/*
 * devres.c  --  Voltage/Current Regulator framework devres implementation.
 *
 * Copyright 2013 Linaro Ltd
 *
 *  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/kernel.h>
#include <linux/err.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/driver.h>
#include <linux/module.h>

#include "internal.h"

enum {
	NORMAL_GET,
	EXCLUSIVE_GET,
	OPTIONAL_GET,
};

static void devm_regulator_release(struct device *dev, void *res)
{
	regulator_put(*(struct regulator **)res);
}

static struct regulator *_devm_regulator_get(struct device *dev, const char *id,
					     int get_type)
{
	struct regulator **ptr, *regulator;

	ptr = devres_alloc(devm_regulator_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	switch (get_type) {
	case NORMAL_GET:
		regulator = regulator_get(dev, id);
		break;
	case EXCLUSIVE_GET:
		regulator = regulator_get_exclusive(dev, id);
		break;
	case OPTIONAL_GET:
		regulator = regulator_get_optional(dev, id);
		break;
	default:
		regulator = ERR_PTR(-EINVAL);
	}

	if (!IS_ERR(regulator)) {
		*ptr = regulator;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return regulator;
}

/**
 * devm_regulator_get - Resource managed regulator_get()
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Managed regulator_get(). Regulators returned from this function are
 * automatically regulator_put() on driver detach. See regulator_get() for more
 * information.
 */
struct regulator *devm_regulator_get(struct device *dev, const char *id)
{
	return _devm_regulator_get(dev, id, NORMAL_GET);
}
EXPORT_SYMBOL_GPL(devm_regulator_get);

/**
 * devm_regulator_get_exclusive - Resource managed regulator_get_exclusive()
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Managed regulator_get_exclusive(). Regulators returned from this function
 * are automatically regulator_put() on driver detach. See regulator_get() for
 * more information.
 */
struct regulator *devm_regulator_get_exclusive(struct device *dev,
					       const char *id)
{
	return _devm_regulator_get(dev, id, EXCLUSIVE_GET);
}
EXPORT_SYMBOL_GPL(devm_regulator_get_exclusive);

/**
 * devm_regulator_get_optional - Resource managed regulator_get_optional()
 * @dev: device for regulator "consumer"
 * @id: Supply name or regulator ID.
 *
 * Managed regulator_get_optional(). Regulators returned from this
 * function are automatically regulator_put() on driver detach. See
 * regulator_get_optional() for more information.
 */
struct regulator *devm_regulator_get_optional(struct device *dev,
					      const char *id)
{
	return _devm_regulator_get(dev, id, OPTIONAL_GET);
}
EXPORT_SYMBOL_GPL(devm_regulator_get_optional);

static int devm_regulator_match(struct device *dev, void *res, void *data)
{
	struct regulator **r = res;
	if (!r || !*r) {
		WARN_ON(!r || !*r);
		return 0;
	}
	return *r == data;
}

/**
 * devm_regulator_put - Resource managed regulator_put()
 * @regulator: regulator to free
 *
 * Deallocate a regulator allocated with devm_regulator_get(). Normally
 * this function will not need to be called and the resource management
 * code will ensure that the resource is freed.
 */
void devm_regulator_put(struct regulator *regulator)
{
	int rc;

	rc = devres_release(regulator->dev, devm_regulator_release,
			    devm_regulator_match, regulator);
	if (rc != 0)
		WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_regulator_put);

/**
 * devm_regulator_bulk_get - managed get multiple regulator consumers
 *
 * @dev:           Device to supply
 * @num_consumers: Number of consumers to register
 * @consumers:     Configuration of consumers; clients are stored here.
 *
 * @return 0 on success, an errno on failure.
 *
 * This helper function allows drivers to get several regulator
 * consumers in one operation with management, the regulators will
 * automatically be freed when the device is unbound.  If any of the
 * regulators cannot be acquired then any regulators that were
 * allocated will be freed before returning to the caller.
 */
int devm_regulator_bulk_get(struct device *dev, int num_consumers,
			    struct regulator_bulk_data *consumers)
{
	int i;
	int ret;

	for (i = 0; i < num_consumers; i++)
		consumers[i].consumer = NULL;

	for (i = 0; i < num_consumers; i++) {
		consumers[i].consumer = devm_regulator_get(dev,
							   consumers[i].supply);
		if (IS_ERR(consumers[i].consumer)) {
			ret = PTR_ERR(consumers[i].consumer);
			dev_err(dev, "Failed to get supply '%s': %d\n",
				consumers[i].supply, ret);
			consumers[i].consumer = NULL;
			goto err;
		}
	}

	return 0;

err:
	for (i = 0; i < num_consumers && consumers[i].consumer; i++)
		devm_regulator_put(consumers[i].consumer);

	return ret;
}
EXPORT_SYMBOL_GPL(devm_regulator_bulk_get);

static void devm_rdev_release(struct device *dev, void *res)
{
	regulator_unregister(*(struct regulator_dev **)res);
}

/**
 * devm_regulator_register - Resource managed regulator_register()
 * @regulator_desc: regulator to register
 * @config: runtime configuration for regulator
 *
 * Called by regulator drivers to register a regulator.  Returns a
 * valid pointer to struct regulator_dev on success or an ERR_PTR() on
 * error.  The regulator will automatically be released when the device
 * is unbound.
 */
struct regulator_dev *devm_regulator_register(struct device *dev,
				  const struct regulator_desc *regulator_desc,
				  const struct regulator_config *config)
{
	struct regulator_dev **ptr, *rdev;

	ptr = devres_alloc(devm_rdev_release, sizeof(*ptr),
			   GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	rdev = regulator_register(regulator_desc, config);
	if (!IS_ERR(rdev)) {
		*ptr = rdev;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return rdev;
}
EXPORT_SYMBOL_GPL(devm_regulator_register);

static int devm_rdev_match(struct device *dev, void *res, void *data)
{
	struct regulator_dev **r = res;
	if (!r || !*r) {
		WARN_ON(!r || !*r);
		return 0;
	}
	return *r == data;
}

/**
 * devm_regulator_unregister - Resource managed regulator_unregister()
 * @regulator: regulator to free
 *
 * Unregister a regulator registered with devm_regulator_register().
 * Normally this function will not need to be called and the resource
 * management code will ensure that the resource is freed.
 */
void devm_regulator_unregister(struct device *dev, struct regulator_dev *rdev)
{
	int rc;

	rc = devres_release(dev, devm_rdev_release, devm_rdev_match, rdev);
	if (rc != 0)
		WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_regulator_unregister);