sh: Use internal watchdog timer to perform reset

This patches will trigger a reboot using the watchdog
timer instead of double fault.  Unlike the previous
method, this one actually works in 32 bit mode.

Reset should also be cleaner.

Signed-off-by: Jon Frosdick <jon.frosdick@st.com>
Signed-off-by: Carl Shaw <carl.shaw@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 9fee977f176b..0673c4746be3 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -32,15 +32,35 @@
 #include <asm/ubc.h>
 #include <asm/fpu.h>
 #include <asm/syscalls.h>
+#include <asm/watchdog.h>
 
 int ubc_usercnt = 0;
 
+#ifdef CONFIG_32BIT
+static void watchdog_trigger_immediate(void)
+{
+        sh_wdt_write_cnt(0xFF);
+        sh_wdt_write_csr(0xC2);
+}
+
+void machine_restart(char * __unused)
+{
+        local_irq_disable();
+
+        /* Use watchdog timer to trigger reset */
+        watchdog_trigger_immediate();
+
+        while (1)
+                cpu_sleep();
+}
+#else
 void machine_restart(char * __unused)
 {
         /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
         asm volatile("ldc %0, sr\n\t"
                      "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
 }
+#endif
 
 void machine_halt(void)
 {