regulator: helper routine to extract regulator_init_data

Voltage/Current Regulators

Optional properties:

- regulator-name: A string used as a descriptive name for regulator outputs

- regulator-min-microvolt: smallest voltage consumers may set

- regulator-max-microvolt: largest voltage consumers may set

- regulator-microvolt-offset: Offset applied to voltages to compensate for voltage drops

- regulator-min-microamp: smallest current consumers may set

- regulator-max-microamp: largest current consumers may set

- regulator-always-on: boolean, regulator should never be disabled

- regulator-boot-on: bootloader/firmware enabled regulator

- <name>-supply: phandle to the parent supply/regulator node

Example:

	xyzreg: regulator@0 {

		regulator-min-microvolt = <1000000>;

		regulator-max-microvolt = <2500000>;

		regulator-always-on;

		vin-supply = <&vin>;

	};

Regulator Consumers:

Consumer nodes can reference one or more of its supplies/

regulators using the below bindings.

- <name>-supply: phandle to the regulator node

These are the same bindings that a regulator in the above

example used to reference its own supply, in which case

its just seen as a special case of a regulator being a

consumer itself.

Example of a consumer device node (mmc) referencing two

regulators (twl-reg1 and twl-reg2),

	twl-reg1: regulator@0 {

		...

		...

		...

	};

	twl-reg2: regulator@1 {

		...

		...

		...

	};

	mmc: mmc@0x0 {

		...

		...

		vmmc-supply = <&twl-reg1>;

		vmmcaux-supply = <&twl-reg2>;

	};

obj-$(CONFIG_REGULATOR) += core.o dummy.o

obj-$(CONFIG_OF) += of_regulator.o

obj-$(CONFIG_REGULATOR_FIXED_VOLTAGE) += fixed.o

obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o

obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o

/*

 * OF helpers for regulator framework

 *

 * Copyright (C) 2011 Texas Instruments, Inc.

 * Rajendra Nayak <rnayak@ti.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 */

#include <linux/slab.h>

#include <linux/of.h>

#include <linux/regulator/machine.h>

static void of_get_regulation_constraints(struct device_node *np,

					struct regulator_init_data **init_data)

{

	const __be32 *min_uV, *max_uV, *uV_offset;

	const __be32 *min_uA, *max_uA;

	struct regulation_constraints *constraints = &(*init_data)->constraints;

	constraints->name = of_get_property(np, "regulator-name", NULL);

	min_uV = of_get_property(np, "regulator-min-microvolt", NULL);

	if (min_uV)

		constraints->min_uV = be32_to_cpu(*min_uV);

	max_uV = of_get_property(np, "regulator-max-microvolt", NULL);

	if (max_uV)

		constraints->max_uV = be32_to_cpu(*max_uV);

	/* Voltage change possible? */

	if (constraints->min_uV != constraints->max_uV)

		constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;

	uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);

	if (uV_offset)

		constraints->uV_offset = be32_to_cpu(*uV_offset);

	min_uA = of_get_property(np, "regulator-min-microamp", NULL);

	if (min_uA)

		constraints->min_uA = be32_to_cpu(*min_uA);

	max_uA = of_get_property(np, "regulator-max-microamp", NULL);

	if (max_uA)

		constraints->max_uA = be32_to_cpu(*max_uA);

	/* Current change possible? */

	if (constraints->min_uA != constraints->max_uA)

		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;

	if (of_find_property(np, "regulator-boot-on", NULL))

		constraints->boot_on = true;

	if (of_find_property(np, "regulator-always-on", NULL))

		constraints->always_on = true;

	else /* status change should be possible if not always on. */

		constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;

}

/**

 * of_get_regulator_init_data - extract regulator_init_data structure info

 * @dev: device requesting for regulator_init_data

 *

 * Populates regulator_init_data structure by extracting data from device

 * tree node, returns a pointer to the populated struture or NULL if memory

 * alloc fails.

 */

struct regulator_init_data *of_get_regulator_init_data(struct device *dev)

{

	struct regulator_init_data *init_data;

	if (!dev->of_node)

		return NULL;

	init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);

	if (!init_data)

		return NULL; /* Out of memory? */

	of_get_regulation_constraints(dev->of_node, &init_data);

	return init_data;

}

/*

 * OpenFirmware regulator support routines

 *

 */

#ifndef __LINUX_OF_REG_H

#define __LINUX_OF_REG_H

#if defined(CONFIG_OF)

extern struct regulator_init_data

	*of_get_regulator_init_data(struct device *dev);

#else

static inline struct regulator_init_data

	*of_get_regulator_init_data(struct device *dev)

{

	return NULL;

}

#endif /* CONFIG_OF */

#endif /* __LINUX_OF_REG_H */