watchdog: fix watchdog get lefttime error [1/1]

PD#SWPL-6937

Problem:
1.get lefttime error by 'cat sys/class/watchdog/watchdog0/timeleft' cmd.
2.if DTS is configured to feed watchdog by Android, the system will
restart automatically after wake up.

Solution:
1.modify the code to get time.
2.when the system wakes up, first judge whether the watchdog runs,
and then decide whether to start the watchdog.

Verify:
test pass on u200

Change-Id: If64888ffdd5651e8cfcace5ea0d0da31641bb397
Signed-off-by: Yingyuan Zhu <yingyuan.zhu@amlogic.com>

diff --git a/drivers/amlogic/watchdog/meson_wdt.c b/drivers/amlogic/watchdog/meson_wdt.c
index 4da2517..bb48362 100644 (file)
--- a/drivers/amlogic/watchdog/meson_wdt.c
+++ b/drivers/amlogic/watchdog/meson_wdt.c
@@ -54,6 +54,7 @@ struct aml_wdt_dev {
        void __iomem *reg_base;
        struct notifier_block pm_notifier;
        struct notifier_block reboot_notifier;
+       bool is_running; /* 1:enable 0:disable */
 };
 
 static void aml_update_bits(void __iomem  *reg, unsigned int mask,
@@ -108,7 +109,9 @@ static int aml_wdt_start(struct watchdog_device *wdog)
        if (wdev->boot_queue)
                cancel_delayed_work(&wdev->boot_queue);
 #endif
+       wdev->is_running = true;
        dev_info(wdev->dev, "start watchdog\n");
+
        return 0;
 }
 
@@ -119,6 +122,7 @@ static int aml_wdt_stop(struct watchdog_device *wdog)
        mutex_lock(&wdev->lock);
        disable_watchdog(wdev);
        mutex_unlock(&wdev->lock);
+       wdev->is_running = false;
        dev_info(wdev->dev, "stop watchdog\n");
 
        return 0;
@@ -153,12 +157,14 @@ static int aml_wdt_set_timeout(struct watchdog_device *wdog,
 unsigned int aml_wdt_get_timeleft(struct watchdog_device *wdog)
 {
        struct aml_wdt_dev *wdev = watchdog_get_drvdata(wdog);
-       unsigned int timeleft;
+       unsigned long timeleft, tick;
 
        mutex_lock(&wdev->lock);
        timeleft = read_watchdog_tcnt(wdev);
+       tick = readl(wdev->reg_base + TCNT) & 0xffff;
        mutex_unlock(&wdev->lock);
-       return timeleft/wdev->one_second;
+
+       return (tick - timeleft)/wdev->one_second;
 }
 
 static void boot_moniter_work(struct work_struct *work)
@@ -255,14 +261,18 @@ static int aml_wtd_pm_notify(struct notifier_block *nb, unsigned long event,
        wdev = container_of(nb, struct aml_wdt_dev, pm_notifier);
 
        if (event == PM_SUSPEND_PREPARE) {
-               disable_watchdog(wdev);
-               dev_info(wdev->dev,
-                       "pm_notify: disable watchdog, event = %lu\n", event);
+               if (wdev->is_running) {
+                       disable_watchdog(wdev);
+                       dev_info(wdev->dev,
+                        "pm_notify: disable watchdog, event = %lu\n", event);
+               }
        }
        if (event == PM_POST_SUSPEND) {
-               enable_watchdog(wdev);
-               dev_info(wdev->dev,
-                       "pm_notify: enable watchdog, event = %lu\n", event);
+               if (wdev->is_running) {
+                       enable_watchdog(wdev);
+                       dev_info(wdev->dev,
+                        "pm_notify: enable watchdog, event = %lu\n", event);
+               }
        }
        return NOTIFY_OK;
 }
@@ -338,14 +348,13 @@ static int aml_wdt_probe(struct platform_device *pdev)
 
        watchdog_set_drvdata(aml_wdt, wdev);
        platform_set_drvdata(pdev, aml_wdt);
+       wdev->is_running = false;
        if (wdev->reset_watchdog_method == 1) {
 
                INIT_DELAYED_WORK(&wdev->boot_queue, boot_moniter_work);
                mod_delayed_work(system_freezable_wq, &wdev->boot_queue,
         round_jiffies(msecs_to_jiffies(wdev->reset_watchdog_time*1000)));
-               enable_watchdog(wdev);
-               set_watchdog_cnt(wdev,
-                                wdev->default_timeout * wdev->one_second);
+               aml_wdt_start(aml_wdt);
                dev_info(wdev->dev, "creat work queue for watch dog\n");
        }
        ret = watchdog_register_device(aml_wdt);