1 files changed, 61 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c
index 5eb0b58b2e95..818452ac905d 100644
--- a/arch/arm/mach-omap2/devices.c
+++ b/arch/arm/mach-omap2/devices.c
@@ -914,11 +914,72 @@ static inline void omap_init_vout(void) {}
 
 /*-------------------------------------------------------------------------*/
 
+/*
+ * Inorder to avoid any assumptions from bootloader regarding WDT
+ * settings, WDT module is reset during init. This enables the watchdog
+ * timer. Hence it is required to disable the watchdog after the WDT reset
+ * during init. Otherwise the system would reboot as per the default
+ * watchdog timer registers settings.
+ */
+#define OMAP_WDT_WPS    (0x34)
+#define OMAP_WDT_SPR    (0x48)
+
+static int omap2_disable_wdt(struct omap_hwmod *oh, void *unused)
+{
+        void __iomem *base;
+        int ret;
+
+        if (!oh) {
+                pr_err("%s: Could not look up wdtimer_hwmod\n", __func__);
+                return -EINVAL;
+        }
+
+        base = omap_hwmod_get_mpu_rt_va(oh);
+        if (!base) {
+                pr_err("%s: Could not get the base address for %s\n",
+                                oh->name, __func__);
+                return -EINVAL;
+        }
+
+        /* Enable the clocks before accessing the WDT registers */
+        ret = omap_hwmod_enable(oh);
+        if (ret) {
+                pr_err("%s: Could not enable clocks for %s\n",
+                                oh->name, __func__);
+                return ret;
+        }
+
+        /* sequence required to disable watchdog */
+        __raw_writel(0xAAAA, base + OMAP_WDT_SPR);
+        while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
+                cpu_relax();
+
+        __raw_writel(0x5555, base + OMAP_WDT_SPR);
+        while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
+                cpu_relax();
+
+        ret = omap_hwmod_idle(oh);
+        if (ret)
+                pr_err("%s: Could not disable clocks for %s\n",
+                                oh->name, __func__);
+
+        return ret;
+}
+
+static void __init omap_disable_wdt(void)
+{
+        if (cpu_class_is_omap2())
+                omap_hwmod_for_each_by_class("wd_timer",
+                                                omap2_disable_wdt, NULL);
+        return;
+}
+
 static int __init omap2_init_devices(void)
 {
         /* please keep these calls, and their implementations above,
          * in alphabetical order so they're easier to sort through.
          */
+        omap_disable_wdt();
         omap_hsmmc_reset();
         omap_init_camera();
         omap_init_mbox();