[mirror_ubuntu-focal-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;

	int enable_gpio;
	bool enable_high;
	bool is_enabled;

	struct gpio *gpios;
	int nr_gpios;

	struct gpio_regulator_state *states;
	int nr_states;

	int state;
};

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

	return data->is_enabled;
}

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

	if (gpio_is_valid(data->enable_gpio)) {
		gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
		data->is_enabled = true;
	}

	return 0;
}

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

	if (gpio_is_valid(data->enable_gpio)) {
		gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
		data->is_enabled = false;
	}

	return 0;
}

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_value(struct regulator_dev *dev,
					int min, int max, 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 &&
		    data->states[ptr].value <= max) {
			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_set_voltage(struct regulator_dev *dev,
					int min_uV, int max_uV,
					unsigned *selector)
{
	return gpio_regulator_set_value(dev, min_uV, max_uV, selector);
}

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)
{
	return gpio_regulator_set_value(dev, min_uA, max_uA, NULL);
}

static struct regulator_ops gpio_regulator_voltage_ops = {
	.is_enabled = gpio_regulator_is_enabled,
	.enable = gpio_regulator_enable,
	.disable = gpio_regulator_disable,
	.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 = {
	.is_enabled = gpio_regulator_is_enabled,
	.enable = gpio_regulator_enable,
	.disable = gpio_regulator_disable,
	.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->enable_gpio = config->enable_gpio;

	if (gpio_is_valid(config->enable_gpio)) {
		drvdata->enable_high = config->enable_high;

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

		/* set output direction without changing state
		 * to prevent glitch
		 */
		if (config->enabled_at_boot) {
			drvdata->is_enabled = true;
			ret = gpio_direction_output(config->enable_gpio,
						    config->enable_high);
		} else {
			drvdata->is_enabled = false;
			ret = gpio_direction_output(config->enable_gpio,
						    !config->enable_high);
		}

		if (ret) {
			dev_err(&pdev->dev,
			   "Could not configure regulator enable GPIO %d direction: %d\n",
						config->enable_gpio, ret);
			goto err_enablegpio;
		}
	} else {
		/* Regulator without GPIO control is considered
		 * always enabled
		 */
		drvdata->is_enabled = true;
	}

	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_enablegpio;
	}

	/* 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;

	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_enablegpio:
	if (gpio_is_valid(config->enable_gpio))
		gpio_free(config->enable_gpio);
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);

	if (gpio_is_valid(drvdata->enable_gpio))
		gpio_free(drvdata->enable_gpio);

	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
	39	int enable_gpio;
	40	bool enable_high;
	41	bool is_enabled;
3f0292ae HS	42
	43	struct gpio *gpios;
	44	int nr_gpios;
	45
	46	struct gpio_regulator_state *states;
	47	int nr_states;
	48
	49	int state;
	50	};
	51
	52	static int gpio_regulator_is_enabled(struct regulator_dev *dev)
	53	{
	54	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	55
	56	return data->is_enabled;
	57	}
	58
	59	static int gpio_regulator_enable(struct regulator_dev *dev)
	60	{
	61	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	62
	63	if (gpio_is_valid(data->enable_gpio)) {
	64	gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
	65	data->is_enabled = true;
	66	}
	67
	68	return 0;
	69	}
	70
	71	static int gpio_regulator_disable(struct regulator_dev *dev)
	72	{
	73	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	74
	75	if (gpio_is_valid(data->enable_gpio)) {
	76	gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
	77	data->is_enabled = false;
	78	}
	79
	80	return 0;
	81	}
	82
3f0292ae HS	83	static int gpio_regulator_get_value(struct regulator_dev *dev)
	84	{
	85	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	86	int ptr;
	87
	88	for (ptr = 0; ptr < data->nr_states; ptr++)
	89	if (data->states[ptr].gpios == data->state)
	90	return data->states[ptr].value;
	91
	92	return -EINVAL;
	93	}
	94
	95	static int gpio_regulator_set_value(struct regulator_dev *dev,
b0e4d7bf	96	int min, int max, unsigned *selector)
3f0292ae HS	97	{
3f0292ae HS	98	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
00926369	99	int ptr, target = 0, state, best_val = INT_MAX;
3f0292ae	100
3f0292ae	101	for (ptr = 0; ptr < data->nr_states; ptr++)
4dbd8f63 AL	102	if (data->states[ptr].value < best_val &&
4dbd8f63 AL	103	data->states[ptr].value >= min &&
00926369	104	data->states[ptr].value <= max) {
3f0292ae	105	target = data->states[ptr].gpios;
00926369	106	best_val = data->states[ptr].value;
b0e4d7bf HS	107	if (selector)
b0e4d7bf HS	108	*selector = ptr;
00926369	109	}
3f0292ae	110
4dbd8f63	111	if (best_val == INT_MAX)
3f0292ae HS	112	return -EINVAL;
	113
	114	for (ptr = 0; ptr < data->nr_gpios; ptr++) {
	115	state = (target & (1 << ptr)) >> ptr;
	116	gpio_set_value(data->gpios[ptr].gpio, state);
	117	}
	118	data->state = target;
	119
	120	return 0;
	121	}
	122
	123	static int gpio_regulator_set_voltage(struct regulator_dev *dev,
	124	int min_uV, int max_uV,
	125	unsigned *selector)
	126	{
b0e4d7bf	127	return gpio_regulator_set_value(dev, min_uV, max_uV, selector);
3f0292ae HS	128	}
	129
	130	static int gpio_regulator_list_voltage(struct regulator_dev *dev,
	131	unsigned selector)
	132	{
	133	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	134
	135	if (selector >= data->nr_states)
	136	return -EINVAL;
	137
	138	return data->states[selector].value;
	139	}
	140
	141	static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
	142	int min_uA, int max_uA)
	143	{
b0e4d7bf	144	return gpio_regulator_set_value(dev, min_uA, max_uA, NULL);
3f0292ae HS	145	}
	146
	147	static struct regulator_ops gpio_regulator_voltage_ops = {
	148	.is_enabled = gpio_regulator_is_enabled,
	149	.enable = gpio_regulator_enable,
	150	.disable = gpio_regulator_disable,
3f0292ae HS	151	.get_voltage = gpio_regulator_get_value,
	152	.set_voltage = gpio_regulator_set_voltage,
	153	.list_voltage = gpio_regulator_list_voltage,
	154	};
	155
	156	static struct regulator_ops gpio_regulator_current_ops = {
	157	.is_enabled = gpio_regulator_is_enabled,
	158	.enable = gpio_regulator_enable,
	159	.disable = gpio_regulator_disable,
3f0292ae HS	160	.get_current_limit = gpio_regulator_get_value,
	161	.set_current_limit = gpio_regulator_set_current_limit,
	162	};
	163
	164	static int __devinit gpio_regulator_probe(struct platform_device *pdev)
	165	{
	166	struct gpio_regulator_config *config = pdev->dev.platform_data;
	167	struct gpio_regulator_data *drvdata;
c172708d	168	struct regulator_config cfg = { };
3f0292ae HS	169	int ptr, ret, state;
3f0292ae HS	170
02b55216 MB	171	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
02b55216 MB	172	GFP_KERNEL);
3f0292ae HS	173	if (drvdata == NULL) {
	174	dev_err(&pdev->dev, "Failed to allocate device data\n");
	175	return -ENOMEM;
	176	}
	177
	178	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	179	if (drvdata->desc.name == NULL) {
	180	dev_err(&pdev->dev, "Failed to allocate supply name\n");
	181	ret = -ENOMEM;
	182	goto err;
	183	}
	184
	185	drvdata->gpios = kmemdup(config->gpios,
	186	config->nr_gpios * sizeof(struct gpio),
	187	GFP_KERNEL);
	188	if (drvdata->gpios == NULL) {
	189	dev_err(&pdev->dev, "Failed to allocate gpio data\n");
	190	ret = -ENOMEM;
	191	goto err_name;
	192	}
	193
	194	drvdata->states = kmemdup(config->states,
	195	config->nr_states *
	196	sizeof(struct gpio_regulator_state),
	197	GFP_KERNEL);
	198	if (drvdata->states == NULL) {
	199	dev_err(&pdev->dev, "Failed to allocate state data\n");
	200	ret = -ENOMEM;
	201	goto err_memgpio;
	202	}
	203	drvdata->nr_states = config->nr_states;
	204
	205	drvdata->desc.owner = THIS_MODULE;
a2a8222b	206	drvdata->desc.enable_time = config->startup_delay;
3f0292ae HS	207
	208	/* handle regulator type*/
	209	switch (config->type) {
	210	case REGULATOR_VOLTAGE:
	211	drvdata->desc.type = REGULATOR_VOLTAGE;
	212	drvdata->desc.ops = &gpio_regulator_voltage_ops;
	213	drvdata->desc.n_voltages = config->nr_states;
	214	break;
	215	case REGULATOR_CURRENT:
	216	drvdata->desc.type = REGULATOR_CURRENT;
	217	drvdata->desc.ops = &gpio_regulator_current_ops;
	218	break;
	219	default:
	220	dev_err(&pdev->dev, "No regulator type set\n");
	221	ret = -EINVAL;
	222	goto err_memgpio;
	223	break;
	224	}
	225
	226	drvdata->enable_gpio = config->enable_gpio;
3f0292ae HS	227
	228	if (gpio_is_valid(config->enable_gpio)) {
	229	drvdata->enable_high = config->enable_high;
	230
	231	ret = gpio_request(config->enable_gpio, config->supply_name);
	232	if (ret) {
	233	dev_err(&pdev->dev,
	234	"Could not obtain regulator enable GPIO %d: %d\n",
	235	config->enable_gpio, ret);
	236	goto err_memstate;
	237	}
	238
	239	/* set output direction without changing state
	240	* to prevent glitch
	241	*/
	242	if (config->enabled_at_boot) {
	243	drvdata->is_enabled = true;
	244	ret = gpio_direction_output(config->enable_gpio,
	245	config->enable_high);
	246	} else {
	247	drvdata->is_enabled = false;
	248	ret = gpio_direction_output(config->enable_gpio,
	249	!config->enable_high);
	250	}
	251
	252	if (ret) {
	253	dev_err(&pdev->dev,
	254	"Could not configure regulator enable GPIO %d direction: %d\n",
	255	config->enable_gpio, ret);
	256	goto err_enablegpio;
	257	}
	258	} else {
	259	/* Regulator without GPIO control is considered
	260	* always enabled
	261	*/
	262	drvdata->is_enabled = true;
	263	}
	264
	265	drvdata->nr_gpios = config->nr_gpios;
	266	ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
	267	if (ret) {
	268	dev_err(&pdev->dev,
	269	"Could not obtain regulator setting GPIOs: %d\n", ret);
	270	goto err_enablegpio;
	271	}
	272
	273	/* build initial state from gpio init data. */
	274	state = 0;
	275	for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
	276	if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
	277	state \|= (1 << ptr);
	278	}
	279	drvdata->state = state;
	280
c172708d MB	281	cfg.dev = &pdev->dev;
c172708d MB	282	cfg.init_data = config->init_data;
7d4be2f5	283	cfg.driver_data = drvdata;
c172708d MB	284
c172708d MB	285	drvdata->dev = regulator_register(&drvdata->desc, &cfg);
3f0292ae HS	286	if (IS_ERR(drvdata->dev)) {
	287	ret = PTR_ERR(drvdata->dev);
	288	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
	289	goto err_stategpio;
	290	}
	291
	292	platform_set_drvdata(pdev, drvdata);
	293
	294	return 0;
	295
	296	err_stategpio:
	297	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
	298	err_enablegpio:
	299	if (gpio_is_valid(config->enable_gpio))
	300	gpio_free(config->enable_gpio);
	301	err_memstate:
	302	kfree(drvdata->states);
	303	err_memgpio:
	304	kfree(drvdata->gpios);
	305	err_name:
	306	kfree(drvdata->desc.name);
	307	err:
3f0292ae HS	308	return ret;
	309	}
	310
	311	static int __devexit gpio_regulator_remove(struct platform_device *pdev)
	312	{
	313	struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
	314
	315	regulator_unregister(drvdata->dev);
	316
	317	gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
	318
	319	kfree(drvdata->states);
	320	kfree(drvdata->gpios);
	321
	322	if (gpio_is_valid(drvdata->enable_gpio))
	323	gpio_free(drvdata->enable_gpio);
	324
	325	kfree(drvdata->desc.name);
3f0292ae HS	326
	327	return 0;
	328	}
	329
	330	static struct platform_driver gpio_regulator_driver = {
	331	.probe = gpio_regulator_probe,
	332	.remove = __devexit_p(gpio_regulator_remove),
	333	.driver = {
	334	.name = "gpio-regulator",
	335	.owner = THIS_MODULE,
	336	},
	337	};
	338
	339	static int __init gpio_regulator_init(void)
	340	{
	341	return platform_driver_register(&gpio_regulator_driver);
	342	}
	343	subsys_initcall(gpio_regulator_init);
	344
	345	static void __exit gpio_regulator_exit(void)
	346	{
	347	platform_driver_unregister(&gpio_regulator_driver);
	348	}
	349	module_exit(gpio_regulator_exit);
	350
	351	MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
	352	MODULE_DESCRIPTION("gpio voltage regulator");
	353	MODULE_LICENSE("GPL");
	354	MODULE_ALIAS("platform:gpio-regulator");