regulator: of: Added a property to indicate bypass mode support

Added a property to indicate if the regulator supports bypass mode.
Also modified of_get_regulation_constraints() to check for that
property and set appropriate constraints.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/regulator/regulator.txt

@@ -9,6 +9,7 @@ Optional properties:
 - regulator-max-microamp: largest current consumers may set
 - regulator-always-on: boolean, regulator should never be disabled
 - regulator-boot-on: bootloader/firmware enabled regulator
+- regulator-allow-bypass: allow the regulator to go into bypass mode
 - <name>-supply: phandle to the parent supply/regulator node
 - regulator-ramp-delay: ramp delay for regulator(in uV/uS)
 

drivers/regulator/of_regulator.c

@@ -61,6 +61,9 @@ static void of_get_regulation_constraints(struct device_node *np,
 	else /* status change should be possible if not always on. */
 		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
 
+	if (of_property_read_bool(np, "regulator-allow-bypass"))
+		constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
+
 	ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
 	if (ramp_delay)
 		constraints->ramp_delay = be32_to_cpu(*ramp_delay);