Commit 920f91e5 authored by Søren Andersen's avatar Søren Andersen Committed by Linus Torvalds
Browse files

drivers/rtc/rtc-ds1374.c: add watchdog support 



Add support for the watchdog functionality of the DS1374 rtc.  Based on
the m41t80 watchdog functionality Note: watchdog uses the same registers
as alarm.

[akpm@linux-foundation.org: don't forget mutex_unlock() in ds1374_wdt_open() error path]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarSoeren Andersen <san@rosetechnology.dk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e9bc7363

drivers/rtc/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -192,6 +192,14 @@ config RTC_DRV_DS1374 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-ds1374.



config RTC_DRV_DS1374_WDT

	bool "Dallas/Maxim DS1374 watchdog timer"

	depends on RTC_DRV_DS1374

	help

	  If you say Y here you will get support for the

	  watchdog timer in the Dallas Semiconductor DS1374

	  real-time clock chips.



config RTC_DRV_DS1672

	tristate "Dallas/Maxim DS1672"

	help

drivers/rtc/rtc-ds1374.c

+285 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 * Based on code by Randy Vinson <rvinson@mvista.com>,

 * which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>.

 *

 * Copyright (C) 2014 Rose Technology

 * Copyright (C) 2006-2007 Freescale Semiconductor

 *

 * 2005 (c) MontaVista Software, Inc. This file is licensed under
@@ -26,6 +27,13 @@ 
#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
@@ -49,6 +57,14 @@ static const struct i2c_device_id ds1374_id[] = { 
};

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;
@@ -162,6 +178,7 @@ static int ds1374_set_time(struct device *dev, struct rtc_time *time) 
	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.
@@ -263,6 +280,7 @@ out: 
	mutex_unlock(&ds1374->mutex);

	return ret;

}

#endif



static irqreturn_t ds1374_irq(int irq, void *dev_id)

{
@@ -307,6 +325,7 @@ 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);
@@ -331,15 +350,260 @@ 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("rtc-ds1374 - 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;



		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:

		return put_user(wdt_margin, (int __user *)arg);

	case WDIOC_SETOPTIONS:

		if (copy_from_user(&options, (int __user *)arg, sizeof(int)))

			return -EFAULT;



		if (options & WDIOS_DISABLECARD) {

			pr_info("rtc-ds1374: disable watchdog\n");

			ds1374_wdt_disable();

		}



		if (options & WDIOS_ENABLECARD) {

			pr_info("rtc-ds1374: enable watchdog\n");

			ds1374_wdt_settimeout(wdt_margin);

			ds1374_wdt_ping();

		}



		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)

{
@@ -378,12 +642,33 @@ static int ds1374_probe(struct i2c_client *client, 
		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

	int res;



	res = misc_deregister(&ds1374_miscdev);

	if (!res)

		ds1374_miscdev.parent = NULL;

	unregister_reboot_notifier(&ds1374_wdt_notifier);

#endif



	if (client->irq > 0) {

		mutex_lock(&ds1374->mutex);

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