[RESEND,v3,1/3] Watchdog: Omap: Changes for the new watchdog framework

Commit Message

Zumeng Chen July 15, 2012, 7:44 a.m. UTC

This patch implements the current watchdog framework for OMAP WDTimer,
which factored out the common components, so the driver can just focus
on the hardware related parts.

Signed-off-by: Zumeng Chen <[e-mail]>
---
 drivers/watchdog/omap_wdt.c |  342 ++++++++++++++++---------------------------
 drivers/watchdog/omap_wdt.h |    5 +
 2 files changed, 128 insertions(+), 219 deletions(-)

Comments

Vaibhav Hiremath July 16, 2012, 1:10 p.m. UTC | #1

On Sun, Jul 15, 2012 at 13:14:04, Zumeng Chen wrote:
> This patch implements the current watchdog framework for OMAP WDTimer,
> which factored out the common components, so the driver can just focus
> on the hardware related parts.
> 
> Signed-off-by: Zumeng Chen <[e-mail]>
> ---
>  drivers/watchdog/omap_wdt.c |  342 ++++++++++++++++---------------------------
>  drivers/watchdog/omap_wdt.h |    5 +
>  2 files changed, 128 insertions(+), 219 deletions(-)
> 
> diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
> index 8285d65..cc5bc3e 100644
> --- a/drivers/watchdog/omap_wdt.c
> +++ b/drivers/watchdog/omap_wdt.c
> @@ -24,6 +24,9 @@
>   *
>   * Copyright (c) 2005 David Brownell
>   *	Use the driver model and standard identifiers; handle bigger timeouts.
> + *
> + * Copyright (c) 2012 WindRiver
> + *	Changes cater for the current watchdog framework.
>   */
>  
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> @@ -33,7 +36,6 @@
>  #include <linux/kernel.h>
>  #include <linux/fs.h>
>  #include <linux/mm.h>
> -#include <linux/miscdevice.h>
>  #include <linux/watchdog.h>
>  #include <linux/reboot.h>
>  #include <linux/init.h>
> @@ -50,8 +52,6 @@
>  
>  #include "omap_wdt.h"
>  
> -static struct platform_device *omap_wdt_dev;
> -
>  static unsigned timer_margin;
>  module_param(timer_margin, uint, 0);
>  MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
> @@ -59,32 +59,14 @@ MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
>  static unsigned int wdt_trgr_pattern = 0x1234;
>  static DEFINE_SPINLOCK(wdt_lock);
>  
> -struct omap_wdt_dev {
> +struct omap_wdt_drvdata {
> +	struct watchdog_device wdt;
>  	void __iomem    *base;          /* physical */
>  	struct device   *dev;
> -	int             omap_wdt_users;
>  	struct resource *mem;
> -	struct miscdevice omap_wdt_miscdev;
>  };
>  
> -static void omap_wdt_ping(struct omap_wdt_dev *wdev)
> -{
> -	void __iomem    *base = wdev->base;
> -
> -	/* wait for posted write to complete */
> -	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> -		cpu_relax();
> -
> -	wdt_trgr_pattern = ~wdt_trgr_pattern;
> -	__raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
> -
> -	/* wait for posted write to complete */
> -	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> -		cpu_relax();
> -	/* reloaded WCRR from WLDR */
> -}
> -
> -static void omap_wdt_enable(struct omap_wdt_dev *wdev)
> +static void omap_wdt_enable(struct omap_wdt_drvdata *wdev)
>  {
>  	void __iomem *base = wdev->base;
>  
> @@ -98,7 +80,7 @@ static void omap_wdt_enable(struct omap_wdt_dev *wdev)
>  		cpu_relax();
>  }
>  
> -static void omap_wdt_disable(struct omap_wdt_dev *wdev)
> +static void omap_wdt_disable(struct omap_wdt_drvdata *wdev)
>  {
>  	void __iomem *base = wdev->base;
>  
> @@ -121,12 +103,19 @@ static void omap_wdt_adjust_timeout(unsigned new_timeout)
>  	timer_margin = new_timeout;
>  }
>  
> -static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
> +static int omap_wdt_set_timeout(struct watchdog_device *wdt_dev,
> +				    unsigned int new_timeout)
>  {
> -	u32 pre_margin = GET_WLDR_VAL(timer_margin);
> -	void __iomem *base = wdev->base;
> +	u32 pre_margin;
> +	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
> +	void __iomem *base = omap_wdev->base;
>  
> -	pm_runtime_get_sync(wdev->dev);
> +	pm_runtime_get_sync(omap_wdev->dev);
> +	omap_wdt_disable(omap_wdev);
> +
> +	/* adjust timeout based on the new timeout */
> +	omap_wdt_adjust_timeout(new_timeout);
> +	pre_margin = GET_WLDR_VAL(timer_margin);
>  
>  	/* just count up at 32 KHz */
>  	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
> @@ -136,147 +125,88 @@ static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
>  	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
>  		cpu_relax();
>  
> -	pm_runtime_put_sync(wdev->dev);
> +	omap_wdt_enable(omap_wdev);
> +	wdt_dev->timeout = new_timeout;
> +	pm_runtime_put_sync(omap_wdev->dev);
> +	return 0;
>  }
>  
> -/*
> - *	Allow only one task to hold it open
> - */
> -static int omap_wdt_open(struct inode *inode, struct file *file)
> +static int omap_wdt_ping(struct watchdog_device *wdt_dev)
>  {
> -	struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
> -	void __iomem *base = wdev->base;
> -
> -	if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users)))
> -		return -EBUSY;
> -
> -	pm_runtime_get_sync(wdev->dev);
> +	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
> +	void __iomem    *base = omap_wdev->base;
>  
> -	/* initialize prescaler */
> -	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> -		cpu_relax();
> +	pm_runtime_get_sync(omap_wdev->dev);
> +	spin_lock(&wdt_lock);
>  
> -	__raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
> -	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> +	/* wait for posted write to complete */
> +	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
>  		cpu_relax();
>  
> -	file->private_data = (void *) wdev;
> +	wdt_trgr_pattern = ~wdt_trgr_pattern;
> +	__raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
>  
> -	omap_wdt_set_timeout(wdev);
> -	omap_wdt_ping(wdev); /* trigger loading of new timeout value */
> -	omap_wdt_enable(wdev);
> +	/* wait for posted write to complete */
> +	/* reloaded WCRR from WLDR */
> +	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> +		cpu_relax();
>  
> -	pm_runtime_put_sync(wdev->dev);
> +	spin_unlock(&wdt_lock);
> +	pm_runtime_put_sync(omap_wdev->dev);
>  
> -	return nonseekable_open(inode, file);
> +	return 0;
>  }
>  
> -static int omap_wdt_release(struct inode *inode, struct file *file)
> +static int omap_wdt_start(struct watchdog_device *wdt_dev)
>  {
> -	struct omap_wdt_dev *wdev = file->private_data;
> +	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
> +	void __iomem *base = omap_wdev->base;
>  
> -	/*
> -	 *      Shut off the timer unless NOWAYOUT is defined.
> -	 */
> -#ifndef CONFIG_WATCHDOG_NOWAYOUT
> -	pm_runtime_get_sync(wdev->dev);
> +	pm_runtime_get_sync(omap_wdev->dev);
> +	/* initialize prescaler */
> +	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> +		cpu_relax();
>  
> -	omap_wdt_disable(wdev);
> +	__raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
> +	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> +		cpu_relax();
>  
> -	pm_runtime_put_sync(wdev->dev);
> -#else
> -	pr_crit("Unexpected close, not stopping!\n");
> -#endif
> -	wdev->omap_wdt_users = 0;
> +	omap_wdt_set_timeout(&omap_wdev->wdt, timer_margin);
> +	pm_runtime_put_sync(omap_wdev->dev);
>  
>  	return 0;
>  }
>  
> -static ssize_t omap_wdt_write(struct file *file, const char __user *data,
> -		size_t len, loff_t *ppos)
> +static int omap_wdt_stop(struct watchdog_device *wdt_dev)
>  {
> -	struct omap_wdt_dev *wdev = file->private_data;
> -
> -	/* Refresh LOAD_TIME. */
> -	if (len) {
> -		pm_runtime_get_sync(wdev->dev);
> -		spin_lock(&wdt_lock);
> -		omap_wdt_ping(wdev);
> -		spin_unlock(&wdt_lock);
> -		pm_runtime_put_sync(wdev->dev);
> -	}
> -	return len;
> -}
> +	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
>  
> -static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
> -						unsigned long arg)
> -{
> -	struct omap_wdt_dev *wdev;
> -	int new_margin;
> -	static const struct watchdog_info ident = {
> -		.identity = "OMAP Watchdog",
> -		.options = WDIOF_SETTIMEOUT,
> -		.firmware_version = 0,
> -	};
> -
> -	wdev = file->private_data;
> -
> -	switch (cmd) {
> -	case WDIOC_GETSUPPORT:
> -		return copy_to_user((struct watchdog_info __user *)arg, &ident,
> -				sizeof(ident));
> -	case WDIOC_GETSTATUS:
> -		return put_user(0, (int __user *)arg);
> -	case WDIOC_GETBOOTSTATUS:
> -		if (cpu_is_omap16xx())
> -			return put_user(__raw_readw(ARM_SYSST),
> -					(int __user *)arg);
> -		if (cpu_is_omap24xx())
> -			return put_user(omap_prcm_get_reset_sources(),
> -					(int __user *)arg);
> -		return put_user(0, (int __user *)arg);
> -	case WDIOC_KEEPALIVE:
> -		pm_runtime_get_sync(wdev->dev);
> -		spin_lock(&wdt_lock);
> -		omap_wdt_ping(wdev);
> -		spin_unlock(&wdt_lock);
> -		pm_runtime_put_sync(wdev->dev);
> -		return 0;
> -	case WDIOC_SETTIMEOUT:
> -		if (get_user(new_margin, (int __user *)arg))
> -			return -EFAULT;
> -		omap_wdt_adjust_timeout(new_margin);
> -
> -		pm_runtime_get_sync(wdev->dev);
> -		spin_lock(&wdt_lock);
> -		omap_wdt_disable(wdev);
> -		omap_wdt_set_timeout(wdev);
> -		omap_wdt_enable(wdev);
> -
> -		omap_wdt_ping(wdev);
> -		spin_unlock(&wdt_lock);
> -		pm_runtime_put_sync(wdev->dev);
> -		/* Fall */
> -	case WDIOC_GETTIMEOUT:
> -		return put_user(timer_margin, (int __user *)arg);
> -	default:
> -		return -ENOTTY;
> -	}
> +	pm_runtime_get_sync(omap_wdev->dev);
> +	omap_wdt_disable(omap_wdev);
> +	pm_runtime_put_sync(omap_wdev->dev);
> +
> +	return 0;
>  }
>  
> -static const struct file_operations omap_wdt_fops = {
> +static const struct watchdog_ops omap_wdt_ops = {
>  	.owner = THIS_MODULE,
> -	.write = omap_wdt_write,
> -	.unlocked_ioctl = omap_wdt_ioctl,
> -	.open = omap_wdt_open,
> -	.release = omap_wdt_release,
> -	.llseek = no_llseek,
> +	.start = omap_wdt_start,
> +	.stop = omap_wdt_stop,
> +	.ping = omap_wdt_ping,
> +	.set_timeout = omap_wdt_set_timeout,
> +};
> +
> +static const struct watchdog_info omap_wdt_info = {
> +	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
> +		   WDIOF_CARDRESET,
> +	.identity = "Omap Watchdog",
>  };
>  
>  static int __devinit omap_wdt_probe(struct platform_device *pdev)
>  {
> +	struct omap_wdt_drvdata *omap_drvdata;
> +	struct watchdog_device *omap_wdev;
>  	struct resource *res, *mem;
> -	struct omap_wdt_dev *wdev;
>  	int ret;
>  
>  	/* reserve static register mappings */
> @@ -286,68 +216,62 @@ static int __devinit omap_wdt_probe(struct platform_device *pdev)
>  		goto err_get_resource;
>  	}
>  
> -	if (omap_wdt_dev) {
> -		ret = -EBUSY;
> -		goto err_busy;
> -	}
> -
>  	mem = request_mem_region(res->start, resource_size(res), pdev->name);
>  	if (!mem) {
>  		ret = -EBUSY;
>  		goto err_busy;
>  	}
>  
> -	wdev = kzalloc(sizeof(struct omap_wdt_dev), GFP_KERNEL);
> -	if (!wdev) {
> +	omap_drvdata = devm_kzalloc(&pdev->dev, sizeof(struct omap_wdt_drvdata),
> +			       GFP_KERNEL);
> +	if (!omap_drvdata) {
> +		dev_err(&pdev->dev, "Unable to allocate watchdog device\n");
>  		ret = -ENOMEM;
>  		goto err_kzalloc;
>  	}
>  
> -	wdev->omap_wdt_users = 0;
> -	wdev->mem = mem;
> -	wdev->dev = &pdev->dev;
> +	omap_drvdata->dev = &pdev->dev;
> +	omap_wdev = &omap_drvdata->wdt;
> +	omap_wdev->info = &omap_wdt_info;
> +	omap_wdev->ops = &omap_wdt_ops;
> +	omap_wdev->timeout = TIMER_MARGIN_DEFAULT;
> +	omap_wdev->min_timeout = 1;
> +	omap_wdev->max_timeout = TIMER_MARGIN_MAX;
> +#ifdef CONFIG_WATCHDOG_NOWAYOUT
> +	watchdog_set_nowayout(omap_wdev, true);
> +#endif
> +	watchdog_set_drvdata(omap_wdev, omap_drvdata);
>  
> -	wdev->base = ioremap(res->start, resource_size(res));
> -	if (!wdev->base) {
> +	omap_drvdata->base = ioremap(res->start, resource_size(res));
> +	if (!omap_drvdata->base) {
>  		ret = -ENOMEM;
> -		goto err_ioremap;
> +		goto err_kzalloc;
>  	}
>  
> -	platform_set_drvdata(pdev, wdev);
> -
> -	pm_runtime_enable(wdev->dev);
> -	pm_runtime_get_sync(wdev->dev);
> -
> -	omap_wdt_disable(wdev);
> -	omap_wdt_adjust_timeout(timer_margin);
> -
> -	wdev->omap_wdt_miscdev.parent = &pdev->dev;
> -	wdev->omap_wdt_miscdev.minor = WATCHDOG_MINOR;
> -	wdev->omap_wdt_miscdev.name = "watchdog";
> -	wdev->omap_wdt_miscdev.fops = &omap_wdt_fops;
> -
> -	ret = misc_register(&(wdev->omap_wdt_miscdev));
> -	if (ret)
> -		goto err_misc;
> -
> -	pr_info("OMAP Watchdog Timer Rev 0x%02x: initial timeout %d sec\n",
> -		__raw_readl(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
> -		timer_margin);
> -
> -	pm_runtime_put_sync(wdev->dev);
> -
> -	omap_wdt_dev = pdev;
> +	ret = watchdog_register_device(&omap_drvdata->wdt);
> +	if (ret < 0)
> +		goto err_register_wd;
> +
> +	pm_runtime_enable(&pdev->dev);
> +	pm_runtime_get_sync(&pdev->dev);
> +	omap_wdt_disable(omap_drvdata);
> +	pm_runtime_put_sync(&pdev->dev);
> +	platform_set_drvdata(pdev, omap_drvdata);
> +
> +	/* For omap16xx we just keep it original as-is */
> +	if (cpu_is_omap16xx())
> +		omap_wdev->bootstatus = __raw_readw(ARM_SYSST);
> +	else
> +		omap_wdev->bootstatus = (omap_prcm_get_reset_sources() & 0x10)
> +					 >> OMAP3_PRM_RSTST_WD_BIT;

CPU check is really not receommended in driver, you should avoid this.
I understand that, driver was already doing this, but can this be handled by 
IP rev? if not, you may want to use pdata for this.

Also I understand that, this is tied to prcm code base as far as omap2 is concerned. May be Tony or others can comment on this.

Thanks,
Vaibhav

> +	pr_info("OMAP WDTimer Rev 0x%02x: Initial timeout %dsec status= 0x%x\n",
> +		 __raw_readl(omap_drvdata->base + OMAP_WATCHDOG_REV)
> +		 & 0xFF, timer_margin, omap_wdev->bootstatus);
>  
>  	return 0;
>  
> -err_misc:
> -	pm_runtime_disable(wdev->dev);
> -	platform_set_drvdata(pdev, NULL);
> -	iounmap(wdev->base);
> -
> -err_ioremap:
> -	wdev->base = NULL;
> -	kfree(wdev);
> +err_register_wd:
> +	iounmap(omap_drvdata->base);
>  
>  err_kzalloc:
>  	release_mem_region(res->start, resource_size(res));
> @@ -358,34 +282,17 @@ err_get_resource:
>  	return ret;
>  }
>  
> -static void omap_wdt_shutdown(struct platform_device *pdev)
> -{
> -	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> -
> -	if (wdev->omap_wdt_users) {
> -		pm_runtime_get_sync(wdev->dev);
> -		omap_wdt_disable(wdev);
> -		pm_runtime_put_sync(wdev->dev);
> -	}
> -}
> -
>  static int __devexit omap_wdt_remove(struct platform_device *pdev)
>  {
> -	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> +	struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
>  	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  
> -	pm_runtime_disable(wdev->dev);
> -	if (!res)
> -		return -ENOENT;
> +	pm_runtime_disable(&pdev->dev);
>  
> -	misc_deregister(&(wdev->omap_wdt_miscdev));
>  	release_mem_region(res->start, resource_size(res));
>  	platform_set_drvdata(pdev, NULL);
>  
> -	iounmap(wdev->base);
> -
> -	kfree(wdev);
> -	omap_wdt_dev = NULL;
> +	iounmap(omap_wdev->base);
>  
>  	return 0;
>  }
> @@ -400,12 +307,12 @@ static int __devexit omap_wdt_remove(struct platform_device *pdev)
>  
>  static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
>  {
> -	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> +	struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
>  
> -	if (wdev->omap_wdt_users) {
> -		pm_runtime_get_sync(wdev->dev);
> -		omap_wdt_disable(wdev);
> -		pm_runtime_put_sync(wdev->dev);
> +	if (test_bit(WDOG_DEV_OPEN, &omap_wdev->wdt.status)) {
> +		pm_runtime_get_sync(&pdev->dev);
> +		omap_wdt_disable(omap_wdev);
> +		pm_runtime_put_sync(&pdev->dev);
>  	}
>  
>  	return 0;
> @@ -413,13 +320,12 @@ static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
>  
>  static int omap_wdt_resume(struct platform_device *pdev)
>  {
> -	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> -
> -	if (wdev->omap_wdt_users) {
> -		pm_runtime_get_sync(wdev->dev);
> -		omap_wdt_enable(wdev);
> -		omap_wdt_ping(wdev);
> -		pm_runtime_put_sync(wdev->dev);
> +	struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
> +	if (test_bit(WDOG_DEV_OPEN, &omap_wdev->wdt.status)) {
> +		pm_runtime_get_sync(&pdev->dev);
> +		omap_wdt_enable(omap_wdev);
> +		omap_wdt_ping(&omap_wdev->wdt);
> +		pm_runtime_put_sync(&pdev->dev);
>  	}
>  
>  	return 0;
> @@ -433,7 +339,6 @@ static int omap_wdt_resume(struct platform_device *pdev)
>  static struct platform_driver omap_wdt_driver = {
>  	.probe		= omap_wdt_probe,
>  	.remove		= __devexit_p(omap_wdt_remove),
> -	.shutdown	= omap_wdt_shutdown,
>  	.suspend	= omap_wdt_suspend,
>  	.resume		= omap_wdt_resume,
>  	.driver		= {
> @@ -446,5 +351,4 @@ module_platform_driver(omap_wdt_driver);
>  
>  MODULE_AUTHOR("George G. Davis");
>  MODULE_LICENSE("GPL");
> -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
>  MODULE_ALIAS("platform:omap_wdt");
> diff --git a/drivers/watchdog/omap_wdt.h b/drivers/watchdog/omap_wdt.h
> index 09b774c..cf5f037 100644
> --- a/drivers/watchdog/omap_wdt.h
> +++ b/drivers/watchdog/omap_wdt.h
> @@ -51,4 +51,9 @@
>  #define PTV			0	/* prescale */
>  #define GET_WLDR_VAL(secs)	(0xffffffff - ((secs) * (32768/(1<<PTV))) + 1)
>  
> +/* MPU_WD_RST bit in PRM_RSTST show Omap WDTimer reset event.
> + * 0x0 = 0x0 : No watchdog reset.
> + * 0x1 = 0x1 : watchdog reset has occurred. */
> +#define OMAP3_PRM_RSTST_WD_BIT		4
> +
>  #endif				/* _OMAP_WATCHDOG_H */
> -- 
> 1.7.5.4
> 
> 

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Patch

diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
index 8285d65..cc5bc3e 100644
--- a/drivers/watchdog/omap_wdt.c
+++ b/drivers/watchdog/omap_wdt.c
@@ -24,6 +24,9 @@ 
  *
  * Copyright (c) 2005 David Brownell
  *	Use the driver model and standard identifiers; handle bigger timeouts.
+ *
+ * Copyright (c) 2012 WindRiver
+ *	Changes cater for the current watchdog framework.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -33,7 +36,6 @@ 
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
-#include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/reboot.h>
 #include <linux/init.h>
@@ -50,8 +52,6 @@ 
 
 #include "omap_wdt.h"
 
-static struct platform_device *omap_wdt_dev;
-
 static unsigned timer_margin;
 module_param(timer_margin, uint, 0);
 MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
@@ -59,32 +59,14 @@  MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
 static unsigned int wdt_trgr_pattern = 0x1234;
 static DEFINE_SPINLOCK(wdt_lock);
 
-struct omap_wdt_dev {
+struct omap_wdt_drvdata {
+	struct watchdog_device wdt;
 	void __iomem    *base;          /* physical */
 	struct device   *dev;
-	int             omap_wdt_users;
 	struct resource *mem;
-	struct miscdevice omap_wdt_miscdev;
 };
 
-static void omap_wdt_ping(struct omap_wdt_dev *wdev)
-{
-	void __iomem    *base = wdev->base;
-
-	/* wait for posted write to complete */
-	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
-		cpu_relax();
-
-	wdt_trgr_pattern = ~wdt_trgr_pattern;
-	__raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
-
-	/* wait for posted write to complete */
-	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
-		cpu_relax();
-	/* reloaded WCRR from WLDR */
-}
-
-static void omap_wdt_enable(struct omap_wdt_dev *wdev)
+static void omap_wdt_enable(struct omap_wdt_drvdata *wdev)
 {
 	void __iomem *base = wdev->base;
 
@@ -98,7 +80,7 @@  static void omap_wdt_enable(struct omap_wdt_dev *wdev)
 		cpu_relax();
 }
 
-static void omap_wdt_disable(struct omap_wdt_dev *wdev)
+static void omap_wdt_disable(struct omap_wdt_drvdata *wdev)
 {
 	void __iomem *base = wdev->base;
 
@@ -121,12 +103,19 @@  static void omap_wdt_adjust_timeout(unsigned new_timeout)
 	timer_margin = new_timeout;
 }
 
-static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
+static int omap_wdt_set_timeout(struct watchdog_device *wdt_dev,
+				    unsigned int new_timeout)
 {
-	u32 pre_margin = GET_WLDR_VAL(timer_margin);
-	void __iomem *base = wdev->base;
+	u32 pre_margin;
+	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
+	void __iomem *base = omap_wdev->base;
 
-	pm_runtime_get_sync(wdev->dev);
+	pm_runtime_get_sync(omap_wdev->dev);
+	omap_wdt_disable(omap_wdev);
+
+	/* adjust timeout based on the new timeout */
+	omap_wdt_adjust_timeout(new_timeout);
+	pre_margin = GET_WLDR_VAL(timer_margin);
 
 	/* just count up at 32 KHz */
 	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
@@ -136,147 +125,88 @@  static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
 	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
 		cpu_relax();
 
-	pm_runtime_put_sync(wdev->dev);
+	omap_wdt_enable(omap_wdev);
+	wdt_dev->timeout = new_timeout;
+	pm_runtime_put_sync(omap_wdev->dev);
+	return 0;
 }
 
-/*
- *	Allow only one task to hold it open
- */
-static int omap_wdt_open(struct inode *inode, struct file *file)
+static int omap_wdt_ping(struct watchdog_device *wdt_dev)
 {
-	struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
-	void __iomem *base = wdev->base;
-
-	if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users)))
-		return -EBUSY;
-
-	pm_runtime_get_sync(wdev->dev);
+	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
+	void __iomem    *base = omap_wdev->base;
 
-	/* initialize prescaler */
-	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
-		cpu_relax();
+	pm_runtime_get_sync(omap_wdev->dev);
+	spin_lock(&wdt_lock);
 
-	__raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
-	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
+	/* wait for posted write to complete */
+	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
 		cpu_relax();
 
-	file->private_data = (void *) wdev;
+	wdt_trgr_pattern = ~wdt_trgr_pattern;
+	__raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
 
-	omap_wdt_set_timeout(wdev);
-	omap_wdt_ping(wdev); /* trigger loading of new timeout value */
-	omap_wdt_enable(wdev);
+	/* wait for posted write to complete */
+	/* reloaded WCRR from WLDR */
+	while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
+		cpu_relax();
 
-	pm_runtime_put_sync(wdev->dev);
+	spin_unlock(&wdt_lock);
+	pm_runtime_put_sync(omap_wdev->dev);
 
-	return nonseekable_open(inode, file);
+	return 0;
 }
 
-static int omap_wdt_release(struct inode *inode, struct file *file)
+static int omap_wdt_start(struct watchdog_device *wdt_dev)
 {
-	struct omap_wdt_dev *wdev = file->private_data;
+	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
+	void __iomem *base = omap_wdev->base;
 
-	/*
-	 *      Shut off the timer unless NOWAYOUT is defined.
-	 */
-#ifndef CONFIG_WATCHDOG_NOWAYOUT
-	pm_runtime_get_sync(wdev->dev);
+	pm_runtime_get_sync(omap_wdev->dev);
+	/* initialize prescaler */
+	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
+		cpu_relax();
 
-	omap_wdt_disable(wdev);
+	__raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
+	while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
+		cpu_relax();
 
-	pm_runtime_put_sync(wdev->dev);
-#else
-	pr_crit("Unexpected close, not stopping!\n");
-#endif
-	wdev->omap_wdt_users = 0;
+	omap_wdt_set_timeout(&omap_wdev->wdt, timer_margin);
+	pm_runtime_put_sync(omap_wdev->dev);
 
 	return 0;
 }
 
-static ssize_t omap_wdt_write(struct file *file, const char __user *data,
-		size_t len, loff_t *ppos)
+static int omap_wdt_stop(struct watchdog_device *wdt_dev)
 {
-	struct omap_wdt_dev *wdev = file->private_data;
-
-	/* Refresh LOAD_TIME. */
-	if (len) {
-		pm_runtime_get_sync(wdev->dev);
-		spin_lock(&wdt_lock);
-		omap_wdt_ping(wdev);
-		spin_unlock(&wdt_lock);
-		pm_runtime_put_sync(wdev->dev);
-	}
-	return len;
-}
+	struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
 
-static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
-						unsigned long arg)
-{
-	struct omap_wdt_dev *wdev;
-	int new_margin;
-	static const struct watchdog_info ident = {
-		.identity = "OMAP Watchdog",
-		.options = WDIOF_SETTIMEOUT,
-		.firmware_version = 0,
-	};
-
-	wdev = file->private_data;
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		return copy_to_user((struct watchdog_info __user *)arg, &ident,
-				sizeof(ident));
-	case WDIOC_GETSTATUS:
-		return put_user(0, (int __user *)arg);
-	case WDIOC_GETBOOTSTATUS:
-		if (cpu_is_omap16xx())
-			return put_user(__raw_readw(ARM_SYSST),
-					(int __user *)arg);
-		if (cpu_is_omap24xx())
-			return put_user(omap_prcm_get_reset_sources(),
-					(int __user *)arg);
-		return put_user(0, (int __user *)arg);
-	case WDIOC_KEEPALIVE:
-		pm_runtime_get_sync(wdev->dev);
-		spin_lock(&wdt_lock);
-		omap_wdt_ping(wdev);
-		spin_unlock(&wdt_lock);
-		pm_runtime_put_sync(wdev->dev);
-		return 0;
-	case WDIOC_SETTIMEOUT:
-		if (get_user(new_margin, (int __user *)arg))
-			return -EFAULT;
-		omap_wdt_adjust_timeout(new_margin);
-
-		pm_runtime_get_sync(wdev->dev);
-		spin_lock(&wdt_lock);
-		omap_wdt_disable(wdev);
-		omap_wdt_set_timeout(wdev);
-		omap_wdt_enable(wdev);
-
-		omap_wdt_ping(wdev);
-		spin_unlock(&wdt_lock);
-		pm_runtime_put_sync(wdev->dev);
-		/* Fall */
-	case WDIOC_GETTIMEOUT:
-		return put_user(timer_margin, (int __user *)arg);
-	default:
-		return -ENOTTY;
-	}
+	pm_runtime_get_sync(omap_wdev->dev);
+	omap_wdt_disable(omap_wdev);
+	pm_runtime_put_sync(omap_wdev->dev);
+
+	return 0;
 }
 
-static const struct file_operations omap_wdt_fops = {
+static const struct watchdog_ops omap_wdt_ops = {
 	.owner = THIS_MODULE,
-	.write = omap_wdt_write,
-	.unlocked_ioctl = omap_wdt_ioctl,
-	.open = omap_wdt_open,
-	.release = omap_wdt_release,
-	.llseek = no_llseek,
+	.start = omap_wdt_start,
+	.stop = omap_wdt_stop,
+	.ping = omap_wdt_ping,
+	.set_timeout = omap_wdt_set_timeout,
+};
+
+static const struct watchdog_info omap_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
+		   WDIOF_CARDRESET,
+	.identity = "Omap Watchdog",
 };
 
 static int __devinit omap_wdt_probe(struct platform_device *pdev)
 {
+	struct omap_wdt_drvdata *omap_drvdata;
+	struct watchdog_device *omap_wdev;
 	struct resource *res, *mem;
-	struct omap_wdt_dev *wdev;
 	int ret;
 
 	/* reserve static register mappings */
@@ -286,68 +216,62 @@  static int __devinit omap_wdt_probe(struct platform_device *pdev)
 		goto err_get_resource;
 	}
 
-	if (omap_wdt_dev) {
-		ret = -EBUSY;
-		goto err_busy;
-	}
-
 	mem = request_mem_region(res->start, resource_size(res), pdev->name);
 	if (!mem) {
 		ret = -EBUSY;
 		goto err_busy;
 	}
 
-	wdev = kzalloc(sizeof(struct omap_wdt_dev), GFP_KERNEL);
-	if (!wdev) {
+	omap_drvdata = devm_kzalloc(&pdev->dev, sizeof(struct omap_wdt_drvdata),
+			       GFP_KERNEL);
+	if (!omap_drvdata) {
+		dev_err(&pdev->dev, "Unable to allocate watchdog device\n");
 		ret = -ENOMEM;
 		goto err_kzalloc;
 	}
 
-	wdev->omap_wdt_users = 0;
-	wdev->mem = mem;
-	wdev->dev = &pdev->dev;
+	omap_drvdata->dev = &pdev->dev;
+	omap_wdev = &omap_drvdata->wdt;
+	omap_wdev->info = &omap_wdt_info;
+	omap_wdev->ops = &omap_wdt_ops;
+	omap_wdev->timeout = TIMER_MARGIN_DEFAULT;
+	omap_wdev->min_timeout = 1;
+	omap_wdev->max_timeout = TIMER_MARGIN_MAX;
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+	watchdog_set_nowayout(omap_wdev, true);
+#endif
+	watchdog_set_drvdata(omap_wdev, omap_drvdata);
 
-	wdev->base = ioremap(res->start, resource_size(res));
-	if (!wdev->base) {
+	omap_drvdata->base = ioremap(res->start, resource_size(res));
+	if (!omap_drvdata->base) {
 		ret = -ENOMEM;
-		goto err_ioremap;
+		goto err_kzalloc;
 	}
 
-	platform_set_drvdata(pdev, wdev);
-
-	pm_runtime_enable(wdev->dev);
-	pm_runtime_get_sync(wdev->dev);
-
-	omap_wdt_disable(wdev);
-	omap_wdt_adjust_timeout(timer_margin);
-
-	wdev->omap_wdt_miscdev.parent = &pdev->dev;
-	wdev->omap_wdt_miscdev.minor = WATCHDOG_MINOR;
-	wdev->omap_wdt_miscdev.name = "watchdog";
-	wdev->omap_wdt_miscdev.fops = &omap_wdt_fops;
-
-	ret = misc_register(&(wdev->omap_wdt_miscdev));
-	if (ret)
-		goto err_misc;
-
-	pr_info("OMAP Watchdog Timer Rev 0x%02x: initial timeout %d sec\n",
-		__raw_readl(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
-		timer_margin);
-
-	pm_runtime_put_sync(wdev->dev);
-
-	omap_wdt_dev = pdev;
+	ret = watchdog_register_device(&omap_drvdata->wdt);
+	if (ret < 0)
+		goto err_register_wd;
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+	omap_wdt_disable(omap_drvdata);
+	pm_runtime_put_sync(&pdev->dev);
+	platform_set_drvdata(pdev, omap_drvdata);
+
+	/* For omap16xx we just keep it original as-is */
+	if (cpu_is_omap16xx())
+		omap_wdev->bootstatus = __raw_readw(ARM_SYSST);
+	else
+		omap_wdev->bootstatus = (omap_prcm_get_reset_sources() & 0x10)
+					 >> OMAP3_PRM_RSTST_WD_BIT;
+	pr_info("OMAP WDTimer Rev 0x%02x: Initial timeout %dsec status= 0x%x\n",
+		 __raw_readl(omap_drvdata->base + OMAP_WATCHDOG_REV)
+		 & 0xFF, timer_margin, omap_wdev->bootstatus);
 
 	return 0;
 
-err_misc:
-	pm_runtime_disable(wdev->dev);
-	platform_set_drvdata(pdev, NULL);
-	iounmap(wdev->base);
-
-err_ioremap:
-	wdev->base = NULL;
-	kfree(wdev);
+err_register_wd:
+	iounmap(omap_drvdata->base);
 
 err_kzalloc:
 	release_mem_region(res->start, resource_size(res));
@@ -358,34 +282,17 @@  err_get_resource:
 	return ret;
 }
 
-static void omap_wdt_shutdown(struct platform_device *pdev)
-{
-	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
-
-	if (wdev->omap_wdt_users) {
-		pm_runtime_get_sync(wdev->dev);
-		omap_wdt_disable(wdev);
-		pm_runtime_put_sync(wdev->dev);
-	}
-}
-
 static int __devexit omap_wdt_remove(struct platform_device *pdev)
 {
-	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
+	struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
-	pm_runtime_disable(wdev->dev);
-	if (!res)
-		return -ENOENT;
+	pm_runtime_disable(&pdev->dev);
 
-	misc_deregister(&(wdev->omap_wdt_miscdev));
 	release_mem_region(res->start, resource_size(res));
 	platform_set_drvdata(pdev, NULL);
 
-	iounmap(wdev->base);
-
-	kfree(wdev);
-	omap_wdt_dev = NULL;
+	iounmap(omap_wdev->base);
 
 	return 0;
 }
@@ -400,12 +307,12 @@  static int __devexit omap_wdt_remove(struct platform_device *pdev)
 
 static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
 {
-	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
+	struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
 
-	if (wdev->omap_wdt_users) {
-		pm_runtime_get_sync(wdev->dev);
-		omap_wdt_disable(wdev);
-		pm_runtime_put_sync(wdev->dev);
+	if (test_bit(WDOG_DEV_OPEN, &omap_wdev->wdt.status)) {
+		pm_runtime_get_sync(&pdev->dev);
+		omap_wdt_disable(omap_wdev);
+		pm_runtime_put_sync(&pdev->dev);
 	}
 
 	return 0;
@@ -413,13 +320,12 @@  static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
 
 static int omap_wdt_resume(struct platform_device *pdev)
 {
-	struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
-
-	if (wdev->omap_wdt_users) {
-		pm_runtime_get_sync(wdev->dev);
-		omap_wdt_enable(wdev);
-		omap_wdt_ping(wdev);
-		pm_runtime_put_sync(wdev->dev);
+	struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
+	if (test_bit(WDOG_DEV_OPEN, &omap_wdev->wdt.status)) {
+		pm_runtime_get_sync(&pdev->dev);
+		omap_wdt_enable(omap_wdev);
+		omap_wdt_ping(&omap_wdev->wdt);
+		pm_runtime_put_sync(&pdev->dev);
 	}
 
 	return 0;
@@ -433,7 +339,6 @@  static int omap_wdt_resume(struct platform_device *pdev)
 static struct platform_driver omap_wdt_driver = {
 	.probe		= omap_wdt_probe,
 	.remove		= __devexit_p(omap_wdt_remove),
-	.shutdown	= omap_wdt_shutdown,
 	.suspend	= omap_wdt_suspend,
 	.resume		= omap_wdt_resume,
 	.driver		= {
@@ -446,5 +351,4 @@  module_platform_driver(omap_wdt_driver);
 
 MODULE_AUTHOR("George G. Davis");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 MODULE_ALIAS("platform:omap_wdt");
diff --git a/drivers/watchdog/omap_wdt.h b/drivers/watchdog/omap_wdt.h
index 09b774c..cf5f037 100644
--- a/drivers/watchdog/omap_wdt.h
+++ b/drivers/watchdog/omap_wdt.h
@@ -51,4 +51,9 @@ 
 #define PTV			0	/* prescale */
 #define GET_WLDR_VAL(secs)	(0xffffffff - ((secs) * (32768/(1<<PTV))) + 1)
 
+/* MPU_WD_RST bit in PRM_RSTST show Omap WDTimer reset event.
+ * 0x0 = 0x0 : No watchdog reset.
+ * 0x1 = 0x1 : watchdog reset has occurred. */
+#define OMAP3_PRM_RSTST_WD_BIT		4
+
 #endif				/* _OMAP_WATCHDOG_H */