1 files changed, 45 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/wd_timer.c b/arch/arm/mach-omap2/wd_timer.c
index 4067669d96c4..b2f1c67043a2 100644
--- a/arch/arm/mach-omap2/wd_timer.c
+++ b/arch/arm/mach-omap2/wd_timer.c
@@ -14,6 +14,7 @@
 #include <plat/omap_hwmod.h>
 
 #include "wd_timer.h"
+#include "common.h"
 
 /*
  * In order to avoid any assumptions from bootloader regarding WDT
@@ -25,6 +26,8 @@
 #define OMAP_WDT_WPS            0x34
 #define OMAP_WDT_SPR            0x48
 
+/* Maximum microseconds to wait for OMAP module to softreset */
+#define MAX_MODULE_SOFTRESET_WAIT       10000
 
 int omap2_wd_timer_disable(struct omap_hwmod *oh)
 {
@@ -54,3 +57,45 @@ int omap2_wd_timer_disable(struct omap_hwmod *oh)
         return 0;
 }
 
+/**
+ * omap2_wdtimer_reset - reset and disable the WDTIMER IP block
+ * @oh: struct omap_hwmod *
+ *
+ * After the WDTIMER IP blocks are reset on OMAP2/3, we must also take
+ * care to execute the special watchdog disable sequence.  This is
+ * because the watchdog is re-armed upon OCP softreset.  (On OMAP4,
+ * this behavior was apparently changed and the watchdog is no longer
+ * re-armed after an OCP soft-reset.)  Returns -ETIMEDOUT if the reset
+ * did not complete, or 0 upon success.
+ *
+ * XXX Most of this code should be moved to the omap_hwmod.c layer
+ * during a normal merge window.  omap_hwmod_softreset() should be
+ * renamed to omap_hwmod_set_ocp_softreset(), and omap_hwmod_softreset()
+ * should call the hwmod _ocp_softreset() code.
+ */
+int omap2_wd_timer_reset(struct omap_hwmod *oh)
+{
+        int c = 0;
+
+        /* Write to the SOFTRESET bit */
+        omap_hwmod_softreset(oh);
+
+        /* Poll on RESETDONE bit */
+        omap_test_timeout((omap_hwmod_read(oh,
+                                           oh->class->sysc->syss_offs)
+                           & SYSS_RESETDONE_MASK),
+                          MAX_MODULE_SOFTRESET_WAIT, c);
+
+        if (oh->class->sysc->srst_udelay)
+                udelay(oh->class->sysc->srst_udelay);
+
+        if (c == MAX_MODULE_SOFTRESET_WAIT)
+                pr_warning("%s: %s: softreset failed (waited %d usec)\n",
+                           __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
+        else
+                pr_debug("%s: %s: softreset in %d usec\n", __func__,
+                         oh->name, c);
+
+        return (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT :
+                omap2_wd_timer_disable(oh);
+}