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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
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+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);