Index: sys/dev/extres/regulator/regnode_if.m
===================================================================
--- sys/dev/extres/regulator/regnode_if.m
+++ sys/dev/extres/regulator/regnode_if.m
@@ -90,6 +90,15 @@
 	int		*uvolt;
 };
 
+#
+# Check if a given voltage is supported by the regulator
+# Returns 0 on success or a standard errno value.
+#
+METHOD int check_voltage {
+	struct regnode	*regnode;
+	int		uvolt;
+};
+
 #
 # Stop (shutdown) regulator
 # Returns 0 on success or a standard errno value.
Index: sys/dev/extres/regulator/regulator.h
===================================================================
--- sys/dev/extres/regulator/regulator.h
+++ sys/dev/extres/regulator/regulator.h
@@ -134,6 +134,7 @@
 int regulator_status(regulator_t reg, int *status);
 int regulator_get_voltage(regulator_t reg, int *uvolt);
 int regulator_set_voltage(regulator_t reg, int min_uvolt, int max_uvolt);
+int regulator_check_voltage(regulator_t reg, int uvolt);
 
 #ifdef FDT
 int regulator_get_by_ofw_property(device_t dev, phandle_t node, char *name,
Index: sys/dev/extres/regulator/regulator.c
===================================================================
--- sys/dev/extres/regulator/regulator.c
+++ sys/dev/extres/regulator/regulator.c
@@ -72,6 +72,7 @@
 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 int regnode_method_check_voltage(struct regnode *regnode, int uvolt);
 static void regulator_constraint(void *dummy);
 static void regulator_shutdown(void *dummy);
 
@@ -84,6 +85,7 @@
 	REGNODEMETHOD(regnode_status,		regnode_method_status),
 	REGNODEMETHOD(regnode_set_voltage,	regnode_method_set_voltage),
 	REGNODEMETHOD(regnode_get_voltage,	regnode_method_get_voltage),
+	REGNODEMETHOD(regnode_check_voltage,	regnode_method_check_voltage),
 
 	REGNODEMETHOD_END
 };
@@ -278,6 +280,16 @@
 	    (regnode->std_param.max_uvolt - regnode->std_param.min_uvolt) / 2);
 }
 
+static int
+regnode_method_check_voltage(struct regnode *regnode, int uvolt)
+{
+
+	if ((uvolt > regnode->std_param.max_uvolt) ||
+	    (uvolt < regnode->std_param.min_uvolt))
+		return (ERANGE);
+	return (0);
+}
+
 /* ----------------------------------------------------------------------------
  *
  * Internal functions.
@@ -995,6 +1007,22 @@
 	return (rv);
 }
 
+int
+regulator_check_voltage(regulator_t reg, int uvolt)
+{
+	int rv;
+	struct regnode *regnode;
+
+	regnode = reg->regnode;
+	KASSERT(regnode->ref_cnt > 0,
+	   ("Attempt to access unreferenced regulator: %s\n", regnode->name));
+
+	REG_TOPO_SLOCK();
+	rv = REGNODE_CHECK_VOLTAGE(regnode, uvolt);
+	REG_TOPO_UNLOCK();
+	return (rv);
+}
+
 const char *
 regulator_get_name(regulator_t reg)
 {