ar7240: add watchdog support for carambola/skylab

u-boot/board/ar7240/carambola2/Makefile

@@ -5,6 +5,7 @@ LIB	= lib$(BOARD).a
 OBJS	= $(BOARD).o flash.o ../common/ar7240_flash.o ../common/ar7240_s26_phy.o
 OBJS	+= carambola_factory.o
 OBJS	+= ../common/usb_boot.o
+OBJS	+= ../common/watchdog.o
 SOBJS	= ../common/lowlevel_init.o
 SOBJS	+= hornet_pll_init.o
 

u-boot/board/ar7240/common/watchdog.c

@@ -0,0 +1,13 @@
+#include <common.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include "ar7240_soc.h"
+
+void hw_watchdog_reset(void)
+{
+  /* around 15 seconds */
+  ar7240_reg_wr(AR7240_WATCHDOG_TMR, 0xfffffffful);
+
+  /* do a full chip reset */
+  ar7240_reg_wr(AR7240_WATCHDOG_TMR_CONTROL, 0x3);
+}