[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.
 */
static 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, dev->of_node);
	if (!config->init_data)
		return NULL;

	init_data = config->init_data;
	init_data->constraints.apply_uV = 0;

	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);

	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);

	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);

	if (data->microvolts)
		return data->microvolts;
	else
		return -EINVAL;
}

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_gpio_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 struct regulator_ops fixed_voltage_ops = {
	.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;
	struct fixed_voltage_data *drvdata;
	int ret;

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

	if (!config)
		return -ENOMEM;

	drvdata = devm_kzalloc(&pdev->dev, 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;

	if (config->microvolts)
		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)) {
		int gpio_flag;
		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");

		/*
		 * 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;
		gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;

		if (config->gpio_is_open_drain)
			gpio_flag |= GPIOF_OPEN_DRAIN;

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

		drvdata->desc.ops = &fixed_voltage_gpio_ops;

	} else {
		drvdata->desc.ops = &fixed_voltage_ops;
	}

	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
					  config->init_data, drvdata,
					  pdev->dev.of_node);
	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:
	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);

	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	*/
bc91396b AL	54	static struct fixed_voltage_config *
bc91396b AL	55	of_get_fixed_voltage_config(struct device *dev)
cef49102 RN	56	{
	57	struct fixed_voltage_config *config;
	58	struct device_node *np = dev->of_node;
	59	const __be32 *delay;
	60	struct regulator_init_data *init_data;
	61
	62	config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
	63	GFP_KERNEL);
	64	if (!config)
	65	return NULL;
	66
d9a861cc	67	config->init_data = of_get_regulator_init_data(dev, dev->of_node);
4b864af1 AL	68	if (!config->init_data)
	69	return NULL;
	70
cef49102	71	init_data = config->init_data;
0c437c4a	72	init_data->constraints.apply_uV = 0;
cef49102 RN	73
	74	config->supply_name = init_data->constraints.name;
	75	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
	76	config->microvolts = init_data->constraints.min_uV;
	77	} else {
	78	dev_err(dev,
	79	"Fixed regulator specified with variable voltages\n");
	80	return NULL;
	81	}
	82
	83	if (init_data->constraints.boot_on)
	84	config->enabled_at_boot = true;
	85
	86	config->gpio = of_get_named_gpio(np, "gpio", 0);
	87	delay = of_get_property(np, "startup-delay-us", NULL);
	88	if (delay)
	89	config->startup_delay = be32_to_cpu(*delay);
	90
	91	if (of_find_property(np, "enable-active-high", NULL))
	92	config->enable_high = true;
	93
	94	return config;
	95	}
	96
4b74ff65 MB	97	static int fixed_voltage_is_enabled(struct regulator_dev *dev)
4b74ff65 MB	98	{
86d9884b RQ	99	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	100
	101	return data->is_enabled;
4b74ff65 MB	102	}
	103
	104	static int fixed_voltage_enable(struct regulator_dev *dev)
	105	{
86d9884b RQ	106	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
86d9884b RQ	107
9d442061 MB	108	gpio_set_value_cansleep(data->gpio, data->enable_high);
9d442061 MB	109	data->is_enabled = true;
86d9884b RQ	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
9d442061 MB	118	gpio_set_value_cansleep(data->gpio, !data->enable_high);
9d442061 MB	119	data->is_enabled = false;
86d9884b	120
4b74ff65 MB	121	return 0;
	122	}
	123
17133dc8 MB	124	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	125	{
	126	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	127
	128	return data->startup_delay;
	129	}
	130
4b74ff65 MB	131	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	132	{
	133	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	134
aebe4958 MB	135	if (data->microvolts)
	136	return data->microvolts;
	137	else
	138	return -EINVAL;
4b74ff65 MB	139	}
4b74ff65 MB	140
9035cefc MB	141	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	142	unsigned selector)
	143	{
	144	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	145
	146	if (selector != 0)
	147	return -EINVAL;
	148
	149	return data->microvolts;
	150	}
	151
9d442061	152	static struct regulator_ops fixed_voltage_gpio_ops = {
4b74ff65 MB	153	.is_enabled = fixed_voltage_is_enabled,
4b74ff65 MB	154	.enable = fixed_voltage_enable,
86d9884b	155	.disable = fixed_voltage_disable,
17133dc8	156	.enable_time = fixed_voltage_enable_time,
4b74ff65	157	.get_voltage = fixed_voltage_get_voltage,
9035cefc	158	.list_voltage = fixed_voltage_list_voltage,
4b74ff65 MB	159	};
4b74ff65 MB	160
9d442061 MB	161	static struct regulator_ops fixed_voltage_ops = {
	162	.get_voltage = fixed_voltage_get_voltage,
	163	.list_voltage = fixed_voltage_list_voltage,
	164	};
	165
8ab3343d	166	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65	167	{
22d881c0	168	struct fixed_voltage_config *config;
4b74ff65 MB	169	struct fixed_voltage_data *drvdata;
	170	int ret;
	171
cef49102 RN	172	if (pdev->dev.of_node)
cef49102 RN	173	config = of_get_fixed_voltage_config(&pdev->dev);
22d881c0 AL	174	else
	175	config = pdev->dev.platform_data;
	176
	177	if (!config)
	178	return -ENOMEM;
cef49102	179
c45bb35f MB	180	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
c45bb35f MB	181	GFP_KERNEL);
4b74ff65	182	if (drvdata == NULL) {
c53ad7fe	183	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	184	ret = -ENOMEM;
	185	goto err;
	186	}
	187
	188	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	189	if (drvdata->desc.name == NULL) {
c53ad7fe	190	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	191	ret = -ENOMEM;
	192	goto err;
	193	}
	194	drvdata->desc.type = REGULATOR_VOLTAGE;
	195	drvdata->desc.owner = THIS_MODULE;
1c37f8a8 SH	196
	197	if (config->microvolts)
	198	drvdata->desc.n_voltages = 1;
4b74ff65 MB	199
4b74ff65 MB	200	drvdata->microvolts = config->microvolts;
86d9884b	201	drvdata->gpio = config->gpio;
eda79a30	202	drvdata->startup_delay = config->startup_delay;
86d9884b RQ	203
86d9884b RQ	204	if (gpio_is_valid(config->gpio)) {
a4d9f179	205	int gpio_flag;
86d9884b RQ	206	drvdata->enable_high = config->enable_high;
	207
	208	/* FIXME: Remove below print warning
	209	*
	210	* config->gpio must be set to -EINVAL by platform code if
	211	* GPIO control is not required. However, early adopters
	212	* not requiring GPIO control may forget to initialize
	213	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	214	* for GPIO control.
	215	*
	216	* This warning will be removed once there are a couple of users
	217	* for this driver.
	218	*/
	219	if (!config->gpio)
	220	dev_warn(&pdev->dev,
	221	"using GPIO 0 for regulator enable control\n");
	222
a4d9f179 LD	223	/*
a4d9f179 LD	224	* set output direction without changing state
86d9884b RQ	225	* to prevent glitch
	226	*/
	227	drvdata->is_enabled = config->enabled_at_boot;
	228	ret = drvdata->is_enabled ?
	229	config->enable_high : !config->enable_high;
a4d9f179 LD	230	gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
	231
	232	if (config->gpio_is_open_drain)
	233	gpio_flag \|= GPIOF_OPEN_DRAIN;
86d9884b	234
a4d9f179 LD	235	ret = gpio_request_one(config->gpio, gpio_flag,
a4d9f179 LD	236	config->supply_name);
86d9884b RQ	237	if (ret) {
86d9884b RQ	238	dev_err(&pdev->dev,
a4d9f179	239	"Could not obtain regulator enable GPIO %d: %d\n",
86d9884b	240	config->gpio, ret);
a4d9f179	241	goto err_name;
86d9884b RQ	242	}
86d9884b RQ	243
9d442061 MB	244	drvdata->desc.ops = &fixed_voltage_gpio_ops;
9d442061 MB	245
86d9884b	246	} else {
9d442061	247	drvdata->desc.ops = &fixed_voltage_ops;
86d9884b	248	}
4b74ff65	249
bcf3402c	250	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
1bb50b28 RZ	251	config->init_data, drvdata,
1bb50b28 RZ	252	pdev->dev.of_node);
4b74ff65 MB	253	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	254	ret = PTR_ERR(drvdata->dev);
c53ad7fe	255	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b	256	goto err_gpio;
4b74ff65 MB	257	}
	258
	259	platform_set_drvdata(pdev, drvdata);
	260
	261	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	262	drvdata->microvolts);
	263
	264	return 0;
	265
86d9884b RQ	266	err_gpio:
	267	if (gpio_is_valid(config->gpio))
	268	gpio_free(config->gpio);
4b74ff65 MB	269	err_name:
	270	kfree(drvdata->desc.name);
	271	err:
4b74ff65 MB	272	return ret;
	273	}
	274
8ab3343d	275	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	276	{
	277	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	278
	279	regulator_unregister(drvdata->dev);
86d9884b RQ	280	if (gpio_is_valid(drvdata->gpio))
86d9884b RQ	281	gpio_free(drvdata->gpio);
80099c70	282	kfree(drvdata->desc.name);
86d9884b	283
4b74ff65 MB	284	return 0;
	285	}
	286
cef49102 RN	287	#if defined(CONFIG_OF)
	288	static const struct of_device_id fixed_of_match[] __devinitconst = {
	289	{ .compatible = "regulator-fixed", },
	290	{},
	291	};
	292	MODULE_DEVICE_TABLE(of, fixed_of_match);
	293	#else
	294	#define fixed_of_match NULL
	295	#endif
	296
4b74ff65	297	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	298	.probe = reg_fixed_voltage_probe,
8ab3343d DT	299	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	300	.driver = {
4b74ff65 MB	301	.name = "reg-fixed-voltage",
8ab3343d	302	.owner = THIS_MODULE,
cef49102	303	.of_match_table = fixed_of_match,
4b74ff65 MB	304	},
	305	};
	306
	307	static int __init regulator_fixed_voltage_init(void)
	308	{
	309	return platform_driver_register(&regulator_fixed_voltage_driver);
	310	}
5a1b22be	311	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	312
	313	static void __exit regulator_fixed_voltage_exit(void)
	314	{
	315	platform_driver_unregister(&regulator_fixed_voltage_driver);
	316	}
	317	module_exit(regulator_fixed_voltage_exit);
	318
	319	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	320	MODULE_DESCRIPTION("Fixed voltage regulator");
	321	MODULE_LICENSE("GPL");
38c53c89	322	MODULE_ALIAS("platform:reg-fixed-voltage");