Index: head/sys/arm/allwinner/axp209.c
===================================================================
--- head/sys/arm/allwinner/axp209.c
+++ head/sys/arm/allwinner/axp209.c
@@ -753,6 +753,7 @@
 	REGNODEMETHOD(regnode_enable,		axp2xx_regnode_enable),
 	REGNODEMETHOD(regnode_set_voltage,	axp2xx_regnode_set_voltage),
 	REGNODEMETHOD(regnode_get_voltage,	axp2xx_regnode_get_voltage),
+	REGNODEMETHOD(regnode_check_voltage,	regnode_method_check_voltage),
 	REGNODEMETHOD_END
 };
 DEFINE_CLASS_1(axp2xx_regnode, axp2xx_regnode_class, axp2xx_regnode_methods,
Index: head/sys/arm/allwinner/axp81x.c
===================================================================
--- head/sys/arm/allwinner/axp81x.c
+++ head/sys/arm/allwinner/axp81x.c
@@ -866,6 +866,7 @@
 	REGNODEMETHOD(regnode_enable,		axp8xx_regnode_enable),
 	REGNODEMETHOD(regnode_set_voltage,	axp8xx_regnode_set_voltage),
 	REGNODEMETHOD(regnode_get_voltage,	axp8xx_regnode_get_voltage),
+	REGNODEMETHOD(regnode_check_voltage,	regnode_method_check_voltage),
 	REGNODEMETHOD_END
 };
 DEFINE_CLASS_1(axp8xx_regnode, axp8xx_regnode_class, axp8xx_regnode_methods,
Index: head/sys/arm64/rockchip/rk805.c
===================================================================
--- head/sys/arm64/rockchip/rk805.c
+++ head/sys/arm64/rockchip/rk805.c
@@ -362,6 +362,7 @@
 	REGNODEMETHOD(regnode_enable,		rk805_regnode_enable),
 	REGNODEMETHOD(regnode_set_voltage,	rk805_regnode_set_voltage),
 	REGNODEMETHOD(regnode_get_voltage,	rk805_regnode_get_voltage),
+	REGNODEMETHOD(regnode_check_voltage,	regnode_method_check_voltage),
 	REGNODEMETHOD_END
 };
 DEFINE_CLASS_1(rk805_regnode, rk805_regnode_class, rk805_regnode_methods,
Index: head/sys/dev/extres/regulator/regnode_if.m
===================================================================
--- head/sys/dev/extres/regulator/regnode_if.m
+++ head/sys/dev/extres/regulator/regnode_if.m
@@ -91,6 +91,15 @@
 };
 
 #
+# 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: head/sys/dev/extres/regulator/regulator.h
===================================================================
--- head/sys/dev/extres/regulator/regulator.h
+++ head/sys/dev/extres/regulator/regulator.h
@@ -117,6 +117,10 @@
 int regnode_get_voltage(struct regnode *regnode, int *uvolt);
 int regnode_set_voltage(struct regnode *regnode, int min_uvolt, int max_uvolt);
 int regnode_set_constraint(struct regnode *regnode);
+
+/* Standard method that aren't default */
+int regnode_method_check_voltage(struct regnode *regnode, int uvolt);
+
 #ifdef FDT
 phandle_t regnode_get_ofw_node(struct regnode *regnode);
 #endif
@@ -134,6 +138,7 @@
 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: head/sys/dev/extres/regulator/regulator.c
===================================================================
--- head/sys/dev/extres/regulator/regulator.c
+++ head/sys/dev/extres/regulator/regulator.c
@@ -84,6 +84,7 @@
 	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 +279,16 @@
 	    (regnode->std_param.max_uvolt - regnode->std_param.min_uvolt) / 2);
 }
 
+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.
@@ -991,6 +1002,22 @@
 		reg->min_uvolt = min_uvolt;
 		reg->max_uvolt = max_uvolt;
 	}
+	REG_TOPO_UNLOCK();
+	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);
 }
Index: head/sys/dev/extres/regulator/regulator_fixed.c
===================================================================
--- head/sys/dev/extres/regulator/regulator_fixed.c
+++ head/sys/dev/extres/regulator/regulator_fixed.c
@@ -80,6 +80,7 @@
 	REGNODEMETHOD(regnode_enable,		regnode_fixed_enable),
 	REGNODEMETHOD(regnode_status,		regnode_fixed_status),
 	REGNODEMETHOD(regnode_stop,		regnode_fixed_stop),
+	REGNODEMETHOD(regnode_check_voltage,	regnode_method_check_voltage),
 	REGNODEMETHOD_END
 };
 DEFINE_CLASS_1(regnode_fixed, regnode_fixed_class, regnode_fixed_methods,