[deliverable/linux.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/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/delay.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;
	unsigned startup_delay;

	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_enable_time(struct regulator_dev *dev)
{
	struct gpio_regulator_data *data = rdev_get_drvdata(dev);

	return data->startup_delay;
}

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)
{
	struct gpio_regulator_data *data = rdev_get_drvdata(dev);
	int ptr, target, state;

	target = -1;
	for (ptr = 0; ptr < data->nr_states; ptr++)
		if (data->states[ptr].value >= min &&
		    data->states[ptr].value <= max)
			target = data->states[ptr].gpios;

	if (target < 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 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);
}

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);
}

static struct regulator_ops gpio_regulator_voltage_ops = {
	.is_enabled = gpio_regulator_is_enabled,
	.enable = gpio_regulator_enable,
	.disable = gpio_regulator_disable,
	.enable_time = gpio_regulator_enable_time,
	.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,
	.enable_time = gpio_regulator_enable_time,
	.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;
	int ptr, ret, state;

	drvdata = kzalloc(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;

	/* 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;
	drvdata->startup_delay = config->startup_delay;

	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;

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

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