[mirror_ubuntu-artful-kernel.git] / drivers / regulator / gpio-regulator.c

/*
 * gpio-regulator.c
 *
 * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
 *
 * based on 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/machine.h>
#include <linux/regulator/gpio-regulator.h>
#include <linux/gpio.h>
#include <linux/slab.h>

struct gpio_regulator_data {
	struct regulator_desc desc;
	struct regulator_dev *dev;

	struct gpio *gpios;
	int nr_gpios;

	struct gpio_regulator_state *states;
	int nr_states;

	int state;
};

static int gpio_regulator_get_value(struct regulator_dev *dev)
{
	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	int ptr;

	for (ptr = 0; ptr < data->nr_states; ptr++)
		if (data->states[ptr].gpios == data->state)
			return data->states[ptr].value;

	return -EINVAL;
}

static int gpio_regulator_set_voltage(struct regulator_dev *dev,
					int min_uV, int max_uV,
					unsigned *selector)
{
	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	int ptr, target = 0, state, best_val = INT_MAX;

	for (ptr = 0; ptr < data->nr_states; ptr++)
		if (data->states[ptr].value < best_val &&
		    data->states[ptr].value >= min_uV &&
		    data->states[ptr].value <= max_uV) {
			target = data->states[ptr].gpios;
			best_val = data->states[ptr].value;
			if (selector)
				*selector = ptr;
		}

	if (best_val == INT_MAX)
		return -EINVAL;

	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
		state = (target & (1 << ptr)) >> ptr;
		gpio_set_value(data->gpios[ptr].gpio, state);
	}
	data->state = target;

	return 0;
}

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

	if (selector >= data->nr_states)
		return -EINVAL;

	return data->states[selector].value;
}

static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
					int min_uA, int max_uA)
{
	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	int ptr, target = 0, state, best_val = 0;

	for (ptr = 0; ptr < data->nr_states; ptr++)
		if (data->states[ptr].value > best_val &&
		    data->states[ptr].value >= min_uA &&
		    data->states[ptr].value <= max_uA) {
			target = data->states[ptr].gpios;
			best_val = data->states[ptr].value;
		}

	if (best_val == 0)
		return -EINVAL;

	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
		state = (target & (1 << ptr)) >> ptr;
		gpio_set_value(data->gpios[ptr].gpio, state);
	}
	data->state = target;

	return 0;
}

static struct regulator_ops gpio_regulator_voltage_ops = {
	.get_voltage = gpio_regulator_get_value,
	.set_voltage = gpio_regulator_set_voltage,
	.list_voltage = gpio_regulator_list_voltage,
};

static struct regulator_ops gpio_regulator_current_ops = {
	.get_current_limit = gpio_regulator_get_value,
	.set_current_limit = gpio_regulator_set_current_limit,
};

static int __devinit gpio_regulator_probe(struct platform_device *pdev)
{
	struct gpio_regulator_config *config = pdev->dev.platform_data;
	struct gpio_regulator_data *drvdata;
	struct regulator_config cfg = { };
	int ptr, ret, state;

	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
			       GFP_KERNEL);
	if (drvdata == NULL) {
		dev_err(&pdev->dev, "Failed to allocate device data\n");
		return -ENOMEM;
	}

	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->gpios = kmemdup(config->gpios,
				 config->nr_gpios * sizeof(struct gpio),
				 GFP_KERNEL);
	if (drvdata->gpios == NULL) {
		dev_err(&pdev->dev, "Failed to allocate gpio data\n");
		ret = -ENOMEM;
		goto err_name;
	}

	drvdata->states = kmemdup(config->states,
				  config->nr_states *
					 sizeof(struct gpio_regulator_state),
				  GFP_KERNEL);
	if (drvdata->states == NULL) {
		dev_err(&pdev->dev, "Failed to allocate state data\n");
		ret = -ENOMEM;
		goto err_memgpio;
	}
	drvdata->nr_states = config->nr_states;

	drvdata->desc.owner = THIS_MODULE;
	drvdata->desc.enable_time = config->startup_delay;

	/* handle regulator type*/
	switch (config->type) {
	case REGULATOR_VOLTAGE:
		drvdata->desc.type = REGULATOR_VOLTAGE;
		drvdata->desc.ops = &gpio_regulator_voltage_ops;
		drvdata->desc.n_voltages = config->nr_states;
		break;
	case REGULATOR_CURRENT:
		drvdata->desc.type = REGULATOR_CURRENT;
		drvdata->desc.ops = &gpio_regulator_current_ops;
		break;
	default:
		dev_err(&pdev->dev, "No regulator type set\n");
		ret = -EINVAL;
		goto err_memgpio;
		break;
	}

	drvdata->nr_gpios = config->nr_gpios;
	ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
	if (ret) {
		dev_err(&pdev->dev,
		   "Could not obtain regulator setting GPIOs: %d\n", ret);
		goto err_memstate;
	}

	/* build initial state from gpio init data. */
	state = 0;
	for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
		if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
			state |= (1 << ptr);
	}
	drvdata->state = state;

	cfg.dev = &pdev->dev;
	cfg.init_data = config->init_data;
	cfg.driver_data = drvdata;

	if (config->enable_gpio >= 0)
		cfg.ena_gpio = config->enable_gpio;
	cfg.ena_gpio_invert = !config->enable_high;
	if (config->enabled_at_boot) {
		if (config->enable_high)
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
		else
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
	} else {
		if (config->enable_high)
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
		else
			cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
	}

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

	platform_set_drvdata(pdev, drvdata);

	return 0;

err_stategpio:
	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
err_memstate:
	kfree(drvdata->states);
err_memgpio:
	kfree(drvdata->gpios);
err_name:
	kfree(drvdata->desc.name);
err:
	return ret;
}

static int __devexit gpio_regulator_remove(struct platform_device *pdev)
{
	struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);

	regulator_unregister(drvdata->dev);

	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);

	kfree(drvdata->states);
	kfree(drvdata->gpios);

	kfree(drvdata->desc.name);

	return 0;
}

static struct platform_driver gpio_regulator_driver = {
	.probe		= gpio_regulator_probe,
	.remove		= __devexit_p(gpio_regulator_remove),
	.driver		= {
		.name		= "gpio-regulator",
		.owner		= THIS_MODULE,
	},
};

static int __init gpio_regulator_init(void)
{
	return platform_driver_register(&gpio_regulator_driver);
}
subsys_initcall(gpio_regulator_init);

static void __exit gpio_regulator_exit(void)
{
	platform_driver_unregister(&gpio_regulator_driver);
}
module_exit(gpio_regulator_exit);

MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_DESCRIPTION("gpio voltage regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-regulator");
Commit	Line	Data
3f0292ae HS	1	/*
	2	* gpio-regulator.c
	3	*
	4	* Copyright 2011 Heiko Stuebner <heiko@sntech.de>
	5	*
	6	* based on fixed.c
	7	*
	8	* Copyright 2008 Wolfson Microelectronics PLC.
	9	*
	10	* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
	11	*
	12	* Copyright (c) 2009 Nokia Corporation
	13	* Roger Quadros <ext-roger.quadros@nokia.com>
	14	*
	15	* This program is free software; you can redistribute it and/or
	16	* modify it under the terms of the GNU General Public License as
	17	* published by the Free Software Foundation; either version 2 of the
	18	* License, or (at your option) any later version.
	19	*
	20	* This is useful for systems with mixed controllable and
	21	* non-controllable regulators, as well as for allowing testing on
	22	* systems with no controllable regulators.
	23	*/
	24
	25	#include <linux/err.h>
	26	#include <linux/mutex.h>
ecc37edf	27	#include <linux/module.h>
3f0292ae HS	28	#include <linux/platform_device.h>
	29	#include <linux/regulator/driver.h>
	30	#include <linux/regulator/machine.h>
	31	#include <linux/regulator/gpio-regulator.h>
	32	#include <linux/gpio.h>
3f0292ae HS	33	#include <linux/slab.h>
	34
	35	struct gpio_regulator_data {
	36	struct regulator_desc desc;
	37	struct regulator_dev *dev;
	38
3f0292ae HS	39	struct gpio *gpios;
	40	int nr_gpios;
	41
	42	struct gpio_regulator_state *states;
	43	int nr_states;
	44
	45	int state;
	46	};
	47
3f0292ae HS	48	static int gpio_regulator_get_value(struct regulator_dev *dev)
	49	{
	50	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	51	int ptr;
	52
	53	for (ptr = 0; ptr < data->nr_states; ptr++)
	54	if (data->states[ptr].gpios == data->state)
	55	return data->states[ptr].value;
	56
	57	return -EINVAL;
	58	}
	59
eb0c5686 HS	60	static int gpio_regulator_set_voltage(struct regulator_dev *dev,
	61	int min_uV, int max_uV,
	62	unsigned *selector)
3f0292ae HS	63	{
3f0292ae HS	64	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
00926369	65	int ptr, target = 0, state, best_val = INT_MAX;
3f0292ae	66
3f0292ae	67	for (ptr = 0; ptr < data->nr_states; ptr++)
4dbd8f63	68	if (data->states[ptr].value < best_val &&
eb0c5686 HS	69	data->states[ptr].value >= min_uV &&
eb0c5686 HS	70	data->states[ptr].value <= max_uV) {
3f0292ae	71	target = data->states[ptr].gpios;
00926369	72	best_val = data->states[ptr].value;
b0e4d7bf HS	73	if (selector)
b0e4d7bf HS	74	*selector = ptr;
00926369	75	}
3f0292ae	76
4dbd8f63	77	if (best_val == INT_MAX)
3f0292ae HS	78	return -EINVAL;
	79
	80	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
	81	state = (target & (1 << ptr)) >> ptr;
	82	gpio_set_value(data->gpios[ptr].gpio, state);
	83	}
	84	data->state = target;
	85
	86	return 0;
	87	}
	88
3f0292ae HS	89	static int gpio_regulator_list_voltage(struct regulator_dev *dev,
	90	unsigned selector)
	91	{
	92	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	93
	94	if (selector >= data->nr_states)
	95	return -EINVAL;
	96
	97	return data->states[selector].value;
	98	}
	99
	100	static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
	101	int min_uA, int max_uA)
	102	{
eb0c5686 HS	103	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	104	int ptr, target = 0, state, best_val = 0;
	105
	106	for (ptr = 0; ptr < data->nr_states; ptr++)
	107	if (data->states[ptr].value > best_val &&
	108	data->states[ptr].value >= min_uA &&
	109	data->states[ptr].value <= max_uA) {
	110	target = data->states[ptr].gpios;
	111	best_val = data->states[ptr].value;
	112	}
	113
	114	if (best_val == 0)
	115	return -EINVAL;
	116
	117	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
	118	state = (target & (1 << ptr)) >> ptr;
	119	gpio_set_value(data->gpios[ptr].gpio, state);
	120	}
	121	data->state = target;
	122
	123	return 0;
3f0292ae HS	124	}
	125
	126	static struct regulator_ops gpio_regulator_voltage_ops = {
3f0292ae HS	127	.get_voltage = gpio_regulator_get_value,
	128	.set_voltage = gpio_regulator_set_voltage,
	129	.list_voltage = gpio_regulator_list_voltage,
	130	};
	131
	132	static struct regulator_ops gpio_regulator_current_ops = {
3f0292ae HS	133	.get_current_limit = gpio_regulator_get_value,
	134	.set_current_limit = gpio_regulator_set_current_limit,
	135	};
	136
	137	static int __devinit gpio_regulator_probe(struct platform_device *pdev)
	138	{
	139	struct gpio_regulator_config *config = pdev->dev.platform_data;
	140	struct gpio_regulator_data *drvdata;
c172708d	141	struct regulator_config cfg = { };
3f0292ae HS	142	int ptr, ret, state;
3f0292ae HS	143
02b55216 MB	144	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
02b55216 MB	145	GFP_KERNEL);
3f0292ae HS	146	if (drvdata == NULL) {
	147	dev_err(&pdev->dev, "Failed to allocate device data\n");
	148	return -ENOMEM;
	149	}
	150
	151	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	152	if (drvdata->desc.name == NULL) {
	153	dev_err(&pdev->dev, "Failed to allocate supply name\n");
	154	ret = -ENOMEM;
	155	goto err;
	156	}
	157
	158	drvdata->gpios = kmemdup(config->gpios,
	159	config->nr_gpios * sizeof(struct gpio),
	160	GFP_KERNEL);
	161	if (drvdata->gpios == NULL) {
	162	dev_err(&pdev->dev, "Failed to allocate gpio data\n");
	163	ret = -ENOMEM;
	164	goto err_name;
	165	}
	166
	167	drvdata->states = kmemdup(config->states,
	168	config->nr_states *
	169	sizeof(struct gpio_regulator_state),
	170	GFP_KERNEL);
	171	if (drvdata->states == NULL) {
	172	dev_err(&pdev->dev, "Failed to allocate state data\n");
	173	ret = -ENOMEM;
	174	goto err_memgpio;
	175	}
	176	drvdata->nr_states = config->nr_states;
	177
	178	drvdata->desc.owner = THIS_MODULE;
a2a8222b	179	drvdata->desc.enable_time = config->startup_delay;
3f0292ae HS	180
	181	/* handle regulator type*/
	182	switch (config->type) {
	183	case REGULATOR_VOLTAGE:
	184	drvdata->desc.type = REGULATOR_VOLTAGE;
	185	drvdata->desc.ops = &gpio_regulator_voltage_ops;
	186	drvdata->desc.n_voltages = config->nr_states;
	187	break;
	188	case REGULATOR_CURRENT:
	189	drvdata->desc.type = REGULATOR_CURRENT;
	190	drvdata->desc.ops = &gpio_regulator_current_ops;
	191	break;
	192	default:
	193	dev_err(&pdev->dev, "No regulator type set\n");
	194	ret = -EINVAL;
	195	goto err_memgpio;
	196	break;
	197	}
	198
3f0292ae HS	199	drvdata->nr_gpios = config->nr_gpios;
	200	ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
	201	if (ret) {
	202	dev_err(&pdev->dev,
	203	"Could not obtain regulator setting GPIOs: %d\n", ret);
4b7c948f	204	goto err_memstate;
3f0292ae HS	205	}
	206
	207	/* build initial state from gpio init data. */
	208	state = 0;
	209	for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
	210	if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
	211	state \|= (1 << ptr);
	212	}
	213	drvdata->state = state;
	214
c172708d MB	215	cfg.dev = &pdev->dev;
c172708d MB	216	cfg.init_data = config->init_data;
7d4be2f5	217	cfg.driver_data = drvdata;
c172708d	218
4b7c948f AL	219	if (config->enable_gpio >= 0)
	220	cfg.ena_gpio = config->enable_gpio;
	221	cfg.ena_gpio_invert = !config->enable_high;
	222	if (config->enabled_at_boot) {
	223	if (config->enable_high)
	224	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_HIGH;
	225	else
	226	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_LOW;
	227	} else {
	228	if (config->enable_high)
	229	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_LOW;
	230	else
	231	cfg.ena_gpio_flags \|= GPIOF_OUT_INIT_HIGH;
	232	}
	233
c172708d	234	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
3f0292ae HS	235	if (IS_ERR(drvdata->dev)) {
	236	ret = PTR_ERR(drvdata->dev);
	237	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
	238	goto err_stategpio;
	239	}
	240
	241	platform_set_drvdata(pdev, drvdata);
	242
	243	return 0;
	244
	245	err_stategpio:
	246	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
3f0292ae HS	247	err_memstate:
	248	kfree(drvdata->states);
	249	err_memgpio:
	250	kfree(drvdata->gpios);
	251	err_name:
	252	kfree(drvdata->desc.name);
	253	err:
3f0292ae HS	254	return ret;
	255	}
	256
	257	static int __devexit gpio_regulator_remove(struct platform_device *pdev)
	258	{
	259	struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
	260
	261	regulator_unregister(drvdata->dev);
	262
	263	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
	264
	265	kfree(drvdata->states);
	266	kfree(drvdata->gpios);
	267
3f0292ae	268	kfree(drvdata->desc.name);
3f0292ae HS	269
	270	return 0;
	271	}
	272
	273	static struct platform_driver gpio_regulator_driver = {
	274	.probe = gpio_regulator_probe,
	275	.remove = __devexit_p(gpio_regulator_remove),
	276	.driver = {
	277	.name = "gpio-regulator",
	278	.owner = THIS_MODULE,
	279	},
	280	};
	281
	282	static int __init gpio_regulator_init(void)
	283	{
	284	return platform_driver_register(&gpio_regulator_driver);
	285	}
	286	subsys_initcall(gpio_regulator_init);
	287
	288	static void __exit gpio_regulator_exit(void)
	289	{
	290	platform_driver_unregister(&gpio_regulator_driver);
	291	}
	292	module_exit(gpio_regulator_exit);
	293
	294	MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
	295	MODULE_DESCRIPTION("gpio voltage regulator");
	296	MODULE_LICENSE("GPL");
	297	MODULE_ALIAS("platform:gpio-regulator");