[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);

	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);

	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_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;
	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;
	drvdata->desc.ops = &fixed_voltage_ops;

	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)) {
		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,
					  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);
	107
	108	if (gpio_is_valid(data->gpio)) {
	109	gpio_set_value_cansleep(data->gpio, data->enable_high);
8ab3343d	110	data->is_enabled = true;
86d9884b RQ	111	}
	112
	113	return 0;
	114	}
	115
	116	static int fixed_voltage_disable(struct regulator_dev *dev)
	117	{
	118	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	119
	120	if (gpio_is_valid(data->gpio)) {
	121	gpio_set_value_cansleep(data->gpio, !data->enable_high);
8ab3343d	122	data->is_enabled = false;
86d9884b RQ	123	}
86d9884b RQ	124
4b74ff65 MB	125	return 0;
	126	}
	127
17133dc8 MB	128	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	129	{
	130	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	131
	132	return data->startup_delay;
	133	}
	134
4b74ff65 MB	135	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	136	{
	137	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	138
aebe4958 MB	139	if (data->microvolts)
	140	return data->microvolts;
	141	else
	142	return -EINVAL;
4b74ff65 MB	143	}
4b74ff65 MB	144
9035cefc MB	145	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	146	unsigned selector)
	147	{
	148	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	149
	150	if (selector != 0)
	151	return -EINVAL;
	152
	153	return data->microvolts;
	154	}
	155
4b74ff65 MB	156	static struct regulator_ops fixed_voltage_ops = {
	157	.is_enabled = fixed_voltage_is_enabled,
	158	.enable = fixed_voltage_enable,
86d9884b	159	.disable = fixed_voltage_disable,
17133dc8	160	.enable_time = fixed_voltage_enable_time,
4b74ff65	161	.get_voltage = fixed_voltage_get_voltage,
9035cefc	162	.list_voltage = fixed_voltage_list_voltage,
4b74ff65 MB	163	};
4b74ff65 MB	164
8ab3343d	165	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65	166	{
22d881c0	167	struct fixed_voltage_config *config;
4b74ff65 MB	168	struct fixed_voltage_data *drvdata;
	169	int ret;
	170
cef49102 RN	171	if (pdev->dev.of_node)
cef49102 RN	172	config = of_get_fixed_voltage_config(&pdev->dev);
22d881c0 AL	173	else
	174	config = pdev->dev.platform_data;
	175
	176	if (!config)
	177	return -ENOMEM;
cef49102	178
c45bb35f MB	179	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
c45bb35f MB	180	GFP_KERNEL);
4b74ff65	181	if (drvdata == NULL) {
c53ad7fe	182	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	183	ret = -ENOMEM;
	184	goto err;
	185	}
	186
	187	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	188	if (drvdata->desc.name == NULL) {
c53ad7fe	189	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	190	ret = -ENOMEM;
	191	goto err;
	192	}
	193	drvdata->desc.type = REGULATOR_VOLTAGE;
	194	drvdata->desc.owner = THIS_MODULE;
9035cefc	195	drvdata->desc.ops = &fixed_voltage_ops;
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
	204	if (gpio_is_valid(config->gpio)) {
	205	drvdata->enable_high = config->enable_high;
	206
	207	/* FIXME: Remove below print warning
	208	*
	209	* config->gpio must be set to -EINVAL by platform code if
	210	* GPIO control is not required. However, early adopters
	211	* not requiring GPIO control may forget to initialize
	212	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	213	* for GPIO control.
	214	*
	215	* This warning will be removed once there are a couple of users
	216	* for this driver.
	217	*/
	218	if (!config->gpio)
	219	dev_warn(&pdev->dev,
	220	"using GPIO 0 for regulator enable control\n");
	221
	222	ret = gpio_request(config->gpio, config->supply_name);
	223	if (ret) {
	224	dev_err(&pdev->dev,
	225	"Could not obtain regulator enable GPIO %d: %d\n",
	226	config->gpio, ret);
	227	goto err_name;
	228	}
	229
	230	/* set output direction without changing state
	231	* to prevent glitch
	232	*/
	233	drvdata->is_enabled = config->enabled_at_boot;
	234	ret = drvdata->is_enabled ?
	235	config->enable_high : !config->enable_high;
	236
	237	ret = gpio_direction_output(config->gpio, ret);
	238	if (ret) {
	239	dev_err(&pdev->dev,
	240	"Could not configure regulator enable GPIO %d direction: %d\n",
	241	config->gpio, ret);
	242	goto err_gpio;
	243	}
	244
	245	} else {
	246	/* Regulator without GPIO control is considered
	247	* always enabled
	248	*/
8ab3343d	249	drvdata->is_enabled = true;
86d9884b	250	}
4b74ff65	251
bcf3402c	252	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
1bb50b28 RZ	253	config->init_data, drvdata,
1bb50b28 RZ	254	pdev->dev.of_node);
4b74ff65 MB	255	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	256	ret = PTR_ERR(drvdata->dev);
c53ad7fe	257	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b	258	goto err_gpio;
4b74ff65 MB	259	}
	260
	261	platform_set_drvdata(pdev, drvdata);
	262
	263	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	264	drvdata->microvolts);
	265
	266	return 0;
	267
86d9884b RQ	268	err_gpio:
	269	if (gpio_is_valid(config->gpio))
	270	gpio_free(config->gpio);
4b74ff65 MB	271	err_name:
	272	kfree(drvdata->desc.name);
	273	err:
4b74ff65 MB	274	return ret;
	275	}
	276
8ab3343d	277	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	278	{
	279	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	280
	281	regulator_unregister(drvdata->dev);
86d9884b RQ	282	if (gpio_is_valid(drvdata->gpio))
86d9884b RQ	283	gpio_free(drvdata->gpio);
80099c70	284	kfree(drvdata->desc.name);
86d9884b	285
4b74ff65 MB	286	return 0;
	287	}
	288
cef49102 RN	289	#if defined(CONFIG_OF)
	290	static const struct of_device_id fixed_of_match[] __devinitconst = {
	291	{ .compatible = "regulator-fixed", },
	292	{},
	293	};
	294	MODULE_DEVICE_TABLE(of, fixed_of_match);
	295	#else
	296	#define fixed_of_match NULL
	297	#endif
	298
4b74ff65	299	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	300	.probe = reg_fixed_voltage_probe,
8ab3343d DT	301	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	302	.driver = {
4b74ff65 MB	303	.name = "reg-fixed-voltage",
8ab3343d	304	.owner = THIS_MODULE,
cef49102	305	.of_match_table = fixed_of_match,
4b74ff65 MB	306	},
	307	};
	308
	309	static int __init regulator_fixed_voltage_init(void)
	310	{
	311	return platform_driver_register(&regulator_fixed_voltage_driver);
	312	}
5a1b22be	313	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	314
	315	static void __exit regulator_fixed_voltage_exit(void)
	316	{
	317	platform_driver_unregister(&regulator_fixed_voltage_driver);
	318	}
	319	module_exit(regulator_fixed_voltage_exit);
	320
	321	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	322	MODULE_DESCRIPTION("Fixed voltage regulator");
	323	MODULE_LICENSE("GPL");
38c53c89	324	MODULE_ALIAS("platform:reg-fixed-voltage");