[net-next-2.6.git] / drivers / regulator / fixed.c

/*
 * fixed.c
 *
 * Copyright 2008 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 * Copyright (c) 2009 Nokia Corporation
 * Roger Quadros <ext-roger.quadros@nokia.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>
#include <linux/gpio.h>
#include <linux/delay.h>

struct fixed_voltage_data {
	struct regulator_desc desc;
	struct regulator_dev *dev;
	int microvolts;
	int gpio;
	unsigned startup_delay;
	bool enable_high;
	bool is_enabled;
};

static int fixed_voltage_is_enabled(struct regulator_dev *dev)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->is_enabled;
}

static int fixed_voltage_enable(struct regulator_dev *dev)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (gpio_is_valid(data->gpio)) {
		gpio_set_value_cansleep(data->gpio, data->enable_high);
		data->is_enabled = true;
	}

	return 0;
}

static int fixed_voltage_disable(struct regulator_dev *dev)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (gpio_is_valid(data->gpio)) {
		gpio_set_value_cansleep(data->gpio, !data->enable_high);
		data->is_enabled = false;
	}

	return 0;
}

static int fixed_voltage_enable_time(struct regulator_dev *dev)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->startup_delay;
}

static int fixed_voltage_get_voltage(struct regulator_dev *dev)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->microvolts;
}

static int fixed_voltage_list_voltage(struct regulator_dev *dev,
				      unsigned selector)
{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (selector != 0)
		return -EINVAL;

	return data->microvolts;
}

static struct regulator_ops fixed_voltage_ops = {
	.is_enabled = fixed_voltage_is_enabled,
	.enable = fixed_voltage_enable,
	.disable = fixed_voltage_disable,
	.enable_time = fixed_voltage_enable_time,
	.get_voltage = fixed_voltage_get_voltage,
	.list_voltage = fixed_voltage_list_voltage,
};

static int __devinit reg_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) {
		dev_err(&pdev->dev, "Failed to allocate device data\n");
		ret = -ENOMEM;
		goto err;
	}

	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	if (drvdata->desc.name == NULL) {
		dev_err(&pdev->dev, "Failed to allocate supply name\n");
		ret = -ENOMEM;
		goto err;
	}
	drvdata->desc.type = REGULATOR_VOLTAGE;
	drvdata->desc.owner = THIS_MODULE;
	drvdata->desc.ops = &fixed_voltage_ops;
	drvdata->desc.n_voltages = 1;

	drvdata->microvolts = config->microvolts;
	drvdata->gpio = config->gpio;
	drvdata->startup_delay = config->startup_delay;

	if (gpio_is_valid(config->gpio)) {
		drvdata->enable_high = config->enable_high;

		/* FIXME: Remove below print warning
		 *
		 * config->gpio must be set to -EINVAL by platform code if
		 * GPIO control is not required. However, early adopters
		 * not requiring GPIO control may forget to initialize
		 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
		 * for GPIO control.
		 *
		 * This warning will be removed once there are a couple of users
		 * for this driver.
		 */
		if (!config->gpio)
			dev_warn(&pdev->dev,
				"using GPIO 0 for regulator enable control\n");

		ret = gpio_request(config->gpio, config->supply_name);
		if (ret) {
			dev_err(&pdev->dev,
			   "Could not obtain regulator enable GPIO %d: %d\n",
							config->gpio, ret);
			goto err_name;
		}

		/* set output direction without changing state
		 * to prevent glitch
		 */
		drvdata->is_enabled = config->enabled_at_boot;
		ret = drvdata->is_enabled ?
				config->enable_high : !config->enable_high;

		ret = gpio_direction_output(config->gpio, ret);
		if (ret) {
			dev_err(&pdev->dev,
			   "Could not configure regulator enable GPIO %d direction: %d\n",
							config->gpio, ret);
			goto err_gpio;
		}

	} else {
		/* Regulator without GPIO control is considered
		 * always enabled
		 */
		drvdata->is_enabled = true;
	}

	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
					  config->init_data, drvdata);
	if (IS_ERR(drvdata->dev)) {
		ret = PTR_ERR(drvdata->dev);
		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
		goto err_gpio;
	}

	platform_set_drvdata(pdev, drvdata);

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

	return 0;

err_gpio:
	if (gpio_is_valid(config->gpio))
		gpio_free(config->gpio);
err_name:
	kfree(drvdata->desc.name);
err:
	kfree(drvdata);
	return ret;
}

static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
{
	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);

	regulator_unregister(drvdata->dev);
	if (gpio_is_valid(drvdata->gpio))
		gpio_free(drvdata->gpio);
	kfree(drvdata->desc.name);
	kfree(drvdata);

	return 0;
}

static struct platform_driver regulator_fixed_voltage_driver = {
	.probe		= reg_fixed_voltage_probe,
	.remove		= __devexit_p(reg_fixed_voltage_remove),
	.driver		= {
		.name		= "reg-fixed-voltage",
		.owner		= THIS_MODULE,
	},
};

static int __init regulator_fixed_voltage_init(void)
{
	return platform_driver_register(&regulator_fixed_voltage_driver);
}
subsys_initcall(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");
MODULE_ALIAS("platform:reg-fixed-voltage");
Commit	Line	Data
4b74ff65 MB	1	/*
	2	* fixed.c
	3	*
	4	* Copyright 2008 Wolfson Microelectronics PLC.
	5	*
	6	* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
	7	*
86d9884b RQ	8	* Copyright (c) 2009 Nokia Corporation
	9	* Roger Quadros <ext-roger.quadros@nokia.com>
	10	*
4b74ff65 MB	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License as
	13	* published by the Free Software Foundation; either version 2 of the
	14	* License, or (at your option) any later version.
	15	*
	16	* This is useful for systems with mixed controllable and
	17	* non-controllable regulators, as well as for allowing testing on
	18	* systems with no controllable regulators.
	19	*/
	20
	21	#include <linux/err.h>
	22	#include <linux/mutex.h>
	23	#include <linux/platform_device.h>
	24	#include <linux/regulator/driver.h>
	25	#include <linux/regulator/fixed.h>
86d9884b	26	#include <linux/gpio.h>
eda79a30	27	#include <linux/delay.h>
4b74ff65 MB	28
	29	struct fixed_voltage_data {
	30	struct regulator_desc desc;
	31	struct regulator_dev *dev;
	32	int microvolts;
86d9884b	33	int gpio;
eda79a30	34	unsigned startup_delay;
8ab3343d DT	35	bool enable_high;
8ab3343d DT	36	bool is_enabled;
4b74ff65 MB	37	};
	38
	39	static int fixed_voltage_is_enabled(struct regulator_dev *dev)
	40	{
86d9884b RQ	41	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	42
	43	return data->is_enabled;
4b74ff65 MB	44	}
	45
	46	static int fixed_voltage_enable(struct regulator_dev *dev)
	47	{
86d9884b RQ	48	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	49
	50	if (gpio_is_valid(data->gpio)) {
	51	gpio_set_value_cansleep(data->gpio, data->enable_high);
8ab3343d	52	data->is_enabled = true;
86d9884b RQ	53	}
	54
	55	return 0;
	56	}
	57
	58	static int fixed_voltage_disable(struct regulator_dev *dev)
	59	{
	60	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	61
	62	if (gpio_is_valid(data->gpio)) {
	63	gpio_set_value_cansleep(data->gpio, !data->enable_high);
8ab3343d	64	data->is_enabled = false;
86d9884b RQ	65	}
86d9884b RQ	66
4b74ff65 MB	67	return 0;
	68	}
	69
17133dc8 MB	70	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	71	{
	72	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	73
	74	return data->startup_delay;
	75	}
	76
4b74ff65 MB	77	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	78	{
	79	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	80
	81	return data->microvolts;
	82	}
	83
9035cefc MB	84	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	85	unsigned selector)
	86	{
	87	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	88
	89	if (selector != 0)
	90	return -EINVAL;
	91
	92	return data->microvolts;
	93	}
	94
4b74ff65 MB	95	static struct regulator_ops fixed_voltage_ops = {
	96	.is_enabled = fixed_voltage_is_enabled,
	97	.enable = fixed_voltage_enable,
86d9884b	98	.disable = fixed_voltage_disable,
17133dc8	99	.enable_time = fixed_voltage_enable_time,
4b74ff65	100	.get_voltage = fixed_voltage_get_voltage,
9035cefc	101	.list_voltage = fixed_voltage_list_voltage,
4b74ff65 MB	102	};
4b74ff65 MB	103
8ab3343d	104	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65 MB	105	{
	106	struct fixed_voltage_config *config = pdev->dev.platform_data;
	107	struct fixed_voltage_data *drvdata;
	108	int ret;
	109
	110	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
	111	if (drvdata == NULL) {
c53ad7fe	112	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	113	ret = -ENOMEM;
	114	goto err;
	115	}
	116
	117	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	118	if (drvdata->desc.name == NULL) {
c53ad7fe	119	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	120	ret = -ENOMEM;
	121	goto err;
	122	}
	123	drvdata->desc.type = REGULATOR_VOLTAGE;
	124	drvdata->desc.owner = THIS_MODULE;
9035cefc MB	125	drvdata->desc.ops = &fixed_voltage_ops;
9035cefc MB	126	drvdata->desc.n_voltages = 1;
4b74ff65 MB	127
4b74ff65 MB	128	drvdata->microvolts = config->microvolts;
86d9884b	129	drvdata->gpio = config->gpio;
eda79a30	130	drvdata->startup_delay = config->startup_delay;
86d9884b RQ	131
	132	if (gpio_is_valid(config->gpio)) {
	133	drvdata->enable_high = config->enable_high;
	134
	135	/* FIXME: Remove below print warning
	136	*
	137	* config->gpio must be set to -EINVAL by platform code if
	138	* GPIO control is not required. However, early adopters
	139	* not requiring GPIO control may forget to initialize
	140	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	141	* for GPIO control.
	142	*
	143	* This warning will be removed once there are a couple of users
	144	* for this driver.
	145	*/
	146	if (!config->gpio)
	147	dev_warn(&pdev->dev,
	148	"using GPIO 0 for regulator enable control\n");
	149
	150	ret = gpio_request(config->gpio, config->supply_name);
	151	if (ret) {
	152	dev_err(&pdev->dev,
	153	"Could not obtain regulator enable GPIO %d: %d\n",
	154	config->gpio, ret);
	155	goto err_name;
	156	}
	157
	158	/* set output direction without changing state
	159	* to prevent glitch
	160	*/
	161	drvdata->is_enabled = config->enabled_at_boot;
	162	ret = drvdata->is_enabled ?
	163	config->enable_high : !config->enable_high;
	164
	165	ret = gpio_direction_output(config->gpio, ret);
	166	if (ret) {
	167	dev_err(&pdev->dev,
	168	"Could not configure regulator enable GPIO %d direction: %d\n",
	169	config->gpio, ret);
	170	goto err_gpio;
	171	}
	172
	173	} else {
	174	/* Regulator without GPIO control is considered
	175	* always enabled
	176	*/
8ab3343d	177	drvdata->is_enabled = true;
86d9884b	178	}
4b74ff65	179
bcf3402c MB	180	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
bcf3402c MB	181	config->init_data, drvdata);
4b74ff65 MB	182	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	183	ret = PTR_ERR(drvdata->dev);
c53ad7fe	184	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b	185	goto err_gpio;
4b74ff65 MB	186	}
	187
	188	platform_set_drvdata(pdev, drvdata);
	189
	190	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	191	drvdata->microvolts);
	192
	193	return 0;
	194
86d9884b RQ	195	err_gpio:
	196	if (gpio_is_valid(config->gpio))
	197	gpio_free(config->gpio);
4b74ff65 MB	198	err_name:
	199	kfree(drvdata->desc.name);
	200	err:
	201	kfree(drvdata);
	202	return ret;
	203	}
	204
8ab3343d	205	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	206	{
	207	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	208
	209	regulator_unregister(drvdata->dev);
86d9884b RQ	210	if (gpio_is_valid(drvdata->gpio))
86d9884b RQ	211	gpio_free(drvdata->gpio);
80099c70 DC	212	kfree(drvdata->desc.name);
80099c70 DC	213	kfree(drvdata);
86d9884b	214
4b74ff65 MB	215	return 0;
	216	}
	217
	218	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	219	.probe = reg_fixed_voltage_probe,
8ab3343d DT	220	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	221	.driver = {
4b74ff65 MB	222	.name = "reg-fixed-voltage",
8ab3343d	223	.owner = THIS_MODULE,
4b74ff65 MB	224	},
	225	};
	226
	227	static int __init regulator_fixed_voltage_init(void)
	228	{
	229	return platform_driver_register(&regulator_fixed_voltage_driver);
	230	}
5a1b22be	231	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	232
	233	static void __exit regulator_fixed_voltage_exit(void)
	234	{
	235	platform_driver_unregister(&regulator_fixed_voltage_driver);
	236	}
	237	module_exit(regulator_fixed_voltage_exit);
	238
	239	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	240	MODULE_DESCRIPTION("Fixed voltage regulator");
	241	MODULE_LICENSE("GPL");
38c53c89	242	MODULE_ALIAS("platform:reg-fixed-voltage");