regulator: add support for fixed regulators.

/*

 * fixed.c

 *

 * Copyright 2008 Wolfson Microelectronics PLC.

 *

 * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.

 *

 * This is useful for systems with mixed controllable and

 * non-controllable regulators, as well as for allowing testing on

 * systems with no controllable regulators.

 */

#include <linux/err.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/regulator/driver.h>

#include <linux/regulator/fixed.h>

struct fixed_voltage_data {

	struct regulator_desc desc;

	struct regulator_dev *dev;

	int microvolts;

};

static int fixed_voltage_is_enabled(struct regulator_dev *dev)

{

	return 1;

}

static int fixed_voltage_enable(struct regulator_dev *dev)

{

	return 0;

}

static int fixed_voltage_get_voltage(struct regulator_dev *dev)

{

	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->microvolts;

}

static struct regulator_ops fixed_voltage_ops = {

	.is_enabled = fixed_voltage_is_enabled,

	.enable = fixed_voltage_enable,

	.get_voltage = fixed_voltage_get_voltage,

};

static int regulator_fixed_voltage_probe(struct platform_device *pdev)

{

	struct fixed_voltage_config *config = pdev->dev.platform_data;

	struct fixed_voltage_data *drvdata;

	int ret;

	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);

	if (drvdata == NULL) {

		ret = -ENOMEM;

		goto err;

	}

	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);

	if (drvdata->desc.name == NULL) {

		ret = -ENOMEM;

		goto err;

	}

	drvdata->desc.type = REGULATOR_VOLTAGE;

	drvdata->desc.owner = THIS_MODULE;

	drvdata->desc.ops = &fixed_voltage_ops,

	drvdata->microvolts = config->microvolts;

	drvdata->dev = regulator_register(&drvdata->desc, drvdata);

	if (IS_ERR(drvdata->dev)) {

		ret = PTR_ERR(drvdata->dev);

		goto err_name;

	}

	platform_set_drvdata(pdev, drvdata);

	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,

		drvdata->microvolts);

	return 0;

err_name:

	kfree(drvdata->desc.name);

err:

	kfree(drvdata);

	return ret;

}

static int regulator_fixed_voltage_remove(struct platform_device *pdev)

{

	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);

	regulator_unregister(drvdata->dev);

	kfree(drvdata->desc.name);

	kfree(drvdata);

	return 0;

}

static struct platform_driver regulator_fixed_voltage_driver = {

	.probe		= regulator_fixed_voltage_probe,

	.remove		= regulator_fixed_voltage_remove,

	.driver		= {

		.name		= "reg-fixed-voltage",

	},

};

static int __init regulator_fixed_voltage_init(void)

{

	return platform_driver_register(&regulator_fixed_voltage_driver);

}

module_init(regulator_fixed_voltage_init);

static void __exit regulator_fixed_voltage_exit(void)

{

	platform_driver_unregister(&regulator_fixed_voltage_driver);

}

module_exit(regulator_fixed_voltage_exit);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");

MODULE_DESCRIPTION("Fixed voltage regulator");

MODULE_LICENSE("GPL");