watchdog: imx2: Convert to use infrastructure triggered keepalives
authorGuenter Roeck <linux@roeck-us.net>
Sun, 28 Feb 2016 21:12:20 +0000 (13:12 -0800)
committerWim Van Sebroeck <wim@iguana.be>
Wed, 16 Mar 2016 20:11:23 +0000 (21:11 +0100)
The watchdog infrastructure now supports handling watchdog keepalive
if the watchdog is running while the watchdog device is closed.
Convert the driver to use this infrastructure.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/imx2_wdt.c

index 4cb59a23aab016750c665d6c09ec5081f9dbc501..331aed831dac8419198d78e77b895b2d5ec883e0 100644 (file)
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/io.h>
-#include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
-#include <linux/timer.h>
 #include <linux/watchdog.h>
 
 #define DRIVER_NAME "imx2-wdt"
@@ -60,7 +58,6 @@
 struct imx2_wdt_device {
        struct clk *clk;
        struct regmap *regmap;
-       struct timer_list timer;        /* Pings the watchdog when closed */
        struct watchdog_device wdog;
 };
 
@@ -147,16 +144,6 @@ static int imx2_wdt_ping(struct watchdog_device *wdog)
        return 0;
 }
 
-static void imx2_wdt_timer_ping(unsigned long arg)
-{
-       struct watchdog_device *wdog = (struct watchdog_device *)arg;
-       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
-
-       /* ping it every wdog->timeout / 2 seconds to prevent reboot */
-       imx2_wdt_ping(wdog);
-       mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2);
-}
-
 static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
                                unsigned int new_timeout)
 {
@@ -173,40 +160,19 @@ static int imx2_wdt_start(struct watchdog_device *wdog)
 {
        struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 
-       if (imx2_wdt_is_running(wdev)) {
-               /* delete the timer that pings the watchdog after close */
-               del_timer_sync(&wdev->timer);
+       if (imx2_wdt_is_running(wdev))
                imx2_wdt_set_timeout(wdog, wdog->timeout);
-       else
+       else
                imx2_wdt_setup(wdog);
 
-       return imx2_wdt_ping(wdog);
-}
-
-static int imx2_wdt_stop(struct watchdog_device *wdog)
-{
-       /*
-        * 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((unsigned long)wdog);
-       return 0;
-}
-
-static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog)
-{
-       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+       set_bit(WDOG_HW_RUNNING, &wdog->status);
 
-       if (imx2_wdt_is_running(wdev)) {
-               imx2_wdt_set_timeout(wdog, wdog->timeout);
-               imx2_wdt_timer_ping((unsigned long)wdog);
-       }
+       return imx2_wdt_ping(wdog);
 }
 
 static const struct watchdog_ops imx2_wdt_ops = {
        .owner = THIS_MODULE,
        .start = imx2_wdt_start,
-       .stop = imx2_wdt_stop,
        .ping = imx2_wdt_ping,
        .set_timeout = imx2_wdt_set_timeout,
        .restart = imx2_wdt_restart,
@@ -254,7 +220,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
        wdog->info              = &imx2_wdt_info;
        wdog->ops               = &imx2_wdt_ops;
        wdog->min_timeout       = 1;
-       wdog->max_timeout       = IMX2_WDT_MAX_TIME;
+       wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;
        wdog->parent            = &pdev->dev;
 
        ret = clk_prepare_enable(wdev->clk);
@@ -275,9 +241,10 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
        watchdog_set_restart_priority(wdog, 128);
        watchdog_init_timeout(wdog, timeout, &pdev->dev);
 
-       setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog);
-
-       imx2_wdt_ping_if_active(wdog);
+       if (imx2_wdt_is_running(wdev)) {
+               imx2_wdt_set_timeout(wdog, wdog->timeout);
+               set_bit(WDOG_HW_RUNNING, &wdog->status);
+       }
 
        /*
         * Disable the watchdog power down counter at boot. Otherwise the power
@@ -310,7 +277,6 @@ static int __exit imx2_wdt_remove(struct platform_device *pdev)
        watchdog_unregister_device(wdog);
 
        if (imx2_wdt_is_running(wdev)) {
-               del_timer_sync(&wdev->timer);
                imx2_wdt_ping(wdog);
                dev_crit(&pdev->dev, "Device removed: Expect reboot!\n");
        }
@@ -324,10 +290,9 @@ static void imx2_wdt_shutdown(struct platform_device *pdev)
 
        if (imx2_wdt_is_running(wdev)) {
                /*
-                * We are running, we need to delete the timer but will
-                * give max timeout before reboot will take place
+                * We are running, configure max timeout before reboot
+                * will take place.
                 */
-               del_timer_sync(&wdev->timer);
                imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
                imx2_wdt_ping(wdog);
                dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
@@ -345,10 +310,6 @@ static int imx2_wdt_suspend(struct device *dev)
        if (imx2_wdt_is_running(wdev)) {
                imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
                imx2_wdt_ping(wdog);
-
-               /* The watchdog is not active */
-               if (!watchdog_active(wdog))
-                       del_timer_sync(&wdev->timer);
        }
 
        clk_disable_unprepare(wdev->clk);
@@ -374,19 +335,10 @@ static int imx2_wdt_resume(struct device *dev)
                 * watchdog again.
                 */
                imx2_wdt_setup(wdog);
+       }
+       if (imx2_wdt_is_running(wdev)) {
                imx2_wdt_set_timeout(wdog, wdog->timeout);
                imx2_wdt_ping(wdog);
-       } else if (imx2_wdt_is_running(wdev)) {
-               /* Resuming from non-deep sleep state. */
-               imx2_wdt_set_timeout(wdog, wdog->timeout);
-               imx2_wdt_ping(wdog);
-               /*
-                * But the watchdog is not active, then start
-                * the timer again.
-                */
-               if (!watchdog_active(wdog))
-                       mod_timer(&wdev->timer,
-                                 jiffies + wdog->timeout * HZ / 2);
        }
 
        return 0;