[mirror_ubuntu-artful-kernel.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);
	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;
	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 = 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	*/
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
	67	config->init_data = of_get_regulator_init_data(dev);
4b864af1 AL	68	if (!config->init_data)
	69	return NULL;
	70
cef49102 RN	71	init_data = config->init_data;
	72
	73	config->supply_name = init_data->constraints.name;
	74	if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
	75	config->microvolts = init_data->constraints.min_uV;
	76	} else {
	77	dev_err(dev,
	78	"Fixed regulator specified with variable voltages\n");
	79	return NULL;
	80	}
	81
	82	if (init_data->constraints.boot_on)
	83	config->enabled_at_boot = true;
	84
	85	config->gpio = of_get_named_gpio(np, "gpio", 0);
	86	delay = of_get_property(np, "startup-delay-us", NULL);
	87	if (delay)
	88	config->startup_delay = be32_to_cpu(*delay);
	89
	90	if (of_find_property(np, "enable-active-high", NULL))
	91	config->enable_high = true;
	92
	93	return config;
	94	}
	95
4b74ff65 MB	96	static int fixed_voltage_is_enabled(struct regulator_dev *dev)
4b74ff65 MB	97	{
86d9884b RQ	98	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	99
	100	return data->is_enabled;
4b74ff65 MB	101	}
	102
	103	static int fixed_voltage_enable(struct regulator_dev *dev)
	104	{
86d9884b RQ	105	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	106
	107	if (gpio_is_valid(data->gpio)) {
	108	gpio_set_value_cansleep(data->gpio, data->enable_high);
8ab3343d	109	data->is_enabled = true;
86d9884b RQ	110	}
	111
	112	return 0;
	113	}
	114
	115	static int fixed_voltage_disable(struct regulator_dev *dev)
	116	{
	117	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	118
	119	if (gpio_is_valid(data->gpio)) {
	120	gpio_set_value_cansleep(data->gpio, !data->enable_high);
8ab3343d	121	data->is_enabled = false;
86d9884b RQ	122	}
86d9884b RQ	123
4b74ff65 MB	124	return 0;
	125	}
	126
17133dc8 MB	127	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	128	{
	129	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	130
	131	return data->startup_delay;
	132	}
	133
4b74ff65 MB	134	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	135	{
	136	struct fixed_voltage_data *data = rdev_get_drvdata(dev);
	137
	138	return data->microvolts;
	139	}
	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
4b74ff65 MB	152	static struct regulator_ops fixed_voltage_ops = {
	153	.is_enabled = fixed_voltage_is_enabled,
	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
8ab3343d	161	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65	162	{
22d881c0	163	struct fixed_voltage_config *config;
4b74ff65 MB	164	struct fixed_voltage_data *drvdata;
	165	int ret;
	166
cef49102 RN	167	if (pdev->dev.of_node)
cef49102 RN	168	config = of_get_fixed_voltage_config(&pdev->dev);
22d881c0 AL	169	else
	170	config = pdev->dev.platform_data;
	171
	172	if (!config)
	173	return -ENOMEM;
cef49102	174
4b74ff65 MB	175	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
4b74ff65 MB	176	if (drvdata == NULL) {
c53ad7fe	177	dev_err(&pdev->dev, "Failed to allocate device data\n");
4b74ff65 MB	178	ret = -ENOMEM;
	179	goto err;
	180	}
	181
	182	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	183	if (drvdata->desc.name == NULL) {
c53ad7fe	184	dev_err(&pdev->dev, "Failed to allocate supply name\n");
4b74ff65 MB	185	ret = -ENOMEM;
	186	goto err;
	187	}
	188	drvdata->desc.type = REGULATOR_VOLTAGE;
	189	drvdata->desc.owner = THIS_MODULE;
9035cefc MB	190	drvdata->desc.ops = &fixed_voltage_ops;
9035cefc MB	191	drvdata->desc.n_voltages = 1;
4b74ff65 MB	192
4b74ff65 MB	193	drvdata->microvolts = config->microvolts;
86d9884b	194	drvdata->gpio = config->gpio;
eda79a30	195	drvdata->startup_delay = config->startup_delay;
86d9884b RQ	196
	197	if (gpio_is_valid(config->gpio)) {
	198	drvdata->enable_high = config->enable_high;
	199
	200	/* FIXME: Remove below print warning
	201	*
	202	* config->gpio must be set to -EINVAL by platform code if
	203	* GPIO control is not required. However, early adopters
	204	* not requiring GPIO control may forget to initialize
	205	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	206	* for GPIO control.
	207	*
	208	* This warning will be removed once there are a couple of users
	209	* for this driver.
	210	*/
	211	if (!config->gpio)
	212	dev_warn(&pdev->dev,
	213	"using GPIO 0 for regulator enable control\n");
	214
	215	ret = gpio_request(config->gpio, config->supply_name);
	216	if (ret) {
	217	dev_err(&pdev->dev,
	218	"Could not obtain regulator enable GPIO %d: %d\n",
	219	config->gpio, ret);
	220	goto err_name;
	221	}
	222
	223	/* set output direction without changing state
	224	* to prevent glitch
	225	*/
	226	drvdata->is_enabled = config->enabled_at_boot;
	227	ret = drvdata->is_enabled ?
	228	config->enable_high : !config->enable_high;
	229
	230	ret = gpio_direction_output(config->gpio, ret);
	231	if (ret) {
	232	dev_err(&pdev->dev,
	233	"Could not configure regulator enable GPIO %d direction: %d\n",
	234	config->gpio, ret);
	235	goto err_gpio;
	236	}
	237
	238	} else {
	239	/* Regulator without GPIO control is considered
	240	* always enabled
	241	*/
8ab3343d	242	drvdata->is_enabled = true;
86d9884b	243	}
4b74ff65	244
bcf3402c	245	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
2c043bcb	246	config->init_data, drvdata, NULL);
4b74ff65 MB	247	if (IS_ERR(drvdata->dev)) {
4b74ff65 MB	248	ret = PTR_ERR(drvdata->dev);
c53ad7fe	249	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b	250	goto err_gpio;
4b74ff65 MB	251	}
	252
	253	platform_set_drvdata(pdev, drvdata);
	254
	255	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	256	drvdata->microvolts);
	257
	258	return 0;
	259
86d9884b RQ	260	err_gpio:
	261	if (gpio_is_valid(config->gpio))
	262	gpio_free(config->gpio);
4b74ff65 MB	263	err_name:
	264	kfree(drvdata->desc.name);
	265	err:
	266	kfree(drvdata);
	267	return ret;
	268	}
	269
8ab3343d	270	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
4b74ff65 MB	271	{
	272	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
	273
	274	regulator_unregister(drvdata->dev);
86d9884b RQ	275	if (gpio_is_valid(drvdata->gpio))
86d9884b RQ	276	gpio_free(drvdata->gpio);
80099c70 DC	277	kfree(drvdata->desc.name);
80099c70 DC	278	kfree(drvdata);
86d9884b	279
4b74ff65 MB	280	return 0;
	281	}
	282
cef49102 RN	283	#if defined(CONFIG_OF)
	284	static const struct of_device_id fixed_of_match[] __devinitconst = {
	285	{ .compatible = "regulator-fixed", },
	286	{},
	287	};
	288	MODULE_DEVICE_TABLE(of, fixed_of_match);
	289	#else
	290	#define fixed_of_match NULL
	291	#endif
	292
4b74ff65	293	static struct platform_driver regulator_fixed_voltage_driver = {
8ab3343d DT	294	.probe = reg_fixed_voltage_probe,
8ab3343d DT	295	.remove = __devexit_p(reg_fixed_voltage_remove),
4b74ff65 MB	296	.driver = {
4b74ff65 MB	297	.name = "reg-fixed-voltage",
8ab3343d	298	.owner = THIS_MODULE,
cef49102	299	.of_match_table = fixed_of_match,
4b74ff65 MB	300	},
	301	};
	302
	303	static int __init regulator_fixed_voltage_init(void)
	304	{
	305	return platform_driver_register(&regulator_fixed_voltage_driver);
	306	}
5a1b22be	307	subsys_initcall(regulator_fixed_voltage_init);
4b74ff65 MB	308
	309	static void __exit regulator_fixed_voltage_exit(void)
	310	{
	311	platform_driver_unregister(&regulator_fixed_voltage_driver);
	312	}
	313	module_exit(regulator_fixed_voltage_exit);
	314
	315	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	316	MODULE_DESCRIPTION("Fixed voltage regulator");
	317	MODULE_LICENSE("GPL");
38c53c89	318	MODULE_ALIAS("platform:reg-fixed-voltage");