USB: usbsevseg: fix max length
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / regulator / gpio-regulator.c
blobf0acf52498bd4e312aee97fda6711ec0e498291e
1 /*
2 * gpio-regulator.c
4 * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
6 * based on fixed.c
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;
40 int enable_gpio;
41 bool enable_high;
42 bool is_enabled;
43 unsigned startup_delay;
45 struct gpio *gpios;
46 int nr_gpios;
48 struct gpio_regulator_state *states;
49 int nr_states;
51 int state;
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;
70 return 0;
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;
82 return 0;
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);
95 int ptr;
97 for (ptr = 0; ptr < data->nr_states; ptr++)
98 if (data->states[ptr].gpios == data->state)
99 return data->states[ptr].value;
101 return -EINVAL;
104 static int gpio_regulator_set_value(struct regulator_dev *dev,
105 int min, int max)
107 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
108 int ptr, target, state;
110 target = -1;
111 for (ptr = 0; ptr < data->nr_states; ptr++)
112 if (data->states[ptr].value >= min &&
113 data->states[ptr].value <= max)
114 target = data->states[ptr].gpios;
116 if (target < 0)
117 return -EINVAL;
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;
125 return 0;
128 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
129 int min_uV, int max_uV,
130 unsigned *selector)
132 return gpio_regulator_set_value(dev, min_uV, max_uV);
135 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
136 unsigned selector)
138 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
140 if (selector >= data->nr_states)
141 return -EINVAL;
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 int ptr, ret, state;
177 drvdata = kzalloc(sizeof(struct gpio_regulator_data), GFP_KERNEL);
178 if (drvdata == NULL) {
179 dev_err(&pdev->dev, "Failed to allocate device data\n");
180 return -ENOMEM;
183 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
184 if (drvdata->desc.name == NULL) {
185 dev_err(&pdev->dev, "Failed to allocate supply name\n");
186 ret = -ENOMEM;
187 goto err;
190 drvdata->gpios = kmemdup(config->gpios,
191 config->nr_gpios * sizeof(struct gpio),
192 GFP_KERNEL);
193 if (drvdata->gpios == NULL) {
194 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
195 ret = -ENOMEM;
196 goto err_name;
199 drvdata->states = kmemdup(config->states,
200 config->nr_states *
201 sizeof(struct gpio_regulator_state),
202 GFP_KERNEL);
203 if (drvdata->states == NULL) {
204 dev_err(&pdev->dev, "Failed to allocate state data\n");
205 ret = -ENOMEM;
206 goto err_memgpio;
208 drvdata->nr_states = config->nr_states;
210 drvdata->desc.owner = THIS_MODULE;
212 /* handle regulator type*/
213 switch (config->type) {
214 case REGULATOR_VOLTAGE:
215 drvdata->desc.type = REGULATOR_VOLTAGE;
216 drvdata->desc.ops = &gpio_regulator_voltage_ops;
217 drvdata->desc.n_voltages = config->nr_states;
218 break;
219 case REGULATOR_CURRENT:
220 drvdata->desc.type = REGULATOR_CURRENT;
221 drvdata->desc.ops = &gpio_regulator_current_ops;
222 break;
223 default:
224 dev_err(&pdev->dev, "No regulator type set\n");
225 ret = -EINVAL;
226 goto err_memgpio;
227 break;
230 drvdata->enable_gpio = config->enable_gpio;
231 drvdata->startup_delay = config->startup_delay;
233 if (gpio_is_valid(config->enable_gpio)) {
234 drvdata->enable_high = config->enable_high;
236 ret = gpio_request(config->enable_gpio, config->supply_name);
237 if (ret) {
238 dev_err(&pdev->dev,
239 "Could not obtain regulator enable GPIO %d: %d\n",
240 config->enable_gpio, ret);
241 goto err_memstate;
244 /* set output direction without changing state
245 * to prevent glitch
247 if (config->enabled_at_boot) {
248 drvdata->is_enabled = true;
249 ret = gpio_direction_output(config->enable_gpio,
250 config->enable_high);
251 } else {
252 drvdata->is_enabled = false;
253 ret = gpio_direction_output(config->enable_gpio,
254 !config->enable_high);
257 if (ret) {
258 dev_err(&pdev->dev,
259 "Could not configure regulator enable GPIO %d direction: %d\n",
260 config->enable_gpio, ret);
261 goto err_enablegpio;
263 } else {
264 /* Regulator without GPIO control is considered
265 * always enabled
267 drvdata->is_enabled = true;
270 drvdata->nr_gpios = config->nr_gpios;
271 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
272 if (ret) {
273 dev_err(&pdev->dev,
274 "Could not obtain regulator setting GPIOs: %d\n", ret);
275 goto err_enablegpio;
278 /* build initial state from gpio init data. */
279 state = 0;
280 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
281 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
282 state |= (1 << ptr);
284 drvdata->state = state;
286 drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
287 config->init_data, drvdata);
288 if (IS_ERR(drvdata->dev)) {
289 ret = PTR_ERR(drvdata->dev);
290 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
291 goto err_stategpio;
294 platform_set_drvdata(pdev, drvdata);
296 return 0;
298 err_stategpio:
299 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
300 err_enablegpio:
301 if (gpio_is_valid(config->enable_gpio))
302 gpio_free(config->enable_gpio);
303 err_memstate:
304 kfree(drvdata->states);
305 err_memgpio:
306 kfree(drvdata->gpios);
307 err_name:
308 kfree(drvdata->desc.name);
309 err:
310 kfree(drvdata);
311 return ret;
314 static int __devexit gpio_regulator_remove(struct platform_device *pdev)
316 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
318 regulator_unregister(drvdata->dev);
320 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
322 kfree(drvdata->states);
323 kfree(drvdata->gpios);
325 if (gpio_is_valid(drvdata->enable_gpio))
326 gpio_free(drvdata->enable_gpio);
328 kfree(drvdata->desc.name);
329 kfree(drvdata);
331 return 0;
334 static struct platform_driver gpio_regulator_driver = {
335 .probe = gpio_regulator_probe,
336 .remove = __devexit_p(gpio_regulator_remove),
337 .driver = {
338 .name = "gpio-regulator",
339 .owner = THIS_MODULE,
343 static int __init gpio_regulator_init(void)
345 return platform_driver_register(&gpio_regulator_driver);
347 subsys_initcall(gpio_regulator_init);
349 static void __exit gpio_regulator_exit(void)
351 platform_driver_unregister(&gpio_regulator_driver);
353 module_exit(gpio_regulator_exit);
355 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
356 MODULE_DESCRIPTION("gpio voltage regulator");
357 MODULE_LICENSE("GPL");
358 MODULE_ALIAS("platform:gpio-regulator");