[deliverable/linux.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/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/fixed.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/machine.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;
};


/**
 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
 * @dev: device requesting for fixed_voltage_config
 *
 * 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 *dev)
{
	struct fixed_voltage_config *config;
	struct device_node *np = dev->of_node;
	const __be32 *delay;
	struct regulator_init_data *init_data;

	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
								 GFP_KERNEL);
	if (!config)
		return NULL;

	config->init_data = of_get_regulator_init_data(dev);
	if (!config->init_data)
		return NULL;

	init_data = config->init_data;

	config->supply_name = init_data->constraints.name;
	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
		config->microvolts = init_data->constraints.min_uV;
	} else {
		dev_err(dev,
			 "Fixed regulator specified with variable voltages\n");
		return NULL;
	}

	if (init_data->constraints.boot_on)
		config->enabled_at_boot = true;

	config->gpio = of_get_named_gpio(np, "gpio", 0);
	delay = of_get_property(np, "startup-delay-us", NULL);
	if (delay)
		config->startup_delay = be32_to_cpu(*delay);

	if (of_find_property(np, "enable-active-high", NULL))
		config->enable_high = true;

	return config;
}

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;

	if (pdev->dev.of_node)
		config = of_get_fixed_voltage_config(&pdev->dev);

	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, NULL);
	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;
}

#if defined(CONFIG_OF)
static const struct of_device_id fixed_of_match[] __devinitconst = {
	{ .compatible = "regulator-fixed", },
	{},
};
MODULE_DEVICE_TABLE(of, fixed_of_match);
#else
#define fixed_of_match NULL
#endif

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,
		.of_match_table = fixed_of_match,
	},
};

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>
65602c32	23	#include <linux/module.h>
4b74ff65 MB	24	#include <linux/platform_device.h>
	25	#include <linux/regulator/driver.h>
	26	#include <linux/regulator/fixed.h>
86d9884b	27	#include <linux/gpio.h>
eda79a30	28	#include <linux/delay.h>
5a0e3ad6	29	#include <linux/slab.h>
cef49102 RN	30	#include <linux/of.h>
	31	#include <linux/of_gpio.h>
	32	#include <linux/regulator/of_regulator.h>
	33	#include <linux/regulator/machine.h>
4b74ff65 MB	34
	35	struct fixed_voltage_data {
	36	struct regulator_desc desc;
	37	struct regulator_dev *dev;
	38	int microvolts;
86d9884b	39	int gpio;
eda79a30	40	unsigned startup_delay;
8ab3343d DT	41	bool enable_high;
8ab3343d DT	42	bool is_enabled;
4b74ff65 MB	43	};
4b74ff65 MB	44
cef49102 RN	45
	46	/**
	47	* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
	48	* @dev: device requesting for fixed_voltage_config
	49	*
	50	* Populates fixed_voltage_config structure by extracting data from device
	51	* tree node, returns a pointer to the populated structure of NULL if memory
	52	* alloc fails.
	53	*/
	54	struct fixed_voltage_config of_get_fixed_voltage_config(struct device dev)
	55	{
	56	struct fixed_voltage_config *config;
	57	struct device_node *np = dev->of_node;
	58	const __be32 *delay;
	59	struct regulator_init_data *init_data;
	60
	61	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
	62	GFP_KERNEL);
	63	if (!config)
	64	return NULL;
	65
	66	config->init_data = of_get_regulator_init_data(dev);
4b864af1 AL	67	if (!config->init_data)
	68	return NULL;
	69
cef49102 RN	70	init_data = config->init_data;
	71
	72	config->supply_name = init_data->constraints.name;
	73	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
	74	config->microvolts = init_data->constraints.min_uV;
	75	} else {
	76	dev_err(dev,
	77	"Fixed regulator specified with variable voltages\n");
	78	return NULL;
	79	}
	80
	81	if (init_data->constraints.boot_on)
	82	config->enabled_at_boot = true;
	83
	84	config->gpio = of_get_named_gpio(np, "gpio", 0);
	85	delay = of_get_property(np, "startup-delay-us", NULL);
	86	if (delay)
	87	config->startup_delay = be32_to_cpu(*delay);
	88
	89	if (of_find_property(np, "enable-active-high", NULL))
	90	config->enable_high = true;
	91
	92	return config;
	93	}
	94
4b74ff65 MB	95	static int fixed_voltage_is_enabled(struct regulator_dev *dev)
4b74ff65 MB	96	{
86d9884b RQ	97	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	98
	99	return data->is_enabled;
4b74ff65 MB	100	}
	101
	102	static int fixed_voltage_enable(struct regulator_dev *dev)
	103	{
86d9884b RQ	104	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	105
	106	if (gpio_is_valid(data->gpio)) {
	107	gpio_set_value_cansleep(data->gpio, data->enable_high);
8ab3343d	108	data->is_enabled = true;
86d9884b RQ	109	}
	110
	111	return 0;
	112	}
	113
	114	static int fixed_voltage_disable(struct regulator_dev *dev)
	115	{
	116	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	117
	118	if (gpio_is_valid(data->gpio)) {
	119	gpio_set_value_cansleep(data->gpio, !data->enable_high);
8ab3343d	120	data->is_enabled = false;
86d9884b RQ	121	}
86d9884b RQ	122
4b74ff65 MB	123	return 0;
	124	}
	125
17133dc8 MB	126	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	127	{
	128	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	129
	130	return data->startup_delay;
	131	}
	132
4b74ff65 MB	133	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	134	{
	135	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	136
	137	return data->microvolts;
	138	}
	139
9035cefc MB	140	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	141	unsigned selector)
	142	{
	143	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	144
	145	if (selector != 0)
	146	return -EINVAL;
	147
	148	return data->microvolts;
	149	}
	150
4b74ff65 MB	151	static struct regulator_ops fixed_voltage_ops = {
	152	.is_enabled = fixed_voltage_is_enabled,
	153	.enable = fixed_voltage_enable,
86d9884b	154	.disable = fixed_voltage_disable,
17133dc8	155	.enable_time = fixed_voltage_enable_time,
4b74ff65	156	.get_voltage = fixed_voltage_get_voltage,
9035cefc	157	.list_voltage = fixed_voltage_list_voltage,
4b74ff65 MB	158	};
4b74ff65 MB	159
8ab3343d	160	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65 MB	161	{
	162	struct fixed_voltage_config *config = pdev->dev.platform_data;
	163	struct fixed_voltage_data *drvdata;
	164	int ret;
	165
cef49102 RN	166	if (pdev->dev.of_node)
	167	config = of_get_fixed_voltage_config(&pdev->dev);
	168
4b74ff65 MB	169	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
4b74ff65 MB	170	if (drvdata == NULL) {
c53ad7fe	171	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	172	ret = -ENOMEM;
	173	goto err;
	174	}
	175
	176	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	177	if (drvdata->desc.name == NULL) {
c53ad7fe	178	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	179	ret = -ENOMEM;
	180	goto err;
	181	}
	182	drvdata->desc.type = REGULATOR_VOLTAGE;
	183	drvdata->desc.owner = THIS_MODULE;
9035cefc MB	184	drvdata->desc.ops = &fixed_voltage_ops;
9035cefc MB	185	drvdata->desc.n_voltages = 1;
4b74ff65 MB	186
4b74ff65 MB	187	drvdata->microvolts = config->microvolts;
86d9884b	188	drvdata->gpio = config->gpio;
eda79a30	189	drvdata->startup_delay = config->startup_delay;
86d9884b RQ	190
	191	if (gpio_is_valid(config->gpio)) {
	192	drvdata->enable_high = config->enable_high;
	193
	194	/* FIXME: Remove below print warning
	195	*
	196	* config->gpio must be set to -EINVAL by platform code if
	197	* GPIO control is not required. However, early adopters
	198	* not requiring GPIO control may forget to initialize
	199	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	200	* for GPIO control.
	201	*
	202	* This warning will be removed once there are a couple of users
	203	* for this driver.
	204	*/
	205	if (!config->gpio)
	206	dev_warn(&pdev->dev,
	207	"using GPIO 0 for regulator enable control\n");
	208
	209	ret = gpio_request(config->gpio, config->supply_name);
	210	if (ret) {
	211	dev_err(&pdev->dev,
	212	"Could not obtain regulator enable GPIO %d: %d\n",
	213	config->gpio, ret);
	214	goto err_name;
	215	}
	216
	217	/* set output direction without changing state
	218	* to prevent glitch
	219	*/
	220	drvdata->is_enabled = config->enabled_at_boot;
	221	ret = drvdata->is_enabled ?
	222	config->enable_high : !config->enable_high;
	223
	224	ret = gpio_direction_output(config->gpio, ret);
	225	if (ret) {
	226	dev_err(&pdev->dev,
	227	"Could not configure regulator enable GPIO %d direction: %d\n",
	228	config->gpio, ret);
	229	goto err_gpio;
	230	}
	231
	232	} else {
	233	/* Regulator without GPIO control is considered
	234	* always enabled
	235	*/
8ab3343d	236	drvdata->is_enabled = true;
86d9884b	237	}
4b74ff65	238
bcf3402c	239	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
2c043bcb	240	config->init_data, drvdata, NULL);
4b74ff65 MB	241	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	242	ret = PTR_ERR(drvdata->dev);
c53ad7fe	243	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b	244	goto err_gpio;
4b74ff65 MB	245	}
	246
	247	platform_set_drvdata(pdev, drvdata);
	248
	249	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	250	drvdata->microvolts);
	251
	252	return 0;
	253
86d9884b RQ	254	err_gpio:
	255	if (gpio_is_valid(config->gpio))
	256	gpio_free(config->gpio);
4b74ff65 MB	257	err_name:
	258	kfree(drvdata->desc.name);
	259	err:
	260	kfree(drvdata);
	261	return ret;
	262	}
	263
8ab3343d	264	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	265	{
	266	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	267
	268	regulator_unregister(drvdata->dev);
86d9884b RQ	269	if (gpio_is_valid(drvdata->gpio))
86d9884b RQ	270	gpio_free(drvdata->gpio);
80099c70 DC	271	kfree(drvdata->desc.name);
80099c70 DC	272	kfree(drvdata);
86d9884b	273
4b74ff65 MB	274	return 0;
	275	}
	276
cef49102 RN	277	#if defined(CONFIG_OF)
	278	static const struct of_device_id fixed_of_match[] __devinitconst = {
	279	{ .compatible = "regulator-fixed", },
	280	{},
	281	};
	282	MODULE_DEVICE_TABLE(of, fixed_of_match);
	283	#else
	284	#define fixed_of_match NULL
	285	#endif
	286
4b74ff65	287	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	288	.probe = reg_fixed_voltage_probe,
8ab3343d DT	289	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	290	.driver = {
4b74ff65 MB	291	.name = "reg-fixed-voltage",
8ab3343d	292	.owner = THIS_MODULE,
cef49102	293	.of_match_table = fixed_of_match,
4b74ff65 MB	294	},
	295	};
	296
	297	static int __init regulator_fixed_voltage_init(void)
	298	{
	299	return platform_driver_register(&regulator_fixed_voltage_driver);
	300	}
5a1b22be	301	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	302
	303	static void __exit regulator_fixed_voltage_exit(void)
	304	{
	305	platform_driver_unregister(&regulator_fixed_voltage_driver);
	306	}
	307	module_exit(regulator_fixed_voltage_exit);
	308
	309	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	310	MODULE_DESCRIPTION("Fixed voltage regulator");
	311	MODULE_LICENSE("GPL");
38c53c89	312	MODULE_ALIAS("platform:reg-fixed-voltage");