watchdog: tegra_wdt: Several changes to watchdog driver

Add a config option to enable the watchdog driver from probe
Reduce the default timeout to 30 seconds
Read the reset reason and print a messge if the last reboot was
	due to watchdog reset

Change-Id: I7500ef236089b06ffcff3d8e7d86a5b9060b59cb
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1addd785739a41d0d26925922f724ba71ce6b971..f775da5a1be526a2e916ed7cdf87484968da49da 100644 (file)
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -205,6 +205,12 @@ config TEGRA_WATCHDOG
          To compile this driver as a module, choose M here: the
          module will be called tegra_wdt.
 
+config TEGRA_WATCHDOG_ENABLE_ON_PROBE
+       tristate "Tegra watchdog"
+       depends on ARCH_TEGRA && TEGRA_WATCHDOG
+       help
+         Say Y here to enable the tegra watchdog at driver
+         probe time, rather than when the device is opened.
 
 config EP93XX_WATCHDOG
        tristate "EP93xx Watchdog"

diff --git a/drivers/watchdog/tegra_wdt.c b/drivers/watchdog/tegra_wdt.c
index d7a9d7609a1f738053bfd1d257e15cdef15f7ad4..d7ad6238d4f3b4e1b5d94a02150f4e09b3b4351d 100644 (file)
--- a/drivers/watchdog/tegra_wdt.c
+++ b/drivers/watchdog/tegra_wdt.c
@@ -50,7 +50,7 @@
 #define WDT_SEL_TMR1   (0 << 4)
 #define WDT_SYS_RST    (1 << 2)
 
-static int heartbeat = 60;
+static int heartbeat = 30;
 
 struct tegra_wdt {
        struct miscdevice       miscdev;
@@ -208,6 +208,7 @@ static int tegra_wdt_probe(struct platform_device *pdev)
 {
        struct resource *res_src, *res_wdt, *res_irq;
        struct tegra_wdt *wdt;
+       u32 src;
        int ret = 0;
 
        if (pdev->id != -1) {
@@ -262,6 +263,10 @@ static int tegra_wdt_probe(struct platform_device *pdev)
                goto fail;
        }
 
+       src = readl(wdt->wdt_source);
+       if (src & BIT(12))
+               dev_info(&pdev->dev, "last reset due to watchdog timeout\n");
+
        tegra_wdt_disable(wdt);
 
        ret = request_irq(res_irq->start, tegra_wdt_interrupt, IRQF_DISABLED,
@@ -292,6 +297,9 @@ 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
+       tegra_wdt_enable(wdt);
+#endif
        return 0;
 fail:
        if (wdt->irq != -1)