dm: regulator: add fixed voltage regulator driver

This driver implements regulator operations for fixed Voltage/Current
value regulators. beside the standard regulator constraints, which are
put into the uclass platform data, a typical fixed regulator node provides
few additional properties like:
- gpio
- gpio-open-drain
- enable-active-high
- startup-delay-us
The only 'gpio' is used by this driver and is kept in structure of type
'fixed_regulator_platdata', as a device platform data (dev->platdata).

The driver implements:
- get_value
- get_current
- get_enable
- set_enable

The regulator calls and commands can be used for fixed-regulator devices,
and the proper error will be returned for prohibited.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/doc/device-tree-bindings/regulator/fixed.txt b/doc/device-tree-bindings/regulator/fixed.txt
new file mode 100644
index 0000000000..4ff39b8f51
--- /dev/null
+++ b/doc/device-tree-bindings/regulator/fixed.txt
@@ -0,0 +1,38 @@
+Fixed Voltage regulator
+
+Binding:
+The binding is done by the property "compatible" - this is different, than for
+binding by the node prefix (doc/device-tree-bindings/regulator/regulator.txt).
+
+Required properties:
+- compatible: "regulator-fixed"
+- regulator-name: this is required by the regulator uclass
+
+Optional properties:
+- gpio: GPIO to use for enable control
+- regulator constraints (binding info: regulator.txt)
+
+Other kernel-style properties, are currently not used.
+
+Note:
+For the regulator constraints, driver expects that:
+- regulator-min-microvolt is equal to regulator-max-microvolt
+- regulator-min-microamp is equal to regulator-max-microamp
+
+Example:
+fixed_regulator@0 {
+	/* Mandatory */
+	compatible = "regulator-fixed";
+	regulator-name = "LED_3.3V";
+
+	/* Optional: */
+	gpio = <&gpc1 0 GPIO_ACTIVE_LOW>;
+
+	/* Optional for regulator uclass */
+	regulator-min-microvolt = <3300000>;
+	regulator-max-microvolt = <3300000>;
+	regulator-min-microamp = <15000>;
+	regulator-max-microamp = <15000>;
+	regulator-always-on;
+	regulator-boot-on;
+};