Index: sys/dev/extres/regulator/regulator.c
===================================================================
--- sys/dev/extres/regulator/regulator.c
+++ sys/dev/extres/regulator/regulator.c
@@ -71,6 +71,7 @@
 static int regnode_method_set_voltage(struct regnode *regnode, int min_uvolt,
     int max_uvolt, int *udelay);
 static int regnode_method_get_voltage(struct regnode *regnode, int *uvolt);
+static void regulator_shutdown(void *dummy);
 
 /*
  * Regulator controller methods.
@@ -151,6 +152,29 @@
 #define REGNODE_XLOCK(_sc)	sx_xlock(&((_sc)->lock))
 #define REGNODE_UNLOCK(_sc)	sx_unlock(&((_sc)->lock))
 
+SYSINIT(regulator_shutdown, SI_SUB_LAST, SI_ORDER_ANY, regulator_shutdown,
+    NULL);
+
+static void
+regulator_shutdown(void *dummy)
+{
+	struct regnode *entry;
+	int disable = 1;
+
+	REG_TOPO_SLOCK();
+	TUNABLE_INT_FETCH("hw.regulator.disable_unused", &disable);
+	TAILQ_FOREACH(entry, &regnode_list, reglist_link) {
+		if (entry->enable_cnt == 0 &&
+		    entry->std_param.always_on == 0 && disable) {
+			if (bootverbose)
+				printf("regulator: shuting down %s\n",
+				    entry->name);
+			regnode_stop(entry, 0);
+		}
+	}
+	REG_TOPO_UNLOCK();
+}
+
 /*
  * sysctl handler
  */