Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / arch / arm / mach-omap2 / wd_timer.c

diff --git a/arch/arm/mach-omap2/wd_timer.c b/arch/arm/mach-omap2/wd_timer.c
new file mode 100644 (file)
index 0000000..4067669
--- /dev/null
+++ b/arch/arm/mach-omap2/wd_timer.c
@@ -0,0 +1,56 @@
+/*
+ * OMAP2+ MPU WD_TIMER-specific code
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/err.h>
+
+#include <plat/omap_hwmod.h>
+
+#include "wd_timer.h"
+
+/*
+ * In order 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
+
+
+int omap2_wd_timer_disable(struct omap_hwmod *oh)
+{
+       void __iomem *base;
+
+       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;
+       }
+
+       /* 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();
+
+       return 0;
+}
+