4 * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
8 * Copyright 2008 Wolfson Microelectronics PLC.
10 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
12 * Copyright (c) 2009 Nokia Corporation
13 * Roger Quadros <ext-roger.quadros@nokia.com>
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.
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.
25 #include <linux/err.h>
26 #include <linux/mutex.h>
27 #include <linux/module.h>
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>
33 #include <linux/delay.h>
34 #include <linux/slab.h>
36 struct gpio_regulator_data {
37 struct regulator_desc desc;
38 struct regulator_dev *dev;
43 unsigned startup_delay;
48 struct gpio_regulator_state *states;
54 static int gpio_regulator_is_enabled(struct regulator_dev *dev)
56 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
58 return data->is_enabled;
61 static int gpio_regulator_enable(struct regulator_dev *dev)
63 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
65 if (gpio_is_valid(data->enable_gpio)) {
66 gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
67 data->is_enabled = true;
73 static int gpio_regulator_disable(struct regulator_dev *dev)
75 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
77 if (gpio_is_valid(data->enable_gpio)) {
78 gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
79 data->is_enabled = false;
85 static int gpio_regulator_enable_time(struct regulator_dev *dev)
87 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
89 return data->startup_delay;
92 static int gpio_regulator_get_value(struct regulator_dev *dev)
94 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
97 for (ptr = 0; ptr < data->nr_states; ptr++)
98 if (data->states[ptr].gpios == data->state)
99 return data->states[ptr].value;
104 static int gpio_regulator_set_value(struct regulator_dev *dev,
107 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
108 int ptr, target, state, best_val = INT_MAX;
110 for (ptr = 0; ptr < data->nr_states; ptr++)
111 if (data->states[ptr].value < best_val &&
112 data->states[ptr].value >= min &&
113 data->states[ptr].value <= max)
114 target = data->states[ptr].gpios;
116 if (best_val == INT_MAX)
119 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
120 state = (target & (1 << ptr)) >> ptr;
121 gpio_set_value(data->gpios[ptr].gpio, state);
123 data->state = target;
128 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
129 int min_uV, int max_uV,
132 return gpio_regulator_set_value(dev, min_uV, max_uV);
135 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
138 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
140 if (selector >= data->nr_states)
143 return data->states[selector].value;
146 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
147 int min_uA, int max_uA)
149 return gpio_regulator_set_value(dev, min_uA, max_uA);
152 static struct regulator_ops gpio_regulator_voltage_ops = {
153 .is_enabled = gpio_regulator_is_enabled,
154 .enable = gpio_regulator_enable,
155 .disable = gpio_regulator_disable,
156 .enable_time = gpio_regulator_enable_time,
157 .get_voltage = gpio_regulator_get_value,
158 .set_voltage = gpio_regulator_set_voltage,
159 .list_voltage = gpio_regulator_list_voltage,
162 static struct regulator_ops gpio_regulator_current_ops = {
163 .is_enabled = gpio_regulator_is_enabled,
164 .enable = gpio_regulator_enable,
165 .disable = gpio_regulator_disable,
166 .enable_time = gpio_regulator_enable_time,
167 .get_current_limit = gpio_regulator_get_value,
168 .set_current_limit = gpio_regulator_set_current_limit,
171 static int __devinit gpio_regulator_probe(struct platform_device *pdev)
173 struct gpio_regulator_config *config = pdev->dev.platform_data;
174 struct gpio_regulator_data *drvdata;
175 struct regulator_config cfg = { };
178 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
180 if (drvdata == NULL) {
181 dev_err(&pdev->dev, "Failed to allocate device data\n");
185 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
186 if (drvdata->desc.name == NULL) {
187 dev_err(&pdev->dev, "Failed to allocate supply name\n");
192 drvdata->gpios = kmemdup(config->gpios,
193 config->nr_gpios * sizeof(struct gpio),
195 if (drvdata->gpios == NULL) {
196 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
201 drvdata->states = kmemdup(config->states,
203 sizeof(struct gpio_regulator_state),
205 if (drvdata->states == NULL) {
206 dev_err(&pdev->dev, "Failed to allocate state data\n");
210 drvdata->nr_states = config->nr_states;
212 drvdata->desc.owner = THIS_MODULE;
214 /* handle regulator type*/
215 switch (config->type) {
216 case REGULATOR_VOLTAGE:
217 drvdata->desc.type = REGULATOR_VOLTAGE;
218 drvdata->desc.ops = &gpio_regulator_voltage_ops;
219 drvdata->desc.n_voltages = config->nr_states;
221 case REGULATOR_CURRENT:
222 drvdata->desc.type = REGULATOR_CURRENT;
223 drvdata->desc.ops = &gpio_regulator_current_ops;
226 dev_err(&pdev->dev, "No regulator type set\n");
232 drvdata->enable_gpio = config->enable_gpio;
233 drvdata->startup_delay = config->startup_delay;
235 if (gpio_is_valid(config->enable_gpio)) {
236 drvdata->enable_high = config->enable_high;
238 ret = gpio_request(config->enable_gpio, config->supply_name);
241 "Could not obtain regulator enable GPIO %d: %d\n",
242 config->enable_gpio, ret);
246 /* set output direction without changing state
249 if (config->enabled_at_boot) {
250 drvdata->is_enabled = true;
251 ret = gpio_direction_output(config->enable_gpio,
252 config->enable_high);
254 drvdata->is_enabled = false;
255 ret = gpio_direction_output(config->enable_gpio,
256 !config->enable_high);
261 "Could not configure regulator enable GPIO %d direction: %d\n",
262 config->enable_gpio, ret);
266 /* Regulator without GPIO control is considered
269 drvdata->is_enabled = true;
272 drvdata->nr_gpios = config->nr_gpios;
273 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
276 "Could not obtain regulator setting GPIOs: %d\n", ret);
280 /* build initial state from gpio init data. */
282 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
283 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
286 drvdata->state = state;
288 cfg.dev = &pdev->dev;
289 cfg.init_data = config->init_data;
290 cfg.driver_data = &drvdata;
292 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
293 if (IS_ERR(drvdata->dev)) {
294 ret = PTR_ERR(drvdata->dev);
295 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
299 platform_set_drvdata(pdev, drvdata);
304 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
306 if (gpio_is_valid(config->enable_gpio))
307 gpio_free(config->enable_gpio);
309 kfree(drvdata->states);
311 kfree(drvdata->gpios);
313 kfree(drvdata->desc.name);
318 static int __devexit gpio_regulator_remove(struct platform_device *pdev)
320 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
322 regulator_unregister(drvdata->dev);
324 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
326 kfree(drvdata->states);
327 kfree(drvdata->gpios);
329 if (gpio_is_valid(drvdata->enable_gpio))
330 gpio_free(drvdata->enable_gpio);
332 kfree(drvdata->desc.name);
337 static struct platform_driver gpio_regulator_driver = {
338 .probe = gpio_regulator_probe,
339 .remove = __devexit_p(gpio_regulator_remove),
341 .name = "gpio-regulator",
342 .owner = THIS_MODULE,
346 static int __init gpio_regulator_init(void)
348 return platform_driver_register(&gpio_regulator_driver);
350 subsys_initcall(gpio_regulator_init);
352 static void __exit gpio_regulator_exit(void)
354 platform_driver_unregister(&gpio_regulator_driver);
356 module_exit(gpio_regulator_exit);
358 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
359 MODULE_DESCRIPTION("gpio voltage regulator");
360 MODULE_LICENSE("GPL");
361 MODULE_ALIAS("platform:gpio-regulator");