regulator: fixed: add property for gpio open drain flag

Add property for the gpio flag open drain when registering
fixed regulator.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Documentation/devicetree/bindings/regulator/fixed-regulator.txt

@@ -8,6 +8,8 @@ Optional properties:
 - startup-delay-us: startup time in microseconds
 - enable-active-high: Polarity of GPIO is Active high
 If this property is missing, the default assumed is Active low.
+- gpio-open-drain: GPIO is open drain type.
+  If this property is missing then default assumption is false.
 
 Any property defined as part of the core regulator
 binding, defined in regulator.txt, can also be used.
@@ -25,5 +27,6 @@ Example:
 		gpio = <&gpio1 16 0>;
 		startup-delay-us = <70000>;
 		enable-active-high;
-		regulator-boot-on
+		regulator-boot-on;
+		gpio-open-drain;
 	};

drivers/regulator/fixed.c

@@ -90,6 +90,9 @@ of_get_fixed_voltage_config(struct device *dev)
 	if (of_find_property(np, "enable-active-high", NULL))
 		config->enable_high = true;
 
+	if (of_find_property(np, "gpio-open-drain", NULL))
+		config->gpio_is_open_drain = true;
+
 	return config;
 }