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Commit 91700361 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Guenter Roeck
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watchdog: ep93xx_wdt: cleanup and let the core handle the heartbeat 



Cleanup this driver and remove the 200ms heartbeat timer. The core now
has the ability to handle the heartbeat.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
[groeck: Dropped 0-initialization of static variable]
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 8751f90c

drivers/watchdog/ep93xx_wdt.c

+44 −70
Original line number Diff line number Diff line
@@ -19,21 +19,13 @@ 
 * for us to rely on the user space daemon alone. So we ping the

 * wdt each ~200msec and eventually stop doing it if the user space

 * daemon dies.

 *

 * TODO:

 *

 *	- Test last reset from watchdog status

 *	- Add a few missing ioctls

 */



#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/watchdog.h>

#include <linux/timer.h>

#include <linux/io.h>



#define WDT_VERSION	"0.4"



/* default timeout (secs) */

#define WDT_TIMEOUT 30
@@ -41,59 +33,48 @@ static bool nowayout = WATCHDOG_NOWAYOUT; 
module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");



static unsigned int timeout = WDT_TIMEOUT;

static unsigned int timeout;

module_param(timeout, uint, 0);

MODULE_PARM_DESC(timeout,

	"Watchdog timeout in seconds. (1<=timeout<=3600, default="

				__MODULE_STRING(WDT_TIMEOUT) ")");



static void __iomem *mmio_base;

static struct timer_list timer;

static unsigned long next_heartbeat;

MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");



#define EP93XX_WATCHDOG		0x00

#define EP93XX_WDSTATUS		0x04



/* reset the wdt every ~200ms - the heartbeat of the device is 0.250 seconds*/

#define WDT_INTERVAL (HZ/5)



static void ep93xx_wdt_timer_ping(unsigned long data)

{

	if (time_before(jiffies, next_heartbeat))

		writel(0x5555, mmio_base + EP93XX_WATCHDOG);



	/* Re-set the timer interval */

	mod_timer(&timer, jiffies + WDT_INTERVAL);

}

struct ep93xx_wdt_priv {

	void __iomem *mmio;

	struct watchdog_device wdd;

};



static int ep93xx_wdt_start(struct watchdog_device *wdd)

{

	next_heartbeat = jiffies + (timeout * HZ);

	struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);



	writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);

	mod_timer(&timer, jiffies + WDT_INTERVAL);

	writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);



	return 0;

}



static int ep93xx_wdt_stop(struct watchdog_device *wdd)

{

	del_timer_sync(&timer);

	writel(0xaa55, mmio_base + EP93XX_WATCHDOG);

	struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);



	writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);



	return 0;

}



static int ep93xx_wdt_keepalive(struct watchdog_device *wdd)

static int ep93xx_wdt_ping(struct watchdog_device *wdd)

{

	/* user land ping */

	next_heartbeat = jiffies + (timeout * HZ);

	struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);



	writel(0x5555, priv->mmio + EP93XX_WATCHDOG);



	return 0;

}



static const struct watchdog_info ep93xx_wdt_ident = {

	.options	= WDIOF_CARDRESET |

			  WDIOF_SETTIMEOUT |

			  WDIOF_MAGICCLOSE |

			  WDIOF_KEEPALIVEPING,

	.identity	= "EP93xx Watchdog",
@@ -103,55 +84,50 @@ static const struct watchdog_ops ep93xx_wdt_ops = { 
	.owner		= THIS_MODULE,

	.start		= ep93xx_wdt_start,

	.stop		= ep93xx_wdt_stop,

	.ping		= ep93xx_wdt_keepalive,

};



static struct watchdog_device ep93xx_wdt_wdd = {

	.info		= &ep93xx_wdt_ident,

	.ops		= &ep93xx_wdt_ops,

	.ping		= ep93xx_wdt_ping,

};



static int ep93xx_wdt_probe(struct platform_device *pdev)

{

	struct ep93xx_wdt_priv *priv;

	struct watchdog_device *wdd;

	struct resource *res;

	unsigned long val;

	int err;

	int ret;



	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	mmio_base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(mmio_base))

		return PTR_ERR(mmio_base);



	if (timeout < 1 || timeout > 3600) {

		timeout = WDT_TIMEOUT;

		dev_warn(&pdev->dev,

			"timeout value must be 1<=x<=3600, using %d\n",

			timeout);

	}

	priv->mmio = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(priv->mmio))

		return PTR_ERR(priv->mmio);



	val = readl(mmio_base + EP93XX_WATCHDOG);

	ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;

	ep93xx_wdt_wdd.timeout = timeout;

	ep93xx_wdt_wdd.parent = &pdev->dev;

	val = readl(priv->mmio + EP93XX_WATCHDOG);



	watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout);

	wdd = &priv->wdd;

	wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;

	wdd->info = &ep93xx_wdt_ident;

	wdd->ops = &ep93xx_wdt_ops;

	wdd->min_timeout = 1;

	wdd->max_hw_heartbeat_ms = 200;

	wdd->parent = &pdev->dev;



	setup_timer(&timer, ep93xx_wdt_timer_ping, 1);

	watchdog_set_nowayout(wdd, nowayout);



	err = watchdog_register_device(&ep93xx_wdt_wdd);

	if (err)

		return err;

	wdd->timeout = WDT_TIMEOUT;

	watchdog_init_timeout(wdd, timeout, &pdev->dev);



	dev_info(&pdev->dev,

		"EP93XX watchdog, driver version " WDT_VERSION "%s\n",

		(val & 0x08) ? " (nCS1 disable detected)" : "");

	watchdog_set_drvdata(wdd, priv);



	return 0;

}

	ret = devm_watchdog_register_device(&pdev->dev, wdd);

	if (ret)

		return ret;



	dev_info(&pdev->dev, "EP93XX watchdog driver %s\n",

		(val & 0x08) ? " (nCS1 disable detected)" : "");



static int ep93xx_wdt_remove(struct platform_device *pdev)

{

	watchdog_unregister_device(&ep93xx_wdt_wdd);

	return 0;

}
@@ -160,7 +136,6 @@ static struct platform_driver ep93xx_wdt_driver = { 
		.name	= "ep93xx-wdt",

	},

	.probe		= ep93xx_wdt_probe,

	.remove		= ep93xx_wdt_remove,

};



module_platform_driver(ep93xx_wdt_driver);
@@ -170,4 +145,3 @@ MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 
MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");

MODULE_DESCRIPTION("EP93xx Watchdog");

MODULE_LICENSE("GPL");
 
MODULE_VERSION(WDT_VERSION);