watchdog: tegra_wdt: Several changes to watchdog driver

Fix not re-enabling watchdog resume if it was enabled in probe
Add clearing watchdog interrupt in probe
Remove tegra_wdt_set_timeout

Change-Id: I8fdbb6da3eda64a85a73ed85ab979a5ee0261c37
Signed-off-by: Dmitriy Gruzman <dmitriy.gruzman@motorola.com>

diff --git a/drivers/watchdog/tegra_wdt.c b/drivers/watchdog/tegra_wdt.c
index d7ad6238d4f3b4e1b5d94a02150f4e09b3b4351d..d11b99816ca6cb7644e278e9043d1a621d2e1b33 100644 (file)
--- a/drivers/watchdog/tegra_wdt.c
+++ b/drivers/watchdog/tegra_wdt.c
@@ -40,17 +40,17 @@
 #define MAX_WDT_PERIOD 1000
 
 #define TIMER_PTV      0x0
- #define TIMER_EN      (1 << 31)
- #define TIMER_PERIODIC        (1 << 30)
+#define TIMER_EN       (1 << 31)
+#define TIMER_PERIODIC (1 << 30)
 
 #define TIMER_PCR      0x4
- #define TIMER_PCR_INTR        (1 << 30)
+#define TIMER_PCR_INTR (1 << 30)
 
 #define WDT_EN         (1 << 5)
 #define WDT_SEL_TMR1   (0 << 4)
 #define WDT_SYS_RST    (1 << 2)
 
-static int heartbeat = 30;
+static int heartbeat = 30; /* must be greater than MIN_WDT_PERIOD and lower than MAX_WDT_PERIOD */
 
 struct tegra_wdt {
        struct miscdevice       miscdev;
@@ -67,31 +67,13 @@ struct tegra_wdt {
 
 static struct tegra_wdt *tegra_wdt_dev;
 
-static void tegra_wdt_set_timeout(struct tegra_wdt *wdt, int sec)
-{
-       u32 ptv, src;
-
-       ptv = readl(wdt->wdt_timer + TIMER_PTV);
-       src = readl(wdt->wdt_source);
-
-       writel(0, wdt->wdt_source);
-       wdt->timeout = clamp(sec, MIN_WDT_PERIOD, MAX_WDT_PERIOD);
-       if (ptv & TIMER_EN) {
-               /* since the watchdog reset occurs when a second interrupt
-                * is asserted before the first is processed, program the
-                * timer period to one-half of the watchdog period */
-               ptv = wdt->timeout * 1000000ul / 2;
-               ptv |= (TIMER_EN | TIMER_PERIODIC);
-               writel(ptv, wdt->wdt_timer + TIMER_PTV);
-       }
-       writel(src, wdt->wdt_source);
-}
-
-
 static void tegra_wdt_enable(struct tegra_wdt *wdt)
 {
        u32 val;
 
+       /* since the watchdog reset occurs when a second interrupt
+        * is asserted before the first is processed, program the
+        * timer period to one-half of the watchdog period */
        val = wdt->timeout * 1000000ul / 2;
        val |= (TIMER_EN | TIMER_PERIODIC);
        writel(val, wdt->wdt_timer + TIMER_PTV);
@@ -133,7 +115,7 @@ static int tegra_wdt_open(struct inode *inode, struct file *file)
                return -EBUSY;
 
        wdt->enabled = true;
-       tegra_wdt_set_timeout(wdt, heartbeat);
+       wdt->timeout = heartbeat;
        tegra_wdt_enable(wdt);
        file->private_data = wdt;
        return nonseekable_open(inode, file);
@@ -179,7 +161,7 @@ static long tegra_wdt_ioctl(struct file *file, unsigned int cmd,
                        return -EFAULT;
                spin_lock(&lock);
                tegra_wdt_disable(wdt);
-               tegra_wdt_set_timeout(wdt, new_timeout);
+               wdt->timeout = clamp(new_timeout, MIN_WDT_PERIOD, MAX_WDT_PERIOD);
                tegra_wdt_enable(wdt);
                spin_unlock(&lock);
        case WDIOC_GETTIMEOUT:
@@ -268,6 +250,7 @@ static int tegra_wdt_probe(struct platform_device *pdev)
                dev_info(&pdev->dev, "last reset due to watchdog timeout\n");
 
        tegra_wdt_disable(wdt);
+       writel(TIMER_PCR_INTR, wdt->wdt_timer + TIMER_PCR);
 
        ret = request_irq(res_irq->start, tegra_wdt_interrupt, IRQF_DISABLED,
                          dev_name(&pdev->dev), wdt);
@@ -280,8 +263,6 @@ static int tegra_wdt_probe(struct platform_device *pdev)
        wdt->res_src = res_src;
        wdt->res_wdt = res_wdt;
 
-       wdt->timeout = heartbeat;
-
        ret = register_reboot_notifier(&wdt->notifier);
        if (ret) {
                dev_err(&pdev->dev, "cannot register reboot notifier\n");
@@ -298,6 +279,8 @@ static int tegra_wdt_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, wdt);
        tegra_wdt_dev = wdt;
 #ifdef CONFIG_TEGRA_WATCHDOG_ENABLE_ON_PROBE
+       wdt->enabled = true;
+       wdt->timeout = heartbeat;
        tegra_wdt_enable(wdt);
 #endif
        return 0;
@@ -334,6 +317,7 @@ static int tegra_wdt_remove(struct platform_device *pdev)
        return 0;
 }
 
+#ifdef CONFIG_PM
 static int tegra_wdt_suspend(struct platform_device *pdev, pm_message_t state)
 {
        struct tegra_wdt *wdt = platform_get_drvdata(pdev);
@@ -351,12 +335,15 @@ static int tegra_wdt_resume(struct platform_device *pdev)
 
        return 0;
 }
+#endif
 
 static struct platform_driver tegra_wdt_driver = {
        .probe          = tegra_wdt_probe,
        .remove         = __devexit_p(tegra_wdt_remove),
+#ifdef CONFIG_PM
        .suspend        = tegra_wdt_suspend,
        .resume         = tegra_wdt_resume,
+#endif
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "tegra_wdt",