sunxi: Implement reset_cpu

There is no way to reset the cpu, so use the watchdog for this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

arch/arm/cpu/armv7/sunxi/board.c

@@ -56,6 +56,13 @@ int gpio_init(void)
 
 void reset_cpu(ulong addr)
 {
+	static const struct sunxi_wdog *wdog =
+		 &((struct sunxi_timer_reg *)SUNXI_TIMER_BASE)->wdog;
+
+	/* Set the watchdog for its shortest interval (.5s) and wait */
+	writel(WDT_MODE_RESET_EN | WDT_MODE_EN, &wdog->mode);
+	writel(WDT_CTRL_KEY | WDT_CTRL_RESTART, &wdog->ctl);
+	while (1);
 }
 
 /* do some early init */

arch/arm/include/asm/arch-sunxi/timer.h

@@ -11,6 +11,11 @@
 #ifndef _SUNXI_TIMER_H_
 #define _SUNXI_TIMER_H_
 
+#define WDT_CTRL_RESTART	(0x1 << 0)
+#define WDT_CTRL_KEY		(0x0a57 << 1)
+#define WDT_MODE_EN		(0x1 << 0)
+#define WDT_MODE_RESET_EN	(0x1 << 1)
+
 #ifndef __ASSEMBLY__
 
 #include <linux/types.h>