev_warn(&client->dev,
adc7b9b6	138	"oscillator discontinuity flagged, time unreliable\n");
bf4994d7 SW	139
	140	stat &= ~(DS1374_REG_SR_OSF \| DS1374_REG_SR_AF);
	141
	142	ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
	143	if (ret < 0)
	144	return ret;
	145
	146	/* If the alarm is pending, clear it before requesting
	147	* the interrupt, so an interrupt event isn't reported
	148	* before everything is initialized.
	149	*/
	150
	151	control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	152	if (control < 0)
	153	return control;
	154
	155	control &= ~(DS1374_REG_CR_WACE \| DS1374_REG_CR_AIE);
	156	return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
	157	}
	158
	159	static int ds1374_read_time(struct device dev, struct rtc_time time)
	160	{
	161	struct i2c_client *client = to_i2c_client(dev);
	162	u32 itime;
	163	int ret;
	164
	165	ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
	166	if (!ret)
	167	rtc_time_to_tm(itime, time);
	168
	169	return ret;
	170	}
	171
	172	static int ds1374_set_time(struct device dev, struct rtc_time time)
	173	{
	174	struct i2c_client *client = to_i2c_client(dev);
	175	unsigned long itime;
	176
	177	rtc_tm_to_time(time, &itime);
	178	return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
	179	}
	180
920f91e5	181	#ifndef CONFIG_RTC_DRV_DS1374_WDT
bf4994d7 SW	182	/* The ds1374 has a decrementer for an alarm, rather than a comparator.
	183	* If the time of day is changed, then the alarm will need to be
	184	* reset.
	185	*/
	186	static int ds1374_read_alarm(struct device dev, struct rtc_wkalrm alarm)
	187	{
	188	struct i2c_client *client = to_i2c_client(dev);
	189	struct ds1374 *ds1374 = i2c_get_clientdata(client);
	190	u32 now, cur_alarm;
	191	int cr, sr;
	192	int ret = 0;
	193
b42f9317	194	if (client->irq <= 0)
bf4994d7 SW	195	return -EINVAL;
	196
	197	mutex_lock(&ds1374->mutex);
	198
	199	cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	200	if (ret < 0)
	201	goto out;
	202
	203	sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
	204	if (ret < 0)
	205	goto out;
	206
	207	ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4);
	208	if (ret)
	209	goto out;
	210
	211	ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3);
	212	if (ret)
	213	goto out;
	214
	215	rtc_time_to_tm(now + cur_alarm, &alarm->time);
	216	alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
	217	alarm->pending = !!(sr & DS1374_REG_SR_AF);
	218
	219	out:
	220	mutex_unlock(&ds1374->mutex);
	221	return ret;
	222	}
	223
	224	static int ds1374_set_alarm(struct device dev, struct rtc_wkalrm alarm)
	225	{
	226	struct i2c_client *client = to_i2c_client(dev);
	227	struct ds1374 *ds1374 = i2c_get_clientdata(client);
	228	struct rtc_time now;
	229	unsigned long new_alarm, itime;
	230	int cr;
	231	int ret = 0;
	232
b42f9317	233	if (client->irq <= 0)
bf4994d7 SW	234	return -EINVAL;
	235
	236	ret = ds1374_read_time(dev, &now);
	237	if (ret < 0)
	238	return ret;
	239
	240	rtc_tm_to_time(&alarm->time, &new_alarm);
	241	rtc_tm_to_time(&now, &itime);
	242
bf4994d7 SW	243	/* This can happen due to races, in addition to dates that are
	244	* truly in the past. To avoid requiring the caller to check for
	245	* races, dates in the past are assumed to be in the recent past
	246	* (i.e. not something that we'd rather the caller know about via
	247	* an error), and the alarm is set to go off as soon as possible.
	248	*/
fa7af8b1	249	if (time_before_eq(new_alarm, itime))
bf4994d7	250	new_alarm = 1;
fa7af8b1 RK	251	else
fa7af8b1 RK	252	new_alarm -= itime;
bf4994d7 SW	253
	254	mutex_lock(&ds1374->mutex);
	255
	256	ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	257	if (ret < 0)
	258	goto out;
	259
	260	/* Disable any existing alarm before setting the new one
	261	* (or lack thereof). */
	262	cr &= ~DS1374_REG_CR_WACE;
	263
	264	ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
	265	if (ret < 0)
	266	goto out;
	267
	268	ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3);
	269	if (ret)
	270	goto out;
	271
	272	if (alarm->enabled) {
	273	cr \|= DS1374_REG_CR_WACE \| DS1374_REG_CR_AIE;
	274	cr &= ~DS1374_REG_CR_WDALM;
	275
	276	ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
	277	}
	278
	279	out:
	280	mutex_unlock(&ds1374->mutex);
	281	return ret;
	282	}
920f91e5	283	#endif
bf4994d7 SW	284
	285	static irqreturn_t ds1374_irq(int irq, void *dev_id)
	286	{
	287	struct i2c_client *client = dev_id;
	288	struct ds1374 *ds1374 = i2c_get_clientdata(client);
	289
	290	disable_irq_nosync(irq);
	291	schedule_work(&ds1374->work);
	292	return IRQ_HANDLED;
	293	}
	294
	295	static void ds1374_work(struct work_struct *work)
	296	{
	297	struct ds1374 *ds1374 = container_of(work, struct ds1374, work);
	298	struct i2c_client *client = ds1374->client;
	299	int stat, control;
	300
	301	mutex_lock(&ds1374->mutex);
	302
	303	stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
	304	if (stat < 0)
28df30e6	305	goto unlock;
bf4994d7 SW	306
	307	if (stat & DS1374_REG_SR_AF) {
	308	stat &= ~DS1374_REG_SR_AF;
	309	i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
	310
	311	control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	312	if (control < 0)
	313	goto out;
	314
	315	control &= ~(DS1374_REG_CR_WACE \| DS1374_REG_CR_AIE);
	316	i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
	317
bf4994d7	318	rtc_update_irq(ds1374->rtc, 1, RTC_AF \| RTC_IRQF);
bf4994d7 SW	319	}
	320
	321	out:
	322	if (!ds1374->exiting)
	323	enable_irq(client->irq);
28df30e6	324	unlock:
bf4994d7 SW	325	mutex_unlock(&ds1374->mutex);
	326	}
	327
920f91e5	328	#ifndef CONFIG_RTC_DRV_DS1374_WDT
16380c15	329	static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
bf4994d7 SW	330	{
	331	struct i2c_client *client = to_i2c_client(dev);
	332	struct ds1374 *ds1374 = i2c_get_clientdata(client);
16380c15	333	int ret;
bf4994d7 SW	334
	335	mutex_lock(&ds1374->mutex);
	336
16380c15 JS	337	ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
	338	if (ret < 0)
	339	goto out;
bf4994d7	340
16380c15	341	if (enabled) {
bf4994d7 SW	342	ret \|= DS1374_REG_CR_WACE \| DS1374_REG_CR_AIE;
bf4994d7 SW	343	ret &= ~DS1374_REG_CR_WDALM;
16380c15 JS	344	} else {
16380c15 JS	345	ret &= ~DS1374_REG_CR_WACE;
bf4994d7	346	}
16380c15	347	ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret);
bf4994d7 SW	348
	349	out:
	350	mutex_unlock(&ds1374->mutex);
	351	return ret;
	352	}
920f91e5	353	#endif
bf4994d7 SW	354
	355	static const struct rtc_class_ops ds1374_rtc_ops = {
	356	.read_time = ds1374_read_time,
	357	.set_time = ds1374_set_time,
920f91e5	358	#ifndef CONFIG_RTC_DRV_DS1374_WDT
bf4994d7 SW	359	.read_alarm = ds1374_read_alarm,
bf4994d7 SW	360	.set_alarm = ds1374_set_alarm,
16380c15	361	.alarm_irq_enable = ds1374_alarm_irq_enable,
920f91e5 SA	362	#endif
	363	};
	364
	365	#ifdef CONFIG_RTC_DRV_DS1374_WDT
	366	/*
	367	*****************************************************************************
	368	*
	369	* Watchdog Driver
	370	*
	371	*****************************************************************************
	372	*/
	373	static struct i2c_client *save_client;
	374	/* Default margin */
	375	#define WD_TIMO 131762
	376
	377	#define DRV_NAME "DS1374 Watchdog"
	378
	379	static int wdt_margin = WD_TIMO;
	380	static unsigned long wdt_is_open;
	381	module_param(wdt_margin, int, 0);
	382	MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");
	383
	384	static const struct watchdog_info ds1374_wdt_info = {
	385	.identity = "DS1374 WTD",
	386	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \|
	387	WDIOF_MAGICCLOSE,
	388	};
	389
	390	static int ds1374_wdt_settimeout(unsigned int timeout)
	391	{
	392	int ret = -ENOIOCTLCMD;
	393	int cr;
	394
	395	ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
	396	if (ret < 0)
	397	goto out;
	398
	399	/* Disable any existing watchdog/alarm before setting the new one */
	400	cr &= ~DS1374_REG_CR_WACE;
	401
	402	ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
	403	if (ret < 0)
	404	goto out;
	405
	406	/* Set new watchdog time */
	407	ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
	408	if (ret) {
a737e835	409	pr_info("couldn't set new watchdog time\n");
920f91e5 SA	410	goto out;
	411	}
	412
	413	/* Enable watchdog timer */
	414	cr \|= DS1374_REG_CR_WACE \| DS1374_REG_CR_WDALM;
	415	cr &= ~DS1374_REG_CR_AIE;
	416
	417	ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
	418	if (ret < 0)
	419	goto out;
	420
	421	return 0;
	422	out:
	423	return ret;
	424	}
	425
	426
	427	/*
	428	* Reload the watchdog timer. (ie, pat the watchdog)
	429	*/
	430	static void ds1374_wdt_ping(void)
	431	{
	432	u32 val;
	433	int ret = 0;
	434
	435	ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3);
	436	if (ret)
	437	pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret);
	438	}
	439
	440	static void ds1374_wdt_disable(void)
	441	{
	442	int ret = -ENOIOCTLCMD;
	443	int cr;
	444
	445	cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
	446	/* Disable watchdog timer */
	447	cr &= ~DS1374_REG_CR_WACE;
	448
	449	ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
	450	}
	451
	452	/*
	453	* Watchdog device is opened, and watchdog starts running.
	454	*/
	455	static int ds1374_wdt_open(struct inode inode, struct file file)
	456	{
	457	struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
	458
	459	if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
	460	mutex_lock(&ds1374->mutex);
	461	if (test_and_set_bit(0, &wdt_is_open)) {
	462	mutex_unlock(&ds1374->mutex);
	463	return -EBUSY;
	464	}
	465	/*
	466	* Activate
	467	*/
	468	wdt_is_open = 1;
	469	mutex_unlock(&ds1374->mutex);
	470	return nonseekable_open(inode, file);
	471	}
	472	return -ENODEV;
	473	}
474
475	/*
476	* Close the watchdog device.
477	*/
478	static int ds1374_wdt_release(struct inode inode, struct file file)
479	{
480	if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
481	clear_bit(0, &wdt_is_open);
482
483	return 0;
484	}
485
486	/*
487	* Pat the watchdog whenever device is written to.
488	*/
489	static ssize_t ds1374_wdt_write(struct file file, const char __user data,
490	size_t len, loff_t *ppos)
491	{
492	if (len) {
493	ds1374_wdt_ping();
494	return 1;
495	}
496	return 0;
497	}
498
499	static ssize_t ds1374_wdt_read(struct file file, char __user data,
500	size_t len, loff_t *ppos)
501	{
502	return 0;
503	}
504
505	/*
506	* Handle commands from user-space.
507	*/
508	static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
509	unsigned long arg)
510	{
511	int new_margin, options;
512
513	switch (cmd) {
514	case WDIOC_GETSUPPORT:
515	return copy_to_user((struct watchdog_info __user *)arg,
516	&ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0;
517
518	case WDIOC_GETSTATUS:
519	case WDIOC_GETBOOTSTATUS:
520	return put_user(0, (int __user *)arg);
521	case WDIOC_KEEPALIVE:
522	ds1374_wdt_ping();
523	return 0;
524	case WDIOC_SETTIMEOUT:
525	if (get_user(new_margin, (int __user *)arg))
526	return -EFAULT;
527
453d0744 MF	528	/* the hardware's tick rate is 4096 Hz, so
	529	* the counter value needs to be scaled accordingly
	530	*/
	531	new_margin <<= 12;
920f91e5 SA	532	if (new_margin < 1 \|\| new_margin > 16777216)
	533	return -EINVAL;
	534
	535	wdt_margin = new_margin;
	536	ds1374_wdt_settimeout(new_margin);
	537	ds1374_wdt_ping();
	538	/* fallthrough */
	539	case WDIOC_GETTIMEOUT:
453d0744 MF	540	/* when returning ... inverse is true */
453d0744 MF	541	return put_user((wdt_margin >> 12), (int __user *)arg);
920f91e5 SA	542	case WDIOC_SETOPTIONS:
	543	if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
	544	return -EFAULT;
	545
	546	if (options & WDIOS_DISABLECARD) {
a737e835	547	pr_info("disable watchdog\n");
920f91e5	548	ds1374_wdt_disable();
538c08f4	549	return 0;
920f91e5 SA	550	}
	551
	552	if (options & WDIOS_ENABLECARD) {
a737e835	553	pr_info("enable watchdog\n");
920f91e5 SA	554	ds1374_wdt_settimeout(wdt_margin);
920f91e5 SA	555	ds1374_wdt_ping();
538c08f4	556	return 0;
920f91e5	557	}
920f91e5 SA	558	return -EINVAL;
	559	}
	560	return -ENOTTY;
	561	}
	562
	563	static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
	564	unsigned long arg)
	565	{
	566	int ret;
	567	struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
	568
	569	mutex_lock(&ds1374->mutex);
	570	ret = ds1374_wdt_ioctl(file, cmd, arg);
	571	mutex_unlock(&ds1374->mutex);
	572
	573	return ret;
	574	}
	575
	576	static int ds1374_wdt_notify_sys(struct notifier_block *this,
	577	unsigned long code, void *unused)
	578	{
	579	if (code == SYS_DOWN \|\| code == SYS_HALT)
	580	/* Disable Watchdog */
	581	ds1374_wdt_disable();
	582	return NOTIFY_DONE;
	583	}
	584
	585	static const struct file_operations ds1374_wdt_fops = {
	586	.owner = THIS_MODULE,
	587	.read = ds1374_wdt_read,
	588	.unlocked_ioctl = ds1374_wdt_unlocked_ioctl,
	589	.write = ds1374_wdt_write,
	590	.open = ds1374_wdt_open,
	591	.release = ds1374_wdt_release,
	592	.llseek = no_llseek,
	593	};
	594
	595	static struct miscdevice ds1374_miscdev = {
	596	.minor = WATCHDOG_MINOR,
	597	.name = "watchdog",
	598	.fops = &ds1374_wdt_fops,
bf4994d7 SW	599	};
bf4994d7 SW	600
920f91e5 SA	601	static struct notifier_block ds1374_wdt_notifier = {
	602	.notifier_call = ds1374_wdt_notify_sys,
	603	};
	604
	605	#endif /CONFIG_RTC_DRV_DS1374_WDT/
	606	/*
	607	*****************************************************************************
	608	*
	609	* Driver Interface
	610	*
	611	*****************************************************************************
	612	*/
d2653e92 JD	613	static int ds1374_probe(struct i2c_client *client,
d2653e92 JD	614	const struct i2c_device_id *id)
bf4994d7 SW	615	{
	616	struct ds1374 *ds1374;
	617	int ret;
	618
d1a96639	619	ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL);
bf4994d7 SW	620	if (!ds1374)
	621	return -ENOMEM;
	622
	623	ds1374->client = client;
	624	i2c_set_clientdata(client, ds1374);
	625
	626	INIT_WORK(&ds1374->work, ds1374_work);
	627	mutex_init(&ds1374->mutex);
	628
	629	ret = ds1374_check_rtc_status(client);
	630	if (ret)
d1a96639	631	return ret;
bf4994d7	632
b42f9317	633	if (client->irq > 0) {
d1a96639	634	ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0,
adc7b9b6	635	"ds1374", client);
bf4994d7 SW	636	if (ret) {
bf4994d7 SW	637	dev_err(&client->dev, "unable to request IRQ\n");
d1a96639	638	return ret;
bf4994d7	639	}
26b3c01f AV	640
26b3c01f AV	641	device_set_wakeup_capable(&client->dev, 1);
bf4994d7 SW	642	}
bf4994d7 SW	643
d1a96639	644	ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
adc7b9b6	645	&ds1374_rtc_ops, THIS_MODULE);
bf4994d7	646	if (IS_ERR(ds1374->rtc)) {
bf4994d7	647	dev_err(&client->dev, "unable to register the class device\n");
d1a96639	648	return PTR_ERR(ds1374->rtc);
bf4994d7 SW	649	}
bf4994d7 SW	650
920f91e5 SA	651	#ifdef CONFIG_RTC_DRV_DS1374_WDT
	652	save_client = client;
	653	ret = misc_register(&ds1374_miscdev);
	654	if (ret)
	655	return ret;
	656	ret = register_reboot_notifier(&ds1374_wdt_notifier);
	657	if (ret) {
	658	misc_deregister(&ds1374_miscdev);
	659	return ret;
	660	}
	661	ds1374_wdt_settimeout(131072);
	662	#endif
	663
bf4994d7	664	return 0;
bf4994d7 SW	665	}
bf4994d7 SW	666
5a167f45	667	static int ds1374_remove(struct i2c_client *client)
bf4994d7 SW	668	{
bf4994d7 SW	669	struct ds1374 *ds1374 = i2c_get_clientdata(client);
920f91e5	670	#ifdef CONFIG_RTC_DRV_DS1374_WDT
f368ed60 GKH	671	misc_deregister(&ds1374_miscdev);
f368ed60 GKH	672	ds1374_miscdev.parent = NULL;
920f91e5 SA	673	unregister_reboot_notifier(&ds1374_wdt_notifier);
920f91e5 SA	674	#endif
bf4994d7	675
b42f9317	676	if (client->irq > 0) {
bf4994d7 SW	677	mutex_lock(&ds1374->mutex);
	678	ds1374->exiting = 1;
	679	mutex_unlock(&ds1374->mutex);
	680
d1a96639	681	devm_free_irq(&client->dev, client->irq, client);
9db8995b	682	cancel_work_sync(&ds1374->work);
bf4994d7 SW	683	}
bf4994d7 SW	684
bf4994d7 SW	685	return 0;
	686	}
	687
8b80ef64	688	#ifdef CONFIG_PM_SLEEP
bc96ba74	689	static int ds1374_suspend(struct device *dev)
986e36a5	690	{
bc96ba74 MB	691	struct i2c_client *client = to_i2c_client(dev);
bc96ba74 MB	692
0d9030a2	693	if (client->irq > 0 && device_may_wakeup(&client->dev))
986e36a5 MP	694	enable_irq_wake(client->irq);
	695	return 0;
	696	}
	697
bc96ba74	698	static int ds1374_resume(struct device *dev)
986e36a5	699	{
bc96ba74 MB	700	struct i2c_client *client = to_i2c_client(dev);
bc96ba74 MB	701
0d9030a2	702	if (client->irq > 0 && device_may_wakeup(&client->dev))
986e36a5 MP	703	disable_irq_wake(client->irq);
	704	return 0;
	705	}
8b80ef64	706	#endif
bc96ba74 MB	707
	708	static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
	709
bf4994d7 SW	710	static struct i2c_driver ds1374_driver = {
	711	.driver = {
	712	.name = "rtc-ds1374",
abac12e1	713	.of_match_table = of_match_ptr(ds1374_of_match),
8b80ef64	714	.pm = &ds1374_pm,
bf4994d7 SW	715	},
bf4994d7 SW	716	.probe = ds1374_probe,
5a167f45	717	.remove = ds1374_remove,
3760f736	718	.id_table = ds1374_id,
bf4994d7 SW	719	};
bf4994d7 SW	720
0abc9201	721	module_i2c_driver(ds1374_driver);
bf4994d7 SW	722
	723	MODULE_AUTHOR("Scott Wood <[email protected]>");
	724	MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver");
	725	MODULE_LICENSE("GPL");