drivers/watchdog/imx2_wdt.c - kernel/msm-5.4 - Gitiles

 /*
  * Watchdog driver for IMX2 and later processors
  *
  *  Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
  *
  * some parts adapted by similar drivers from Darius Augulis and Vladimir
  * Zapolskiy, additional improvements by Wim Van Sebroeck.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  *
  * NOTE: MX1 has a slightly different Watchdog than MX2 and later:
  *
  *			MX1:		MX2+:
  *			----		-----
  * Registers:		32-bit		16-bit
  * Stopable timer:	Yes		No
  * Need to enable clk:	No		Yes
  * Halt on suspend:	Manual		Can be automatic
  */

 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
 #include <linux/watchdog.h>
 #include <linux/clk.h>
 #include <linux/fs.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
 #include <linux/timer.h>
 #include <linux/jiffies.h>

 #define DRIVER_NAME "imx2-wdt"

 #define IMX2_WDT_WCR		0x00		/* Control Register */
 #define IMX2_WDT_WCR_WT		(0xFF << 8)	/* -> Watchdog Timeout Field */
 #define IMX2_WDT_WCR_WRE	(1 << 3)	/* -> WDOG Reset Enable */
 #define IMX2_WDT_WCR_WDE	(1 << 2)	/* -> Watchdog Enable */

 #define IMX2_WDT_WSR		0x02		/* Service Register */
 #define IMX2_WDT_SEQ1		0x5555		/* -> service sequence 1 */
 #define IMX2_WDT_SEQ2		0xAAAA		/* -> service sequence 2 */

 #define IMX2_WDT_WRSR		0x04		/* Reset Status Register */
 #define IMX2_WDT_WRSR_TOUT	(1 << 1)	/* -> Reset due to Timeout */

 #define IMX2_WDT_MAX_TIME	128
 #define IMX2_WDT_DEFAULT_TIME	60		/* in seconds */

 #define WDOG_SEC_TO_COUNT(s)	((s * 2 - 1) << 8)

 #define IMX2_WDT_STATUS_OPEN	0
 #define IMX2_WDT_STATUS_STARTED	1
 #define IMX2_WDT_EXPECT_CLOSE	2

 static struct {
 	struct clk *clk;
 	void __iomem *base;
 	unsigned timeout;
 	unsigned long status;
 	struct timer_list timer;	/* Pings the watchdog when closed */
 } imx2_wdt;

 static struct miscdevice imx2_wdt_miscdev;

 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


 static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
 module_param(timeout, uint, 0);
 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
 				__MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");

 static const struct watchdog_info imx2_wdt_info = {
 	.identity = "imx2+ watchdog",
 	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 };

 static inline void imx2_wdt_setup(void)
 {
 	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);

 	/* Strip the old watchdog Time-Out value */
 	val &= ~IMX2_WDT_WCR_WT;
 	/* Generate reset if WDOG times out */
 	val &= ~IMX2_WDT_WCR_WRE;
 	/* Keep Watchdog Disabled */
 	val &= ~IMX2_WDT_WCR_WDE;
 	/* Set the watchdog's Time-Out value */
 	val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);

 	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);

 	/* enable the watchdog */
 	val |= IMX2_WDT_WCR_WDE;
 	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
 }

 static inline void imx2_wdt_ping(void)
 {
 	__raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
 	__raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
 }

 static void imx2_wdt_timer_ping(unsigned long arg)
 {
 	/* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
 	imx2_wdt_ping();
 	mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
 }

 static void imx2_wdt_start(void)
 {
 	if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
 		/* at our first start we enable clock and do initialisations */
 		clk_prepare_enable(imx2_wdt.clk);

 		imx2_wdt_setup();
 	} else	/* delete the timer that pings the watchdog after close */
 		del_timer_sync(&imx2_wdt.timer);

 	/* Watchdog is enabled - time to reload the timeout value */
 	imx2_wdt_ping();
 }

 static void imx2_wdt_stop(void)
 {
 	/* we don't need a clk_disable, it cannot be disabled once started.
 	 * We use a timer to ping the watchdog while /dev/watchdog is closed */
 	imx2_wdt_timer_ping(0);
 }

 static void imx2_wdt_set_timeout(int new_timeout)
 {
 	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);

 	/* set the new timeout value in the WSR */
 	val &= ~IMX2_WDT_WCR_WT;
 	val |= WDOG_SEC_TO_COUNT(new_timeout);
 	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
 }

 static int imx2_wdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
 		return -EBUSY;

 	imx2_wdt_start();
 	return nonseekable_open(inode, file);
 }

 static int imx2_wdt_close(struct inode *inode, struct file *file)
 {
 	if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
 		imx2_wdt_stop();
 	else {
 		dev_crit(imx2_wdt_miscdev.parent,
 			"Unexpected close: Expect reboot!\n");
 		imx2_wdt_ping();
 	}

 	clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
 	clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
 	return 0;
 }

 static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
 							unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	int new_value;
 	u16 val;

 	switch (cmd) {
 	case WDIOC_GETSUPPORT:
 		return copy_to_user(argp, &imx2_wdt_info,
 			sizeof(struct watchdog_info)) ? -EFAULT : 0;

 	case WDIOC_GETSTATUS:
 		return put_user(0, p);

 	case WDIOC_GETBOOTSTATUS:
 		val = __raw_readw(imx2_wdt.base + IMX2_WDT_WRSR);
 		new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
 		return put_user(new_value, p);

 	case WDIOC_KEEPALIVE:
 		imx2_wdt_ping();
 		return 0;

 	case WDIOC_SETTIMEOUT:
 		if (get_user(new_value, p))
 			return -EFAULT;
 		if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME))
 			return -EINVAL;
 		imx2_wdt_set_timeout(new_value);
 		imx2_wdt.timeout = new_value;
 		imx2_wdt_ping();

 		/* Fallthrough to return current value */
 	case WDIOC_GETTIMEOUT:
 		return put_user(imx2_wdt.timeout, p);

 	default:
 		return -ENOTTY;
 	}
 }

 static ssize_t imx2_wdt_write(struct file *file, const char __user *data,
 						size_t len, loff_t *ppos)
 {
 	size_t i;
 	char c;

 	if (len == 0)	/* Can we see this even ? */
 		return 0;

 	clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
 	/* scan to see whether or not we got the magic character */
 	for (i = 0; i != len; i++) {
 		if (get_user(c, data + i))
 			return -EFAULT;
 		if (c == 'V')
 			set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
 	}

 	imx2_wdt_ping();
 	return len;
 }

 static const struct file_operations imx2_wdt_fops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
 	.unlocked_ioctl = imx2_wdt_ioctl,
 	.open = imx2_wdt_open,
 	.release = imx2_wdt_close,
 	.write = imx2_wdt_write,
 };

 static struct miscdevice imx2_wdt_miscdev = {
 	.minor = WATCHDOG_MINOR,
 	.name = "watchdog",
 	.fops = &imx2_wdt_fops,
 };

 static int __init imx2_wdt_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct resource *res;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	imx2_wdt.base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(imx2_wdt.base))
 		return PTR_ERR(imx2_wdt.base);

 	imx2_wdt.clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(imx2_wdt.clk)) {
 		dev_err(&pdev->dev, "can't get Watchdog clock\n");
 		return PTR_ERR(imx2_wdt.clk);
 	}

 	imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
 	if (imx2_wdt.timeout != timeout)
 		dev_warn(&pdev->dev, "Initial timeout out of range! "
 			"Clamped from %u to %u\n", timeout, imx2_wdt.timeout);

 	setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);

 	imx2_wdt_miscdev.parent = &pdev->dev;
 	ret = misc_register(&imx2_wdt_miscdev);
 	if (ret)
 		goto fail;

 	dev_info(&pdev->dev,
 		"IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
 						imx2_wdt.timeout, nowayout);
 	return 0;

 fail:
 	imx2_wdt_miscdev.parent = NULL;
 	clk_put(imx2_wdt.clk);
 	return ret;
 }

 static int __exit imx2_wdt_remove(struct platform_device *pdev)
 {
 	misc_deregister(&imx2_wdt_miscdev);

 	if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
 		del_timer_sync(&imx2_wdt.timer);

 		dev_crit(imx2_wdt_miscdev.parent,
 			"Device removed: Expect reboot!\n");
 	} else
 		clk_put(imx2_wdt.clk);

 	imx2_wdt_miscdev.parent = NULL;
 	return 0;
 }

 static void imx2_wdt_shutdown(struct platform_device *pdev)
 {
 	if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
 		/* we are running, we need to delete the timer but will give
 		 * max timeout before reboot will take place */
 		del_timer_sync(&imx2_wdt.timer);
 		imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
 		imx2_wdt_ping();

 		dev_crit(imx2_wdt_miscdev.parent,
 			"Device shutdown: Expect reboot!\n");
 	}
 }

 static const struct of_device_id imx2_wdt_dt_ids[] = {
 	{ .compatible = "fsl,imx21-wdt", },
 	{ /* sentinel */ }
 };

 static struct platform_driver imx2_wdt_driver = {
 	.remove		= __exit_p(imx2_wdt_remove),
 	.shutdown	= imx2_wdt_shutdown,
 	.driver		= {
 		.name	= DRIVER_NAME,
 		.owner	= THIS_MODULE,
 		.of_match_table = imx2_wdt_dt_ids,
 	},
 };

 module_platform_driver_probe(imx2_wdt_driver, imx2_wdt_probe);

 MODULE_AUTHOR("Wolfram Sang");
 MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 MODULE_ALIAS("platform:" DRIVER_NAME);
	/*
	* Watchdog driver for IMX2 and later processors
	*
	* Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
	*
	* some parts adapted by similar drivers from Darius Augulis and Vladimir
	* Zapolskiy, additional improvements by Wim Van Sebroeck.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*
	* NOTE: MX1 has a slightly different Watchdog than MX2 and later:
	*
	* MX1: MX2+:
	* ---- -----
	* Registers: 32-bit 16-bit
	* Stopable timer: Yes No
	* Need to enable clk: No Yes
	* Halt on suspend: Manual Can be automatic
	*/

	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/miscdevice.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/platform_device.h>
	#include <linux/watchdog.h>
	#include <linux/clk.h>
	#include <linux/fs.h>
	#include <linux/io.h>
	#include <linux/uaccess.h>
	#include <linux/timer.h>
	#include <linux/jiffies.h>

	#define DRIVER_NAME "imx2-wdt"

	#define IMX2_WDT_WCR 0x00 /* Control Register */
	#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
	#define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */
	#define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */

	#define IMX2_WDT_WSR 0x02 /* Service Register */
	#define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */
	#define IMX2_WDT_SEQ2 0xAAAA /* -> service sequence 2 */

	#define IMX2_WDT_WRSR 0x04 /* Reset Status Register */
	#define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */

	#define IMX2_WDT_MAX_TIME 128
	#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */

	#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)

	#define IMX2_WDT_STATUS_OPEN 0
	#define IMX2_WDT_STATUS_STARTED 1
	#define IMX2_WDT_EXPECT_CLOSE 2

	static struct {
	struct clk *clk;
	void __iomem *base;
	unsigned timeout;
	unsigned long status;
	struct timer_list timer; /* Pings the watchdog when closed */
	} imx2_wdt;

	static struct miscdevice imx2_wdt_miscdev;

	static bool nowayout = WATCHDOG_NOWAYOUT;
	module_param(nowayout, bool, 0);
	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


	static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
	module_param(timeout, uint, 0);
	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
	__MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");

	static const struct watchdog_info imx2_wdt_info = {
	.identity = "imx2+ watchdog",
	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	};

	static inline void imx2_wdt_setup(void)
	{
	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);

	/* Strip the old watchdog Time-Out value */
	val &= ~IMX2_WDT_WCR_WT;
	/* Generate reset if WDOG times out */
	val &= ~IMX2_WDT_WCR_WRE;
	/* Keep Watchdog Disabled */
	val &= ~IMX2_WDT_WCR_WDE;
	/* Set the watchdog's Time-Out value */
	val \|= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);

	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);

	/* enable the watchdog */
	val \|= IMX2_WDT_WCR_WDE;
	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
	}

	static inline void imx2_wdt_ping(void)
	{
	__raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
	__raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
	}

	static void imx2_wdt_timer_ping(unsigned long arg)
	{
	/* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
	imx2_wdt_ping();
	mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
	}

	static void imx2_wdt_start(void)
	{
	if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
	/* at our first start we enable clock and do initialisations */
	clk_prepare_enable(imx2_wdt.clk);

	imx2_wdt_setup();
	} else /* delete the timer that pings the watchdog after close */
	del_timer_sync(&imx2_wdt.timer);

	/* Watchdog is enabled - time to reload the timeout value */
	imx2_wdt_ping();
	}

	static void imx2_wdt_stop(void)
	{
	/* we don't need a clk_disable, it cannot be disabled once started.
	* We use a timer to ping the watchdog while /dev/watchdog is closed */
	imx2_wdt_timer_ping(0);
	}

	static void imx2_wdt_set_timeout(int new_timeout)
	{
	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);

	/* set the new timeout value in the WSR */
	val &= ~IMX2_WDT_WCR_WT;
	val \|= WDOG_SEC_TO_COUNT(new_timeout);
	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
	}

	static int imx2_wdt_open(struct inode inode, struct file file)
	{
	if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
	return -EBUSY;

	imx2_wdt_start();
	return nonseekable_open(inode, file);
	}

	static int imx2_wdt_close(struct inode inode, struct file file)
	{
	if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
	imx2_wdt_stop();
	else {
	dev_crit(imx2_wdt_miscdev.parent,
	"Unexpected close: Expect reboot!\n");
	imx2_wdt_ping();
	}

	clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
	clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
	return 0;
	}

	static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	void __user argp = (void __user )arg;
	int __user *p = argp;
	int new_value;
	u16 val;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
	return copy_to_user(argp, &imx2_wdt_info,
	sizeof(struct watchdog_info)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
	return put_user(0, p);

	case WDIOC_GETBOOTSTATUS:
	val = __raw_readw(imx2_wdt.base + IMX2_WDT_WRSR);
	new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
	return put_user(new_value, p);

	case WDIOC_KEEPALIVE:
	imx2_wdt_ping();
	return 0;

	case WDIOC_SETTIMEOUT:
	if (get_user(new_value, p))
	return -EFAULT;
	if ((new_value < 1) \|\| (new_value > IMX2_WDT_MAX_TIME))
	return -EINVAL;
	imx2_wdt_set_timeout(new_value);
	imx2_wdt.timeout = new_value;
	imx2_wdt_ping();

	/* Fallthrough to return current value */
	case WDIOC_GETTIMEOUT:
	return put_user(imx2_wdt.timeout, p);

	default:
	return -ENOTTY;
	}
	}

	static ssize_t imx2_wdt_write(struct file file, const char __user data,
	size_t len, loff_t *ppos)
	{
	size_t i;
	char c;

	if (len == 0) /* Can we see this even ? */
	return 0;

	clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
	/* scan to see whether or not we got the magic character */
	for (i = 0; i != len; i++) {
	if (get_user(c, data + i))
	return -EFAULT;
	if (c == 'V')
	set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
	}

	imx2_wdt_ping();
	return len;
	}

	static const struct file_operations imx2_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.unlocked_ioctl = imx2_wdt_ioctl,
	.open = imx2_wdt_open,
	.release = imx2_wdt_close,
	.write = imx2_wdt_write,
	};

	static struct miscdevice imx2_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &imx2_wdt_fops,
	};

	static int __init imx2_wdt_probe(struct platform_device *pdev)
	{
	int ret;
	struct resource *res;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	imx2_wdt.base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(imx2_wdt.base))
	return PTR_ERR(imx2_wdt.base);

	imx2_wdt.clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(imx2_wdt.clk)) {
	dev_err(&pdev->dev, "can't get Watchdog clock\n");
	return PTR_ERR(imx2_wdt.clk);
	}

	imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
	if (imx2_wdt.timeout != timeout)
	dev_warn(&pdev->dev, "Initial timeout out of range! "
	"Clamped from %u to %u\n", timeout, imx2_wdt.timeout);

	setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);

	imx2_wdt_miscdev.parent = &pdev->dev;
	ret = misc_register(&imx2_wdt_miscdev);
	if (ret)
	goto fail;

	dev_info(&pdev->dev,
	"IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
	imx2_wdt.timeout, nowayout);
	return 0;

	fail:
	imx2_wdt_miscdev.parent = NULL;
	clk_put(imx2_wdt.clk);
	return ret;
	}

	static int __exit imx2_wdt_remove(struct platform_device *pdev)
	{
	misc_deregister(&imx2_wdt_miscdev);

	if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
	del_timer_sync(&imx2_wdt.timer);

	dev_crit(imx2_wdt_miscdev.parent,
	"Device removed: Expect reboot!\n");
	} else
	clk_put(imx2_wdt.clk);

	imx2_wdt_miscdev.parent = NULL;
	return 0;
	}

	static void imx2_wdt_shutdown(struct platform_device *pdev)
	{
	if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
	/* we are running, we need to delete the timer but will give
	* max timeout before reboot will take place */
	del_timer_sync(&imx2_wdt.timer);
	imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
	imx2_wdt_ping();

	dev_crit(imx2_wdt_miscdev.parent,
	"Device shutdown: Expect reboot!\n");
	}
	}

	static const struct of_device_id imx2_wdt_dt_ids[] = {
	{ .compatible = "fsl,imx21-wdt", },
	{ /* sentinel */ }
	};

	static struct platform_driver imx2_wdt_driver = {
	.remove = __exit_p(imx2_wdt_remove),
	.shutdown = imx2_wdt_shutdown,
	.driver = {
	.name = DRIVER_NAME,
	.owner = THIS_MODULE,
	.of_match_table = imx2_wdt_dt_ids,
	},
	};

	module_platform_driver_probe(imx2_wdt_driver, imx2_wdt_probe);

	MODULE_AUTHOR("Wolfram Sang");
	MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	MODULE_ALIAS("platform:" DRIVER_NAME);