[RFC PATCH 06/11] DT: regulator: Helper routine to extract fixed_voltage_config

[Rajendra Nayak <rnayak@ti.com>]

The helper routine defined here (of_get_fixed_voltage_config) can
be used to extract information about fixed regulators (which are not
software controlable) from device tree.

Add documenation about additional bindings for fixed
regulators that can be passed through DT.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
---
 .../devicetree/bindings/regulator/regulator.txt    |   19 ++++++++++++
 drivers/of/of_regulator.c                          |   31 ++++++++++++++++++++
 include/linux/of_regulator.h                       |    7 ++++
 3 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt
index 001e5ce..f8c51d8 100644
--- a/Documentation/devicetree/bindings/regulator/regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/regulator.txt
@@ -2,6 +2,8 @@ Voltage/Current Regulators
 
 Required properties:
 - compatible: Must be "regulator";
+or
+- compatible: Must be "regulator-fixed"; /* For Fixed volatge regulator */
 
 Optional properties:
 - supply-regulator: Name of the parent regulator
@@ -24,6 +26,13 @@ Optional properties:
 - always-on: boolean, regulator should never be disabled
 - boot-on: bootloader/firmware enabled regulator
 - apply-uV: apply uV constraint if min == max
+# For fixed voltage regulators
+- supply-name: Name of the regulator supply
+- microvolts: Output voltage of regulator
+- gpio: gpio to use for enable control
+- startup-delay: startup time in microseconds
+- enable-high: Polarity of enable GPIO, 1 = Active High, 0 = Active low
+- enabled-at-boot: 1 = yes, 0 = no
 
 Example:
 
@@ -35,3 +44,13 @@ Example:
 		change-voltage;
 		always-on;
 	};
+
+	abc-fixedregulator {
+		compatible = "regulator-fixed";
+		supply-name = "fixed-supply";
+		microvolts = <1800000>;
+		gpio = <43>;
+		startup-delay = <70000>;
+		enable-high;
+		enabled-at-boot;
+	};
diff --git a/drivers/of/of_regulator.c b/drivers/of/of_regulator.c
index f01d275..4d7a49d 100644
--- a/drivers/of/of_regulator.c
+++ b/drivers/of/of_regulator.c
@@ -13,6 +13,7 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/regulator/machine.h>
+#include <linux/regulator/fixed.h>
 
 static void of_get_regulation_constraints(struct device_node *np,
 					struct regulator_init_data **init_data)
@@ -83,3 +84,33 @@ struct regulator_init_data *of_get_regulator_init_data(struct device_node *np)
 	return init_data;
 }
 EXPORT_SYMBOL(of_get_regulator_init_data);
+
+/**
+ * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
+ * @np: Pointer to fixed-regulator device tree node
+ *
+ * Populates fixed_voltage_config structure by extracting data from device
+ * tree node, returns a pointer to the populated structure of NULL if memory
+ * alloc fails.
+ */
+struct fixed_voltage_config *of_get_fixed_voltage_config(struct device_node *np)
+{
+	struct fixed_voltage_config *config;
+
+	config = kzalloc(sizeof(struct fixed_voltage_config), GFP_KERNEL);
+	if (!config)
+		return NULL;
+
+	config->supply_name = (char *)of_get_property(np, "supply-name", NULL);
+	of_property_read_u32(np, "microvolts", &config->microvolts);
+	of_property_read_u32(np, "gpio", &config->gpio);
+	of_property_read_u32(np, "startup-delay", &config->startup_delay);
+	if (of_find_property(np, "enable-high", NULL))
+		config->enable_high = true;
+	if (of_find_property(np, "enabled-at-boot", NULL))
+		config->enabled_at_boot = true;
+	config->init_data = of_get_regulator_init_data(np);
+
+	return config;
+}
+EXPORT_SYMBOL(of_get_fixed_voltage_config);
diff --git a/include/linux/of_regulator.h b/include/linux/of_regulator.h
index 5eb048c..39860c5 100644
--- a/include/linux/of_regulator.h
+++ b/include/linux/of_regulator.h
@@ -11,12 +11,19 @@
 #if defined(CONFIG_OF_REGULATOR)
 extern struct regulator_init_data
 	*of_get_regulator_init_data(struct device_node *np);
+extern struct fixed_voltage_config
+	*of_get_fixed_voltage_config(struct device_node *np);
 #else
 static inline struct regulator_init_data
 	*of_get_regulator_init_data(struct device_node *np)
 {
 	return NULL;
 }
+static inline struct fixed_voltage_config
+	*of_get_fixed_voltage_config(struct device_node *np)
+{
+	return NULL;
+}
 #endif /* CONFIG_OF_REGULATOR */
 
 #endif /* __LINUX_OF_REG_H */
-- 
1.7.1